# US 4,399,453 A · Low thermal impedance plastic package

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- Number: US 4,399,453 A
- Document ID: US4399453A
- Status: Granted
- Kind: A
- Application number: 06/246,506
- Filed: 1981-03-23
- Granted: 1983-08-16
- Earliest claimed: 1981-03-23
- Assignees: Motorola, Inc.
- Inventors: Howard M. Berg; Gary L. Lewis; Curtis W. Mitchell
- Web page: https://patentgrep.com/patent/US4399453A

## CPC

- H10H 20/8582: {characterised by their shape}
- G02B 6/421: {the intermediate optical component consisting of a short length of fibre, e.g. fibre stub}
- G02B 6/4292: {the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements}
- H10H 20/8581: {characterised by their material}
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A package for fiber optic semiconductor devices is disclosed in which heat is conducted by both a heat spreader and through a plastic enclosure portion of the package.

## Claims

### Claim 1

A fiber optic semiconductor device having a low thermal impedance comprising:
a thermally conductive header;
a semiconductor chip, having a photo-active area, thermally connected to said header;
a segment of fiber optically connected to said photo-active area; and
heat spreader means thermally coupled to said header, said heat spreader means extending outwardly from said header for conducting heat away from said semiconductor chip;
a cylindrical, thermally conductive member orthogonal to and thermally connected to said heat spreader; and
plastic enclosure means engaging said heat spreader for enclosing said semiconductor chip, said cylindrical member, and said fiber, said fiber extending through a surface of said enclosure means, and wherein said cylindrical member conducts heat away from said semiconductor chip through said enclosure means.

### Claim 2 (depends on 1)

The package as set forth in claim 1 wherein said cylindrical member comprises a lip portion, the convex side of which engages said header and the concave side of which engages said heat spreader.

### Claim 3 (depends on 2)

The package as set forth in claim 2 wherein said header, heat spreader, and cylindrical member each comprise metal or metal alloy.

### Claim 4 (depends on 2)

The package as set forth in claim 2 wherein said heat spreader comprises fastening means at the outward ends thereof.

### Claim 5 (depends on 1)

The package as set forth in claim 1 and further comprising:
thermally conducting, electrically insulating means interconnecting said chip and said header.

### Claim 6 (depends on 1)

The package as set forth in claim 1 and further comprising:
a lens positioned adjacent said photo-active area for optically connecting said fiber and said photo-active area.

### Claim 7 (depends on 1)

The package as set forth in claim 1 wherein said package is characterized by a thermal impedance of less than 250.degree. C. per watt of power dissipated by said chip.