A pull test for PCB-to-wire connections is a mechanical test used to determine the strength of the connection between a printed circuit board (PCB) and a wire or cable. This test ensures that the soldered or crimped connections between the wires and the PCB pads are strong enough to withstand mechanical stresses, such as pulling or tugging, that the assembly might experience during its intended use.

Here’s a general overview of how a PCB-to-wire connection pull test might be conducted:

  1. Sample Preparation: Prepare a sample of the PCB assembly with the wires or cables attached to the appropriate pads on the PCB. The wires could be soldered or crimped, depending on the type of connection used.
  2. Fixturing: The sample assembly is securely mounted in a fixture or holder that can apply a controlled pulling force to the wires. The fixture should mimic the real-world conditions under which the assembly will be subjected to mechanical stress.
  3. Pulling Mechanism: A pulling mechanism is used to apply a controlled force to the wires. This force is usually applied perpendicular to the PCB surface, simulating a scenario where the wires might be tugged or pulled.
  4. Force Measurement: During the pull test, the force applied to the wires is measured using load cells or force gauges. This measurement helps determine the maximum force the connection can withstand before failing.
  5. Test Procedure: The test procedure involves gradually increasing the pulling force at a controlled rate until the connection separates from the PCB or reaches a predetermined failure threshold. The force at which the connection fails is recorded.
  6. Data Analysis: The recorded force data is analyzed to assess the strength of the connection. The maximum force reached before failure indicates the connection’s mechanical reliability.
  7. Pass/Fail Criteria: Pass/fail criteria are established based on the specific requirements of the PCB assembly. The assembly might be deemed acceptable if the connections can withstand a specific minimum force without failing. The criteria could be defined by industry standards or the application’s specific requirements.
  8. Reporting: A test report is generated, documenting the test procedure, the equipment used, the test results, and whether the assembly passed or failed the pull test.

It’s important to note that the specific details of the pull test can vary based on factors such as the type of PCB-to-wire connections, the intended application of the assembly, industry standards, and regulatory requirements. Manufacturers often perform these tests during the quality control process to ensure the reliability of their products.