R&D and production bonders by Finetech are equipped to perform high accuracy laser bar assemblies, including placing and bonding laser bars to sub-mounts and sub-assemblies to heat sinks. As opposed to single lasers, laser bars consist of several single edge-emitting lasers comprised in a silicon bar. Bundling the light results in significantly increased output power in a wide range of applications.
Laser bars are high power products, used wherever small and efficient light-emitting units are needed. They mainly serve as pumping sources for optical resonators of high power lasers, and are often found in medical appliances.
What are the challenges?
- Fully-automatic processes
- Sensitive components with brittle materials and optically active areas
- Delicate edges and facettes
- High magnification need for the complete length of the laser bar/submount
- Perfect coplanarity required to ensure proper thermal management
- Highest placement accuracy needed to ensure defined overhang
- Automatic 2-point alignment of long components for perfect angle precision
- Short cycle times with ultrafast heating capability
- Solder materials are prone to oxidation; process gas integration required
- Stacked mounting (lasers to submount) requires different solder materials with appropriate profiles
- Cooling issues caused by bonding voids
- Deformation of laser bar results in decreased emitting power (SMILE)
- Thermal warpage shortens lifespan of the component
- Deformation (SMILE)
The higher the SMILE value, the more the beam quality of the optical system is affected
- Temperature distribution (HOTSPOT)
Faulty or inhomogeneous solder layers can cause local temperature fluctuations that may result in breakdown of single emitters
Mechanical pressure or strain warpage may result in shortened lifespan
The Finetech Solution
Tools & Modules
- Automatic Bonding Force Module provides controlled forces and secure handling
- Active and passive self-levelling tools guarantee even bond line, preventing SMILE effects
- Unique vision system, in combination with pivoting placement arm, minimizes alignment and placement error
- Process gas integration to reduce/avoid oxidation and increase quality of bonding
- IPM allows comprehensive process control and reproducible processes
Step-by-step: Complete Laser Bar Assembly Process
- Load submount on heating module
- Pick-up laser bar from presentation
- Align laser bar to sub-mount
- Place and bond laser bar to sub-mount (i.e. using AuSn)
- Pick-up sub-assembly
- Load heat sink on heating module (i.e. CS-mount)
- Align sub-assembly to heat sink
- Place and bond sub-assembly to heat sink (i.e. using Indium)
- Mount N-contact sheet to top face of laser bar (i.e. InSn)
Process Gas Integration
- Sophisticated support of AuSn and Indium joints under defined atmosphere
- Employment of formic acid as a process gas for shielding and reduction of oxide layers
- Self-sufficient formic acid gas generation
- Safe handling of fluid formic acid
- Numerous standard and custom process gas integration methods with controlled injection and outlet
- Automatic control of activation time and concentration for repeatable results
FINEPLACER® Production Bonder
FINEPLACER® systems for production environments enable highly stable automated assembly processes with the focus on maximum yield. They feature a high degree of configurability for a wide spectrum of technologies and applications.
Our team will be happy to assist you with finding the best equipment solution for your production requirements.
FINEPLACER® Laboratory Bonder
Due to the modular design approach, FINEPLACER® laboratory bonding systems can be configured for virtually any application challenge.
The main distinguishing features between the machines are the
- degree of motorisation
- optical resolution
- placement accuracy and
- working area
Our team will be happy to assist you with finding the best equipment solution for your specific application requirements.