Solder mask inkjet inks for manufacturing printed circuit boards

Patent metadata

Field	Value
Publication number	US-11098215-B2
Application number	US-201716348161-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 10, 2016
Publication date	Aug 24, 2021
Grant date	Aug 24, 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 a polymerizable adhesion promoter and a phenolic compound including at least two phenolic groups. 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 polymerizable compound;
an adhesion promoter; and
a phenolic compound including at least two phenolic groups; wherein
the adhesion promoter has a chemical structure according to Formula I, or a salt thereof:

wherein
n is 0 or 1;
R 1 is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group;
L 1 represents a divalent linking group including 20 carbon atoms or less in which L 1 is linked to carboxylic acid via an aliphatic carbon atom;
X represents O or NR 4 ;
R 4 is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkaryl group, a substituted or unsubstituted aralkyl group, and a substituted or unsubstituted (hetero)aryl group;
R 4 and L 1 may represent atoms that form a 5 to 8 membered ring;
R 2 and R 3 are independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.

2. The radiation curable solder mask inkjet ink according to claim 1 , wherein R 1 is a hydrogen atom or a methyl group.

3. The radiation curable solder mask inkjet ink according to claim 1 , wherein X is an oxygen atom or NH.

4. The radiation curable solder mask inkjet ink according to claim 1 , wherein L 1 represents a substituted or unsubstituted alkylene group.

5. The radiation curable solder mask inkjet ink according to claim 1 , wherein the phenolic compound has a structure according to Formula II:

wherein
R 5 and R 6 are independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a hydroxyl group, and a substituted or unsubstituted alkoxy group;
Y is selected from the group consisting of CR 7 R 8 , SO 2 , SO, S, O, and CO;
R 7 and R 8 are independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkaryl group, a substituted or unsubstituted aralkyl group, and a substituted or unsubstituted (hetero)aryl group; and
R 7 and R 8 may represent atoms that form a 5 to 8 membered ring.

6. The radiation curable solder mask inkjet ink according to claim 5 , wherein Y is CR 7 R 8 or SO 2 , and R 7 and R 8 represent a hydrogen atom or an alkyl group.

7. The radiation curable solder mask inkjet ink according to claim 1 , wherein the phenolic compound is a phenolic resin or a hydroxystyrene based resin.

8. 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 inkjet ink.

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

10. The radiation curable solder mask inkjet ink according to claim 1 , wherein the 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.

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

12. 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.

13. The method according to claim 12 , wherein the step of curing is performed using UV radiation.

14. The method according to claim 12 , further comprising:
heating the jetted solder mask inkjet ink.

15. The method according to claim 12 , wherein the electronic device is a printed circuit board.

Assignees

• Agfa Gevaert Nv
• Electra Polymer Ltd
• Agfa Gevaert

Inventors

• Torfs Rita
• Van Aert Hubertus
• Loccufier Johan
• Sauvageot Marion

Classifications

• C09D11/322

  Pigment inks · CPC title

• C09D11/037

  characterised by the pigment · CPC title

• H05K2203/013

  Inkjet printing, e.g. for printing insulating material or resist · CPC title

• H05K1/092

  Dispersed materials, e.g. conductive pastes or inks · CPC title

• H05K3/287

  Photosensitive compositions · CPC title