Browse Prior Art Database

SEMICONDUCTOR LASER BODY HEAT SINK

IP.com Disclosure Number: IPCOM000025533D
Original Publication Date: 1985-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 4 page(s) / 117K

Publishing Venue

Xerox Disclosure Journal

Abstract

Headers for support and heat sinking of semiconductor lasers are generally fabricated of copper. The laser is mounted I'P side" down to make effective use of the heat sink. The soldering of the laser to the heat sink is critical for mainly two reasons: (I) to ensure that areas of the I'P side" are uniformly in engagement with the heat sink to eliminate hot spots and (2) to align the front mirror facet of the laser with the front edge of the copper heat sink.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 59% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

SEMICONDUCTOR LASER BODY HEAT SINK
Joseph C. Tramontana

Proposed Classification
U.S. Cl. 372/45 Int. Cl. HOls 3/19

p- CLADDING LAYER

n-CLADDING LAYER

I

n- SUBSTRATE

COPPER HEADER 21

    -.-c( +44m COPPER HEADER 21

-

 2 f/G TRANSFER HEAT . 1 A- WELL 26
HEAT TRANSFER
WELL 30
\

LASER

HE AT TRANSFER

WELL 26

.

/ CONTACT 32

n-CLADDING LAYER

o*-

FIG. 3

Volume 10 Number 6 November/December 1985 379

[This page contains 1 picture or other non-text object]

Page 2 of 4

SEMICONDUCTOR LASER BODY HEAT SINK (Contld)

LASER STRIPE 24

Headers for support and heat sinking of semiconductor lasers are generally fabricated of copper. The laser is mounted I'P side" down to make effective use of the heat sink. The soldering of the laser to the heat sink is critical for mainly two reasons: (I) to ensure that areas of the I'P side" are uniformly in engagement with the heat sink to eliminate hot spots and (2) to align the front mirror facet of the laser with the front edge of the copper heat sink.

It would be advantageous to mount the laser right side up, i.e., "N side" down, so that proper alignment at the header edge would not be required. Also, improved means for uniformly heat sinking the laser as well as providing the laser with greater heat sinking capacity, in particular, when mounted "N side" down, would be highly advantageous if not required. Such improved heat sinking means is illustrated in Figures 1-4.

In Figure 1, laser 10 comprises substrate 12 of n-GaAs, cladding layer 14 of n- Gal-xA1xAs, active layer 16 of doped or undoped GaAs, cladding layer 18 of p- Cal-xA1,As, and cap layer 20 of p+-GaAs. A proton implant 22 is formed through cap layer 20 into cladding layer 18 delineating a stripe contact 24.

As illustrated in Figures 1 and 2, heat transfer wells 26 are etched into the body of the laser crystal in a manner to be as close as possible to stripe contact 24 but leave intact the operating region of laser 10. The bottom of wells 26 may reach into n-cladding layer 14 or n-substrate 12. Wells 26 are filled with a heat transfer fluid, such as solder, indiu...