This application claims the benefit of Korean Patent Application No. 10-2021-0090542, filed on Jul. 9, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
The present invention relates to a semiconductor package having a package housing in an engraved surface form and a method of manufacturing the same, wherein in the semiconductor package, a thickness of a heat transfer connector used to join and transfer heat to a heat sink may be adjusted through a stopper, which is engraved using a laser, and uniformly maintained to suppress delamination and to improve heat transfer efficiency.
As well known in the art, electrical and electronic components, in particular, semiconductor components, generate heat while they operate so that a heat sink is used to prevent overheating and to maintain their performances.
In particular, semiconductor components applied in a high-power application field prevent overheating by using a heat sink which circulates a coolant. Here, the heat sink includes a cooling part member for contacting the circulating coolant so as to cool heat transferred from a semiconductor component to the cooling part member.
In order to bond a heat sink 50 to an exposed surface A of the lower substrate 21 or the upper substrate 22 by using an adhesive 40, a grinding wheel 11 is used to remove the over-molded sealing member disposed at the upper part of the lower substrate 21 or the upper substrate 22.
However, when the sealing member is removed by the grinding wheel as described above, consumption of the sealing member increases and a metal layer forming the substrate is cut while grinding the sealing member by the grinding wheel so that an insulating layer such as ceramic may be cracked. Here, when a thickness of the metal layer grows in order to prevent such a crack, costs may increase. Also, metal particles generated after grinding remain between the sealing member so that problems on insulation voltage may occur and delamination may be generated due to stress on the semiconductor package.
In addition, when the adhesive is coated for bonding to the heat sink, a gap between the surface of the substrate and the sealing member is uneven and thus, a thickness of the adhesive, in particular, the thickness at both ends of the adhesive may not be uniform. Accordingly, heat transfer efficiency is lowered and delamination is generated.
The present invention provides a semiconductor package having a package housing in an engraved surface form and a method of manufacturing the same, wherein in the semiconductor package, a thickness of a heat transfer connector used to join and transfer heat to a heat sink may be adjusted through a stopper, which is engraved using a laser, and uniformly maintained to suppress delamination and to improve heat transfer efficiency.
According to an aspect of the present invention, there is provided semiconductor package having a package housing in an engraved surface form including: at least one substrate on which at least one semiconductor chip is installed; at least one terminal lead electrically connected to the substrates; electrical connectors for connecting the semiconductor chips to the substrates or the terminal leads; a package housing covering the semiconductor chips, the electrical connectors, and the at least one substrate; at least one stopper which is formed of a material same as that of the package housing, is higher by a certain height than exposed surfaces of the substrates, is disposed on the exposed surfaces of the substrates, or covers at least a part of the exposed surfaces; and at least one heat sink transmitting heat from the semiconductor chips and radiating heat, wherein the at least a part of the exposed surfaces of the at least one substrate is formed on the upper surface, the lower surface, or the upper and lower surfaces of the package housing and the exposed surfaces of the at least one substrate are joined to the heat sinks by using heat transfer connectors interposed therebetween.
According to another embodiment of the present invention, there is provided a semiconductor package having a package housing in an engraved surface form including: at least one substrate on which at least one semiconductor chip is installed; at least one terminal lead electrically connected to the substrates; electrical connectors for connecting the semiconductor chips to the substrates or the terminal leads; a package housing covering the semiconductor chips, the electrical connectors, and the at least one substrate; at least one stopper which is formed of a material same as that of the package housing, is higher by a certain height than exposed surfaces of the substrates, and is not overlapped with the exposed surfaces of the substrates; and at least one heat sink transmitting heat from the semiconductor chips and radiating heat, wherein the at least a part of the exposed surfaces of the at least one substrate is formed on the upper surface, the lower surface, or the upper and lower surfaces of the package housing and the exposed surfaces of the at least one substrate are joined to the heat sinks by using heat transfer connectors interposed therebetween.
The substrates may be metal substrates or include at least one insulating layer.
The height of the stoppers may be 1 μm through 1 mm.
The stoppers may be formed to be high in the form of at least any one plane including a circle, a quadrangle, and a polygon.
The at least one stopper may be formed by partially engraving the surface of the package housing using a laser.
The height of the at least one stopper may be determined by the partial surface of the package housing which is not engraved.
The electrical connectors may be formed of any one single metal including Au, Ag, Al, and Cu or an alloy containing 50 weight % or more of any one or more metal including Au, Ag, Al, and Cu.
The electrical connectors may be conductive spacers in a hexahedral or a cylindrical form.
