Patent Application
20240222146
The present invention relates to a semiconductor package manufacturing technology, and more particularly, to a release film for a semiconductor package, a manufacturing method thereof, and a semiconductor package manufacturing method using the same.
In the packaging process of a semiconductor device, a molding process is a process of encapsulating a chip and a carrier substrate on which the chip is mounted with a molding material. A mold molding apparatus is used to encapsulate a semiconductor device, and as a molding material, an epoxy molding compound (EMC) in which an inorganic material and various auxiliary materials are added to a mold resin such as an epoxy resin is mainly used. A molding material including the mold resin is injected into a metal mold to form a mold.
In the packaging process, a method of interposing a release film between the mold and the mold resin may be used as a method of releasing the mold and the molded product after curing of the mold material is completed. The release film is supplied into a molding apparatus, is introduced into a mold temperature-controlled to a molding processing temperature, and is closely adhered to the mold by vacuum suction, and a mold resin is filled thereon. Accordingly, the release film may be disposed between the mold and the mold resin. When the mold is opened at a time when the mold resin is cured, the molded product may be peeled off from the release film.
Conventional release films are mainly made of ETFE (ethylene tetrafluoroethylene) resin. The ETFE release film has thermoplasticity and is mainly manufactured by a T-die ejection method using an extruder. Since the ETFE release film has thermoplastic properties, at a high heating temperature required during the EMC molding process, there is a problem that the release film may not withstand the pressure and the edge portion may be ruptured, which may cause contamination of the mold molding apparatus. Therefore, the ETPE release film has a limitation that it is mainly used at a temperature of about 165° C. or less. In addition, when EMC molding is performed using the ETFE release film, since fume-gas generated from EMC has high permeability through the release film, mold contamination due to fume-gas occurs, and as a result, a cycle of frequently cleaning the mold is required. Therefore, there is a problem that productivity is reduced.
In addition, in the case of a conventional release film, dust or foreign substances may adhere to the film due to an electrification phenomenon, which may cause process defects and mold contamination. Furthermore, in the process of peeling the release film from the mold, the semiconductor devices are damaged or destroyed by electric discharge, resulting in product defects.
Previously, the release films for semiconductor packages including inorganic fillers or polymer antistatic materials have been proposed, but in these cases, there is a problem that antistatic properties are lost during a high-temperature packaging process, or the mold is contaminated due to the drop-off of the inorganic fillers. Furthermore, there is a problem that since the release film is stretched by about 2 mm from the edge portion of the substrate during the packaging process, the antistatic properties of the release film may be lost or deteriorated.
As another process in which a release film is used, an underfill process among semiconductor packaging processes is a process for filling a lower portion of a device in a semiconductor package such as a ball grid array (BGA), a chip scale package (CSP), or a flip chip, and the like, by using an insulating resin. The underfill serves to correct the mismatch in the coefficient of thermal expansion (CTE) between the printed circuit board and the semiconductor device, and also may serve to prevent or minimize the effects of physical shock, chemical shock, and moisture. In addition, the underfill may have a function for dissipating heat generated in the semiconductor device, that is, a heat dissipation function. Such an underfill process is one of the important technical elements in semiconductor packaging.
In a general underfill process, there may occur a problem that the resin material for underfill flows out to a surface portion of the mold apparatus (i.e., a mold) to contaminate the mold apparatus. Therefore, after performing the underfill process, in order to perform the next underfill process, it is necessary to perform a cleaning operation on the mold apparatus. This cleaning operation reduces the process efficiency and becomes a factor to reduce the packaging throughput. In addition, when the substrate on which the semiconductor device is mounted is loaded onto a high-temperature mold apparatus, there is a problem that the substrate is deformed to be convex downwardly (that is, into a U-shape) due to a difference in coefficient of thermal expansion (CTE) between the substrate and the semiconductor device. As a result of it, the workability is deteriorated. Accordingly, there is a need to develop a technology capable of overcoming the problems of the conventional underfill process.
The technical object to be achieved by the present invention is to provide a release film for semiconductor package which has excellent mechanical properties which may withstand high temperature and high pressure conditions without rupture during the molding process of a semiconductor package, and has also excellent mold release properties, and may maintain excellent antistatic performance even during high temperature processing.
In addition, another technical object of the present invention is to provide a release film for a semiconductor package capable of maintaining excellent antistatic properties even when a part of the release film is stretched during the molding process of the semiconductor package.
Another technical object to be achieved by the present invention is to provide a method for forming an underfill capable of significantly improving process efficiency by preventing a problem of contamination of a mold apparatus (i.e., a mold) during an underfill process, and a method for manufacturing a semiconductor package using the same.
In addition, another technical object to be achieved by the present invention is to provide an underfill forming method which may solve the problem of deterioration in workability due to substrate deformation on a mold apparatus (i.e., a mold) during the underfill process, and a method of manufacturing a semiconductor package to which the same is applied.
In addition, the technical object to be achieved by the present invention is to provide a method of manufacturing the above-described release film for a semiconductor package.
The problem to be solved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned will be understood by those skilled in the art from the following description.
According to an embodiment of the present invention, there is provided a release film for a semiconductor package, comprising: an intermediate body layer including a structure in which at least one polyurethane layer and at least one antistatic layer are laminated; a first release layer disposed on a lower surface of the intermediate body layer and having a first fine unevenness for releasability on a lower surface portion; and a second release layer disposed on an upper surface of the intermediate body layer and having second a fine unevenness for releasability on an upper surface portion, and wherein the at least one polyurethane layer includes thermosetting polyurethane having a cross-linkage.
The antistatic layer may include a carbon nanotube (CNT). A content of the CNT in the antistatic layer may be about 30˜90 wt %. The CNT may include a multi-walled CNT (MWCNT).
The intermediate body layer may include an intermediate polyurethane layer, a first antistatic layer disposed on a lower surface of the intermediate polyurethane layer, and a second antistatic layer disposed on an upper surface of the intermediate polyurethane layer, and the intermediate polyurethane layer may correspond to the polyurethane layer, and the first and second antistatic layers may correspond to the antistatic layer.
The intermediate body layer may include a first polyurethane layer, a second polyurethane layer and an intermediate antistatic layer disposed between the first and second polyurethane layers, and the first and second polyurethane layers may correspond to the polyurethane layer, and the intermediate antistatic layer may correspond to the antistatic layer.
The polyurethane layer may have a thickness in a range of about 10 μm to 70 μm. The antistatic layer may have a thickness in a range of about 0.1 μm to 2 μm. The release film may have a thickness in a range of about 30 μm to 140 μm.
At least one of the first and second release layers may have the same material composition as that of the polyurethane layer. At least one of the first and second release layers may have a material composition different from that of the polyurethane layer.
At least one of the first and second release layers may include an inorganic material. When the first release layer includes the inorganic material, the first fine unevenness may be formed on the lower surface portion of the first release layer by the inorganic material. When the second release layer includes the inorganic material, the second fine unevenness may be formed on the upper surface portion of the second release layer by the inorganic material.
According to another embodiment of the present invention, there is provided a manufacturing method of a release film for a semiconductor package, the method comprising: preparing a polyurethane layer including thermosetting polyurethane having a cross-linkage; forming a first release layer on any one of a lower surface and an upper surface of the polyurethane layer, and wherein the first release layer is formed while a first antistatic layer is being interposed between the polyurethane layer and the first release layer; and forming a second release layer on the other one of the lower surface and the upper surface of the polyurethane layer, and wherein the second release layer is formed while a second antistatic layer is being interposed between the polyurethane layer and the second release layer and wherein the first release layer has a first fine unevenness for releasability on an opposite surface to a surface in contact with the first antistatic layer, and the second release layer has a second fine unevenness for releasability on an opposite surface to a surface in contact with the second antistatic layer.
