Enhancing die flatness

Patent metadata

Field	Value
Publication number	US-10300649-B2
Application number	US-201715827220-A
Country	US
Kind code	B2
Filing date	Nov 30, 2017
Priority date	Aug 29, 2017
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

Methods and apparatus for enhancing the flatness of a die by applying adhesive to a shim having a selected flatness, rotating the shim to spread the adhesive to a layer having a uniform thickness, evacuating a chamber to create a vacuum; manipulating a die onto the adhesive layer in the chamber; and reducing a level of the vacuum to pressure the die onto the adhesive layer such that the bow in the die is reduced as the die conforms to the shim.

First claim

What is claimed is:

1. A method, comprising:
applying adhesive to a shim having a selected flatness;
rotating the shim to spread the adhesive to a layer having a uniform thickness;
evacuating a chamber to create a vacuum;
manipulating a die onto the adhesive layer in the chamber; and
reducing a level of the vacuum to pressure the die onto the adhesive layer such that the bow in the die is reduced as the die conforms to the shim.

2. The method according to claim 1 , further including spin coating the adhesive to achieve the uniform thickness.

3. The method according to claim 1 , further including heating the adhesive before and/or during rotation of the shim.

4. The method according to claim 1 , further including placing the shim on a rotatable chuck.

5. The method according to claim 4 , further including heating the chuck.

6. The method according to claim 1 , further including controlling a pressure in the chamber to remove voids in the adhesive as the die is bonded to the adhesive.

7. The method according to claim 6 , further including curing the adhesive.

8. A sensor IC package fabricated in accordance with claim 1 .

9. A method of fabricating a sensor IC package, comprising:
applying, in an oven vacuum chamber, adhesive to a shim having a selected flatness;
rotating the shim to spread the adhesive to a layer having a uniform thickness;
evacuating the vacuum chamber to create a vacuum;
manipulating a die onto the adhesive layer in the vacuum chamber; and
reducing a level of the vacuum in the vacuum chamber to pressure the die onto the adhesive layer such that the bow in the die is reduced as the die conforms to the shim.

10. The method according to claim 9 , further including spin coating the adhesive to achieve the uniform thickness.

11. The method according to claim 9 , further including heating the adhesive before and/or during rotation of the shim.

12. The method according to claim 9 , further including placing the shim on a rotatable chuck.

13. The method according to claim 12 , further including heating the chuck.

14. The method according to claim 9 , further including controlling a pressure in the vacuum chamber to remove voids in the adhesive as the die is bonded to the adhesive.

15. A sensor IC package fabricated in accordance with claim 9 .

16. The sensor IC package of claim 8 , wherein the die comprises a FPA die.

17. The sensor IC package of claim 15 , wherein the die comprises a FPA die.

Assignees

• Raytheon Co

Inventors

• Cahill Andrew
• Harris Sean F
• Lofgreen Daniel D

Classifications

• H10W42/121 Primary

  protecting against mechanical damage (H10W76/00, H10W74/00 take precedence) · CPC title

• B29C48/305

  having a wide opening, e.g. for forming sheets · CPC title

• B29C2948/92904

  Die; Nozzle zone · CPC title

• B29C2948/92571

  Position, e.g. linear or angular · CPC title

• B29C48/154

  Coating solid articles, i.e. non-hollow articles · CPC title