PCBA board needs to be electrical and functional tested before delivery to customer. The normal methods include FCT (function test) and ICT (in circuit test). Few decades ago, ICT was popular in electronic manufacturing industry. Many big digital product companies (such as mobile) took ICT to test almost every single component on board, in order to verify if it complies with design range and parameters and avoid of some incidence like “a broken capacitor impacts a complex board”.
However, electronic components become compacted and complicated with rapid development of semiconductor industry. Its engineering processes are very standard and stable, which makes ICT used in narrow fields. Various PCBA manufacturers start to not use ICT as major testing method and head for FCT. Factory will get FCT testing solution, programming and document from customer and then issue testing jigs, on which PCBA boards can be tested and function verified according to FCT procedures. In this way, all boards would be 100% tested before they are passed to customer’s hands.
Another main reason of FCT replacing ICT is the cost. FCT is much more cost-effective, because it’s customized according to customer testing solution and test jig cost is approximately $200 ~ $500 USD. But the cost of professional ICT device will be $15,000 ~ $50,000 USD. What’s more, ICT needs to contact many testing points. A customized probe looks very complicated and costs much. That’s why ICT still lives on some production line for high quantity products.
A growing trend is that ICT machine vendors begins to integrate function test into their devices. But FCT is hard to be standardized, so it looks difficult to develop a FCT machine in compliance with various PCBA boards. In general, issuing a testing jig according to design takes 3~7 days and $300 ~ $1,000 USD, which is more flexible with small-medium business and batches production lines.