I have to design the connections between different electrical components inside a wireless equipment. The "traditional" way to connect each one with the others is the PCB, but the particular shape of the volume (imagine a cylinder with a circular section where h1 = 5mm, h2 = 9mm and R = 60mm, see fig. 1) can not contain a "straight" and rigid PCB sheet.

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So, what are the best practices to connect components pins' between each other in this kind of case? I have thought of plain and simple wires but it doesn't seem very "professional" to raw solder them, and not very durable neither. The Flexible Printed Circuit Boards seem to be another alternative but how are the components placed on them?

  • 5
    \$\begingroup\$ The radius is much larger than the heights. What is so big that it can't be put on a circular PCB? \$\endgroup\$
    – Matt Young
    Aug 29, 2015 at 20:47
  • \$\begingroup\$ This example was a simplified case, the actual volume isn't cylindrical, but more complex. I chose this volume to show the inclined shaped of the top plane. \$\endgroup\$
    – mrcendre
    Aug 29, 2015 at 23:29
  • \$\begingroup\$ Better give the real problem, otherwise you will get optimal answers for different problems... Also, what type and amount of components do you need? Are we talking about two 10W resitors, or about a bunch of LQPF-100 chips with supporting components? \$\endgroup\$ Aug 30, 2015 at 6:46

1 Answer 1


Circular PCB board outlines are commonly used inside 4-20mA loop sensors and BLDC fan controllers, it's just a matter of using a circular board outline that fits inside the housing (instead of the usual "coupon" rectangular board outline). Depending on your CAD layout software, you may have to search out which layer is the "cutting" layer for defining the board outline.

Be sure to note any components that are greater than 4mm height and ensure those go towards the taller area of the housing. Essentially one side of the board becomes a "keep out" area against the taller components.

Flex PCB can work, but requires board stiffeners underneath the areas where the components are mounted. In my experience there's also some reliability/assembly issues with using flex with components mounted. Flex PCB doesn't behave quite like the usual FR4-type PCB, be sure to check whether your contract manufacturer can successfully assemble these; they're much less common.

  • \$\begingroup\$ Thanks for your answer ! But is there any other way, if not using a PCB (which is to thick if added to certain components, even at the taller area of the housing), the components can be linked ? \$\endgroup\$
    – mrcendre
    Aug 29, 2015 at 23:33

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