The first and second antistatic layers may be formed by a coating method by sing an antistatic coating solution. The antistatic coating solution may contain about 0.1 wt % to about 2 wt % of carbon nanotube (CNT). The first and second antistatic layers may be formed by using a micro-gravure coater or a direct gravure coater.
At least one of the first and second release layers may have the same material composition as that of the polyurethane layer. At least one of the first and second release layers may have a material composition different from that of the polyurethane layer.
According to another embodiment of the present invention, there is provided a manufacturing method of a release film for a semiconductor package, the method comprising: preparing first and second polyurethane layers including thermosetting polyurethane having a cross-linkage; and mutually bonding one surface of the first polyurethane layer and one surface of the second polyurethane layer and wherein the first and second polyurethane layers are mutually bonded while an antistatic layer is being interposed between the first and second polyurethane layers; and wherein a first release layer is provided on the other surface of the first polyurethane layer, a second release layer is provided on the other surface of the second polyurethane layer, the first release layer has a first fine unevenness for releasability on an opposite surface to a surface in contact with the first polyurethane layer, and the second release layer has a second fine unevenness for releasability on an opposite surface to a surface in contact with the second polyurethane layer.
The antistatic layer may be formed by a coating method by using an antistatic coating solution. The antistatic coating solution may contain about 0.1 wt % to about 2 wt % of carbon nanotube (CNT). The antistatic layer may be formed using a micro-gravure coater or a direct gravure coater.
At least one of the first and second release layers may have the same material composition as that of the first and second polyurethane layers. At least one of the first and second release layers may have a material composition different from that of the first and second polyurethane layers.
According to another embodiment of the present invention, there is provided a method for forming an underfill, comprising: preparing a device structure including a circuit board having at least one vent hole, a plurality of semiconductor device portions mounted on the circuit board, and a plurality of electrical connection members disposed between the circuit board and the plurality of semiconductor device portions; disposing a first release film on a first mold member having a plurality of suction holes; disposing the device structure on the first release film, such that the circuit board faces the first release film; forming a plurality of ventilation holes at positions of the first release film corresponding to the plurality of suction holes by applying a first suction pressure to the plurality of suction holes; and filling an underfill material between and around the plurality of electrical connection members while sucking gas above the first release film through the plurality of suction holes and the plurality of ventilation holes by applying a second suction pressure to the plurality of suction holes.
The first release film may be a thermosetting polymer film. The first release film may be a thermosetting polyurethane-based polymer film. The first release film may have a thickness in a range of about 15 μm to 60 μm. The first suction pressure may be in a range of about 20 KPa to 90 KPa.
In the forming of the plurality of ventilation holes, a temperature of the first mold member may be in a range of about 50° C. to 250° C. The plurality of ventilation holes may have a diameter in the range of about 0.05 mm to about 8 mm.
The first mold member may include a first support pin portion disposed on a first edge region and a second support pin portion disposed on a second edge region, the first release film may include a first through hole formed at a position corresponding to the first support pin portion, and a second through hole formed at a position corresponding to the second support pin portion, and, in the disposing of the first release film on the first mold member, the first support pin portion may be inserted into the first through hole, and the second support pin portion may be inserted into the second through hole.
In the filling the underfill material, a portion of the underfill material may pass through the vent hole of the circuit board and contact an upper surface of the first release film.
Before the filling the underfill material, a second mold member facing the first mold member may be disposed on the device structure. The second mold member may be disposed while a second release film is being interposed between the second mold member and the device structure. After the disposing the second mold member, the filling the underfill material may be performed through a molded underfill (MUF) process.
According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor package, comprising: preparing a device structure including a circuit board having at least one vent hole, a plurality of semiconductor device portions mounted on the circuit board, and a plurality of electrical connection members disposed between the circuit board and the plurality of semiconductor device portions; disposing a first release film on a first mold member having a plurality of suction holes; disposing the device structure on the first release film, such that the circuit board faces the first release film; forming a plurality of ventilation holes at positions of the first release film corresponding to the plurality of suction holes by applying a first suction pressure to the plurality of suction holes; filling an underfill material between and around the plurality of electrical connection members while sucking gas above the first release film through the plurality of suction holes and the plurality of ventilation holes by applying a second suction pressure to the plurality of suction holes; separating the device structure on which the underfill material is formed from the first mold member and the first release film; and dividing the device structure into a plurality of unit devices.
The first release film may be a thermosetting polymer film. The first release film may be a thermosetting polyurethane-based polymer film. The first release film may have a thickness in a range of about 15 μm to 60 μm. The first suction pressure may be in a range of about 20 KPa to 90 KPa. In the forming the plurality of ventilation holes, a temperature of the first mold member may be in a range of about 50° C. to 250° C. The plurality of ventilation holes may have a diameter in a range of about 0.05 mm to about 8 mm.
The first mold member may include a first support pin portion disposed on a first edge region and a second support pin portion disposed on a second edge region, and the first release film may include a first through hole formed at a position corresponding to the first support pin portion, and a second through hole formed at a position corresponding to the second support pin portion. In the disposing of the first release film on the first mold member, the first support pin portion may be inserted into the first through hole, and the second support pin portion may be inserted into the second through hole.
In the filling the underfill material, a portion of the underfill material may pass through the vent hole of the circuit board and contact an upper surface of the first release film.
Before the filling the underfill material, a second mold member facing the first mold member may be disposed on the device structure. The second mold member may be disposed while a second release film is being interposed between the second mold member and the device structure. After the disposing the second mold member, the filling the underfill material may be performed through a molded underfill (MUF) process.
According to embodiments of the present invention, it is possible to implement a release film for a semiconductor package which has remarkable releasability as well as excellent mechanical properties which may withstand high temperature and high pressure conditions without rupture during a molding process of a semiconductor package, and may maintain excellent antistatic performance even during high temperature processing. In addition, according to embodiments of the present invention, it is possible to implement a release film for a semiconductor package capable of maintaining excellent antistatic properties even when a part of the release film is stretched during the molding process of the semiconductor package. When the release film for a semiconductor package according to the embodiment is used, the defect rate of the semiconductor package may be lowered, productivity may be improved, and characteristics of the manufactured package may be improved.
In addition, according to embodiments of the present invention, process efficiency may be greatly improved by preventing a problem of contamination of a mold device (i.e., a mold) in an underfill process during a semiconductor package manufacturing process. In addition, according to embodiments of the present invention, it is possible to effectively solve the problem of deterioration of workability due to deformation of a substrate on the mold device (i.e., the mold) in the underfill process during the manufacturing process of the semiconductor package.
Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The embodiments of the present invention to be described below are provided to more clearly explain the present invention to those having common knowledge in the related art, and the scope of the present invention is not limited by the following embodiments. The following embodiment may be modified in many different forms.
The terminology used herein is used to describe specific embodiments, and is not used to limit the present invention. As used herein, terms in the singular form may include the plural form unless the context clearly dictates otherwise. Also, as used herein, the terms “comprise” and/or “comprising” specifies presence of the stated shape, step, number, action, member, element and/or group thereof; and does not exclude presence or addition of one or more other shapes, steps, numbers, actions, members, elements, and/or groups thereof. In addition, the term “connection” as used herein is a concept that includes not only that certain members are directly connected, but also a concept that other members are Furthermore interposed between the members to be indirectly connected.
