1. Field of the Invention
The present invention relates generally to a method for fabricating semiconductor packages, and more particularly to a method for fabricating BGA semiconductor packages by using a substrate carrier, and a structure and method for positioning semiconductor components.
2. Description of Related Art
A flip-chip ball grid array (FCBGA) semiconductor package integrates both a flip-chip structure and a ball grid array (BGA) structure, wherein an active surface of at least one chip (die) is electrically connected to one surface of a substrate through a plurality of solder bumps, and a plurality of solder balls functioning as I/O terminals is mounted on the other surface of the substrate. Such a package structure not only decreases the package volume, but also eliminates the need for a wires bonding, which accordingly decreases resistance and improves the electrical characteristics of the whole structure. As a result, the signal fading phenomenon that occurs in the signal transfer process can be prevented. Therefore, the FCBGA package structure has become a mainstream packaging technology for next generation chips and electronic components.
Further, to facilitate the mold releasing process, as shown in
Therefore, there is a need to develop a method for fabricating semiconductor packages that can overcome the overflow problem and facilitate the mold releasing process without the need of increasing substrate size.
According to the above drawbacks, an objective of the present invention is to provide a method for fabricating semiconductor packages that can reduce substrate cost.
Another objective of the present invention is to provide a method for fabricating semiconductor packages without the need of increasing length and width of the substrates.
A further objective of the present invention is to provide a method for fabricating semiconductor packages that can overcome the overflow problem without the need of increasing substrate size.
In order to attain the above and other objectives, the present invention discloses a method for fabricating semiconductor packages, which comprises the steps of: preparing a plurality of substrates and a carrier having a plurality of openings, wherein, each of the substrates has at least one chip (die) disposed thereon, the length and width of the substrates are close to the predefined length and width of the semiconductor packages, and the length and width of the openings of the carrier are bigger than the length and width of the substrates; respectively positioning the substrates in the openings of the carrier and blocking the gaps between the substrates and the carrier so as to prevent the gaps from penetrating through the carrier; performing a mold press process so as to form an encapsulant on each of the openings for encapsulating the chip, wherein the length and width of the area covered by the encapsulant are bigger than the length and width of the opening; performing a mold releasing process; and cutting along edges of the substrates according to the predefined length and width of semiconductor packages, thereby obtaining a plurality of semiconductor packages.
The present invention can position the substrates in the openings and block the gaps between the substrates and the carrier by filling an adhesive material such as a solder mask in the gaps between the substrates and the carrier. Alternatively, at least one tape can be attached to the substrates and the carrier, positioning the substrates and blocking the gaps. To ensure that the adhesive material is sufficiently filled in the gaps between the substrates and the carrier, at least one storage hole is disposed at the periphery of the openings. The adhesive material is first filled in the storage hole through a dispensing method, and then by a capillary effect, the adhesive material is further filled in the gaps. Such a method not only simply positions the substrate in the opening, but also prevents the conventional problems such as substrate shift, uneven adhesive material distribution, interface delamination caused by gaps that are too large, and problems such as slow dispensing speed and increased fabrication cost caused by gaps that are too small.
The length and width of the substrates can be 0.1 to 0.5 mm bigger than the predefined length and width of the semiconductor packages. When the length and width of the substrates are 0.1 to 0.5 mm bigger than the predefined length and width of the semiconductor packages, the length and width of the openings can be 0.1 to 0.5 mm bigger than the length and width of the substrates. On the other hand, the length and width of the substrates can be 0.1 to 0.5 mm smaller than the predefined length and width of the semiconductor packages. When the length and width of the substrates are 0.1 to 0.5 mm smaller than the predefined length and width of the semiconductor packages, the length and width of the openings can be 0.1 to 1 mm bigger than predefined length and width of the semiconductor packages.
The carrier can be made of an organic dielectric material such as FR4, FR5 and BT. The carrier can also be made of a metallic material. The method for fabricating semiconductor packages using a metallic carrier comprises the steps of: preparing a plurality of substrates and a metallic carrier having a plurality of openings, wherein, each of the substrates has at least one chip disposed thereon, the length and width of the substrates being close to the predefined length and width of semiconductor packages, and the length and width of the openings of the carrier being bigger than length and width of the substrates; respectively positioning the substrates in the openings of the metallic carrier and blocking the gaps between the substrates and the metallic carrier so as to prevent the gaps from penetrating through the metallic carrier; performing a mold press process so as to form an encapsulant on each of the openings for encapsulating the chip, thus forming a package unit comprising the substrate, chip and encapsulant, wherein the length and width of the area covered by the encapsulant are bigger than the length and width of the opening; performing a mold releasing process; separating the package units from the metallic carrier; and cutting along edges of the substrates of the package units according to the predefined length and width of semiconductor packages, thereby obtaining a plurality of semiconductor packages.
