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Laser Bar Bonding
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The semiconductor laser bar (size about 1mm x 10mm) has to be placed accurately on the heat sink. Usually one of the submount edges are chosen as alignment base. The following challenges have to be faced and solved during the bonding process:
- Precise alignment between the active site of the laser bar and the sub mount edge even if the optical field of the microscope is not large enough to see the whole laser bar in the optical field– the FINETECH approved "two point alignment” method is the solution
- Create a soldering joined without any void and with excellent uniformity, fast temperature ramping within a inert atmosphere is required to avoid solder voids
- High accuracy in parallelism between the surface of the bar and the submount surface
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AuSn Soldering
Layers or bumps of AuSn material located on chip and substrate are soldered together in a temperature and force process. Typical solder temperatures are in the range of 320°C. The bonding force and the environment have to be controlled very precisely during the whole bonding process. |
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Indium Bonding
Indium solder is one of the most widely used solders in high power laser die bonding. Especially in laser die bonding Indium solder has some key advantages: low melting point; remove stress from bonding partners and reduced warpage. |
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Due to its outstanding placement accuracy of ± 0.5 µm FINEPLACER® FEMTO is perfectly suitable for even the most sophisticated indium applications.
Automatic die bonder FINEPLACER® FEMTO has been optimized for the most sophisticated bonding technologies. Due to the high process flexibility, FEMTO is capable to employ different process gases like nitrogen, inert gas and formic acid. With its open system architecture, FINEPLACER® FEMTO can be easily adapted with specific additional modules which allow an outstanding multitude of applications and processes. The spectrum ranges from power laser and laser bar bonding, flip chip and VCSEL bonding over assembly of MEMs and MOEMs, sensors or micro-optics to chip on glass or surface mount photonics.
FEMTO is capable to perform both AuSn and Indium bonding
More information on FINEPLACER® FEMTO. |
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The manual high accuracy sub-micron flip chip bonder FINEPLACER® Lambda with a placement accuracy of up to ± 0.5 µm is capable of various indium and AuSn applications.
Preferred applications for the versatile FINEPLACER® Lambda system are assembly of opto-electronic components (e.g. VCSEL, photo diodes, power and single lasers or laser bars), advanced device packaging (MEMS, sensors, micro-optics, embedded components, surface mount photonics), flip chip bonding and precise die attach. The motorized configuration provides auto-touchdown and die placement also for components which exceeds the optical field of view, very high process reproducibility and up to 10 programmable camera positions. Lambda can be upgraded with a placement mask generator. The optional integration of heated inert gas or formic acid is possible.
More information on FINEPLACER® Lambda. |
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FINEPLACER® Pico AMA is perfectly suitable for automatic laser bar assembly. All steps of laser bar assembly can be carried out by the system - including batch recognition, handling and flipping of laser bar, transfer of submount or heatsink, bonding or soldering. The automatic vision aligment system eliminates the operator influence of the bonding result. After alignment and gently placement of the laser bar the controlled Indium and AuSn soldering process starts. The post bond accuracy of the assembled module can be measured by the integrated measurement module. An accuracy significantly better than 5 µm @ 3 σ can be achieved by the system.
More information on FINEPLACER® Pico AMA |
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Click on the PDF icon to load the application flyer for:
Assembly of Laser Bar |
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![Laser Bar AuSn Submount [click]](http://www.finetechusa.com/media/archive/2068.jpg)
![Indium solder on laser bar [click]](http://www.finetechusa.com/media/archive/2066.jpg)
