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

• US 20060249495A1
• Filed: 07/13/2006
• Published: 11/09/2006
• 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:
  US11/486,288
• Publication Number:
  US 20060249495A1
• Time in Patent Office: Days
• US Class Current: 219/121.690
• 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

A method of using 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 a system for molding comprising:

providing a substrate cleaning device in the system for molding;

introducing a substrate having a surface for molding in the system;

preheating the substrate;

forming a resist layer;

baking the substrate; and

removing contaminants from the substrate using the substrate cleaning device.

2. The method for a system of claim 1, wherein the substrate cleaning device comprises a laser.

3. The method for a system of claim 2, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

4. The method for a system of claim 1, further comprising:

placing the substrate in a mold in the system; and

encapsulating the substrate.

5. A method for use in a system for molding comprising:

providing a substrate cleaning device in the system for molding;

introducing a substrate having a surface for molding in the system;

preheating the substrate;

forming a resist layer;

baking the substrate; and

removing contaminants from the substrate using the substrate cleaning device.

6. The method for use in a system of claim 5, wherein the substrate cleaning device comprises a laser.

7. The method for use in a system of claim 6, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

8. The method for use in a system of claim 5, further comprising:

placing the substrate in a mold in the system; and

encapsulating the substrate.

9. A method for use in a system for molding and cleaning comprising:

providing a substrate cleaning device in the system for molding;

introducing a substrate having a surface for molding in the system;

preheating the substrate;

forming a resist layer;

baking the substrate; and

removing contaminants from the substrate using the substrate cleaning device.

10. The method for use in a system of claim 9, wherein the substrate cleaning device comprises a laser.

11. The method for use in a system of claim 10, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

12. The method for use in a system of claim 9, further comprising:

placing the substrate in a mold in the system; and

encapsulating the substrate.

13. A process for a system for molding comprising:

providing a substrate cleaning device in the system for molding;

introducing a substrate having a surface for molding in the system;

preheating the substrate;

forming a resist layer;

baking the substrate; and

removing contaminants from the substrate using the substrate cleaning device.

14. The process for a system of claim 13, wherein the substrate cleaning device comprises a laser.

15. The process for a system of claim 14, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

16. The process for a system of claim 13, further comprising:

placing the substrate in a mold in the system; and

encapsulating the substrate.

17. A process for use in a system for molding and cleaning comprising:

providing a substrate cleaning device in the system for molding;

introducing a substrate having a surface for molding in the system;

preheating the substrate;

forming a resist layer;

baking the substrate; and

removing contaminants from the substrate using the substrate cleaning device.

18. The process for use in a system for molding and cleaning of claim 17, wherein the substrate cleaning device comprises a laser.

19. The process for use in a system for molding and cleaning of claim 18, wherein the laser comprises one of an Nd:

YAG laser and an excimer laser.

20. The process for use in a system for molding and cleaning of claim 17 further comprising:

placing the substrate in a mold in the system; and

encapsulating the substrate.