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.
One of the great things about working for Miyachi Unitek Corporation is the company’s near-religious zeal for innovation. I feel like it’s really in our “DNA,” - and while it can be frustrating to ‘finish’ a new technical datasheet only to find out that the product has been tweaked/improved in the time it took to print it - it’s something that I’m proud to be a part of. As a company, we have always provided not only equipment, but also complete manufacturing solutions, which require an understanding of both equipment and process. We are always helping people answer the question, “Is there a better way to do this?”
That innovative spirit recently got its just rewards, as Miyachi Unitek was named one of 14 finalists in the Patrick Soon-Shiong Innovation Awards, presented by the Los Angeles Business Journal and NantWorks. We were honored as an organization that “expands the boundaries of its industry and leads the region in impactful innovation.” I have to admit it felt good to get kudos for some of the technical innovations we have spearheaded in the past decade, and recognition for the impact some of these innovations. I’d like to give our readers just a few examples.
- Application of three-dimensional laser cutting for production of arthroscopic surgery devices – This is a method of using a five-axis motion platform to achieve true three dimensional contour cutting for a shaver used to cut away and remove unwanted fragments of the cartilage from a joint during arthroscopic surgery. With this technique, the edge quality of the laser cut tube is nearly flawless, minimizing the extent of secondary manufacturing process steps. This means better shavers, better surgeries, lower risks and ultimately a better quality of life for many people.
- New welding technique enables crack free welding of high silicon Al-Si controlled expansion alloys and aluminum 4047 for aerospace electronic packages – Using a novel concept, we enabled crack-free welding of 70 percent silicon alloys, which are lightweight, high thermal conductivity alloys that are used for RF and microwave packages and other critical heat sinking applications. Miyachi Unitek modified the solidification process without using post weld heat treatment. By using a fillet weld geometry and moving the weld close to the edge of the package the isotherms around the weld are modified such that the thermal gradient is reduced and re-orientated. The result included crack-free welds in the highest silicon content alloy, CE7.
- Advances in laser welding systems and technology for medical device manufacturing – This innovation includes motion and laser control techniques beneficial to hermetic laser seam welding of implantable devices. Using special software to achieve “position-based firing” along the contour, we developed a method that fired the laser in response to its actual position along the contour at any point in time. We also developed new metals joining production methods using “green light” (532nm) pulsed welding lasers, which facilitates precision welding of copper and gold alloys. This offers a true metallurgical weld, consistent high-reliability electrical connections with no long term resistance drift, and a non-contact process that completely eliminates risks of electro-static discharge or physical damage to the parts being joined.
- New force-based bend align increases yield and throughput for manufacturing pump lasers for the telecom industry – This unique force-based algorithm is used for deforming pump laser diode packages back into alignment. The packages are part of fiber laser amplifiers used to boost a telecommunications signal as it’s transmitted over vast distances. With the force based bend align method, the signal is peaked faster and in many cases with increased coupling over position based systems. The increased coupling provides improved amplification of the signal and greater signal to noise ratio.
- Enabling high performance optoelectronic modules using novel gas-conserving resistance welding electrode system – This new projection welding technique dramatically reduces the amount of Xenon gas needed to backfill a package. Xenon has good thermal properties and does not enter into slow chemical reactions with other materials that can cause degraded performance and reliability. However, it is extremely expensive, and many existing processes waste the costly gas during backfilling. The new technique enables packages to be evacuated, and then filled with gas before being hermetically sealed using projection welding. This process consumes as little as 5 cubic centimeters of Xenon gas, costing only $0.75 per part.