Circuit carrier including a silicone polymer coating

Patent metadata

Field	Value
Publication number	US-9754850-B2
Application number	US-201415110907-A
Country	US
Kind code	B2
Filing date	Dec 2, 2014
Priority date	Jan 14, 2014
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A circuit carrier. The circuit carrier has at least one electronic component, the electronic component being soldered to the circuit carrier, in particular with the aid of a flux. The circuit carrier has, in particular, an electrically insulating protective layer for anti-condensation, a surface of the circuit carrier being covered at least partially with the protective layer. The protective layer of the circuit carrier is formed by a silicon polymer layer designed to be activatable with the aid of ultraviolet radiation, the silicon polymer layer having filler particles distributed in the silicon polymer layer, in particular homogenously. At least a part of the filler particles or all filler particles have at least one salt of an alkaline earth metal.

First claim

What is claimed is:

1. A device comprising:
a circuit carrier including:
a strip conductor; and
at least one electronic component soldered to the strip conductor with the aid of a flux; and

a protective layer for anti-condensation that:
at least partially covers a surface of the circuit carrier; and
is formed by a silicon polymer layer with filler particles, that include at least one salt of an alkaline earth metal, homogeneously distributed in the silicon polymer layer;

wherein at least one of:
a matrix of the protective layer is an elastically-formed, completely crosslinked silicone rubber;
at least one part of the filler particles is at least one oxide of at least one alkaline earth metal;
at least one part of the filler particles is arranged at an interface of the protective layer to the circuit carrier, and is formed to decompose acid using an acid deposited from the circuit carrier or remaining from the flux and using a proton transfer reaction; and
a volume proportion of the filler particles in the protective layer is between 5 and 50 percent.

2. A device comprising:
a circuit carrier including:
a strip conductor; and
at least one electronic component soldered to the strip conductor with the aid of a flux; and

a protective layer for anti-condensation that:
at least partially covers a surface of the circuit carrier; and
is formed by a silicon polymer layer with filler particles, that include at least one carbonate or hydrocarbonate salt of an alkaline earth metal, homogeneously distributed in the silicon polymer layer.

3. The circuit carrier as recited in claim 1 , wherein the matrix of the protective layer is the elastically-formed, completely crosslinked silicone rubber.

4. The circuit carrier as recited in claim 3 , wherein the protective layer has an adhesion promoter.

5. The circuit carrier as recited in claim 1 , wherein at least one part of the filler particles is the at least one oxide of the at least one alkaline earth metal.

6. The circuit carrier as recited in claim 1 , wherein at least one part of the filler particles is arranged at the interface of the protective layer to the circuit carrier, and is formed to decompose acid using the acid deposited from the circuit carrier or remaining from the flux and using the proton transfer reaction.

7. The circuit carrier as recited in claim 1 , wherein the volume proportion of the filler particles in the protective layer is between 5 and 50 percent.

8. The circuit carrier as recited in claim 6 , wherein the filler particles are distributed in the protective layer in such a way that the circuit carrier is directly contacted by at least a part of the filler particles.

9. The circuit carrier as recited in claim 1 , wherein a diameter of the filler particles is less than 5 micrometers.

10. A method for generating a circuit carrier, comprising:
soldering at least one electronic component to the circuit carrier with the aid of one of an acid-containing or an acid-releasing flux; and
coating the circuit carrier with the aid of a protective layer, the protective layer being a silicone protective varnish, the silicone protective varnish including filler particles containing a salt of an alkaline earth metal, the salt being calcium carbonate particles with a volume proportion between 10 and 50 percent.

Assignees

• Bosch Gmbh Robert

Inventors

• Faria Isabel
• Pfeiffer Peter
• Elsinger Heiko
• Hahn Andre

Classifications

• H10W90/734

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

• H10W74/40

  characterised by their materials · CPC title

• H10W72/355

  of outermost layers of multilayered die-attach connectors, e.g. material of a coating · CPC title

• H10W72/352

  comprising metals or metalloids, e.g. solders · CPC title

• H10W76/48

  Fillings including materials for absorbing or reacting with moisture or other undesired substances · CPC title