09.03.2021 | Technical topic

Layout Tipps & Tricks

Layout Tipps & Tricks

Anbindung von SMT Bauteilen

General information about tests and testing possibilities

Ginzinger electronic systems offers different possibilities to comprehensively test the function of series-produced assemblies by means of functional and in-circuit tests.
test. For this purpose, the following points must be taken into account in the PCB design:

  •     Provide trap holes for the PCB (asymmetrical, typ. 3.2 mm, not plated through and not tinned.
  •     Test points in each electrical node. Through vias can be used as test points provided they have > 0.8 mm path diameter and are not covered.
  •     Distance of the test points to each other and to the PCB edge 2.54 mm. In exceptional cases and after consultation, the distance can be reduced to 1.27
  •     Place test points evenly distributed on the PCB to balance the forces generated by e.g. contact needles.
  •     In the case of supply voltage networks, several test points should be placed. These should be distributed over the PCB or located at the beginning and end of
        the trace.
  •     and at the end of the trace.
  •     Preferably, test points should only be placed on the solder side.
  •     In the case of metrologically critical components (low-resistance shunts [test points]), a four-wire measurement should be provided.
  •     Components which have an enable input should be switched to "high" or "low" in the design via a pullup/pulldown. Thus there is
  •     This gives the possibility to deactivate them during the test.
  •     SMT and THR solder joints must not be used as test points, as they may be contaminated by flux residues. Contacting
  •     is then not possible.
  •     A test point diameter of 1 mm, but at least 0.8 mm is recommended.

Tips and tricks from 30 years of experience in electronics production can be found in our   EMS Design Guide.

Our practical little helper is already in its 3rd edition. Get one of the limited copies now! Click here to order.



Do you have questions

or want to get in touch?