Detection method for circuit board

Abstract

The invention provides a detection method for a circuit board. The method comprises the following steps: determining a hole-through quality, such as a hole position, a blocking condition of the hole,etc., by comparing a difference of reflection strengths detected by an infrared reflection type sensor and reflected back after an infrared pass through a standard hole and a to-be-detected hole, anddetermining that the to-be-detected circuit board is a unqualified product if a deviation value of the reflection strength reflected back after the infrared passes through the to-be-detected hole in the to-be-detected circuit board and the reflection strength reflected back after the infrared passes through the standard hole in the standard circuit board is not within an inspection standard range;and determining a short circuit condition of each loop of the to-be-detected circuit board by comparing the difference of the inductance value of each loop of the standard circuit board and each loopof the to-be-detected circuit board through a probe, and determining that the to-be-detected circuit board is a unqualified product if the deviation value of the inductance value of the loop of the to-be-detected circuit board and the inductance value of the loop of the standard circuit board is not within the inspection standard range, so that the change of the inductance value is easier to detect. The detection method has the advantages of being accurate in detection result, high in detection efficiency, short in detection time and low in cost.

Description

technical field [0001] The invention relates to the field of circuit board testing, in particular to a circuit board testing method. Background technique [0002] In the existing contact test, the two-terminal test is a solution commonly used by circuit board factories. The existing two-terminal test places test probes at the endpoints of the circuit board circuit to be tested, and measures the circuits of different networks. Whether the resistance value between the nodes of the board circuit is less than the acceptable minimum insulation resistance value between two different networks is set, so as to judge whether there is a short circuit in the insulation network; but there is a specially designed circuit on the circuit board, that is, the circuit board The coil circuits that make up the loop in the loop are in the same network, that is, they are in the conduction state; when there is a short circuit between the circuit board loop coils that are already in the same networ...

AI Technical Summary

Problems solved by technology

[0002] In the existing contact test, the two-terminal test is a solution commonly used by circuit board factories. The existing two-terminal test places test probes at the endpoints of the circuit board circuit to be tested, and measures the circuits of different networks. Whether the resistance value between the nodes of the board circuit is less than the acceptable minimum insulation resistance value between two different networks is set, so as to judge whether there is a short circuit in the insulation network; but there is a specially designed circuit on the circuit board, that is, the circuit board The coil circuits that make up the loop in the loop are in the same network, that is, they are in the conduction state; when there is a short circuit between the circuit board loop coils that are already in the same network, the current value of the circuit board The change is very small, and it cannot be detected at all under the existing resistance test accuracy. Therefore, at present, the circuit board circuit can only be checked visually to see if the coil is intact. The outer circuit board is separated, and then the inner circuit board, insulating layer and outer circuit board are pressed together, so that the loop coil of the inner circuit board is invisible, so visual inspection cannot detect the inner coil of the finished circuit board

[0003] In addition, in the process of circuit board production, the quality problems of holes are often caused, such as under-drilling, under-drilling, and plugged holes. , the existing technology is to inspect the holes visually, but in the process of inspecting workpieces in large quantities, this inspection method takes a long time, has low inspection efficiency, and is easy to miss. In addition, there are also test probes Whether the hole diameter can be passed through the hole is tested, but only the printed board with the same specification and the same hole diameter can be tested. Otherwise, the test board must be remade according to the position of the hole. This inspection method is costly and inefficient.

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