In addition, in the present specification, when a member is said to be located “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members. As used herein, the term “and/or” includes any one and any combination of one or more of those listed items. In addition, as used herein, terms such as “about”, “substantially”, etc. are used as a range of the numerical value or degree, in consideration of inherent manufacturing and material tolerances, or as a meaning close to the range. Furthermore, accurate or absolute numbers provided to aid the understanding of the present application are used to prevent an infringer from using the disclosed present invention unfairly.
Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. The size or the thickness of the regions or the parts illustrated in the accompanying drawings may be slightly exaggerated for clarity and convenience of description. The same reference numerals refer to the same elements throughout the detailed description.
Referring to
The polyurethane layer P10 may include thermosetting polyurethane having a cross-linking bond (cross-linkage). A content of the thermosetting polyurethane in the polyurethane layer P10 may be about 80 wt % or more or about 100 wt %, preferably 80 wt % or more, or about 90 wt % or more. The polyurethane layer P10 may include a thermosetting polyurethane resin as a main constituent material.
In terms of components, the polyurethane resin may have a number average molecular weight (or a weight average molecular weight) of about 50,000 to 500,000. Urethane (polyurethane) may be obtained by reaction of polyol and isocyanate, and may be manufactured by controlling the reaction rate and molecular weight using a catalyst.
As the polyol, one or a mixture of two or more products having a molecular weight of about 500 to 7000 may be used as a raw material. As the ether-based polyol, polypropylene glycol, modified polypropylene glycol, and polytetramethylene glycol (PTMG) may be used. As the polyester-based polyol, polyethylene glycol having a molecular weight in the range of about 500 to 7000, adipate-based polyester polyol which is a polycarbonate-based polycondensation system, and ring-opening polymerization-based lactone-based polyol may be used. One or more of polybutadiene glycol and acryl-based polyol may be mixed and used. However, the above materials are exemplary, and the embodiment of the present invention is not limited thereto.
As the isocyanate material, various diisocyanate-based materials may be used. For example, PPDI may be used as p-phenylene diisocyanate with a molecular weight of 160.1. TDI including isomer of toluene-diisocyanate may be used as toluene-diisocyanate with a molecular weight of 174.2, NDI may be used as 1,5-naphthalene diisocyanate with a molecular weight of 210.2, HDI may be used as 1,6-hexamethylene diisocyanate with a molecular weight of 168.2. MDI may be used as 4,4′-diphenylmethane diisocyanate with a molecular weight of 250.3. IPDI may be used as isoporon diisocyanate with a molecular weight of 222.3, and H12MDI may be used as cyclohexylmethane diisocyanate with a molecular weight of 262. However, the above materials are exemplary, and the present application is not limited thereto.
In addition, a chain extender material may be additionally used in addition to the polyol and isocyanate. The chain extender may serve to increase the molecular weight of the polyurethane and impart various functionalities. One to two or more of the chain extenders may be mixed and used. As the chain extender, ethylene glycol-based material, propylene glycol-based material, butadiene glycol-based material, polyhydric alcohol including silicone, polyhydric alcohol including fluorine, etc. may be used. However, the above materials are exemplary, and the present application is not limited thereto.
As the catalyst, various organic tin-based materials and organic bismuth-based materials may be used. The organotin-based material (an organotin-based compound) may include, for example, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dibutyltin dimercaptide, and the like. Here, dibutyltin dilaurate is (CH3CH2CH2CH2)2Sn[CH3(CH2)10COO]2, stannous octoate is Sn[C7H15COO]2, dibutyltin diacetate is (CH3CH2CH2CH2)2Sn[CH3COO]2, dibutyltin dimercaptide is (CH3CH2CH2CH2)2Sn[SC12H25]. The organic bismuth-based material (an organic bismuth-based compound) may have various molecular weights, and may include, for example, a carboxylate-based catalyst material containing bismuth. Here, the carboxylate-based catalyst material may contain about 9% to about 45% of bismuth. However, the above materials are exemplary, and the present application is not limited thereto.
As a solvent for preparing a polyurethane resin solution, for example, various acetone solvents including DMF (dimethylformamide), DEF (diethylformamide), DMSO (dimethylsulfoxaide), DMAC (dimethylacetamide), toluene, ethyl acetate (EA), methyl ethyl ketone, and the like may be used. However, the above materials are exemplary, and the present application is not limited thereto.
After preparing a resin solution for preparing polyurethane in which the polyol, isocyanate, solvent, etc. are mixed, a polymer cured product having various crosslinking densities may be formed by a reaction using a melamine-based curing agent, its catalyst, and an isocyanate-based curing agent polymerized with various molecular weights. In this case, a curing method using heat may be applied.
In the polyurethane composition, as a first material for the urethane reaction, a polyol such as a polyester-based polyol (e.g., molecular weight 500 to 7000), polyether-based polyol (e.g., molecular weight 200 to 3000) or polycarbonate-based polyol (e.g., molecular weight 500 to 8000) may be applied, and an isocyanate-based material may be applied as a second material for the urethane reaction. As the isocyanate-based material, various isocyanate types containing a yellowing benzene-ring, and various isocyanates including hexamethylene-based, isophorone-based and cyclohexylmethane-based which are non-yellowing types may be used. In addition, a chain extender may be additionally used to increase the molecular weight of the polyurethane. As the chain extender, ethylene glycol-based materials, propylene glycol-based materials, butadiene glycol-based materials, polyhydric alcohols including silicone, polyhydric alcohols including fluorine, etc. may be used, and it is possible to increase the molecular weight of the polyurethane by involving the chain extender in a urethane reaction.
In some cases, the polyurethane layer P10 may contain some (small amount) of other polymer materials or other additives other than the thermosetting polyurethane, for example, an initiator (activator) for crosslinking reaction, a leveling agent and/or an antifoaming agent. As the leveling agent, a modified polyether-based leveling agent including a silicone-based, fluorine-based or non-silicone-based leveling agent may be used, and the leveling agent may be used in a mixture of about 0.1 wt % to 5 wt %. The antifoaming agent is for a defoaming function and for example, a silicone-based or non-silicone-based antifoaming agent may be used. The antifoaming agent may be used in a mixture of about 0.1 wt % to 5 wt %. In addition, as a curing agent for the curing reaction of the prepared polyurethane, a melamine-based curing agent, and an isocyanate-based curing agent polymerized with several molecules may be used. In addition, the curing reaction may be accelerated in the presence of an acid catalyst.
The first and second antistatic layers A10 and A20 may include carbon nanotube (CNT) as an antistatic material. Antistatic properties may be exhibited due to the conductive properties of the CNTs. A plurality (a large amount) of CNTs may be contained in each of the first and second antistatic layers A10 and A20. A plurality of CNTs in each of the first and second antistatic layers A10 and A20 may at least partially form a network structure. The content of the CNTs in each of the first and second antistatic layers A10 and A20 may be about 30 wt % to about 90 wt %. In addition, the CNT may be a multi-walled CNT (MWCNT). When these conditions are satisfied, the first and second antistatic layers A10 and A20 may be advantageous in exhibiting excellent antistatic performance even at a high elongation (or referred to as elongation) of the release film. Even if the release film is stretched to some extent, the plurality of CNTs may maintain a network structure, and antistatic performance may be maintained. The first and second antistatic layers A10 and A20 may also be referred to as ‘electrostatic prevention layers’, ‘antistatic sheets’ or ‘antistatic coating layers’.