The metallic carrier is made of Cu, and a metal plated layer having poor adhesion with the encapsulant is formed on the metallic carrier. The metal plated layer can be made of such as Au, Ni and Cr. Through the poor adhesion between the metal plated layer and the encapsulant, the package units can easily be separated from the metallic carrier, thereby facilitating the fabrication process.
The present invention further discloses a method for positioning a semiconductor component. The method includes: providing a semiconductor component and a carrier having an opening, the opening having a length and width bigger than another length and width of the semiconductor component, at least one storage hole being disposed at a periphery of the opening of the carrier; disposing the semiconductor component in the opening of the carrier; and filling in the storage hole an adhesive material, which is filled in the gaps between the semiconductor component and the carrier through a capillary effect, thus positioning the semiconductor component in the carrier. The semiconductor component is, for example, a substrate.
The present invention further discloses a carrier structure for positioning a semiconductor component. The carrier structure includes: a carrier having an opening for receiving the semiconductor component; and at least a storage hole disposed at a periphery of the opening of the carrier such that an adhesive material can be filled in the storage hole, wherein the adhesive material, through the capillary effect, can be filled in the gaps between the semiconductor component and the carrier, thereby positioning the semiconductor component in the carrier.
According to the present invention, the length and width of the substrates are approximately equal to predefined length and width of the semiconductor package. As the gaps between the substrates and the carrier are all blocked and the projection length and width of the mold cavities for forming the encapsulants are designed to be bigger than the length and width of the openings, the overflow problem is solved and the mold releasing process is facilitated without the need of increasing the substrate size, thereby preventing the waste of substrate material, decreasing material costs and simplifying the fabrication process.
The present invention also discloses a method for positioning a semiconductor component such as a substrate in a carrier while blocking the gaps between the semiconductor component and the carrier, which comprises the step of filling an adhesive material in the storage holes disposed at the periphery of the opening of the carrier. Through the capillary effect, the adhesive material is further filled in the gaps between the semiconductor component and the carrier. Thus, the semiconductor component is simply positioned in the opening of the carrier. As the adhesive material is filled in the gaps through the capillary effect, problems such as semiconductor component shift, uneven adhesive material distribution and interface delamination caused by much bigger gaps can be prevented. Moreover, such problems as too slow of a dispensing speed and increased fabrication costs caused by small gaps that are too small are also avoided.
The following illustrative embodiments are provided to illustrate the disclosure of the present invention; these and other advantages and effects can be apparent to those skilled in the art after reading the disclosure of this specification. The present invention can also be performed or applied by other differing embodiments. The details of the specification may be changed on the basis of different points and applications, and numerous modifications and variations can be made without departing from the spirit of the present invention.
Subsequently, as shown in
As shown in
As described above, the present invention is characterized in that the gaps 17 between the substrate 10 and the carrier 15 are blocked to prevent the overflow of encapsulant 32, and, moreover, the size of the mold cavities 31 for forming the encapsulant 32 is made bigger than that of the openings 16 for facilitating the mold releasing process. Thus, the need for increasing the size of the substrates 10 in order to solve the overflow problem and facilitate the mold releasing process, as in the prior art, is eliminated. Instead, the size of the substrates 10 only needs to be approximately equal to the predefined size of the semiconductor packages 1, thereby decreasing the waste of substrate material.
However, the size of the substrates 10 is not limited to 31.4 mm×31.4 mm. The length and width of the substrates 10 can be 0.1 to 0.5 mm bigger than the predefined length and width of the semiconductor packages 1. Moreover, the size of the openings 16 is not limited to 31.5 mm×31.5 mm. Instead, the length and width of the openings 16 can be 0.1 mm to 0.5 mm bigger than the length and width of the substrates 10. The carrier 15 may be made of an organic dielectric material such as FR4, FR5 and BT.
Furthermore, there are several other methods for positioning the substrates 10 in the openings 16 of the carrier 15 and blocking the gaps 17 between the substrates 10 and the carrier 15 instead of using the tape 25. As shown in
As shown in
Subsequently, as described in the first embodiment, a mold press process, a mold releasing process, a tape removing process, and a ball mounting process are performed sequentially as shown in
As shown in
However, the size of the substrates 10 is not limited to 30.8 mm×30.8 mm. The length and width of the substrates 10 can be 0.1 to 0.5 mm smaller than the predefined length and width of the semiconductor packages 1. Moreover, the size of the openings 16 of the carrier 15 is not limited to 31.5 mm×31.5 mm. Instead, the length and width of the openings 16 can be 0.1 to 1 mm bigger than the predefined length and width of the semiconductor packages 1. Ideally, the length and width of the openings 16 are 0.5 mm bigger than length and width of the semiconductor packages 1.
