Ask Helena & Leo

Question: I am an IPC Certified J-STD-001 Instructor. We solder our wires straight up from the via, then bend them to where we need them to go. We had some assemblies built outside and they tinned and bent them at a right angle, then soldered...

Question: I am performing some modifications to a Raspberry Pi circuit board for a university research group and I was asked to substitute a USB cable for the stock, on-board USB port. I’m having difficulties soldering the braided shield to...

Question: Is there a comprehensive Excel listing of the non-conformities shown in IPC-A-610? (Just a list of defects) This would be used to make a defect tracking database.

Question: Our current soldering process for a product proceeds like the following: two heat excursions, thru reflow, two thru a wave and one thru rework. How many more rework cycles can we do before compromising the reliability of the...

Question: Does the IPC impose limits, or publish a standard on the amount of 160 CPLD lead bending that’s acceptable before restoring to original specifications? I have a surplus of obsolescent components that were damaged during packaging.

Question: What type of impact would it have if the wires were tin-dipped in lead-free solder then were soldered to a board with 63/37 solder? Are there problems that may occur that would cause difficulty in soldering?

Question: Section 6.3.2 on strand damage is confusing in the new Rev E document. Note 3 under the table seems to define damage as anything greater than 10% of the cross sectional area of a strand. This is difficult to explain or visualize on...

Question: Can we bridge two adjacent pins on an IC using bare wire across those two pins? What specification do we reference for the acceptance of the rework performed?

Question: We build components, and we would like to get your suggestion on which max limit column to follow. I am thinking Assembly Max Contaminant, due to the fact that we strip and tin, and solder connections to our components. We are not...

Question: There is a product called Poke Home – Junction Box with the URL to a specification sheet at: http://www.avx.com/docs/Catalogs/wtwpokehomejunctionbox9286.pdf.

Question: We are looking for a hot air rework system. Nothing fancy… just something that will help us to remove parts during rework. We currently have an OK Industries system MTR 4000 series with accessories. This works very well with what we...

Question: What is the spacing requirements between the board and the bottom edge of the component that doesn’t have a spacer or insulator in a supported through-hole terminations?