Each of the first and second antistatic layers A10 and A20 may further include a predetermined polymer material serving as an adhesive. The polymer material may include, for example, silicone. The silicone may be, for example, hybrid silicone. In addition, each of the first and second antistatic layers A10 and A20 may further include a conductive polymer material. The conductive polymer material secures a conductive path between CNT particles, and secures conductivity together with flexibility. As a non-limiting example, the conductive polymer material may be PEDOT:PSS [poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)]. The antistatic performance may be further improved by using a polymer conductor material such as PEDOT:PSS and CNT together. When the silicone is applied to the antistatic layers A10 and A20, a content thereof may be about 5 to 30 wt %. When the conductive polymer material is applied to the antistatic layers A10 and A20, a content thereof may be about 5 to 65 wt %.
The first release layer R10 may have a first surface S10 on an opposite side of the first antistatic layer A10, and the first surface S10 may include the first fine unevenness N10 at least for improving the releasability. In the drawing, the lower surface of the first release layer R10 may be the first surface S10, and the first antistatic layer A10 may be bonded to the upper surface of the first release layer R10. The second release layer R20 may have a second surface S20 on an opposite side of the second antistatic layer S20, and the second surface S20 may include the second fine unevenness N20 at least for improving the releasability. In the drawing, the upper surface of the second release layer R20 may be the second surface S20, and the second antistatic layer A20 may be bonded to the lower surface of the second release layer R20.
The first surface S10 may have a surface roughness Ra of about 5 μm or more due to the first fine unevenness N10. In an embodiment, the surface roughness Ra of the first surface S10 may be about 5 μm to about 20 μm. The second surface S20 may have a surface roughness Ra of about 5 μm or more due to the second fine unevenness N20. In an embodiment, the surface roughness Ra of the second surface S20 may be about 5 μm to about 20 μm. However, the surface roughness Ra of the first surface S10 and the second surface S20 is not limited to the above-mentioned levels, and may be designed differently in some cases.
At least one of the first and second release layers R10 and R20 may have the same material composition as that of the polyurethane layer P10. In this case, at least one of the first and second release layers R10 and R20 may include thermosetting polyurethane having a cross-linkage bond. In this case, the content of the thermosetting polyurethane in at least one of the first and second release layers R10 and R20 may be about 80 wt % or more or about 90 wt % or more. According to an embodiment, the content of the thermosetting polyurethane in at least one of the first and second release layers R10 and R20 may be about 80 wt % to 100 wt %.
However, at least one of the first and second release layers R10 and R20 may have a material composition different from that of the polyurethane layer P10. In this case, at least one of the first and second release layers R10 and R20 may further include an inorganic material. When the first release layer R10 includes the inorganic material, the first fine unevenness N10 may be formed on the lower surface of the first release layer R10, that is, the first surface S10 by the inorganic material. When the second release layer R20 includes the inorganic material, the second fine unevenness N20 may be formed on the upper surface of the second release layer R20, that is, the second surface S20 by the inorganic material.
More specifically, the first release layer R10 may include a base layer portion made of thermosetting polyurethane, and an inorganic material contained in the base layer portion, and the first fine unevenness N10 may be formed by the inorganic material. The inorganic material may, for example, have a form of particle (a plurality of particles). In addition, the inorganic material may include, for example, at least one of silica, calcium carbonate (CaCO3), and barium sulfate (BaSO4). However, the type of inorganic material which may be used in the embodiment of the present invention is not limited to the above-mentioned descriptions, and may be variously changed. When the first release layer R10 includes the inorganic material, the inorganic material may be referred to as a kind of filler. In this case, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the first release layer R10 may be about 60 wt % or more or about 80 wt % or more. For example, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the first release layer R10 may be about 60 wt % to about 97 wt %. The content of the thermosetting polyurethane in the first release layer R10 in the region other than the inorganic material may be about 80 wt % to 100 wt %. In the remaining region except for the inorganic material, the first release layer R10 may include thermosetting polyurethane as a main constituent material or may be composed of thermosetting polyurethane. In addition, in some cases, the first release layer R10 may include an amount (a small amount) of another polymer material or other additives (e.g., a leveling agent, an antifoaming agent, etc.) in addition to the thermosetting polyurethane.
Similar to the first release layer R10, the second release layer R20 may include a base layer portion made of thermosetting polyurethane and an inorganic material contained in the base material layer portion, and the second fine unevenness N20 may be formed by the inorganic material. The material and shape of the inorganic material may be the same as described above. When the second release layer R20 includes the inorganic material, the inorganic material may be referred to as a kind of filler. In this case, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the second release layer R20 may be about 60 wt % or more or about 80 wt % or more. For example, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the second release layer R20 may be about 60 wt % to about 97 wt %. The content of the thermosetting polyurethane in the second release layer R20 in the region other than the inorganic material may be about 80 wt % to 100 wt %. In the remaining region except for the inorganic material, the second release layer R20 may include thermosetting polyurethane as a main constituent material or may be composed of thermosetting polyurethane. In addition, in some cases, the second release layer R20 may include an amount (a small amount) of another polymer material or other additives (e.g., a leveling agent, an antifoaming agent, etc.) in addition to the thermosetting polyurethane.
The release film according to an embodiment of the present invention may have a thickness (a total thickness) in the range of about 30 μm to 140 μm. The thickness of the release film may be, for example, about 50 μm to about 120 μm or about 50 μm to about 100 μm. Under these thickness conditions, the release film may have excellent mechanical properties suitable for a molding process. The thickness of the polyurethane layer P10 may be, for example, about 10 μm to 70 μm, the thickness of the first release layer R10 may be, for example, about 10 μm to 70 μm, and the thickness of the second release layer R20 may be, for example, about 10 μm to 70 μm. The thickness of the first release layer R10 may be the same as or similar to the thickness of the second release layer R20. The thickness of the polyurethane layer P10 may be the same as the thickness of each of the first release layer R10 and the second release layer R20, but may be different. In the latter case, the thickness of the polyurethane layer P10 may be thinner than the thickness of each of the first release layer R10 and the second release layer R20. When the above thickness conditions are satisfied, it may be advantageous for easy formation (manufacturing) and improvement of mechanical properties of the release film.
Meanwhile, each of the first and second antistatic layers A10 and A20 may have a thickness of about 0.1 μm to 2 μm. When these thickness conditions are satisfied, the first and second antistatic layers A10 and A20 may more effectively exhibit antistatic performance in the release film.
Referring to
The first and second polyurethane layers P11 and P21 may include thermosetting polyurethane having a cross-linking bond. A content of the thermosetting polyurethane in the first polyurethane layer P11 may be about 80 wt % or more or about 90 wt % or more. In one embodiment, the content of the thermosetting polyurethane in the first polyurethane layer P11 may be about 80 wt % to 100 wt %. A content of the thermosetting polyurethane in the second polyurethane layer P21 may be about 60 wt % or more or about 80 wt % or more. In one embodiment, the content of the thermosetting polyurethane in the second polyurethane layer P21 may be about 60 wt % to 97 wt %, or about 60 wt % to 100 wt %. Each of the first and second polyurethane layers P11 and P21 may include thermosetting polyurethane as a main constituent material or may be composed of thermosetting polyurethane. In addition, in some cases, at least one of the first and second polyurethane layers P11 and P21 may contain some (a small amount) of other polymer materials or other additives (e.g., leveling agents, antifoaming agents, etc.) in addition to the thermosetting polyurethane. The material composition of each of the first and second polyurethane layers P11 and P21 may be the same as or similar to that of the polyurethane layer P10 of
The first release layer R11 may have a first surface S11 on an opposite side to the first polyurethane layer P11, and the first surface S11 may include a first fine unevenness N11 at least for improving the releasability. In the drawing, the lower surface of the first release layer R11 may be the first surface S11, and the first polyurethane layer P11 may be bonded to the upper surface of the first release layer R11. The second release layer R21 may have a second surface S22 on an opposite side to the second polyurethane layer P21, and the second surface S22 may include a second fine unevenness N22 at least for improving the releasability. In the drawing, the upper surface of the first release layer R21 may be the second surface S22, and the second polyurethane layer P21 may be bonded to the lower surface of the first release layer R21. The range condition of the surface roughness Ra of each of the first surface S11 and the second surface S22 may be the same as or similar to that described for the first surface S10 and the second surface S20 in
At least one of the first and second release layers R11 and R21 may have the same material composition as the polyurethane layers P11 and P21. In this case, at least one of the first and second release layers R11 and R21 may include thermosetting polyurethane having a cross-linking bond. In this case, a content of the thermosetting polyurethane in at least one of the first and second release layers R11 and R21 may be about 80 wt % or more or about 90 wt % or more. According to an embodiment, the content of the thermosetting polyurethane in at least one of the first and second release layers R11 and R21 may be about 80 wt % to 100 wt %.
