Laser soldering concept
The Laser Soldering process utilizes a precisely controlled laser beam to transfer energy to a soldering location where it is absorbed by the substrate, the solder, or the flux. The laser energy is delivered for the exact amount of time required for the reflow in each individual application. This precisely controlled process leads to a fast joining of the involved components. The very short heating and cooling cycle results in a fine intermetallic structure. The accurate and non-contact process guarantees a high quality solder joint in both surface mount and through-hole applications.
The solder alloy can be delivered in a solder wire, solder paste or deposited prior to placement of components. Each method has its own advantages and downsides and used with accordance to specific project requirements.
Furthermore depending on the geometry of a particular PCB board each solder joint can be reflowed individually or in conjunction with neighboring solder joints. During individual reflow the soldering wire is placed next to the joint or a precisely measured amount of solder paste is dispensed prior to delivery of the laser. When consecutive solder joints are located in a close proximity from each other, a continues line of a solder paste can be placed across. Those joints can be reflowed in the following step by tracing the dispense pattern with a spot laser or simultaneously with a laser delivered in a form of a line. Tracing the pattern or simultaneous delivery of a laser method yields shorter process time than individual reflow and is recommended when possible.
Laser soldering gained its recognition throughout the world and is used in many applications where:
- Heat sensitive components are involved, as thanks to very short and precise heat application, laser can be used to solder in components containing plastic housings, LCD displays, micro sensors and other heat sensitive devices.
- Selective components are added to a board with preexisting components that can be damaged or altered if the entire board is reflowed.
- Components on the board have different reflow requirements
- High joint quality and repeatability is required
With LEISTER’s Novolas Laser systems process parameters, such as laser power, process time, and geometry of the laser beam can be easily programmed, allowing for consistent soldering results and flexibility to switch between various applications.
Please contact us to schedule your complimentary application evaluation. At the end of the evaluation we will provide you with a number of your soldered samples for quality review. Additionally we will answer all questions related to process time and other parameters of your particular application.