JPH01310841A - Displacement inspecting method for printed board - Google Patents

Abstract

PURPOSE:To prevent boring of a poor printed board and to improve a yield, by a method wherein, under a state to be superposed with a test circle with a given inner size formed in an inner layer pattern and having no conductor present therein, a hole with a given inner size being lower than that of the test circle, and when, during a work, energization is effected between first and second terminals, disqualification of a printed base board is determined. CONSTITUTION:A test circle 31 is a circular part with a given size d1, which is formed in an inner layer pattern 30 and where a conductor is absent. The test circle has size larger than an inner size d2 of a hole formed by means of a drill 40, and a difference (d1-d2)/2 is a displacement amount being allowable to the inner layer pattern 30. When a part of a test circle 32 makes contact with the drill during a boring work made by means of the drill 40, since energization occurs between terminals 51 and 52, the energization detects the occurrence of a displacement amount being higher than the clearance (d1-d2)/2. In this case, an inspection hole 22 is inspected visually, a direction in which displacement occurs is determined from a position where a conductor appears, from an appearing length, a displacement amount is determined, a determine value forms an offset amount to add it to an initial value, and instruction is made on an NC device to position the drill.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a drill used for manufacturing multilayer prints 1 to substrates, and particularly relates to an improvement suitable for inspecting misalignment between inner layer patterns and through holes.

[Conventional technology]

In multilayer printed circuit boards, it is necessary to overlap the patterns of each layer with sufficient accuracy. Conventional inspection methods include non-destructive inspection using X-rays and destructive inspection such as the TTI ssection method. Briefly, the cross-section method involves cutting out through-hole portions of a multilayer printed circuit board and observing the through-pole cross section. FIG. 3 is a sectional view illustrating the cross-section method. In the figure, 10 is a printed circuit board made of an insulating material such as a glass epoxy resin, 20 is a through pole provided on the printed circuit board 10, and copper foil is installed on the inner peripheral surface and the surfaces of the printed circuit boards 1 to 10 in the vicinity. It is. 30 is one JJ
The pattern here is 2'', Ng'2G.

[Problem to be solved by the invention]

However, the work of cutting out the through-pole 20 of the printed circuit board 10 and the work of polishing its cross section are very time-consuming. Therefore, as a solution to such problems, the present applicant has proposed a pattern base for inspection of printed circuit boards, published in No. 10329/1983.The present invention et al. Therefore, we will propose a new solution that has a check function in the drill for adding soil to the substrate.

[Means for Solving the Problems] A first invention that achieves the objectives as described above is based on a multilayer print board 1 to a first edge connected to an inner layer pattern of a board, and a multilayer print board. A drill having a second end A connected to a drill made of a conductive material for drilling a hole at a predetermined position ζJ has the following configuration and 1. It is something that That is, a test circle with a predetermined inner diameter (d1) provided in the inner layer pattern where there is no conductor is provided at the predetermined position, and a test circle with a predetermined inner diameter smaller than the des1~ circle is set in a state where it overlaps with this des1~ circle. Drill the hole (d2) with the drill). 7. If there is continuity between the first and second terminals during the hole drilling i-1 operation, it is determined to be a failure. The second invention that achieves this purpose is a multilayer print 1.
- A first terminal connected to the inner layer pattern of the board', a drill made of a conductive material for drilling holes at predetermined positions on this multilayer printed circuit board, and a drill provided on the surface of the board. This device includes a wiring pattern and a connected second terminal, and has the following configuration. That is, at the predetermined position, there are C test circles with a predetermined inner diameter (d1) provided in the inner layer pattern where no conductor is present;
The wiring pattern provided on the surface is set up so that it overlaps with this test circle, and a hole with a predetermined inner diameter (d2) smaller than the said D1~circle is drilled using the drill while it overlaps with this test circle. conduct. If there is continuity between the first and second terminals during this hole-drilling operation, the product is determined to be rejected. [Function] Each component of the present invention has the function of 6iE, and the multilayer printed circuit board 1 to the standard board is provided between the first and second terminals due to the clearance between the test circle and the inner diameter of the drill. There is no continuity. However, if there is an excessive positional deviation in the orientation of the inner layer pattern, this clearance will be exceeded and conduction will occur. Note that since the conductivity of the drill is used, the first terminal can be provided on the drill itself or on the surface of the printed circuit board.

