New answers tagged

3

It could be that your contractor's production line is tuned for construction and testing to Class 3, and for some reason it's less trouble and/or less expensive for them to simply bill you for Class 2 and build and test to a higher spec than to build and test to Class 2.


1

I very much doubt there's a significant downside to class 3 inspection when you specified class 2. After all, class 3 is for critical equipment so your boards were inspected to tighter tolerances, etc. I obviously was not a party to your conversation with the manufacturer but I think that what you are interpreting as "caginess" is really just ...


2

A relevant specification is IPC-A-610: Acceptability of Electronic Assemblies, specifically section 7.1.1. Essentially, it states that non-polarized components on the board should all read the same way, e.g. left-right and top-bottom, but the board is not considered defective unless the orientation of the component makes the circuit non-functional. The ...


0

Depends on component. Resistors are symmetric. So direction doesn't matter. So are inductors (coils). Ceramic capacitors are symmetric too (SMD or disk through-hole). Tantalum and electrolytic capacitors are polarized, they have a + and a -. Diodes, obviously, have a direction. Ferrite beads are symmetric. Basically, if some component is not symmetric, there ...


1

This strange behavior lasts event after power-cycling and MCU reset. This behavior can be repaired by reheating the PCB again even with temperature which is lower than melt-point of used solder-paste. Reheating, cooling to freeze, twisting the PCB makes the circuitry work momentarily, but breaks eventually. That is a popular problem due to marginal PCB ...


6

One problem is even if drilling holes you may short the pins to the plane, you would have to have some way to isolate the pins from the metal on the plane if you were to drill holes. It would also be difficult if this were four layer board to determine if there were additional signals or planes running in between the top and the bottom layer. I think a good ...


6

Bend the pot (three of) pins outward, except the two of pot body pins. scratch off the solder-mask of the ground area. Solder the body 2 pins on the peeled off ground plate. Now, wire the 3 pins to signals.


1

Do you have defective PCBs, faults in assembly, or faulty components? Are any/all of these being checked for by your vendor(s)? That your engineer friend ordered extra boards and/or repaired bad boards suggests that the fault was in assembly (you can't really repair a bare PCB that failed electrical testing). Can you not consult with him to determine the ...


1

Different board houses (probably) have different rules, the rules for one as an example are here. So, that's the first thing to know. Then when creating the footprint have the origin be in the right spot (according to the 'rules'). When exporting the 'Pick/Place Data...' in Orcad you can select 'Symbol origin', 'Body center' or 'Pin 1'.


Top 50 recent answers are included