One side of the spacer may be electrically joined to the semiconductor chip on a first substrate using a conductive adhesive and the other side of the spacer may be electrically joined to a second substrate using a conductive adhesive.
The electrical connectors may be electrically connected between the at least one semiconductor chip and the substrates.
The semiconductor chips may be installed on an upper substrate or a lower substrate.
The stoppers may include at least one spherical grain or at least one round groove on the wall thereof.
The diameter of the grains or the depth of the round grooves may be 1 μm through 100 μm.
The heat sink may include at least one metal layer or at least one ceramic layer on one surface thereof.
The thickness of the heat transfer connector interposed between one surface of the heat sink and the exposed surface of the at least one substrate may be 1 μm through 1 mm.
The heat transfer connector may have thermal conductivity of 1 W/m-k through 400 W/m-k.
The heat transfer connectors may be trapped by 60% or more in the stoppers, the exposed surfaces of the substrates, and the one surfaces of the heat sinks.
The at least one semiconductor chip may be structurally connected to one surface of the lower substrate by using an adhesive, the at least one stopper may not be formed on the other surface of the lower substrate, the at least one stopper may be formed on one surface of the upper substrate, and the other surface of the upper substrate may be electrically connected to the semiconductor chips through the electrical connectors.
The at least one semiconductor chip may be structurally connected to one surface of the lower substrate by using an adhesive, the at least one stopper may be formed on the other surface of the lower substrate, the at least one stopper may be formed on one surface of the upper substrate, and the other surface of the upper substrate may be electrically connected to the semiconductor chips through the electrical connectors.
According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor package having a package housing in an engraved surface form including: preparing a lower substrate and the upper substrate to which at least one semiconductor chip is to be installed, electrical connectors, and at least one terminal lead;
structurally connecting the lower substrate, the upper substrate, the semiconductor chips, and the electrical connectors by using conductive adhesives; forming a package housing to cover the semiconductor chips, the electrical connectors, the entire surfaces of the lower and upper substrates being installed, and at least a part of the exposed surfaces of the lower substrate and the upper substrate; partially engraving the surface of the package housing by using a laser to form stoppers to be higher by a certain height than exposed surfaces of the lower substrate or the upper substrate; and joining the exposed surfaces of the at least one substrate to heat sinks by using heat transfer connectors.
The height of the stoppers may be 1 μm through 1 mm.
The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
Hereinafter, the embodiments of the present invention will be described in more detail with reference to the accompanying drawings.
The present invention provides a semiconductor package having a package
housing in an engraved surface form including a stopper 160 overlapped with an exposed surface A of substrates 121 and 122 included in a package housing 150 according to an embodiment of the present invention, a semiconductor package having a package housing in an engraved surface form including the stopper 160 which is not overlapped with the exposed surface A of the substrates 121 and 122 according to another embodiment of the present invention, and a method of manufacturing a semiconductor package having a package housing in an engraved surface form in which the stopper 160 is formed by being engraved using a laser 10.
Referring to
Referring to
Firstly, one or more substrates are formed to install at least one semiconductor chip 110 thereon.
The substrates may be metal substrates or include at least one insulating layer formed of ceramic. As illustrated in
For example, the substrate may be exposed to one surface or both surfaces of the package housing 150 according to a single sided board or a both sided board, and include the lower substrate 121 on which the semiconductor chip 110 is installed, and the upper substrate 122 spaced apart from the lower substrate 121. Also, the semiconductor chips 110 and the upper substrate 122 may be electrically connected to each other by a surface connection method using a spacer 141 which is an electrical connector, and an adhesive 111 may be filled between the semiconductor chip 110 and the electrical connector.
In addition, the semiconductor chips 110 may be installed on the lower substrate 121 or the upper substrate 122 and may be a diode, a thyristor, an Insulated Gate Bipolar Transistor (IGBT), or a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). In particular, the semiconductor chips 110 may be used in devices used to convert or control electricity such as an inverter, a converter, or an On Board Charger (OBC) and thereby, convert electricity into specific current, specific voltage, or specific frequency.
Next, one or more terminal leads 130 are included to electrically connect to the lower substrate 121 and/or the upper substrate 122 and are exposed to the outside of the package housing 150 to apply an electrical signal to the semiconductor chips 110.
Here, the terminal leads 130 may include a metal containing 80 weight % or more of Cu or 60 weight % or more of Al.
Next, the electrical connectors electrically connect the semiconductor chips 110 to the substrates 121 and 122 or the terminal leads 130, and is formed of any one single metal including Au, Ag, Al, and Cu or an alloy containing 50 weight % or more of any one or more metal including Au, Ag, Al, and Cu.
