# US 4,398,660 A · Method of mounting electronic components

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,398,660 A
- Document ID: US4398660A
- Status: Granted
- Kind: A
- Application number: 06/271,036
- Filed: 1981-06-04
- Granted: 1983-08-16
- Earliest claimed: 1981-06-04
- Assignees: RCA Corporation
- Inventors: Thomas R. Pampalone; Anthony Z. Miller
- Web page: https://patentgrep.com/patent/US4398660A

## CPC

- H05K 3/305: {Affixing by adhesive}
- C09J 4/00: Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16}
- C09J 4/06: {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00
- H05K 2201/0209: Inorganic, non-metallic particles
- H05K 2201/10636: Leadless chip, e.g. chip capacitor or resistor
- H05K 2203/087: Using a reactive gas
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y10T 29/49144: by metal fusion
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An improved method for mounting leadless electronic components on printed circuit boards so they can be soldered in place is disclosed. The method utilizes an acrylate adhesive composition which is rapidly cured in two stages by treatment with gaseous sulfur dioxide followed by heat.

## Claims

### Claim 1

A method of mounting leadless electronic components on a printed circuit board comprising:
(a) temporarily attaching said components to said board with an adhesive composition comprising:
(1) 30 to 80% by weight of one or more liquid monomers each containing one or more acrylate moieties;
(2) a finely particulate inert filler;
(3) an effective amount of a free radical initiator containing a hydroperoxide moiety to allow partial curing of the adhesive composition upon exposure to gaseous sulfur dioxide;
(4) an effective amount of a thermal initiator to allow complete curing of the adhesive composition upon exposure to heat; and
(5) a polymeric binder soluble in said liquid monomers in an amount required to provide the desired flexibility and resiliency to the cured adhesive composition;
(b) exposing the board to gaseous sulfur dioxide to partially cure said adhesive composition;
(c) heating the board to complete the cure of said adhesive composition thereby rigidly attaching said components thereto; and
(d) soldering said components to said board.

### Claim 2 (depends on 1)

The method in accordance with claim 1, wherein, in step (b), the board is exposed to gaseous sulfur dioxide for from about 1 to about 10 seconds.

### Claim 3 (depends on 1)

The method in accordance with claim 1, wherein, in step (c), the board is heated to a temperature of from about 130.degree. C. to about 160.degree. C. for about one minute.

### Claim 4 (depends on 1)

The method in accordance with claim 1, wherein, the step (b), the board is exposed to gaseous sulfur dioxide for about 5 seconds and, in step (c), the board is heated to a temperature of about 150.degree. C. for one minute.

### Claim 5 (depends on 1)

The method in accordance with claim 1, wherein said free radical initiator is t-butylhydroperoxide and said thermal initiator is benzoyl peroxide.

### Claim 6 (depends on 1)

The method in accordance with claim 1, wherein at least one of said liquid monomers contains more than one acrylate moiety.

### Claim 7 (depends on 6)

The method in accordance with claim 6, wherein said liquid monomer containing more than one acrylate moiety is selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate and hexamethylenediol diacrylate.

### Claim 8 (depends on 7)

The method in accordance with claim 7, wherein said liquid monomer containing more than one acrylate moiety is hexamethylenediol diacrylate.

### Claim 9 (depends on 1)

The method in accordance with claim 1, wherein said finely particulate inert filler is alumina.