Electronic module for a piece of vehicle-borne aeronautic equipment and a piece of aeronautic equipment for an aeronautic vehicle

Patent metadata

Field	Value
Publication number	US-9526170-B2
Application number	US-201314400997-A
Country	US
Kind code	B2
Filing date	May 14, 2013
Priority date	May 15, 2012
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

An electronics module for use at high temperature (up to 225° C.) in onboard aviation equipment, the module having a thick layer hybrid circuit covered in a sealing coating of poly-p-xylylene.

First claim

The invention claimed is:

1. An electronics module for onboard aviation equipment designed to operate at a maximum temperature of about +225° C., the module including a ceramic hybrid circuit covered in a protective coating of poly-p-xylylene, the circuit comprising at least a first conductive element and a second conductive element, the first element including at least a first metal different from a second metal of the second element and being electrically and mechanically connected to the second conductive element by a connection in such a manner as to oppose diffusion of the first metal into the second metal, and the first element including a third metal for co-operating with the second metal at the connection to form a metallurgical barrier opposing migration of the first metal to the second metal, the second element being a track of silver covered in a coating superposing in succession nickel, palladium, and gold, or a coating superposing in succession nickel and gold.

2. The module according to claim 1 , wherein the first element is a palladium-doped gold wire welded on the second element.

3. The module according to claim 1 , wherein the first element is a copper wire wire bonded on the second element.

4. The module according to claim 1 , wherein the coating has a total thickness that is less than or equal to about 15 μm.

5. The module according to claim 1 , wherein the hybrid circuit includes an aluminum core supporting superposed conductive layers having portions that are connected together by plated-through holes.

6. The aircraft equipment including an electronics module according to claim 1 .

7. The use of an electronics module in onboard aviation equipment that is subjected to temperature variations lying in the range appropriately −60° C. to +225° C., the module including a ceramic hybrid circuit covered in a poly-p-xylylene protective coating, the circuit comprising at least a first conductive element and a second conductive element, the first conductive element including at least a first metal different from a second metal of the second element and being electrically and mechanically connected to the second conductive element via a connection in such a manner as to oppose diffusion of the first metal into the second metal, and the first element including a third metal to co-operate with the second metal at the connection to form a metallurgical barrier opposing migration of the first metal to the second metal.

8. The use according to claim 7 , wherein the metals are selected to have atomic weights that are sufficiently high and/or electronegativity coefficients that are sufficiently close to limit diffusion of one of the metals into the other.

9. The use according to claim 7 , wherein the first element is a palladium-doped gold wire wire bonded on the second element.

10. The use according to claim 7 , wherein the first element is a copper wire bonded on the second element.

11. The use according to claim 7 , wherein the second element is an aluminum-doped pad.

12. The use according to claim 7 , wherein the second element is a silver track covered in a coating comprising superposing in succession nickel, palladium, and gold, or a coating comprising superposing in succession nickel and gold.

13. The use according to claim 7 , wherein the second element is a palladium-doped gold track.

14. The use according to claim 13 , wherein the palladium content is at least 1%.

15. The use according to claim 7 , wherein the first metal is alloyed gold and the second element is solder comprising either a majority of lead, tin, and silver, or else a majority of lead, indium, and silver.

16. The use according to claim 15 , wherein the first element is a silver track covered in a coating comprising superposing in succession nickel, palladium, and gold, or a superposing coating comprising in succession nickel and gold.

17. The use according to claim 7 , wherein the coating has a total thickness that is less than or equal to about 15 μm.

18. The use according to claim 7 , wherein the hybrid circuit includes an aluminum core supporting superposed conductive layers having portions connected together via plated-through holes.

Assignees

• Sagem Defense Securite

Inventors

• Riou Jean-Christophe
• Peyrard Michel
• Bailly Eric

Classifications

• H10W90/754

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/5525

  comprising copper [Cu] · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/5363

  the connected ends being wedge-shaped · CPC title