A global medical instrumentation manufacturer had an application for a membrane switch to serve as a sensor. The membrane switch approach was desired to reduce the weight and space required to perform the task in an ambulatory infusion pump. Superior accuracy was required to ensure the appropriate administration of fluids.
GDSI was invited to address the following problems:
1) The actuation force of the sensor exhibited unacceptable variability.
GDSI’s response was routine. By using its standard screen printing process utilizing optics to establish image to image registration, superior screen printing control for the position of the sensor circuit in relation to the cut edge of the circuit substrate reduced the variability of actuation force to well within acceptable performance levels.
Additional precision with pressure sensitive adhesive layers for the remainder of the sensor construction was also enhanced by optical indexing for die cut layers, and a close tolerance steel rule die.
As a test of compliance and assurance, GDSI performed a full performance parameter functional test on each sensor before shipping to the customer. The customer accepted the test procedure as qualification for ‘dock to stock’ receipts, reducing the cost of their incoming inspection.
2) Silver migration was commonly evident in field failures
GDSI provided its standard response to silver migration – printing carbon over silver with tight tolerance print images made possible by optical imaging.
3) Millimeter spacing on circuit tail was needed to match a ZIF connector
Again, the optical indexing of GDSI screen printing allowed the tight tolerances on the circuit tail to meet the demanding specification of the tight tolerance ZIF connector required by the weight and space limitations of the project.
The result of GDSI’s involvement reduced the cost of production, increased the yield of acceptable product, and helped the customer provide a more reliable instrument for the medical market.