Test and inspection concepts

Who assumes liability for non-functioning assemblies?
- It depends on the testing possibilities and the agreement with you. If you assign us the responsibility for material procurement and a functional test, you will only receive tested and functioning assembled pcbs from us.
Can circuit boards be assembled correctly?
No, because it cannot be 100% ruled out that errors can occur during production. During all assembly steps, errors of all kinds can occur with the most varied of probabilities, e.g.:
  • component electrically defective
  • component mechanically damaged (bent pins)
  • component not assembled
  • component mounted twisted
  • short circuit between pads
The list of possible defects could be continued for a very long time.
The causes of the errors can be due to human error, malfunctioning machines, etc.
However, modules can be delivered to customers without errors. The reasons for this are briefly presented below:
It is the assembler's job to determine the causes of the errors and to reduce the probability of errors occurring. Nevertheless, errors cannot be ruled out 100%. For this reason, once all the assembly, soldering and assembly processes have been completed, all assemblies must be checked for defects using a wide variety of methods, and problems on the defective assemblies must be clearly identified and safely repaired.
Testing procedures in electronics production
The assemblies are checked for presence of errors and defects using test procedures. Often only a combination of several test methods is able to find as many errors as possible. After consultation with our customers, we take over the testing of individual assemblies and devices.
Our inspection and testing methods include:
  • visual inspection
  • AOI-Test
  • functional test
  • functional test
visual inspection
With the visual inspection, defective solder joints, missing components, mechanical damage, components with reversed polarity and incorrect component values ​​can be detected. The visual inspection is performed with the help of microscopes, magnifying glasses or inspection devices. Visual inspection does not provide a 100% guarantee for error-free circuit boards, since electrically defective components cannot be identified. Since the human factor is involved, there is no guarantee that an issue will not be missed.
Automatic optical check (AOI)
  • people get tired
  • people can overlook mistakes
  • People can no longer check the fine structures and components on the printed circuit boards without tools
All this applies to visual inspection, but with the use of AOI testing we are able to identify quickly errors.
The assembled pcbs are checked by a camera system and evaluated by suitable software. For example, missing components, incorrectly assembled components, twisted or shifted components or contamination of the circuit board can be checked. The preparation of an AOI test is associated with programming effort (one-time charge).
Caution: Electrically defective components cannot be detected!!
functional test
The function test is executed as the last manufacturing step. With the help of circuit diagrams and a functional description, we will use an individual or a combined test device for the functional test of your assembled boards. The purpose of a function test is to ensure that the assemblies are free of defects before they are shipped. The functionality of an assembly and its behavior is beeing checked. The test simulates the final electrical environment in which the circuit board will be used.

Advantages:

  • errors in the delivered goods can be ruled out
  • errors are discovered before the device is put into operation
  • fewer complaints, satisfied customers

Disadvantages

  • does not fit well for samples
  • the preparation time is longer
  • is only done by professionals
programming service
Microcontrollers, memory chips, programmable logic, etc.
marking and labelling
Labeling according to customer requirements, serial numbers, traceability
Conclusion: The combination of visual inspection and function test guarantees you 100% successful result.