| Dear all | Please help me to know what kind of tests usually done after SMT Pick & place and reflow oven. | Our appliocation is Mainly fabrication of mother boards. | Thanks | In theory, ICT is the classical answer (In-Circuit Test). In practicality (more often referred to as reality), NONE. The reason is: 1. SMT only components lack the PTH components to complete the network for proper ICT to work. This requires a seperate program and some modifications to the fixture, all at a cost ($$$). 2. Getting the ICT on line for the first article test often takes more time that what most production managers can stand ($$$). Just getting a ICT program stable often takes several test runs and several boards to "wake up" the fixture and get knowledge of the quirks. Time is money. 3. It often takes a Test Engineer to interpret the results for a "pass". This is because no program is perfect unless the parameters are so loose as to pass failures.
The above reasons are becoming less of a problem as testers improve but still exist none-the-less.
Although everyone would love to say they do it; I would bet that 80% of the companys that have ICT do not do test until after final assembly simply due to the cost and time. That's reality.
A good setup process and a good visual first article inspection is what I've seen as the usual "test" (though some use the test features in the pick and place).
I would certainly love to hear from those who are actually using ICT to verify SMT assembly right out of the oven. Just one?
Not a pleasant answer, Scott
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