What are the causes of misjudgment when AOI detector is testing?
Author:Zhang Lingfei Time:2021-06-07 13:33 Browse(712)
What are the reasons for the misjudgment of AOI detector, Touch screen and OLED Forum
In SMT production process, what are the definition and reasons of misjudgment in AOI detector equipment testing? Three understandings and causes of misjudgment: 7 ~ 9 C1 H + M 6 t( t) M4 N    F5} 2J1, components and solder joints have a tendency to have defects, but they are in the acceptable range.
if the components are offset, but they are in the acceptable range; This kind of misjudgment is mainly caused by too strict threshold setting, or it may be the deviation caused by AOI and MV (manual visual inspection) confirmation, which is between the standard of bad and good products9 ^! \: H: X0 M/ [2 s. J' d5 @: X0 S: m/ a! h6 b( t2. However, the DFM design does not consider the testability of AOI, which makes it difficult to judge whether AOI is good or not. In order to ensure the detection effect, some misjudgments will be introduced.

What are the causes of misjudgment when AOI detector is testing?

for example, the pad design is too narrow or too short.
it is difficult to make accurate judgment when AOI is used for detection, and the misjudgment caused by this kind of situation is difficult to eliminate, Unless DFM is improved or solder joint defect detection of such components is abandoned.
5 u 'U8 @! f! Y   ?/ _  _../ q/ t2 d- L5 K9 {" P! Because AOI relies on reflected light for analysis and judgment.
but sometimes it will be interfered by some random factors, resulting in misjudgment.
for example, there are dirt on the solder end of the component or some parts of the printed wire on the pad side are not completely coated or partially exposed.
resulting in poor search, etc.
and there are more detection items.
in addition, there are more detection itemsThe possible false positives will be slightly more.
such false positives are random ones.
they cannot be eliminated.
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|# d7 I, [# h! ` 7 u, y& Y2 S5 y. a         There is a common understanding in AOI industry, that is, AOI false positives are inevitable, but can be reduced.
with the development of artificial intelligence.
machine vision has introduced deep learning algorithm and intelligent image analysis technology, which will reduce AOI detection misjudgment.
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