However, at least one of the first and second release layers R11 and R21 may have a material composition different from that of the polyurethane layers P11 and P21. In this case, at least one of the first and second release layers R11 and R21 may further include an inorganic material. When the first release layer R11 includes the inorganic material, the first fine unevenness N11 may be formed on the lower surface of the first release layer R11, that is, the first surface S11 by the inorganic material. When the second release layer R21 includes the inorganic material, the second fine unevenness N21 may be formed on the upper surface, that is, the second surface S21, of the second release layer R21 by the inorganic material.
The first release layer R11 may include a base layer portion made of thermosetting polyurethane and an inorganic material contained in the base layer portion, and the first fine unevenness N11 may be formed by the inorganic material. The inorganic material may, for example, have a particle type (a plurality of particles). In addition, the inorganic material may include, for example, at least one of silica, calcium carbonate (CaCO3), and barium sulfate (BaSO4). However, the type of inorganic material which may be used in the embodiment of the present invention is not limited to the above-mentioned types, and may be variously changed. When the first release layer R11 includes the inorganic material, the inorganic material may be referred to as a kind of filler. In this case, the content of the thermosetting polyurethane relative to the total amount of the thermosetting polyurethane and the inorganic material in the first release layer R11 may be about 60 wt % or more or about 80 wt % or more. For example, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the first release layer R11 may be about 60 wt % to about 97 wt %. The content of the thermosetting polyurethane in the first release layer R11 in the region other than the inorganic material may be about 80 wt % to 100 wt %. In the remaining region except for the inorganic material, the first release layer R11 may include thermosetting polyurethane as a main constituent material or may be composed of thermosetting polyurethane. Also, in some cases, the first release layer R11 may include an amount (a small amount) of another polymer material or other additives (e.g., a leveling agent, an antifoaming agent, etc.) in addition to the thermosetting polyurethane.
Similar to the first release layer R11, the second release layer R21 may include a base layer portion made of thermosetting polyurethane and an inorganic material contained in the base layer portion, and the second fine unevenness N21 may be formed by the inorganic material. The material and shape of the inorganic material may be the same as described above. When the second release layer R21 includes the inorganic material, the inorganic material may be referred to as a kind of filler. In this case, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the second release layer R21 may be about 60 wt % or more or about 80 wt % or more. For example, the content of the thermosetting polyurethane with respect to the total amount of the thermosetting polyurethane and the inorganic material in the second release layer R21 may be about 60 wt % to about 97 wt %. The content of the thermosetting polyurethane in the second release layer R21 in the region other than the inorganic material may be about 80 wt % to 100 wt %. In the region other than the inorganic material, the second release layer R21 may include thermosetting polyurethane as a main constituent material or may be composed of thermosetting polyurethane. In addition, in some cases, the second release layer R21 may include an amount (a small amount) of another polymer material or other additives (e.g., a leveling agent, an antifoaming agent, etc.) in addition to the thermosetting polyurethane.
The antistatic layer A11 may have the same or similar material composition to the first and second antistatic layers A10 and A20 of
In addition, the antistatic layer A11 may further include a predetermined polymer material serving as an adhesive or the like. The polymer material may include, for example, silicone. The silicone may be, for example, hybrid silicone. In addition, the antistatic layer A11 may further include a polymer conductor material such as PEDOT:PSS. When the silicon is applied to the antistatic layer A11, its content may be about 5 wt % to 30 wt %. When the polymer conductor material such as PEDOT:PSS is applied to the antistatic layer A11, its content may be about 5 wt % to about 65 wt %.
In the embodiment of
Referring to
Although not shown in
Referring to
The first antistatic layer A10 may be formed by a coating method using a micro-gravure coater or a direct gravure coater. When using a micro-gravure coater or a direct gravure coater, it may be advantageous to secure excellent coating properties. However, the type of coating equipment may be changed depending on the case.
The first release layer R10 may be formed on a predetermined base layer (not shown) or a carrier film (not shown). For example, the base layer may be a ‘matte film’. The matte film is a matte-treated film, and the matte treatment in this specification may refer to a matte process for forming a fine unevenness on the surface. The matte film may be, for example, a polyethylene terephthalate (PET) film, but the material of the matte film is not limited thereto and may vary. More specifically, when a polymer-forming solution is applied on the matte-treated surface of the mat film and a cured first release layer R10 is formed therefrom, the first fine unevenness N10 may be formed on the first surface S10 of the first release layer R10 bonded to the matte film. It may be said that the shape of the matte-treated surface of the mat film is transferred to the first surface S10 of the first release layer R10. The polymer-forming solution may include, for example, a urethane-based source material, a solvent, and a curing agent, etc. However, the first release layer R10 may not be formed on the mat film. For example, the first fine unevenness N10 of the first release layer R10 may be formed by an inorganic material included in the first release layer R10.
Referring to
For example, the second antistatic layer A20 may be formed by a coating method using an antistatic coating solution. That is, the second antistatic layer A20 may be formed by coating the antistatic coating solution on the upper surface of the polyurethane layer P10 or the lower surface of the second release layer R20, and drying or curing the coated antistatic coating solution under given conditions. The antistatic coating solution may include CNT. A specific method for forming the second antistatic layer A20 and the composition of the antistatic coating solution may be the same as or similar to those described with respect to the first antistatic layer A10 in
The second release layer R20 may be formed on a predetermined base layer (not shown) or a carrier film (not shown). For example, the base layer may be a ‘matte film’. When a polymer-forming solution is applied on the mat-treated surface of the matte film and a cured second release layer R20 is formed therefrom, the second fine unevenness N20 may be formed on the second surface S20 of the second release layer R20 bonded to the matte film. The polymer-forming solution may include, for example, a urethane-based source material, a solvent, and a curing agent, etc. However, the second release layer R20 may not be formed on the matte film. For example, the second fine unevenness N20 of the second release layer R20 may be formed by an inorganic material included in the second release layer R20.