For example, as illustrated in
Here, one side of the spacer 141 may be electrically joined to the semiconductor chip 110 on a first substrate, that is, the lower substrate 121, using the conductive adhesive 111 and the other side of the spacer 141 may be electrically joined to a second substrate, that is, the upper substrate 122, using a conductive adhesive 123.
Next, the package housing 150 is an insulator for protecting a semiconductor circuit which covers and protects the semiconductor chips 110, the electrical connectors, and one or more substrates 121 and 122 and may be formed of an Epoxy Molding Compound (EMC). However, instead of an epoxy-based material, the package housing 150 may be formed of a composite material such as PolyPhenylene Sulfide (PPS) or PolyButylene Terephtalate (PBT).
Next, the at least one stopper 160 is formed of a material same as that of the package housing 150 and is higher by a certain height that the exposed surface A of the substrates 121 and 122. Accordingly, the thickness of the heat transfer connectors 171 used to join the heat sinks 170 may be adjusted and thus, the thickness at both ends of the heat transfer connectors 171 may be uniformly and constantly maintained.
In this regard, as illustrated in
That is,
More specifically, referring to
Also, referring to
The height H of the stoppers 160, as illustrated in
Also, the height H of the at least one stopper 160 may be determined by the partial surface of the package housing 150 which is not engraved by the laser 10. That is, the height H of the stopper 160 may be determined as a height from the exposed surface A of the substrates 121 and 122 to the partial surface of the package housing 150 which is not engraved.
In addition, as illustrated in
As illustrated in
Referring to
Next, the at least one heat sink 170 circulates a coolant so that heat generated from the semiconductor chips 110 is transmitted and radiated.
For example, at least one metal cooling post 173 is arranged in the inner space of the heat sink 170 in the flow direction of the coolant so that heat generated from the semiconductor package may be efficiently radiated by the coolant which directly contacts the metal cooling posts 173.
Here, as illustrated in
Thermal conductivity of the heat transfer connector 171 may be 1 W/m-k through 400 W/m-k.
The heat transfer connectors 171 may be filled by 60% or more and trapped in the stoppers 160, the exposed surfaces A of the substrates 121 and 122, and the one surfaces 172 of the heat sinks 170.
Accordingly, at least a part of the exposed surface A of one or more substrates 121 and 122 is formed on the upper surface, the lower surface, or the upper and lower surfaces of the package housing 150, and the exposed surface A of one or more substrates 121 and 122 is joined to the heat sink 170 by using the heat transfer connector 171 interposed therebetween. Accordingly, the full thickness of the heat transfer connectors 171 may be uniformly maintained by the stoppers 160.
Here, the height H of the stoppers 160 may be 1 μm through 1 mm and the thickness of the heat transfer connectors 171 used to join the heat sinks 170 may be adjusted by the stoppers 160. Accordingly, the thickness at both ends of the heat transfer connectors 171 may be uniformly and constantly maintained.
Referring to
In the semiconductor package having a package housing in an engraved surface form and the method of manufacturing the same as described above, the thickness of the heat transfer connector used to join and transfer heat to the heat sink may be adjusted through the stopper, which is engraved using the laser, and uniformly maintained to suppress delamination and to improve heat transfer efficiency. Also, compared with the conventional stopper structure using the grinding wheel and the method of manufacturing the same, consumption of the sealing member used for molding the package housing may be minimized, cracks of ceramic used to form an insulating layer of the substrate may be prevented, the thickness of the metal layer having the exposed surfaces of the substrate may be minimized, abnormal insulation voltage occurring due to metal particles generated while grinding which remain between the package housing may be blocked, and stress on the semiconductor package may be minimized to prevent delamination.
According to the present invention, the thickness of the heat transfer connector used to join and transfer heat to the heat sink may be adjusted through the stopper, which is engraved using the laser, and uniformly maintained to suppress delamination and to improve heat transfer efficiency
Also, compared with the conventional stopper structure using the grinding wheel and the method of manufacturing the same, consumption of the sealing member used for molding the package housing may be minimized, cracks of ceramic used to form an insulating layer of the substrate may be prevented, the thickness of the metal layer having the exposed surfaces of the substrate may be minimized, abnormal insulation voltage occurring due to metal particles generated while grinding which remain between the package housing may be blocked, and stress on the semiconductor package may be minimized to prevent delamination.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
Number | Date | Country | Kind |
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10-2021-0090542 | Jul 2021 | KR | national |