Solder mask inkjet inks for manufacturing printed circuit boards

Patent metadata

Field	Value
Publication number	US-11091659-B2
Application number	US-201716348164-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 10, 2016
Publication date	Aug 17, 2021
Grant date	Aug 17, 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 RAFT 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 radiation curable solder mask inkjet ink comprises:
a photoinitiator;
a free radical polymerizable compound; and
an adhesion promoter; wherein
the adhesion promoter has a chemical structure according to Formula I:

wherein
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 or heteroaryl group, OR5, SR6, and NR7R8;
R2 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, and a substituted or unsubstituted aryl or heteroaryl group;
R3 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 or heteroaryl group, and an electron withdrawing group including at least one oxygen carbon double bond or a nitrile group;
R2 and R3 may represent atoms that form a 5 to 8 membered ring;
R4 is selected from the group consisting of an electron withdrawing group including at least one oxygen carbon double bond or a nitrile group, and a substituted or unsubstituted aryl or heteroaryl group;
R5 and R6 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 or heteroaryl group;
R7 and R8 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 or heteroaryl group;
R7 and R8 may represent atoms that form a 5 to 8 membered ring; and
none of R1 to R4 includes a photoinitiating moiety.

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

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

4. The method according to claim 3 , wherein the step of heating is performed at a temperature between 80° C. and 250° C.

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

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

wherein
R9 is selected from the group consisting of OR12, NR13R14, and a substituted or unsubstituted aryl group;
R10 is selected from the group consisting of an ester, an amide, a carboxylic acid, and a nitrile;
R11 represents a substituted or unsubstituted alkyl group;
R12 is 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 or heteroaryl group;
R13 and R14 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 or heteroaryl group; and
R13 and R14 may represent atoms that form a 5 to 8 membered ring.

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

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 or heteroaryl group; and
R16 represents a hydrogen atom or a substituted or unsubstituted alkyl group.

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

wherein
R17 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, and a substituted or unsubstituted aryl or heteroaryl group;
R18 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 or heteroaryl group, and an electron withdrawing group including at least one oxygen carbon double bond or a nitrile group;
R17 and R18 may represent atoms that form a 5 to 8 membered ring; and
R19 is selected from the group consisting of an electron withdrawing group including at least one oxygen carbon double bond or a nitrile group, and a substituted or unsubstituted aryl or heteroaryl group.

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

wherein
R20 and R21 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 or heteroaryl group;
R20 and R21 may represent atoms that form a 5 to 8 membered ring;
R22 and R23 are independently selected from the group consisting of a hydrogen atom and a substituted or unsubstituted alkyl group;
R22 and R23 may represent atoms that form a 5 to 8 membered ring; and
R24 is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group,

Assignees

• Agfa Gevaert Nv
• Electra Polymer Ltd
• Agfa Gevaert

Inventors

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

Classifications

• C09D11/30

  Inkjet printing inks · CPC title

• C09D11/38 Primary

  characterised by non-macromolecular additives other than solvents, pigments or dyes · CPC title

• C09D11/322

  Pigment inks · CPC title

• B41M5/0017

  Application of ink-fixing material, e.g. mordant, precipitating agent, on the substrate prior to printing, e.g. by ink-jet printing, coating or spraying · 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