At least one of the first and second release layers R10 and R20 may have the same material composition as that of the polyurethane layer P10. In this case, at least one of the first and second release layers R10 and R20 may include thermosetting polyurethane having a cross-linking bond. However, at least one of the first and second release layers R10 and R20 may have a material composition different from that of the polyurethane layer P10. In this case, at least one of the first and second release layers R10 and R20 may further include an inorganic material. When the first release layer R10 includes the inorganic material, the first fine unevenness N10 may be formed on the lower surface of the first release layer R10, that is, the first surface S10 by the inorganic material. When the second release layer R20 includes the inorganic material, the second fine unevenness N20 may be formed on the upper surface of the second release layer R20, that is, the second surface S20 by the inorganic material. The inorganic material may, for example, have a particle types (a plurality of particles). In addition, the inorganic material may include, for example, at least one of silica, calcium carbonate (CaCO3) and barium sulfate (BaSO4). At this time, the solution for forming the polymer used to form the first release layer R10 or the second release layer R20 may be a solution in which the inorganic material is mixed with the solution for forming polyurethane for forming the polyurethane layer P10. When at least one of the first and second release layers R10 and R20 includes the inorganic material, a detailed configuration may be the same as that described in
Referring to
Referring to
At least one of the first and second release layers R10 and R20 may have the same material composition as that of the polyurethane layer P10. In this case, at least one of the first and second release layers R10 and R20 may include thermosetting polyurethane having a cross-linking bond. However, at least one of the first and second release layers R10 and R20 may have a material composition different from that of the polyurethane layer P10. In this case, at least one of the first and second release layers R10 and R20 may further include an inorganic material. When at least one of the first and second release layers R10 and R20 includes the inorganic material, a specific configuration may be the same as described above.
Although the method of manufacturing the release film of
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Although the method of manufacturing the release film of
Hereinafter, the manufacturing process of the polyurethane layer which may be applied to the manufacturing method of the release film for a semiconductor package according to embodiments of the present invention will be described in more detail.
The number average molecular weight (a or weight average molecular weight) of the polyurethane resin used in the embodiment of the present invention may be about 50,000 to 500,000. Urethane (polyurethane) may be obtained by reaction of polyol and isocyanate, and may also be manufactured by controlling the reaction rate and molecular weight using a catalyst.
As the polyol, one or a mixture of two or more products having a molecular weight of about 500 to 7,000 may be used as a raw material. As the ether-based polyol, polypropylene glycol, modified polypropylene glycol, and polytetramethylene glycol (PTMG) may be used. As the polyester-based polyol, polyethylene glycol having a molecular weight in the range of about 500 to 7,000, polycarbonate-based polycondensation-based adipate-based polyester polyol, and ring-opening polymerization-based lactone-based polyol may be used. In addition, one or two or more of polybutadiene glycol and acryl-based polyol may be mixed and used. However, the above materials are exemplary, and the present application is not limited thereto.
As the isocyanate material, various diisocyanate-based materials may be used. For example, PPDI may be used as p-phenylene diisocyanate with a molecular weight of 160.1. TDI including isomer of toluene-diisocyanate may be used as toluene-diisocyanate with a molecular weight of 174.2. NDI may be used as 1,5-naphthalene diisocyanate with a molecular weight of 210.2. HDI may be used as 1,6-hexamethylene diisocyanate with a molecular weight of 168.2, MDI may be used as 4,4′-diphenylmethane diisocyanate with a molecular weight of 250.3. IPDI may be used as isoporon diisocyanate with a molecular weight of 222.3, and H12MDI may be used as cyclohexylmethane diisocyanate with a molecular weight of 262. However, the above materials are exemplary, and the present application is not limited thereto.
In addition, a chain extender material may be additionally used in addition to the polyol and isocyanate. The chain extender may serve to increase the molecular weight of the polyurethane and impart various functionalities. One to two or more of the chain extenders may be mixed and used. As the chain extender, ethylene glycol-based material, propylene glycol-based material, butadiene glycol-based material, polyhydric alcohol including silicone, polyhydric alcohol including fluorine, etc. may be used. However, the above materials are exemplary, and the present application is not limited thereto.
As the catalyst, various organic tin-based materials and organic bismuth-based materials may be used. The organotin-based material (an organotin-based compound) may include, for example, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dibutyltin dimercaptide, and the like. Here, dibutyltin dilaurate is (CH3CH2CH2CH2)2Sn[CH3(CH2)10COO]2, stannous octoate is Sn[C7H15COO]2, dibutyltin diacetate is (CH3CH2CH2CH2)2Sn[CH3COO]2, dibutyltin dimercaptide is (CH3CH2CH2CH2)2Sn[SC12H25]. The organic bismuth-based material (an organic bismuth-based compound) may have various molecular weights, and may include, for example, a carboxylate-based catalyst material containing bismuth. Here, the carboxylate-based catalyst material may contain about 9% to about 45% of bismuth. However, the above materials are exemplary, and the present application is not limited thereto.
As a solvent for making a polyurethane resin solution, for example, various acetone solvents and etc. including DMF (dimethylformamide), DEF (diethylformamide), DMSO (dimethylsulfoxaide), DMAC (dimethylacetamide), toluene, ethyl acetate (EA), methyl ethyl ketone may be used. However, the above materials are exemplary, and the present application is not limited thereto.
After preparing a resin solution for preparing polyurethane in which the polyol, isocyanate, solvent, etc. are mixed, a polymer cured product having various crosslinking densities may be formed by reaction using a melamine-based curing agent, its catalyst, and an isocyanate-based curing agent polymerized with various molecular weights. In this case, a curing method using heat may be applied.
The composition of the curable polyurethane which may be applied to an embodiment of the present invention will be described as follows.
As for the polyurethane composition, polyol such as a polyester-based polyol (e.g., molecular weight 500 to 7,000), polyether-based polyol (e.g., molecular weight 200 to 3,000) or polycarbonate-based polyol (e.g., molecular weight 500 to 8,000) may be applied as a first material for the urethane reactioned, and an isocyanate-based material may be applied as a second material for the urethane reaction. As the isocyanate-based material, various isocyanate types containing a yellowing benzene-ring, and various isocyanates including hexamethylene-based, isophorone-based and cyclohexylmethane-based which are non-yellowing types may be used. In addition, a chain extender may be additionally used to increase the molecular weight of the polyurethane. As the chain extender, ethylene glycol-based materials, propylene glycol-based materials, butadiene glycol-based materials, polyhydric alcohols including silicone, polyhydric alcohols including fluorine, etc. may be used, and it is possible to increase the molecular weight of the polyurethane by allowing the chain extender to be involved in a urethane reaction.
As other additives, a leveling agent, an antifoaming agent, a curing agent, and the like may be additionally used. As the leveling agent, a modified polyether-based leveling agent including a silicone-based, fluorine-based or non-silicone-based leveling agent may be used, and the leveling agent may be used in a mixture of about 0.1 wt % to 5 wt %. The antifoaming agent is for a defoaming function, and for example, a silicone-based or non-silicone-based antifoaming agent may be used. The antifoaming agent may be used in a mixture of about 0.1 wt % to 5 wt %. In addition, as a curing agent for the curing reaction of the prepared polyurethane, a melamine-based curing agent and an isocyanate-based curing agent polymerized with several molecules may be used. In addition, the curing reaction may be accelerated in the presence of an acid catalyst.
In embodiments of the present invention, the formation of the polyurethane layer, the formation of the release layer, the formation of the antistatic layer, etc. may be performed by using a roll-to-roll process. In this case, the formation of the polyurethane layer, the formation of the release layer, the formation of the antistatic layer, etc. may be performed by any one of a micro-gravure coater, a direct gravure coater, a comma coater, and a slot die coater.
Referring to
The configuration of the apparatus shown in
In addition, in embodiments of the present invention, a method for bonding two material layers to each other may include both of a method for forming a solution for forming the other material layer on one material layer according to a coating method, or a method in which two material layers are mutually bonded to each other.
