Browse Prior Art Database

PRE ASSEMBLED OPT0 COUPLER IN POWER ISOLATOR

IP.com Disclosure Number: IPCOM000006306D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-21
Document File: 2 page(s) / 72K

Publishing Venue

Motorola

Related People

Victor J. Adams: AUTHOR

Abstract

The 2 amp OPT0 POWER ISOLATOR DEVICE consists of an optical coupling element (5) and a thy&or triac element (3) assembled to a common.lead frame (4) and overmolded in a special white epoxy compound. (See Figure 1). The structure utilizes a complex variety of assembly processes.

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MO7-OROLA INC. Technical Developments Volume 14 December 1991

PRE ASSEMBLED OPT0 COUPLER IN POWER ISOLATOR

by Victor J. Adams

  The 2 amp OPT0 POWER ISOLATOR DEVICE consists of an optical coupling element (5) and a thy&or triac element (3) assembled to a common.lead frame (4) and overmolded in a special white epoxy compound. (See Figure 1). The structure utilizes a complex variety of assembly processes.

ie. 1) wire bonds

ADVANTAGES:

1) Opto coupling element assembly and test would be automated and optimized for yield, reliabil- ity and cost.

2) Over mold compound for Opto Power isolator pkg would be optimized for thermal properties.

3) Mold sweep of the bonding wires would be eliminated.

4) The assembly of the power isolator would be tailored to the triac assembly processes and would avoid multiple passes through wire bonders, die bonders, furnaces etc.

5) The plating scheme would be reduced to Ni on cu.

  Another variation, see Figure 3, would be to have one lead (7) of the opto coupling element (5) con- figured so it would bridge to the triac chip (3) and be assemble like a chip eliminating one wire bond.

l

1 mil gold wire, thermosonically bonded

15 mil aluminum wire, ultrasonically bonded

wires are prone to mold sweep.. a reliabil- ity concern

some bonds are chip to chip, some are chip to post.

2) die attach

conductive epoxy for IR die attach (1)

nonconductive epoxy for detector die attach (2)

reflow solder for triac die attach (3)

  In a reconfigured Opto Power...