Solder mask inkjet inks for manufacturing printed circuit boards

Patent metadata

Field	Value
Publication number	US-10947402-B2
Application number	US-201716348162-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 10, 2016
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

An inkjet method for producing a solder mask in the manufacture of a Printed Circuit uses a solder mask inkjet ink containing at least one photo-initiator, at least one free radical polymerizable compound and at least one allyl sulfone compound 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 method of manufacturing an electronic device, the method comprising:
jetting a radiation curable solder mask inkjet ink onto a dielectric substrate including an electrically conductive pattern; and
curing the jetted solder mask inkjet ink; wherein
the solder mask inkjet ink includes:
a photoinitiator;
a free radical polymerizable compound; and
an adhesion promoter according to Formula I:

wherein
n represents an integer from 0 to 2;
R2 is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group;
E is selected from the group consisting of COR10 and a nitrile;
R10 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 aralkyl group, a substituted or unsubstituted alkaryl group, a substituted or unsubstituted aryl group or heteroaryl group, OR11, and NR12R13;
R11, R12, and R13 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 aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl group or heteroaryl group; and
R12 and R13 may represent atoms that form a 5 to 8 membered ring;
if n=0, then:
R1 is selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, a substituted or unsubstituted aryl group or heteroaryl group, R3C═O, R4C═S, and R5SO 2 ;
R3 and R4 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 aralkyl group, a substituted or unsubstituted alkaryl group, a substituted or unsubstituted aryl group or heteroaryl group, OR6, NR7R8, and SR9;
R5, R6, and R9 are independently selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl group or heteroaryl group;
R7 and R8 are independently selected from 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 aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl group or heteroaryl group; and
R7 and R8 may represent atoms that form a 5 to 8 membered ring;

if n=1 or 2, then:
R1 is selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl group or heteroaryl group.

2. The method according to claim 1 , wherein R2 represents a hydrogen atom.

3. The method according to claim 1 , wherein
E represents COOR14; and
R14 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 aralkyl group, a substituted or unsubstituted alkaryl group, a substituted or unsubstituted aryl group or heteroaryl group, and a substituted or unsubstituted alkyl group optionally substituted in the aliphatic chain by oxygen or nitrogen atoms.

4. The method according to claim 1 , wherein n=2.

5. The method according to claim 1 , wherein the adhesion promoter has a chemical structure according to Formula II:

wherein
R15 is selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl group or heteroaryl group; and
R16 is selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl group or heteroaryl group.

6. The method according to claim 5 , wherein R16 represents a substituted or unsubstituted alkyl group optionally substituted in the aliphatic chain by oxygen or nitrogen atoms.

7. The method 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.

8. The method according to 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.

9. The method according to claim 1 , wherein the radiation curable solder mask inkjet ink includes a cyan pigment, a yellow pigment, or a green pigment.

10. The method according to claim 1 , wherein the step of curing is performed using UV radiation.

11. The method according to claim 1 , wherein the step of curing is performed using UV LED radiation.

12. The method according to claim 1 , further comprising:
heating the jetted solder mask inkjet ink.

13. The method according to claim 12 , wherein the step of heating is performed at a temperature between 80° C. and 250° C.

14. The method according to claim 1 , wherein the electrically conductive pattern includes copper.

15. The method according to claim 1 , wherein the electronic device is a printed circuit board.

Assignees

• Agfa Gevaert Nv
• Electra Polymer Ltd
• Afga Gevaert Nv

Inventors

• Loccufier Johan
• Torfs Rita
• Sauvageot Marion

Classifications

• H05K2203/013

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

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title

• B41M3/006

  Patterns of chemical products used for a specific purpose, e.g. pesticides, perfumes, adhesive patterns; use of microencapsulated material; Printing on smoking articles · CPC title

• H05K1/092

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

• B41M5/0047

  by ink-jet printing · CPC title