Referring to
A predetermined concave portion (a cavity region) may be provided in the first molding tool T10, and the release film 100 may be disposed to cover the concave portion. The release film 100 may be sucked so as to be in close contact with the surface of the concave portion by a vacuum adsorption method (i.e., a suction method). A substrate 200 having a plurality of semiconductor device portion 210 formed thereon may be disposed on a lower surface of the second molding tool T20. A molding material (e.g., EMC) (not shown) may be disposed on a portion of the release film 100 of the concave portion (a cavity region). A heating process for melting the molding material, and a vacuum compression process for attaching the molten molding material to the side of the semiconductor device portion 210 may be performed.
The release film 100 according to the embodiment of the present invention may have excellent mechanical properties which may withstand high temperature and high pressure conditions without rupture during the molding process of a semiconductor package, and also have excellent releasability (peelability). In particular, since the release film 100 includes a thermosetting material, it may have superior mechanical properties than a conventional release film based on a thermoplastic material. Therefore, the release film 100 according to the embodiment of the present invention may not rupture even under conditions of high temperature and high pressure. In addition, since the release film 100 according to the embodiment of the present invention has low permeability to the fume-gas generated during the molding process, the problems such as mold contamination and productivity decrease due to the fume-gas may be prevented.
In addition, the release film 100 according to the embodiment of the present invention may maintain excellent antistatic performance even during a high-temperature process. Even if a portion of the release film 100 is stretched during the semiconductor package molding process, the antistatic performance of the release film 100 may be maintained. Accordingly, it is possible to effectively prevent or suppress problems such as process defects, mold contamination, and damage/destruction of semiconductor devices due to the charging phenomenon during the semiconductor package process. Additionally, since the release film 100 according to an embodiment of the present invention has fine unevenness (refer to N10 and N20 in
Therefore, when the release film 100 according to the embodiment of the present invention is used, the defect rate of the semiconductor package may be lowered, the productivity may be improved, and the characteristics of the manufactured package may be improved.
Table 1 below summarizes the results evaluating the resistance of the release film, resistance (surface resistance) change characteristics by elongation (elongation rate), and substrate adhesion strength of the release film, after manufacturing the release film having the structure shown in
Table 2 below summarizes the results evaluating the resistance of the release film, resistance (surface resistance) change characteristics by elongation (elongation rate), and substrate adhesion strength of the release film, after manufacturing the release film having the structure shown in
Referring to Tables 1 and 2 above, when the wet thickness is about 10 μm to 25 μm or about 10 μm to 20 μm in the embodiment of
Referring to
The circuit board S10 may be a printed circuit board (PCB). For example, the circuit board S10 may be a flexible printed circuit board (FPCB). At least one vent hole VH10 passing through the circuit board S10 in its thickness direction may be formed. One or more vent holes VH10 may be formed, and may be formed in the central portion or edge region of the circuit board S10, or in an intermediate region between the central portion and the edge region. When the plurality of vent holes VH10 are formed, they may be formed to be relatively uniformly distributed over the entire region or substantially the entire region of the circuit board S10, or within a predetermined range. The formation positions and number of the plurality of vent holes VH10 illustrated in
Each of the plurality of semiconductor device portions (units) D10 mounted or arranged on the circuit board S10 may be a semiconductor chip (i.e., a die). The plurality of semiconductor device portions D10 may be disposed to be spaced apart from each other at a predetermined interval. The plurality of semiconductor device portions D10 may be arranged to form a two-dimensional array. A plurality of electrical connection members B10 may be disposed between each of the semiconductor device portions D10 and the circuit board S10 to electrically connect them to each other. The electrical connection member B10 may be a solder bump. A plurality of first electrode pads may be formed on a lower surface of each semiconductor device portion D10, and a plurality of second electrode pads may be formed on an upper surface of the circuit board S10. The plurality of electrical connection members B10 may be disposed to interconnect the plurality of first electrode pads and the plurality of second electrode pads.
An upper molding layer C10 may be further formed on each semiconductor device portion D10. In other words, the device structure DS10 may further include a plurality of upper molding layers C10 formed on the plurality of semiconductor device portions D10. The upper molding layer C10 may be a kind of protective layer, and may be formed by, for example, a molding material such as an epoxy molding compound (EMC). Here, the case in which the upper molding layer C10 is individually formed on each semiconductor device portion D10 is illustrated, but in some cases, one molding layer (an upper molding layer) may be formed to completely cover the upper surfaces of the plurality of semiconductor device portions D10.
According to an embodiment of the present invention, after a first mold member MT10 having a plurality of suction holes SH10 is prepared, a first release film RF10 may be disposed on the first mold member MT10, and the device structure DS10 to be subjected to an underfill process may be disposed on the first release film RF10.
The first mold member MT10 may be referred to as a first molding tool member (an apparatus unit). The first mold member MT10 may be a mold member. For example, the first mold member MT10 may be a lower mold. The plurality of suction holes SH10 may be formed in the first mold member MT10. The plurality of suction holes SH10 may be arranged at a predetermined distance from each other in a regular or patterned manner. The plurality of suction holes SH10 may be formed to pass through the first mold member MT10 in the thickness direction, but in some cases, they may be formed so as to be bent and extended from the upper surface portion of the first mold member MT10 toward the side surface without penetrating in the thickness direction. The plurality of suction holes SH10 may be horizontally spaced apart from the vent hole VH10 so as not to overlap the vent hole VH10 of the circuit board S10. At least an upper end of the suction hole SH10 may be spaced apart from the vent hole VH10 in a horizontal direction so as not to overlap the vent hole VH10. The formation positions and number of the plurality of suction holes SH10 illustrated in
In an embodiment, the first release film RF10 may be a thermosetting polymer film, as described above with reference to
The first release film RF10 may be a thermosetting polyurethane film formed by the above-mentioned thermosetting polyurethane resin. The content of the thermosetting polyurethane in the first release film RF10 may be about 80 wt % to 100 wt %. However, in some cases, the first release film RF10 may include a part (a small amount) of other polymer materials or other additives in addition to the thermosetting polyurethane. Also, in some cases, the first release film RF10 may be formed by other thermosetting polymer other than the thermosetting polyurethane-based polymer.
The first release film RF10 may have a thickness in a range of about 15 μm to about 60 μm. Under this thickness condition, the first release film RF10 may exhibit excellent mechanical properties which simplifies the process for forming a vent hole through rupture by a suction pressure, which will be described later in the underfill process according to the present embodiment. However, since the rupture process may be induced by weakening the strength of the first release film RF10 or increasing the suction pressure to be described later, in this case, the thickness of the first release film RF may be further increased. The first release film RF10 may be a film having releasability on both surfaces (a lower surface and an upper surface), and may be a film having fine unevenness forming surface roughness for improving releasability on at least one surface of the both surfaces. The formation of the fine unevenness may be optional.
