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Double Sided Polymer Circuitry  D/SPC®

Comparison with cross-over, bridged or jumper polymer circuits

GDSI utilizes a proprietary screen printing process to create circuitry which eliminates the failure points of competitive technologies referenced as cross-over, bridged, or jumper circuits which are limited to one side of the circuit substrate.  GDSI prints circuitry on the top and bottom of the substrate.  These circuits are joined by vias through the substrate.   The descriptive pictures presented below are from the identical position in relation to two keypads partially viewed at the top of each picture and from the same part number application.   GDSI replaced the cross-over circuitry with D/SPC® for the customer.  Field failures due to cross over insulation failure have been eliminated.

Cross-over, bridge or jumper

cross over circuitry


Double sided polymer circuitry

All of this circuitry is printed on the top side of the circuit substrate.  Circuit traces are separated by a thin screen printed dielectric – an inherent failure point for silver migration penetrating the dielectric. D/SPC® eliminates the need for screen printed dielectric – 5 mil thick polyester substrate separates the areas where circuitry is printed.  Silver cannot migrate through the polyester substrate.

The performance advantages of D/SPC® are numerous and significant:

  1. Risks of silver migration shorts in the body of the circuit are significantly reduced.
  2. Less space in the X-Y plane is required to run circuit traces.  This allows a smaller circuit footprint or greater circuit density in the same space.
  3. Overall circuit resistance is lower.
  4. Circuit tail traces can always be placed on the inside radius:
    a. greatly reducing the risk of tail creases causing trace cracking
    b. eliminating the risk of high resistance opens developing over the life of the switch
  5. Allows for greater density of keypad positions.
  6. Provides more room and greater density for SMT devices, especially LED’s.
  7. Need for two circuit layers joined in a connector is eliminated.
  8. Enables lower stack up height.
  9. Easy incorporation of full perimeter sealing (gasketing), maximizing water and chemical resistance.
  10. Improves performance of screen printed electroluminescent backlighting.
  11. Improves performance and density of injection molded circuitry.
  12. Reduces line rejects and field failures.

NOTE: Customer HALT tests,100 day cycling tests, and independent lab results have shown that D/SPC® is superior to cross-over circuit designs for measures of durability, reliability and longevity.


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