Method to manufacture potted electronic assemblies for extreme mechanical and thermal environments

Patent metadata

Field	Value
Publication number	US-12418991-B1
Application number	US-202217847173-A
Country	US
Kind code	B1
Filing date	Jun 23, 2022
Priority date	Apr 9, 2020
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A method for manufacturing potted electronic assemblies are described. Embodiments of the method and system may provide a potting compound having a first coefficient of thermal expansion different from a second coefficient of thermal expansion for a circuit board, provide a fiber reinforcement having a third coefficient of thermal expansion selected so that when the potting compound is combined with the fiber reinforcement the combined coefficient of thermal expansion is closer to the second coefficient of thermal expansion than the first coefficient of thermal expansion is to the second coefficient of thermal expansion, and apply the fiber reinforcement and the potting compound to the circuit board.

First claim

What is claimed is:

1. A method for manufacturing potted electronic assemblies, comprising:
providing a low-viscosity resin potting compound having a first coefficient of thermal expansion different from a second coefficient of thermal expansion for a circuit board;
providing a fiber reinforcement having a third coefficient of thermal expansion selected so that when the potting compound is combined with the fiber reinforcement the combined coefficient of thermal expansion is closer to the second coefficient of thermal expansion than the first coefficient of thermal expansion is to the second coefficient of thermal expansion; and
applying the fiber reinforcement and the potting compound to the circuit board.

2. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and
dispersing said fiber reinforcement in the mold.

3. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and
ultrasonically dispersing said fiber reinforcement in the mold.

4. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and
dispersing said fiber reinforcement with a sonicator probe.

5. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and
dispersing said fiber reinforcement with a rotor-stator disperser.

6. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and
mechanically dispersing said fiber reinforcement in the mold.

7. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and

said applying the fiber reinforcement and the potting compound to the circuit board comprising:
curing said potting compound.

8. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement into a mold; and

said applying the fiber reinforcement and the potting compound to the circuit board comprising:
curing said potting compound by heating said potting compound.

9. The method of claim 1 comprising:
said providing said fiber reinforcement comprising:
placing said fiber reinforcement and alcohol or other suitable solvent in a mold; and
dispersing said fiber reinforcement in the alcohol or other suitable solvent, wherein the fiber reinforcement dispersed in the alcohol or other suitable solvent comprises a fiber slug having a molded geometry.

10. The method of claim 9 comprising:
said providing said fiber reinforcement comprising:
after dispersing the fiber reinforcement, removing the fiber slug from the mold.

11. The method of claim 10 comprising:
said applying said fiber reinforcement and said potting compound to the circuit board comprising:
interposing the fiber slug between the circuit board and another circuit board.

12. The method of claim 11 comprising:
said applying said fiber reinforcement and said potting compound to the circuit board comprising:
installing the fiber slug interposed between the circuit board and the another circuit board in a structural housing.

13. The method of claim 11 comprising:
said applying said fiber reinforcement and said potting compound to the circuit board comprising:
after interposing the fiber slug, drying the fiber reinforcement by evaporating the alcohol or other suitable solvent from the fiber slug.

14. The method of claim 13 comprising:
said applying said fiber reinforcement and said potting compound to the circuit board comprising:
impregnating said potting compound into said fiber reinforcement.

15. The method of claim 1 comprising:
said applying said fiber reinforcement and said potting compound to the circuit board comprising:
interposing a fiber slug between the circuit board and another circuit board, wherein the fiber slug comprises a molded geometry of said fiber reinforcement dispersed in alcohol or other suitable solvent.

16. The method of claim 15 comprising:
said applying said fiber reinforcement and said potting compound to the circuit board comprising:
after interposing the fiber slug, drying the fiber reinforcement by evaporating the alcohol or other suitable solvent from the fiber slug; and
impregnating said potting compound into said fiber reinforcement.

17. The method of claim 16 comprising:
said impregnating said potting compound into said fiber reinforcement comprising:
applying a vacuum to the fiber reinforcement in a vacuum chamber.

18. The method of claim 17 comprising:
said impregnating said potting compound into said fiber reinforcement comprising:
after applying the vacuum, applying additional hydrostatic pressure over atmospheric pressure to the vacuum chamber.

19. The method of claim 18 comprising:
said impregnating said potting compound into said fiber reinforcement comprising:
after applying the additional hydrostatic pressure, again applying the vacuum to the vacuum chamber.

Assignees

• General Atomics

Inventors

• Whatley Walter J
• Martinez Noel
• Staley Clay S

Classifications

• H05K3/284 Primary

  for encapsulating mounted components (H05K1/185 takes precedence) · CPC title

• H05K3/325

  by abutting or pinching; Mechanical auxiliary parts therefor · CPC title

• H05K3/24

  Reinforcing of the conductive pattern {(by solder coating H05K3/3465)} · CPC title

• H05K2203/1316

  Moulded encapsulation of mounted components · CPC title

• H05K1/147

  at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit (H05K1/148 takes precedence) · CPC title