Method of attaching a heat sink to an IC package

• US 20030106212A1
• Filed: 01/17/2003
• Published: 06/12/2003
• Est. Priority Date: 04/08/2000
• Status: Active Grant

• Current Assignee: Advanced Semiconductor Engineering Inc (ASE Technology Holding Co., Ltd.)
• Original Assignee: Advanced Semiconductor Engineering Inc (ASE Technology Holding Co., Ltd.)
• Inventors: Chao, Shin-Hua, Wu, Shyh-Ing, Yeh, Gin-Nan, Liao, Kuan-Neng
• Granted Patent: US 6,918,178 B2
• Time in Patent Office: Days
• US Class Current: 29/848
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/451 with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/00015 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49139 : by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49158 : with molding of insulated base
• CPC Class Codes: Y10T 29/49798 : Dividing sequentially from leading end, e.g., by cutting or breaking
• CPC Class Codes: Y10T 83/0457 : By retaining or reinserting product in workpiece
• CPC Class Codes: Y10T 83/0538 : Repetitive transverse severing from leading edge of work
• CPC Class Codes: Y10T 83/2079 : Remaining or re-inserted product portion from base material

Abstract

An improved method of integrally attaching a heat sink to an IC package for enhancing the thermal conductivity of the package. A heat sink matrix, which is dividable into a plurality of individual heat sinks, is attached to an IC package matrix, which is comprised of a plurality of individual IC packages abutting each other in a matrix arrangement. The IC package matrix and the heat sink matrix attached thereto are then simultaneously cut by means of a machine tool into a plurality of individually formed IC packages each with a heat sink attached; thereby, thermal conductivity of a conventional IC package is enhanced.

Claims

1. A method of manufacturing a plurality of IC (Integrated Circuit) packages each having an heat sink integrally attached thereon, comprising the steps of:

providing a communal substrate;

attaching a plurality of semiconductor dies fixedly onto said communal substrate;

providing a heat sink matrix;

providing a molding apparatus;

placing said communal substrate with said semiconductor dies fixedly attached thereon and said heat sink matrix into said molding apparatus;

filling a melted molding material into said molding apparatus to collectively encapsulate said semiconductor dies fixedly attached on said communal substrate and said heat sink matrix thereby forming an IC package matrix integrated with said heat sink matrix after said molding material is permanently set;

extracting said IC package matrix integrated with said heat sink matrix from the molding apparatus; and

dividing said IC package matrix integrated with said heat sink matrix into said IC packages each having said heat sink integrally attached thereon.

2. The method as claimed in claim 1, wherein said molding apparatus comprises:

a lower mold half for holding said communal substrate with said semiconductor dies fixedly attached thereon; and

a upper mold half for holding said heat sink matrix;

wherein, said lower mold half and said upper mold half of the molding apparatus are combined in order to be filled by the molding material during a molding process.

3. The method as claimed in claim 2, wherein said heat sink matrix is held on said upper mold half by means of vacuum suction.

4. The method as claimed in claim 1, wherein said IC package is a BGA (Ball Grid Array) package.

5. The method as claimed in claim 1, wherein said heat sink is made of a copper material.

6. The method as claimed in claim 1, wherein said heat sink is made of an aluminum material.

7. The method as claimed in claim 1, further comprising a step of coating a Cr film on said heat sink matrix before the step of placing said heat sink matrix into said molding apparatus.

8. The method as claimed in claim 1, further comprising a step of coating a chromium oxide film on said heat sink matrix before the step of placing said heat sink matrix into said molding apparatus.

9. The method as claimed in claim 1, further comprising a step of coating a Ni film on said heat sink matrix before the step of placing said heat sink matrix into said molding apparatus.

10. The method as claimed in claim 1, further comprising a step of forming a rough surface on said heat sink matrix before the step of placing said heat sink matrix into said molding apparatus.

11. The method as claimed in claim 1, further comprising a step of forming a notch grid constituted of a network of notches on said heat sink matrix before the step of placing said heat sink matrix into said molding apparatus.

12. The method as claimed in claim 11, wherein said dividing step is conducted by cutting along said notch grid on said heat sink matrix integrated with said IC package matrix.

13. A method of manufacturing a plurality of IC (Integrated Circuit) packages each having a heat sink integrally attached thereon, comprising the steps of:

providing a communal substrate;

attaching a plurality of semiconductor dies fixedly onto said communal substrate;

providing a heat sink matrix having a plurality of dimples formed on a surface thereof;

providing a molding apparatus;

placing said communal substrate with said semiconductor dies fixedly attached thereon and said heat sink matrix into said molding apparatus in a manner that the surface of the heat sink matrix faces toward said communal substrate;

filling a melted molding material into said molding apparatus to collectively encapsulate said semiconductor dies fixedly attached on said communal substrate and said heat sink matrix thereby forming an IC package matrix integrated with said heat sink matrix after said molding material is permanently set wherein the dimples of the heat sink matrix are all filled by the molding material;

extracting said IC package matrix integrated with said heat sink matrix from the molding apparatus; and

dividing said IC package matrix integrated with said heat sink matrix into said IC packages each having said heat sink integrally attached thereon.

14. The method as claimed in claim 13, wherein said dimples are formed by etching the surface of said heat sink matrix.