Datasheet

Chapter B: Operations for advanced users
B.2. Soldering wire bonds from laser chip to
submount
IMPORTANT:
Soldering bonds to the carrier is a delicate operation. Contact
ALPES LASERS before attempting this operation.
As the QCL chip itself is soldered, and the contact pads on the ceramics are made
out of gold, it is not possible to use a normal Lead-Tin solder: the temperature is too
high, the solder will destroy the gold contacts by forming an alloy. ALPES LASERS
recommends the use of pure Indium for soldering, in the form of paste of microscopic
beads in flux.
Figure B.1.: Laser chip wire bonds.
It is of highest importance to never touch any part of the laser chip itself (especially
not the facets) nor the bonds, as this may result in fatal damage to the QCL. Solder
with a very fine tip solder iron at about 170
◦
C, only at the corner of the contact pad
which is most distant from the bonds and the chip, using only very thin and flexible
wires.
100 QCL user’s manual v3.0