ICT (In-Circuit Test) systems can perform electronic testing of component electrical parameters, soldering defects, and circuit continuity on assembled PCB boards. The core test coverage falls into three main categories.
1. Soldering Quality and Basic Continuity Testing
1.1 Solder Joint Defect Detection
Open circuit / cold solder joint detection: identifies contact breaks caused by false soldering or oxidation on component leads and PCB pads.
Short circuit detection: checks for solder bridge faults between adjacent pads and component pins.
Missing solder / wrong component detection: verifies whether components are missing or whether incorrect specifications or models have been installed.
1.2 Trace and Connector Continuity Testing
Tests the continuity of internal PCB traces and connector pins to identify internal trace breakage or poor pin contact.
2. Discrete Component Parameter Testing
Resistors: verifies whether the resistance of SMD or through-hole resistors falls within the specified tolerance range, and detects open or short circuit faults in resistors.
Capacitors: checks capacitance deviation and leakage current. For electrolytic capacitors, polarity reversal can also be verified.
Discrete semiconductors: tests diode forward voltage drop and reverse leakage current, transistor gain (hFE), and pin polarity correctness.
Inductors and transformers: checks coil continuity and inter-turn short circuits, and verifies whether the transformer turns ratio meets design requirements.
3. Integrated Circuit Testing
Digital ICs: checks input/output pin logic level matching, and performs basic gate circuit, microcontroller pin continuity, and level verification.
Analog ICs: verifies whether the output voltage and quiescent current of operational amplifiers and voltage regulators meet nominal parameters.
Some ICT equipment also supports basic read/write function verification for memory chips.
Note: ICT is an offline test device and can only inspect assembled PCB boards. It cannot support powered system-level operation testing. In-depth parameter testing of complex high-frequency integrated circuits needs to be combined with functional testing (FCT).
For custom-machined test fixtures, precision probe modules, or positioning components used in ICT systems, Hansheng Automation provides non-standard part machining services based on customer drawings to support stable contacting and accurate test positioning.
