Most PCB materials like FR2 and FR4 are very resilient to the application of heat during the hot bar reflow soldering (or hot bar bonding) process. But some materials - ceramic substrates in particular - need to be heated in a more controlled fashion to minimize the chance of cracking. Excessive differences in the heat sinking capability of the two parts being joined can also cause solder cracking during cooling. Heat sinking differentials along the solder joint length are the most common design problem to overcome. Small differences may not have much effect on quality, but any large thermal mass change along the joint area will cause inconsistency of temperature and result in a poor solder joint.
Battery tabs seem to have been getting thicker and more conductive over the last several years, as customers seek better performance and higher currents from their battery packs. These thicker battery tabs are usually made of nickel, but nickel-plated copper tabs are gaining in popularity due to their higher conductivity. We’ve had success welding the thicker nickel tabs, but have found the nickel-plated copper to be very difficult to weld. How to overcome that? Add slots and projections to the tab design to focus the current and minimize current shunting. Welding success also depends, in part, on the battery itself; those with thick caps can easily handle the high force and current needed to weld the thicker tabs. If the battery caps are too thin, however, they may get deformed or blown through.
Lately, we’ve been doing a lot of talking about laser cutting. Fine laser cutting, that is. But what, exactly, is ‘fine’ laser cutting? Fine laser cutting applies to the cutting of metals, such as 300 and 400 series stainless steel, aluminum, nickel, titanium, nitinol and copper less than 0.04” (1.0mm) thick. In fact, they can be very thin - 0.0005”-0.002” (10-50 microns) - as the laser imparts no physical force on the part during the process. In addition to the thickness of the part, fine cutting is also defined by cut feature tolerances which can be down to ± 0.0005”.
Got that? OK! Let’s consider a few examples that highlight fine cutting –
Topics: laser cutting
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.
The Medical Design & Manufacturing (MD&M) West exposition and conference is the place to be this week if you want to see the latest innovations in equipment and systems for medical device manufacturing. Despite all the doom and gloom you hear about the manufacturing sector, the medical device industry has been on fire for the last decade, and shows no signs of let up. Innovations in technology are on the rise as everyone is looking to do things smaller, faster, and more reliably. I like to stroll the aisles looking for what’s 'just out.' If you do too, drop by Miyachi Unitek’s booth - #3051.
In a recent blog, we mentioned using projections as “energy directors” to achieve weld joints at specific, pre-defined locations. Ring projections - also known as annular projections - are commonly utilized in the electronic packaging industry to achieve hermetically sealed electronic packages, for transistor outline (TO) packages and, more recently, rectangular packages. Following are some tips for successful design of these ring projections and possible solutions to help you overcome less-than-perfect designs.
Laser micromachining is a process used to make tiny features in parts - measured in micrometers or millimeters. Pulsed lasers effectively complete this work by depositing very small, finite amounts of energy into a material, resulting in extremely precise and reproducible material removal. Suitable deposition of energy enables the laser to ablate, cut, drill, machine or scribe a material. A number of pulsed lasers are available for micromachining; in these examples, we used a 20W single mode pulsed fiber laser marker.
Aluminum alloys, are lightweight, possess good thermal and electrical conductivity, and are relatively inexpensive to work with. Therefore, it’s no surprise that they are being used with increased frequency in product manufacturing applications ranging from batteries and electronics packaging, to automotive components and consumer goods packaging. Laser welding aluminum, however, is more difficult than welding steels for three key reasons: high reflectivity, surface oxide layer, and volatile alloying elements.
Miyachi Unitek is no stranger to patented inventions (at last count, I think the company has 19), and the patent recently issued to NASA raises that number by 1...IMHO.
Topics: laser welding
Laser micro welding of conductive materials like copper has always been somewhat of a difficult proposition due to copper’s high reflectivity at the 1064nm wavelength. 532nm “green” laser welders however, remove this barrier, offering a truly viable method for laser micro welding copper (and other conductive materials) in high volume.