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

• US 20020170897A1
• Filed: 05/21/2001
• Published: 11/21/2002
• Est. Priority Date: 05/21/2001
• Status: Abandoned Application

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Hall, Frank L.
• Application Number:
  US09/863,676
• Publication Number:
  US 20020170897A1
• Time in Patent Office: Days
• US Class Current: 219/121.73
• 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 resist removal method comprising:

providing a substrate having a surface;

forming resist on at least a portion of the surface; and

providing a laser to remove the resist from the substrate.

2. The method according to claim 1 wherein said laser includes a laser associated with an automolding system.

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

YAG laser and an excimer laser.

4. The method according to claim 1 wherein said 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 5 wherein said vision system comprises:

providing a laser scanning system;

detecting changes in the pattern of the substrate.

7. A semiconductor device formed by a laser etching process comprising:

providing a substrate having a surface;

forming resist on at least a portion of the surface; and

etching the resist from the surface c f the substrate using a laser.

8. The method according to claim 7 wherein said laser comprises a laser associated with an automolding system.

9. The method according to claim 7 wherein said laser includes one of an Nd:

YAG laser and an excimer laser.

10. The method according to claim 7 wherein said substrate comprises a ball-grid-array substrate.

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

12. The method according to claim 11 wherein said vision system comprises:

providing a laser scanning system;

detecting changes in the pattern of the substrate.

14. The method according to claim 13 wherein said laser comprises a laser associated with an automolding system.

15. The method according to claim 13 wherein said laser comprises one of an Nd:

YAG laser and an excimer laser.

16. The method according to claim 13 wherein said substrate comprises a ball-grid-array substrate.

17. The method according to claim 13 further comprising a vision system for detecting resist.

18. The method according to claim 17 wherein said vision system comprises:

providing a laser scanning system;

detecting changes in the pattern of the substrate.

13. A method of fabricating a semiconductor device comprising:

providing a substrate having a surface;

forming resist on at least a portion of the surface;

laser etching the resist from the surface of the substrate; and

encapsulating the substrate.

19. A method of enhancing the adhesion of a compound to a surface of a substrate comprising:

providing a substrate having a surface;

roughening the surface of the substrate.

21. An automolding system comprising:

providing a substrate having a surface;

preheating the substrate;

forming a resist layer;

baking the substrate; and

removing contaminants from the substrate using a laser.

20. The method according to claim 21 wherein said roughening comprises removing contamination and foreign particles from said surface of the substrate.

22. The automolding system of claim 21 wherein said laser comprises one of an Nd:

YAG laser and an excimer laser.

23. The automolding system of claim 21 further comprising:

placing the substrate in a mold; and

encapsulating the substrate.