Ask Helena & Leo

Question: We install D-Paks on a number of boards (8.3.14 in IPC-A-610). These parts have a tendency to float during reflow. We have done quite a bit of process work to minimize the floating, but parts do still occasionally float and are...

Question: I have a connector that you insert a 7/30 wire into and hold it in place by tightening a screw. Should the wire be tinned? I have look in my IPC 620 standard and the only reference I see is Section 4.4, indicating that stranded wires...

Question: We are having an issue with the cleanliness of flux. The excess no-clean flux is located in an Ethernet port connector. The units pass all tests with no issues, however; we have recently had a couple of field returns where it was...

Question: Since we are seeing more and more components with gold finish on the solder attachment pads(specifically, leadless ICs mostly with bottom side terminations only for RF circuitry), how would you propose we meet the J-STD requirement...

Question: We have a customer that believes that multiple wash steps is the cause of 0805 resistor failures. They claim that it is devaluing the part. I have never heard of this issue. Could you shed some light on this?

Question: We have some panels of 6 PCBs each, double sided, which were built on our pick and place machine. After the panels were built, it was discovered that a couple panels do not have the silk screening for the component locations on one...

Question: Per J-STD-001D, paragraph 8.3.6.2, Static Extraction Method, the contamination shall be less than 1.56 micrograms/cm². What is the amount of allowable contamination per inches squared?

Question: What is the thumb rule for soldering iron temperature for RoHS & Non-RoHS manual soldering?

Question: I just recently provided the CIS on the IPC-A-620 standard within my organization and the training was very fun. All the documentation provided in the trainer kit is very helpful. After the course, I sent the report of application...

Question: What is the proper hardware installation on a mounting hole when a tooth washer is used?

Question: I’m having trouble discerning the requirements for post lead trimming reflow in the new version of IPC-A-610. It seems to indicate only “leads must be covered by solder”. Can you elaborate on where I may find more conclusive...

Question: I have a question about flag labels. Under IPC standards, is it ok if the label moves on the wire, or harness? In the IPC-A-620 standard, it doesn’t say a lot about flag labels, and my quality inspectors are divided on whether it is...