Solder mask inkjet inks for manufacturing printed circuit boards

Patent metadata

Field	Value
Publication number	US-10995229-B2
Application number	US-201716348163-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 10, 2016
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

An inkjet method for producing a solder mask in the manufacture of a Printed Circuit Board uses a solder mask inkjet ink containing at least one photo-initiator, at least one free radical polymerizable compound and at least one mercapto functionalized carboxylic acid as adhesion promoter. A high quality solder mask withstanding the high thermal stress during the soldering process while maintaining excellent physical properties is produced.

First claim

The invention claimed is:

1. A radiation curable solder mask inkjet ink comprising:
a photoinitiator;
a radical polymerizable compound; and
an adhesion promoter; wherein
the adhesion promoter has a chemical structure according to Formula I:

wherein
L 1 represents an optionally substituted n+m-valent linking group including 1 to 15 carbon atoms; and
n and m independently represent an integer from 1 to 4.

2. The radiation curable solder mask inkjet ink according claim 1 , wherein the free radical polymerizable compound is selected from the group consisting of neopentyl glycol hydroxypivalate diacrylate, isobornyl acrylate, dipropylene glycol diacrylate, trimethylol propane triacrylate, and 2-(vinylethoxy)ethyl acrylate.

3. The radiation curable solder mask inkjet ink according to claim 1 , wherein an amount of the adhesion promoter is between 0.5 and 20 wt % relative to a total weight of the solder mask inkjet ink.

4. The radiation curable solder mask inkjet ink according to claim 1 , further comprising a cyan pigment, a yellow pigment, or a green pigment.

5. A method of manufacturing an electronic device, the method comprising:
jetting a radiation curable solder mask inkjet ink as defined in claim 1 onto a dielectric substrate including an electrically conductive pattern; and
curing the jetted solder mask inkjet ink.

6. The method according to claim 5 , wherein the step of curing is performed using UV radiation.

7. The method according to claim 6 , wherein the step of curing is performed using UV LED radiation.

8. The method according to claim 5 , further comprising:
heating the jetted solder mask inkjet ink.

9. The method according to claim 8 , wherein the step of heating step is performed at a temperature between 80° C. and 250° C.

10. The method according to claim 5 , wherein the electrically conductive pattern includes copper.

11. The method according to claim 5 , wherein the electronic device is a printed circuit board.

Assignees

• Agfa Gevaert Nv
• Electra Polymer Ltd

Inventors

• Torfs Rita
• Sauvageot Marion
• Loccufier Johan

Classifications

• H05K1/09

  Use of materials for the {conductive, e.g. } metallic pattern · CPC title

• B41M5/0047

  by ink-jet printing · CPC title

• C09D11/101 Primary

  Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing · CPC title

• H05K3/287

  Photosensitive compositions · CPC title

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title