High-speed encapsulation of ordnance electronic circuitry
Abstract
Efforts to develop encapsulation materials which allow the processing of 100,000 circuits/mo with mold times of 1 min for housing ordnance electronic circuitry are described. Specifications of the electronic fusing require 96-99% reliability after a storage term of 25 yr and the use of pourable encapsulants, liquid injection molding, and transfer molding have been investigated. Current encapsulation is achieved with polyurethane foam, and the methods are described. A total of 21 molding techniques were tested for lower cost, high reliability encapsulation, and recurring and nonrecurring costs associated with each material were quantified. Chemically blown foams were determined as the least expensive and filled epoxy systems the most expensive. The single-component filled epoxy, Hysol EO-0029 has been found to eliminate a number of assurance steps, and program steps to produce conformal molding are outlined.
- Publication:
-
SAMPE Journal
- Pub Date:
- April 1982
- Bibcode:
- 1982SAMPJ..18...14G
- Keywords:
-
- Circuit Protection;
- Encapsulated Microcircuits;
- Encapsulating;
- Miniature Electronic Equipment;
- Ordnance;
- Aging (Materials);
- Cost Analysis;
- Electrical Properties;
- Epoxy Compounds;
- Injection Molding;
- Mechanical Properties;
- Polyurethane Foam;
- Silicones;
- Electronics and Electrical Engineering