The device structure DS10 may be disposed on the first release film RF10. In this case, the device structure DS10 may be disposed such that the circuit board S10 may face the first release film RF10. The lower surface of the first release film RF10 may be in contact with the upper surface of the first mold member MT10, and the lower end of the device structure DS10, that is, the lower end of the circuit board S10, may be in contact with the upper surface of the first release film RF10. Although not shown in
According to an embodiment of the present invention, the first mold member MT10 may further include a first support pin portion P10 disposed in a first edge region (a first edge or a region adjacent thereto), and a second edge region (a second edge or a region adjacent thereto). In addition, the first release film RF10 may include a first through hole TH1 formed at a position corresponding to the first support pin portion P10, and a second through hole TH2 formed at a position corresponding to the second support pin portion P20. In the step for disposing the first release film RF10 on the first mold member MT10, the first support pin portion P10 may be inserted into the first through hole TH1, and the second support pin portion P20 may be inserted into the second through hole TH2. As described above, by inserting the first and second support pin portions P10 and P20 into the first and second through holes TH1 and TH2, respectively, it may be easy to align the first release film RF10 on the first mold member MT10 and to fix the position thereof. On the other hand, the arrangement, direction, and distance relationship between the first and second support pin portions P10 and P20 and the circuit board S10 shown in
Referring to
The first suction pressure for forming the plurality of ventilation holes AH10 may be, for example, in a range of about 20 KPa to about 90 KPa. In addition, in the step for forming the plurality of ventilation holes AH10, a temperature of the first mold member MT10 may be in a range of about 50° C. to about 250° C. When the suction pressure (i.e., the first suction pressure) condition and temperature condition are satisfied, the plurality of ventilation holes AH10 may be more easily formed by the drilling process, and a subsequent underfill process may also be easily performed by the ventilation hole AH10 aligned in the respective suction holes SH10.
As the first mold member MT10 is heated to the above-described temperature range, the device structure DS10 may also be heated. In this case, due to the difference in the coefficient of thermal expansion between the circuit board S10, and the semiconductor device portion D10 and the upper molding layer C10 of the device structure DS10, the device structure DS10 may be deformed as a convex shape in a downward direction (that is, in a U-shape). However, according to the embodiment of the present invention, when the plurality of ventilation holes AH10 are formed by using the first suction pressure, as the plurality of ventilation holes AH10 are formed, the device structure DS10 positioned above them may be strongly adsorbed and may be pulled downward by a strong instantaneous vacuum pressure through the plurality of ventilation holes AH10. Therefore, even if the device structure DS10 is deformed to be convex downwardly (i.e., U-shape) due to the heating, a plurality of ventilation holes AH10 are formed and a strong vacuum pressure is applied to the device structure DS10. Accordingly, the device structure DS10 may be closely adhered (adsorbed) toward the first mold member MT10 to form a flat structure, and may be fixed toward the first mold member MT10. In this regard, the effect of improving the workability of the underfill process may be obtained.
The plurality of ventilation (air-passing) holes AH10 may have a diameter of, for example, about 0.05 mm to about 8 mm. When the diameter is within this range, a subsequent underfill process using the plurality of ventilation holes AH10 may be more easily performed.
Referring to
The underfill material may be a kind of resin. For example, the underfill material may include a material such as EMC. The underfill material may be supplied to an edge region of the device structure DS10 by using a predetermined dispenser. As the underfill material is supplied from the edge region of the device structure DS10 to the inside thereof, a capillary pressure may act, and the second suction pressure may be applied together with the capillary pressure, thereby performing an underfill process. The second suction pressure may be, for example, in the range of about 20 KPa to about 300 KPa. The second suction pressure may be equal to or substantially less than the first suction pressure described with reference to
In the step for forming the underfill material layer F10, a portion of the underfill material may pass through the vent hole VH10 of the circuit board S10, and contact the upper surface of the first release film RF10. At this time, since the vent hole VH10 and the ventilation hole AH10 do not overlap and are spaced apart in the horizontal direction, the underfill material passing through the vent hole VH10 may not be entered the ventilation hole AH10 or a suction hole SH10. In the embodiment of the present invention, by using the first release film RF10 in which the ventilation hole AH10 is formed, it is possible to fundamentally prevent the problem that the underfill material emitted through the vent hole VH10 contaminates the surface of the first mold member MT10 (i.e., the lower mold). Therefore, after performing one underfill process, the next underfill process may be performed without a separate cleaning process for the surface of the first mold member MT10 (i.e., the lower mold). Accordingly, workability and efficiency of the underfill process may be greatly improved.
Referring to
Referring to
However, according to the embodiment of the present invention, as described with reference to
Referring to
Referring to
Referring to
Referring to
As illustrated in
Referring to
A first insertion groove G1 into which the first support pin portion P10 is inserted and a second insertion groove G2 into which the second support pin portion P20 is inserted may be provided on a lower surface of the second mold member MT20. The second mold member MT20 may be disposed on the first mold member MT10 so that the first and second support pin portions P10 and P20 may be inserted into the first and second insertion grooves G1 and G2, respectively. However, the coupling relationship between the first mold member MT10 and the second mold member MT20 as illustrated herein is merely exemplary, and may be variously changed. Also, the arrangement relationship between the first and second support pin portions P10 and P20 and the second release film RF20 is exemplary and may be variously changed.
Although not shown in
Referring to
The second suction pressure may be, for example, in a range of about 20 KPa to 200 KPa. The second suction pressure may be equal to or substantially smaller than the first suction pressure described with reference to
In the step for forming the MUF material layer MF10, a portion of the underfill material may pass through the vent hole VH10 of the circuit board S10, and contact the upper surface of the first release film RF10. At this time, since the bend hole VH10 and the ventilation hole AH10 do not overlap and are spaced apart in the horizontal direction, the underfill material passing through the vent hole VH10 may not enter the ventilation hole AH10 or a suction hole SH10 below it. In the embodiment of the present invention, by using the first release film RF10 in which the ventilation hole AH10 is formed, it is possible to fundamentally prevent the problem that the underfill material emitted through the vent hole VH10 contaminates the surface of the first mold member MT10 (i.e., the lower mold). Therefore, after performing one underfill process, the next underfill process may be performed without a separate cleaning process for the surface of the first mold member MT10 (i.e., the lower mold). Accordingly, workability and efficiency of the underfill process may be greatly improved.
After performing the underfill process using the method of
Referring to
Referring to
According to the embodiments of the present invention described above, process efficiency may be greatly improved by preventing the problem of contamination of the mold device (i.e., the mold) in the underfill process during a manufacturing process of the semiconductor package. In addition, according to embodiments of the present invention, it is possible to effectively solve the problem of deterioration of workability due to deformation of the substrate on the mold device (i.e., the mold) in the underfill process during the manufacturing process of the semiconductor package. According to embodiments, since the problem due to substrate deformation may be effectively solved while fundamentally preventing contamination of the mold apparatus (i.e., the mold) using a fairly simple method, a high process improvement effect may be obtained at low cost.
The techniques according to an embodiment of the present invention may be applied to various underfill processes as well as a molded underfill (MUF) process. That is, the techniques according to the embodiment may be applied to various underfill processes in which a vent hole (a resin through hole) is formed in the circuit board and the circuit board is brought into close contact with the lower mold through the suction hole of the lower mold. In addition, the techniques according to the embodiment may be applied to all kinds of semiconductor packages which may be manufactured through an underfill process, such as a ball grid array (BGA), a chip scale package (CSP), a flip chip, and a through silicon via (TSV).
In the present specification, preferred embodiments of the present invention have been disclosed, and although specific terms are used, these are only used in a general sense to easily describe the technical contents of the present invention and to help the understanding of the present invention, and are not used to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention may be implemented in addition to the embodiments disclosed herein. It will be appreciated to those of ordinary skill in the art that the methods for forming underfill and manufacturing methods of a semiconductor package using the same according to the embodiments described with reference to
Various embodiments of the present invention relate to semiconductor package manufacturing technology, and more particularly, may be implemented as a release film for a semiconductor package, a manufacturing method thereof, and a manufacturing method of a semiconductor package using the same.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0070252 | May 2021 | KR | national |
| 10-2021-0147520 | Oct 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2021/017699 | 11/29/2021 | WO |
