November 24, 2014


PFC engaged with a prospect that designs, builds and services ruggedized Power Supplies and Embedded Computer Systems for the oil and gas, mining, and military markets. The prospect’s products are built to withstand high vibration and repetitive shocks, extreme temperature conditions, and severe electrical transients.

Pictured right is a field tested unit we received from the prospect. Most of these units are bolted onto a truck chassis and driven into some of the roughest and toughest terrains in the world.

Successinflex2The Problem:

Pictured right, you can see the wire harnesses and flat flexible cables used to interconnect the power supply and embedded computer cards to the input/output panel mount connectors.

  1. Vibration caused intermittent and shorts in the wire harness assemblies and flat flexible cables
  2. Time to assemble the box was long and tedious



The prospect sent a power supply unit and a circuit diagram to PFC design engineering. The objective was to replace the wire harnesses and flat flexible cables to make the product more reliable and simpler to assemble.

Successinflex4Pictured left – PFC engineering disassembled the power supply unit then developed a “paper doll” to provide an outline of the circuit, locate the connector placement requirements and understand airflow issues.


Successinflex6 Successinflex5

Pictured above – a “paper doll” using copper clad to check material thickness and bendability in the application.



Pictured right – preliminary mechanical outline of circuit along with stiffener requirements and drill holes.


Ultimately, PFC engineering provided mechanical drawings, gerber files, material requirements, electrical test fixtures – everything needed to provide a completely assembled circuit.

The circuit was initially ordered in prototype quantities then ordered for production.


Using a flex circuit allowed the prospect:

  • to combine power and signal into a one piece combined solution
  • to remove shock and vibration issues by soldering connectors directly onto the flex – no more crimp contacts, zif connectors or flat flex cable
  • to lower their assembly time by 10X
  • to lower part numbers required for ordering by 40
  • to lower number of vendors required for components by 5