Seam sealing electronic packages is typically the last critical step in the package manufacturing process. Since the completed product performs a vital function and has a high dollar value, creating a barrier to contamination ingress is essential. Whether it’s optoelectronic packages for fiber optic cables transmitting signals in the middle of the ocean, or aerospace RF/microwave packages performing essential functions, the importance of preventing external environmental conditions from penetrating the package just can’t be over-estimated.
So, what’s the best joining technology out there for sealing packages? The answer is…it depends! Resistance welding and laser welding are both well-established technologies; the selection of the right joining technology will be based on package design, throughput, and layout. The technologies rarely compete; they are usually mutually exclusive based on particular parameters.
Use the table below to compare technologies to see which one might work the best for your application.
Before reviewing the table, consider these basic concepts:
- Laser welding
- With regard to mechanical constraints, laser has the advantage because it uses a light beam rather than an electrode which needs to make physical contact with the package
- Laser has lower maintenance costs
- Laser seam welding is recommended for:
- A wider range of lid thicknesses
- Irregularly shape packages
- Packages with mechanical constraints where resistance welding roller electrodes cannot access
- Seam welding on top of the lid, as in RF modules where there are dividing walls inside the package that require joining the lid and the dividing walls that isolate RF emission from various components in the module
- Aluminum and copper packages
- Resistance Welding
- Resistance seam welding can be used for rectangular or circular packages with a lid thickness of 0.004-0.007 inches, made out of nickel or gold-plated Kovar or steel
- Resistance seam welding cannot be used to weld aluminum or copper
- Resistance welding is more accommodating of part plating thickness and the type of plating
- Generally, resistance welding is faster, especially on larger packages
Does that give you a better idea of which technology will work for your specific application? Whichever you opt for, I highly recommend you run samples first to prove the concept. Miyachi Unitek will do that for you at no cost!
Contributors: Geoff Shannon, Laser Technology Manager, Miyachi Unitek Corporation & Mark Sunico, Product Engineer, Miyachi Unitek Corporation