In-circuit-testing (ICT) is usually used on mature products, especially in subcontract manufacturing. It uses a bed-of-nails test fixture to connect with multiple test points on the PCB’s bottom side. With sufficient access points, ICT can transmit test signals into and out of PCBs at high speed to apply evaluation of components and circuits.

What Is an In-circuit Test?

In-circuit test is a form of box testing where an electrical probe tests a piece of electronic equipment like a circuit board or chips, checking for resistance, opens, shorts, capacitance, and other basic quantities that will show whether the board was correctly assembled or not. A bed of nails tester is a traditional electronic test fixture. It has many pins inserted into holes, which are aligned using tooling pins to make contact with test points on a printed circuit board and are also connected to a measuring unit by wires. These devices contain an array of small, spring-loaded pogo pins making contact with one node in the circuitry of the device under test (DUT).

How Does In-circuit Test Work?

By pressing the DUT down against the bed of nails, a reliable contact can be made quickly with hundreds and in some cases thousands of individual test points within the DUT’s circuitry. Devices that have been tested on a bed of nails tester may show a small mark or a dimple which comes from the sharp tips of pogo pins used in the fixture.

It takes a few weeks to create the ICT fixture and do its programming. An ICT fixture can either be vacuum or press-down. Vacuum fixtures give better signal reading versus the press-down fixtures. The bed of nails or in-circuit tester such as 3070 from Agilent is the most common and popular in the contract manufacturing environment.

♦ ICT Programming

An ICT can be conducted either manually or automation through ICT programming. ICT programing is just a way of setting up a computer to perform in-circuit tests without human input. An in-circuit test may be conducted using traditional DIY bed of nail testers or special test equipment.

The device that is used to perform an in-circuit test ( ICT) is referred to as a test fixture. The setup is designed to hold the equipment under test in place and let it be tested by being subjected to controlled electronic test signals. A test fixture provides all the necessary parameters for a test, thus satisfying whatever preconditions there may be.

♦ Significance of ICT Programming

In-circuit testing and ICT programming in general are not just techniques that the manufacturers of electronic gadgets use to show how fancy they are. Here is why many manufacturers take ICT programming very seriously:

In Circuit Test (ICT) & ICT Programming Benefits;

• Although a costly fixture is required, ICT fixtures cover 100% testing so that all power and ground shorts are detected.
• ICT testing does power up testing and eliminates customer debug needs to almost ZERO.
• In-circuit Testing (ICT) does not take a very long time to perform, for example if flying probe takes 20 minutes or so, ICT for the same time might take a minute or so.
• In-circuit testing through manual methods or ICT programming ensures that the electronics that we get our hands on are safe. It checks for resistance, opens, shorts, and other weaknesses that could be safety hazards.
• Test development interface and operating environment is based on standards for an open system with fast integration into an OEM customer’s existing processes.
• ICT programming tests ensure that new gadgets arrive in a functional state. Devices that are tested and found to be working perfectly are packaged for shipment whereas the defective ones are returned to the factory for improvement.
• Highly reliable and comprehensive test catching all manufacturing defects, design faults, and flaws.
• Checks and detects shorts, opens, missing components, wrong value components, wrong polarities, defective components and current leakages in the circuitry.

ICT programming is crucial to the functionality of most electronic devices. Microchips and integrated circuits can be found in the gadgets that we use on a day-to-day basis. Your cell phone, PC, TV and literally any electronic equipment is a result of in-circuit testing and ICT programming. Without the testing prior to final assembly, many devices would arrive non-functional or cease working earlier than their expected life spans.

.Q1 Test Inc. take all the technical work involved in in-circuit testing off your shoulders. Q1 Test Inc professionals boast over 15 years of experience in the test fixture industry. Therefore, by working with them, you can be sure that you will benefit a great deal.