In addition to an organic material such as FR4, FR5, BT and so on, the carrier 15 may also be made of a metallic material. Therein, a metal-plated layer having poor adhesion with the encapsulant 32 is formed on a surface of the carrier 15. A method for fabricating semiconductor packages using such a metallic carrier is shown in
As shown in
As the metallic carrier 45 has a metal plated layer with poor adhesion with the encapsulants 32, the encapsulants 32 can easily be separated from the carrier 45. As shown in
As shown in
In the aforementioned embodiments, the encapsulants 32 formed in the mold press process also encapsulate the conductive bumps 50 (as in
As shown in
Alternatively, as shown in
The semiconductor package 1 in
Referring to
Therefore, the present embodiment is proposed to overcome the above problems.
As shown in
The carrier 15′ may be made of an organic dielectric material selected from the group consisting of FR4, FR5, and BT. The mold press process, the mold releasing process, and the cutting process can then be performed as mentioned above so as to obtain completed semiconductor packages. Alternatively, the carrier 15′ can be made of a metallic material. Referring to the aforementioned embodiment, the mold press process, the mold releasing process, the carrier separating process, and the cutting process can then be performed so as to obtain completed semiconductor packages.
Referring to
The present invention also discloses a method for positioning a semiconductor component, which comprises: providing a semiconductor component and a carrier, wherein, the semiconductor component can be, for example, a substrate 10′ and the carrier 15′ has an opening 16′, the length and width of the opening 16′ being bigger than the length and width of the semiconductor component, and at least one storage hole 150′ being disposed at the periphery of the opening 16′ of the carrier 15′; and disposing the semiconductor component in the opening 16′ of the carrier 15′, and also performing a dispensing process in the storage hole 150′ so as to fill an adhesive material 41′ into the storage hole 150′, wherein the adhesive material 41′ then flows into the gaps 17′ between the semiconductor component and the carrier 15′ by capillary action, thereby positioning the semiconductor component in the carrier 15′.
The present invention further discloses a carrier structure for positioning a semiconductor component, which comprises: a carrier 15′ having an opening 16′ for receiving the semiconductor component; and at least a storage hole 150′ disposed at the periphery of the opening 16′ of the carrier 15′ such that an adhesive material can be filled in the storage hole 150′, which then, through the capillary effect, flows into the gaps between the semiconductor component and the carrier 15′, thereby positioning the semiconductor component in the carrier 15′. The semiconductor component can be, for example, a substrate 10′.
Although the above-described embodiments are slightly different in fabrication methods or selected materials, they have the same characteristics. That is, the length and width of the prepared substrates 10, 10′ are approximately equal to the predefined length and width of semiconductor packages 1. As the gaps 17, 47, 17′ between the substrates 10, 10′ and the carriers 15, 45, 15′ are all blocked, and meanwhile, the projection length and width of the mold cavities 31 for forming the encapsulants 32 are bigger than the length and width of the openings 16, 46, 16′, the overflow problem is overcome and the mold releasing process is facilitated, which thus eliminates the need for increasing the size of the substrates 10, 10′, thereby reducing the material costs and facilitating the fabrication process.
It should be noted that the electrical connecting method of the chips is not limited by the present invention. Instead of using a flip chip method, the chips can also be electrically connected to the substrates through a wire bonding method.
The present invention also discloses a method for positioning a semiconductor component such as a substrate in a carrier while blocking the gaps between the semiconductor component and the carrier, which comprises the step of filling an adhesive material in the storage holes disposed at the periphery of the opening of the carrier. Through the capillary effect, the adhesive material is further filled in the gaps between the semiconductor component and the carrier. Thus, the semiconductor component is simply positioned in the opening of the carrier. As the adhesive material is filled in the gaps through the capillary effect, problems such as semiconductor component shift, uneven adhesive material distribution, and interface delamination caused by gaps that are too large can be prevented. Moreover, such problems as too slow of a dispensing speed and increased fabrication costs caused by gaps that are too small can also be avoided.
The above-described descriptions of the detailed embodiments are only to illustrate the preferred implementation according to the present invention, and are not intended to limit the scope of the present invention. Accordingly, various modifications and variations made by those with ordinary skill in the art should fall within the scope of present invention defined by the appended claims.
Number | Date | Country | Kind |
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093118246 | Jun 2004 | TW | national |
This application is a continuation-in-part of copending application Ser. No. 11/117,158 filed on Apr. 27, 2005, the disclosure of which is expressly incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | 11117158 | Apr 2005 | US |
Child | 11703517 | Feb 2007 | US |