Methods for preparing ball grid array substrates via use of a laser

• US 20050170658A1
• Filed: 03/25/2005
• Published: 08/04/2005
• Est. Priority Date: 05/21/2001
• Status: Abandoned Application

• Current Assignee: Frank L. Hall
• Original Assignee: Frank L. Hall
• Inventors: Hall, Frank L.
• Application Number:
  US11/098,161
• Publication Number:
  US 20050170658A1
• Time in Patent Office: Days
• US Class Current: 438/708
• CPC Class Codes: B08B 7/0042 by laser
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 26/3584 Increasing rugosity, e.g. roughening
• CPC Class Codes: G03F 7/42 Stripping or agents therefor
• CPC Class Codes: H01L 21/4864 Cleaning, e.g. removing of solder
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2223/5448 Located on chip prior to dicing and remaining on chip after dicing
• CPC Class Codes: H01L 2223/54486 Located on package parts, e.g. encapsulation, leads, package substrate
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/3128 the substrate having spherical bumps for external connection
• CPC Class Codes: H01L 23/3142 Sealing arrangements between parts, e.g. adhesion promotors
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 23/49827 Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/381 by special treatment of the substrate

Abstract

The present invention relates to the use of a laser to remove surface contamination and oxidation from a ball grid array substrate. The laser etching can be configured to cover the entire substrate or pinpointed to the epoxy molding compound/solder resist (EMC/SR) interfaces. Additionally, a laser can be used to roughen the surface of a substrate to provide better adhesion when attaching the die to the substrate.

Claims

1. A method for resist removal from a substrate having a surface having resist on at least a portion thereof for use in a system having a laser associated with a mold for a semiconductor device, the resist removed by the system before molding of said substrate in the system, comprising:

removing at least a portion of the resist from the substrate using the laser.

2. The method according to claim 1, further comprising:

flowing filtered gas over the surface having resist on at least a portion thereof while removing a portion of the resist from the substrate.

3. The method according to claim 1, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

4. The method according to claim 1, wherein the substrate comprises a ball-grid-array substrate.

5. The method according to claim 1, further comprising a vision system for detecting resist.

6. The method according to claim 4, wherein the vision system comprises:

providing a laser scanning system; and

detecting changes in a pattern of the substrate.

7. A method of fabricating a semiconductor device in a system including an automolding device, the method comprising:

providing a system having a laser for etching resist from a surface of a substrate;

providing a substrate having a surface;

forming resist on at least a portion of the surface;

laser etching the resist from at least a portion of the surface of the substrate; and

encapsulating the substrate.

8. The method according to claim 7, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

9. The method according to claim 7, wherein the substrate comprises a ball-grid-array substrate.

10. The method according to claim 7, further comprising a vision system for detecting resist.

11. The method according to claim 10, wherein the vision system comprises:

providing a laser scanning system; and

detecting changes in a pattern of the substrate.

12. The method according to claim 7, further comprising flowing a filtered gas over the substrate during etching the resist from at least a portion of the surface of the substrate.

13. The method according to claim 7, further comprising testing the substrate.

14. A method for resist removal from a substrate having a surface having resist on at least a portion thereof for use in a system having a laser associated with a mold for a semiconductor device, the resist removed in the system before molding of said substrate in the system, comprising:

removing at least a portion of the resist from the substrate using the laser.

15. The method according to claim 14, further comprising:

flowing filtered gas over the surface having resist on at least a portion thereof while removing a portion of the resist from the substrate.

16. The method according to claim 14, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

17. The method according to claim 14, wherein the substrate comprises a ball-grid-array substrate.

18. The method according to claim 14, further comprising a vision system for detecting resist.

19. The method according to claim 18, wherein the vision system comprises:

providing a laser scanning system; and

detecting changes in a pattern of the substrate.

20. The method of claim 14, further comprising testing the substrate.