Explaining solder joint defects, one interruption at a time.
“Thank you all for promptly joining this morning’s webmail conference call. Today we are going to review the x-ray images our outside lab FTP’d us yesterday. Please set your phones on mute by pressing *6 if you are not speaking, and set your computers to the link provided by the meeting invite. You can unmute your phones in the same way, by pressing *6, if you wish to contribute to the conversation. You may listen via phone link, or by plugging earbuds into your laptops and activating sound. If you feel compelled to speak, unmute your phone and speak one at a time. We’d like to give equal time to as many members of our several participating engineering groups as possible. We have a big agenda, and many participants, so let’s get started.”
Here we go. Amateur hour.
A practical approach for BGA void analysis.
Simple process steps for inspecting arrays. (But don’t expect them to always be the source of failures.)
After more than 15 years working with people who choose to use x-ray inspection as part of their fault-finding and quality-ensuring procedures, the most common refrain I hear is, “The board’s not working; it must be the BGA.” I do also hear this from those who do not have access to x-ray!
Arguably, as the BGA was the first commonly used component to be placed on boards with all its interconnections hidden from any possibility of post-reflow optical inspection, I suggest the BGA has been the primary driver for the increased uptake of x-ray inspection in recent years. After all, x-ray inspection is nondestructive and can see where optical systems cannot. Perhaps it is the entirely optically hidden nature of the BGA joints that has caused its infamy within electronics manufacturing. By not being able to see the joints that have been made, how can the BGA be ruled out as the cause of the failing circuit? Without some certitude in this, how can a contract manufacturer assuage its client’s belief that all non-working products have been caused by poor reflow under the BGA, rather than by some other mechanism? X-ray inspection goes a long way to help both parties resolve this, and, assuming it isn’t actually the BGA’s fault, the “first likely cause of problem” can be ruled out, and all parties can move on quickly and productively to consider other potential reasons for the issue.
More amazing tales from the front.
“How much bandwidth do you have?”
I had just entered the conference room. He barely said hello, and didn’t wait for me to sit down or unload my laptop from my shoulder. Hardly glanced at my accompanying Sales Rep either. No nonsense, little acknowledgment. Right to the point. He insisted:
“How much bandwidth do you have?”
I replied, inquisitorially, “How much bandwidth do you need?”
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?