How to make a heavenly PCB match.
Love may be blind, but buying printed circuit boards doesn’t have to be. Before running off to the purchasing altar with your newfound love (aka your vendor), here’s some fatherly advice for picking the right PCB manufacturer:
Play the field. Yes, you can be a polygamist when it comes to choosing a vendor. A single manufacturer cannot service all your PCB needs, and not all manufacturers are created equal. Some are simply better than others, whether your needs are military or commercial, prototype or production. It’s OK to have more than one vendor and to give each manufacturer the business that makes sense for you.
Make sure that each PCB supplier understands you will be “dating” other vendors. Having them compete for your business keeps everyone on their toes, especially when it comes to keeping pricing under control.
Follow up on references. Before “swiping right,” check references. And when asking about your future partner’s past, inquire about both the good and bad times. Don’t expect everything to be perfect. Learn how well they handle problems that will inevitably arise from time to time.
The end is nigh for lead in solder, as our columnist Tim O’Neill wrote in July in CIRCUITS ASSEMBLY.
Rules governing use of the materials – Directive 2015/863, aka RoHS 3 – are coming online and will be in full force by 2019.
Suppliers have until July 22, 2019, to meet the stricter provisions, which include no more than 0.1% lead in medical devices, which are joining consumer, industrial and other electronics products on the effectively banned list.
In “Life After SAC 305,” Tim poses the question, What comes next? Already, the future of commonplace unleaded alloys such as SAC is being questioned. As Tim writes, “It is even feasible SAC 305 will be dislodged by a new de facto alloy that better serves the needs of the market.”
Poor SAC. It entered this world under duress – a much-debated compromise that standards bodies and major OEMs agreed on only after reviewing nearly 80 other alloys.
What you think may not be what you see.
Over the past couple months I have been in several discussions where the demise of the North American fabrication industry has been at the core of the various debates. While everyone in these exchanges was coming from different perspectives, ranging from technologist to financier to global consultant to marketer, and ranging in age from “young bucks” to seasoned retirees, the common thread of their thought process was fabrication as an industry in North America is dead or dying.
Various data points cited – accurate or subjectively interpreted – paint a bleak picture. The number of facilities is down to just over 200, with over half of those facilities under $5 million in revenue. New materials and supplies being commercially introduced are more often than not developed in and/or by Asian companies, and the reinvestment in capital equipment in North America pales in comparison to amounts spent everywhere else in the world. Yes, on the surface the picture is depressing – or is it?
Solve capillary issues by increasing solids content.
It is very important to control conformal coating thickness on a printed board assembly. Problems with coating over different surfaces, particularly sharp corners that can lead to shorts from tin whiskers, have been demonstrated many times.
FIGURES 1 and 2 show capillary action on an SOIC and QFP, respectively, where the thickness of the coating is much higher around the leads and the body of the devices. With very high fluidity and spray coating, liquid capillaries under the package are starving the area of the board close to the edge of the pads.
Diligence can pay off. (Sometimes.)
The call punctuated one otherwise listless afternoon.
“Can you come over for a meeting?”
She never wants to order anything from us. She claims her process is perfect, hence no need for testing. She calls only when she wants to vent her spleen or get some free advice. She thinks our on-demand, zero-notice consultation time is limitless. No statute of limitations. She also really likes the value-added component of free advice, which she can mark up and pass along. That advice also tends to make her process more perfect than it already is. Imagine that: perfecting perfection. Did I mention that enabling wisdom was free?
Eliminating waste in medical box-build production.
Contract manufacturers typically have to find middle ground in the use of Lean manufacturing principles. Unless a customer is completely committed to a holistic Lean environment, there will also be some level of waste (muda) in the process attributable to customer-related constraints. That said, use of Lean principles to minimize the seven wastes can help mitigate defects and lower costs that would otherwise occur as a result of inefficiency.
These seven wastes are defined as: