Circuit Technology Center

Rework Option Eliminates Jumper Wires

Rework Option Eliminates Jumper Wires
Image 1. Rework required circuit cuts at 4 locations.
A customer identified a design error involving two component patterns on the secondary side of a circuit board. Two circuits were incorrectly routed.

Although many of the boards were assembled entirely, a large percentage of circuit boards were partially assembled, leaving the affected site vacant.

Two rework methods were proposed.

Rework Option Eliminates Jumper Wires
Image 2. Option 1 - Rework completed using jumper wires.
For those boards that were completely assembled, the most efficient method was to remove the component, a 14-pin gull wing device, and make a series of 4 circuit cuts. See Image 1.

Following the circuit cuts, the 14-pin gull wing component could be re-installed, and insulted jumper wires used to establish the proper connections. See Image 2.

A more effective rework method for the partially assembled circuit boards was to correct the circuit patterns using flat ribbon conductors on the board surface. See image 3.

Once the flat ribbon conductors were soldered in place, they were over-coated with thermoset epoxy to secure them and provide insulation. Then these reworked circuit boards could go through the final assembly process eliminating the post assembly rework. See image 4.
Rework Option Eliminates Jumper Wires
Image 4. Rework completed and 14 pin gull wing component reinstalled.
Rework Option Eliminates Jumper Wires
Image 3. Option 2 - Conductor paths reworked using flat conductor ribbons.

For reference see the following. 4.3.1 Circuit Cut, Surface Circuits
4.2.1 Conductor Repair, Foil Jumper, Epoxy Method

Several members of the Circuit Technology Center team contributed to this feature story.