JPS6312265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inspecting patterns on printed circuit boards, and more particularly to high-density printed pattern inspection methods.

Conventionally, the basic through-hole grid of printed circuit boards is
Since the diameter was 2.54 mm or more, spring probes were placed corresponding to all the through-hole basic grids, and the continuity and insulation of the printed pattern was tested by establishing electrical contact between the through-holes on the printed circuit board and the spring probes. I was able to do that. However, in recent years, as electronic components have become smaller, printed patterns have become more dense, and the basic through-hole lattice has become 1/2 or 1/4 of that of the past, making it difficult to arrange spring probes in correspondence with the basic through-hole lattice. is becoming difficult.

An object of the present invention is to provide a high-density printed circuit board inspection method that can eliminate such drawbacks.

That is, according to the present invention, in a method for testing the continuity and insulation of a printed pattern of a printed circuit board, an area approximately equal to the circuit formation surface of the printed circuit board to be inspected is provided with an integer multiple of the basic lattice for forming through holes in the printed circuit board to be inspected. A step of simultaneously bringing two sets of spring probe units in which a large number of spring probes are planted corresponding to all the grids into contact with the front and back surfaces of the printed circuit board to be inspected, a step of determining the quality of the pattern, and a step of determining the quality of the pattern; Forming through-holes on the printed circuit board to be inspected Form the two sets of spring probe units through-holes on the printed circuit board to be inspected so that any two points of the basic grid are in positions where they simultaneously contact the two spring probes of the two sets of spring probe units. There is obtained a printed circuit board inspection method characterized by including a step of intermittently feeding at the pitch of a basic grid.

Next, details of the present invention will be explained with reference to the drawings. FIG. 1 is a partially enlarged view showing the arrangement of through holes and printed patterns on a printed circuit board to be inspected. In the figure, numeral 1 indicates a through hole, which is formed on a 1.27 mm basic grid. 2 to 8 are printed patterns formed on the printed circuit board to be inspected.
9 shows the planted position of the spring probe that electrically contacts the through-hole, and as shown in the figure, the spring probe is placed on a grid of 2.54 mm, which is twice the size of the basic through-hole grid. Figure 2 is a cross-sectional view showing the state in which the spring probes are in contact with the printed circuit board to be inspected. Two sets of spring probe units 10 and 11 planted on a 2.54 mm grid touch the printed circuit board 12 to be inspected from the front and back sides. Simultaneously make contact and test the continuity and insulation of the printed pattern. 3 to 8 are conceptual diagrams showing the inspection process, where the circle mark 13 indicates the position of the spring probe of the spring probe unit 10 that contacts the back surface of the printed circuit board 12 to be inspected, and the circle mark 14
The triangle mark indicates the position of the spring probe of the spring probe unit 11 that comes into contact with the surface.
First, as shown in FIG. 3, when a spring probe is brought into contact with the printed circuit board 12 shown in FIG. 1, the continuity and insulation of patterns 2 and 6 of the printed patterns 2 to 8 of the printed circuit board 12 to be tested can be tested. Next, by moving only the probe unit 11 that contacts the surface by one pitch of the basic through-hole grid of the printed circuit board to be tested and bringing it into contact with the position shown in FIG. 4, the continuity and insulation of the printed pattern 4 can be tested, and the same can be done. At the position of the spring probe shown in FIG. 5, continuity and insulation of the printed pattern 7 can be tested. Next, by moving only the probe unit 10 that contacts the back surface by one pitch and bringing it into contact with the position shown in FIG. 6, the continuity and insulation of the printed pattern 8 can be tested.
By repeating exactly the same procedure and bringing the spring probe into contact with the positions shown in FIGS. 7 and 8, the continuity and insulation of printed patterns 3, 5 and 4, 8 can be tested, respectively. 1.27 shown in Figure 1 by the steps shown in Figures 3 to 8 above.
It is possible to perform all continuity and insulation tests on printed patterns formed on mm basic grids.

Here, the through hole forming basic grid is 0.635mm
Needless to say, even if the probe unit is small, all continuity and insulation tests can be performed by adjusting the pitch feed amount of the probe unit to 0.635 mm to match the basic grid.

As explained above, according to the present invention, a spring probe unit in which spring probes are placed on a 2.54 mm grid or a 1.27 mm grid, which were conventionally used for inspecting printed circuit boards, can be used.
It can test the continuity and insulation of high-density printed circuit boards with through holes formed on a 0.635mm grid, and can test any printed pattern as long as the through holes are formed on a basic grid. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged view showing an example of the arrangement of through holes and printed patterns on a printed circuit board to be inspected, and FIG. 2 is a sectional view showing a state in which a spring probe is in contact with a printed circuit board to be inspected in an embodiment of the present invention. FIGS. 3 to 8 are conceptual diagrams showing an inspection process according to an embodiment of the present invention. In the figure, 1 is a through hole, 2 to 8 are printed patterns, 9 is a spring probe implantation position, 10 and 11 are spring probe units, 12 is a printed circuit board to be inspected, 13 is a spring probe implantation position of the spring probe unit 10,
Reference numeral 14 indicates a spring probe implantation position of the spring probe unit 11.

Claims (1)

[Claims] 1. In a method of testing the continuity and insulation of a printed pattern on a printed circuit board, in an area approximately equal to the circuit formation surface of the printed circuit board to be inspected, a through hole is formed on the printed circuit board to be inspected, corresponding to all grids that are an integral multiple of the basic grid. A step of simultaneously bringing two sets of spring probe units each having a large number of spring probes into contact with the front and back surfaces of the printed circuit board to be inspected, a step of determining the quality of the pattern, and a step of forming through holes in the printed circuit board to be inspected. Place the two sets of spring probe units at the pitches of the basic grid for forming through holes on the printed circuit board to be inspected so that any two points on the basic grid come into contact with the two spring probes of the two sets of spring probe units at the same time. A method for inspecting a printed circuit board, comprising the step of intermittent feeding.