[Example] The first invention will be described below with reference to the drawings. FIG. 1 is a main part configuration diagram showing an embodiment of the first invention, (
A) is a cross-sectional view, and (B) is a plan view of the inner layer pattern. In the figure, the inspection hole 21 is in a state where the inner layer pattern 30 is accurately positioned, and the circles 1 to 31 are coaxially provided. The test circle 31 is a circular portion of a predetermined inner diameter (d1) where there is no conductor thrown into the inner layer pattern 30, and is larger than the inner diameter (d2) of the hole formed by the drill 40, and this difference Hd1-d2)/2) is the amount of positional deviation allowed for the inner layer pattern 30. The end T-51 is connected to the inner layer pattern 30, and the terminal 52 is connected to the drill 40. The electrical continuity between the inner layer pattern 30 and the drill 40 is tested between the terminals 51 and 52. Note that the tip of the drill 40 is thicker than the shaft, making it easier to discharge cutting waste. Since the inspection hole 21 is in good condition, no conduction occurs between the terminals 51 and 52. The inspection hole 22 is an explanatory diagram when the inner layer pattern 30 is misaligned beyond the allowable range. A part of the circle 32 comes into contact with the hole drilled by the drill 40 during operation (point a in the figure). Therefore, conduction occurs between the terminals 51 and 52, and due to this conduction, the amount of positional deviation or clearance ((d
It can be seen that it is larger than ld2)/2). In this case, it is preferable to visually inspect the inspection hole 22 to determine the direction of misalignment from the position where the conductor appears, and determine the amount of misalignment from the length of the exposed conductor. Then, this obtained value is added to the initial value as an offset amount and is instructed to an NC device etc. to adjust the positioning of the drill. It is possible to manufacture a product with no defects in the conduction state of the inner layer pattern 30. FIG. 2 is a sectional view of essential parts showing an embodiment of the second invention. In the figure, the thickness of the drill 41 is equal between the tip and the shaft. A test circle 33 is formed in the inner layer pattern 30 as in FIG. An outer layer wiring pattern 50 is provided on the surface of the printed circuit board 10 at a position overlapping with the test circle 33. terminal 5
3 is connected to the outer layer wiring pattern 50, and the electrical continuity between the inner layer pattern 30 and the drill 40 and the outer layer wiring pattern 50 is tested between these terminals 51 and 53. The operation of the device configured in this manner will be described next. If the inner layer pattern 30 is positioned correctly, the terminal 51
．． No conduction occurs between 53. If the inner layer pattern 30 is deviated beyond the clearance, conduction will occur between the inner layer pattern 30 and the outer layer wiring pattern 50 during drilling with the drill 40, and therefore conduction will occur between the terminals 51 and 53. In this way, the same problem as the first invention can be solved by using a different configuration. Effects of the Invention As explained above, according to the present invention, the inner layer pattern 30
Check the misalignment on the printed circuit board 10 in advance! -7 Since the inspection can be easily carried out using a small inspection hole, there is no need to drill additional holes in the defective printed circuit board, and the manufacturing cost is reduced. Further, as in the embodiment, the amount of positional deviation is compensated and the drill 40 is
By determining the location of the product, the product yield rate will also increase.

[Brief explanation of the drawing]

Fig. 1 is a main part configuration diagram showing an embodiment of the first invention;
The figure is a sectional view of a main part showing an embodiment of the second invention. FIG. 3 is a cross-sectional view for explaining the cross-section method. 10... Printed circuit board, 21.22... Inspection hole, 3
0...Inner layer pattern, 31-33...Death 1-yen,
40...Drill, 50...Outer layer wiring pattern, 51
~53Figure 3

Claims (2)

[Claims] (1) A first terminal connected to an inner layer pattern of a multilayer printed circuit board, and a second terminal connected to a drill made of a conductive material for drilling holes in a predetermined position of the multilayer printed circuit board. Then, a test circle with a predetermined inner diameter (d1) provided in the inner layer pattern without a conductor is provided at the predetermined position, and a hole with a predetermined inner diameter (d2) smaller than the test circle is inserted in a state that overlaps with this test circle. A method for inspecting positional deviation of a printed circuit board, comprising: drilling a hole with the drill; and determining a failure if there is continuity between the first and second terminals during the drilling. (2) A first terminal connected to an inner layer pattern of a multilayer printed circuit board, a drill made of a conductive material for drilling holes in a predetermined position of this multilayer printed circuit board, and wiring provided on the surface of the printed circuit board. It has a second terminal connected to the pattern, a test circle with a predetermined inner diameter (d1) provided in the inner layer pattern where no conductor is present is provided at the predetermined position, and a test circle is placed on the surface in a state overlapping with this test circle. A hole with a predetermined inner diameter (d2) smaller than the test circle is drilled using the drill in a state where the wiring pattern is overlapped with the test circle, and during this hole-drilling operation, the first A method for inspecting positional deviation of a printed circuit board, characterized in that if there is continuity between the terminal and the second terminal, the method is determined to be a failure.