JPH046117B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method for identifying multilayer circuit boards.

[Technical background of the invention and its problems] Generally, a multilayer circuit board has a conductor pattern layer 1 on the front layer and the back layer, as shown in an enlarged cross section in FIG.
In addition to a, 1n, conductive pattern layers 1b, 1c,
...is provided.

These conductor pattern layers 1a, 1b, ... 1n are generally made of copper foil, and the insulating layers are made of glass fiber-epoxy resin, paper-epoxy resin, paper-epoxy resin, etc.
It is constructed from a composite material such as phenolic resin.

These conductor pattern layers 1a, 1b, ... 1n are composed of many layers such as 4 layers, 6 layers, 8 layers in total of the surface layer and the back layer, and the conductor pattern layer 1 as an intermediate layer.
b, 1c, . . . are all etched into predetermined patterns and embedded between the insulating layers 2a, 2b, .

These intermediate conductor pattern layers 1b, 1c,...
When the multilayer circuit board 3 is completed, it is only slightly visible from the outside, and it is impossible to see through it completely.

When using this multilayer circuit board with various electrical components installed, it is possible to connect the conductor pattern to the outside by applying metal plating (through-hole plating) to the inner surface of the hole drilled from the outside in the conductor pattern of a predetermined layer. It is possible to electrically connect between them.

Since it is necessary to make the holes reliably at the desired conductor pattern positions, two or more holes that serve as reference holes (inner layer reference holes) are usually drilled in advance, and the holes are drilled based on the drawing dimensions using the inner layer reference hole positions as a reference. Drilling holes in predetermined locations is performed.

Conventionally, the following method has been adopted as a method for drilling the interior reference hole.

(b) Based on the pattern of the inner layer reference hole of the intermediate layer that slightly appears on the surface layer, first use a counterbore drill 4 to drill a counterbore hole 5 larger than the inner reference hole, as shown in Figure 2. Open accurately to the position of the conductor pattern layer.

As a result, the conductor pattern layer 1b becomes visible at the bottom of the counterbore hole 5, so while visually checking the inner layer reference hole 6 of the exposed conductor pattern layer 1b, penetrate the entire multilayer circuit board at a predetermined position. Drill a reference hole.

(b) As shown in FIG.
A small piece 7 of vinyl chloride resin film is pasted with adhesive on the inner layer reference hole part b, so that the conductor pattern layer 1
The position of the inner layer reference hole 6 in b is made so that it can be easily seen from the outside, and as in the case of (a), a counterbore hole is drilled at this position with a counterbore drill to set the inner layer reference of the predetermined conductor pattern layer 1b. The position of the hole is exposed, and then the hole is visually drilled at the position of the inner layer reference hole 6 of the conductive pattern layer 1b. With this method, the position of the inner layer reference hole is easy to see from the outside, and by paying attention to the timing at which the counterbore drill ejects the small piece 7 of the PVC resin film when counterbore the hole, it is possible to prevent the counterbore from being erroneously counterbore too deep. can.

However, in both methods (a) and (b), in order to drill at the position of the inner layer reference hole 6 of the predetermined conductor pattern layer 1b, a large counterbore hole is first drilled at the approximate position and the intermediate conductor is This requires two steps: exposing the inner layer reference hole 6 of the pattern layer 1b, and then drilling the inner layer reference hole 6 through the entire multilayer circuit board 3, which has poor workability and is particularly difficult for the counterbore holes to be drilled in the previous step. Because it requires a lot of practice,
The drawback was that it was difficult to automate. Furthermore, as shown in Fig. 4, if the position of the counterbore hole 5 deviates significantly from the position of the inner layer reference hole 6, it becomes difficult to position the drill, and the outline of two connected holes is formed on the top surface, resulting in an external appearance. The problem was that it was not very good.

On the other hand, since the conductor pattern of a multilayer circuit board is determined at the time of design, its type, inner diameter of the internal reference hole, etc.
If information regarding the position etc. is indicated by printing etc. on the multilayer circuit board, the position and size of the internal reference hole can be determined based on the outline of the multilayer circuit board or the position of the conductor pattern exposed from the side part. It is considered to be convenient in terms of process control.

However, this requires a printing process, which requires equipment and time, which is a drawback.

[Purpose of the Invention] The present invention has been made to solve these conventional drawbacks, and it is possible to obtain information such as the inner diameter and position of the inner layer reference hole of a multilayer circuit board without requiring any special process such as a printing process. and its type can be identified,
It is an object of the present invention to provide a multilayer circuit board identification method that can easily drill inner layer reference holes at predetermined positions of a conductor pattern in one step without drilling counterbore holes, and that can also be used for process control. purpose.

[Summary of the Invention] That is, the method for identifying a multilayer circuit board of the present invention is as follows: (A) The conductor pattern of the intermediate layer is attached to the side of the multilayer circuit board to identify the type of the multilayer circuit board and other necessary information regarding the multilayer circuit board. (B) detecting the exposed length and/or spacing of the outer edge of the conductor pattern of the code area; The method is characterized by a step of reading the type of the multilayer circuit board and other necessary information regarding the multilayer circuit board.

[Embodiment of the Invention] An embodiment of the present invention will be described below based on the drawings.

FIG. 5 is a plan view conceptually showing a conductor pattern of a multilayer circuit board.

In FIG. 5, the outer edge of the conductor pattern layer 1b of the multilayer circuit board 3, where the inner layer reference hole 6 is normally provided, is exposed. At the outer edge, a plurality of portions without a conductor pattern, that is, discontinuous portions C of the conductor pattern usually appear on each side.
Since this discontinuous portion C is determined at the design stage of the multilayer circuit board 3, the relative positional relationship between this discontinuous portion C and the inner layer reference hole 6 is determined in advance.

In the present invention, the copper foil exposed at the outer edge has multiple notches at specific lengths/intervals corresponding to codes representing the type of multilayer circuit board, the inner diameter of the interior reference hole, position information, etc. A code area is formed by providing a section by etching or the like.

The correspondence between the code representing the type of multilayer circuit board and the notch in the copper foil of this multilayer circuit board can be done using a binary code, with the exposed part of the copper foil being "1" and the notch being "0". You may even write your own code to do this.

The displayed content may include the type of multilayer circuit board, the inner diameter of the interior reference hole, position information, and other arbitrary information.

In this embodiment, after the multilayer circuit board 3 is completed, the four sides of the multilayer circuit board 3 are ground, each side is smoothed, and the conductive pattern layer 1b of the multilayer circuit board 3 is formed. exposed code area.

Next, the positions of discontinuous points P _X and P _Y of the conductor pattern on each side of the conductor pattern of this multilayer circuit board 3 are detected, and the above-mentioned code is read.
As means for detecting and reading the positions of these discontinuous points _P.sub.X , _P.sub.Y , etc., it is convenient to use electrical contacts, but the method is not limited to this method, and it is also possible to detect them optically, for example.

FIG. 6 is a plan view showing an example of a detection device used for such detection, and FIG. 7 is a side view as seen from that direction.

This detection device 8 includes a base plate 10 having positioning stoppers 9 on its upper surface, and a multilayer circuit board 3.
It consists of vacuum suction cups 11, 11 for fixing the multilayer circuit board 3, and three sets of discontinuity detection devices 12 for detecting discontinuities in the conductor pattern layer exposed on the sides of the multilayer circuit board 3.

The discontinuity detection device 12 includes vacuum suction cups 11, 11.
A fluid cylinder 13 disposed along the side of the multilayer circuit board 3 fixed to the multilayer circuit board 3, a roller-shaped electrical contact 15 fixed to the tip of the piston 14 of the fluid cylinder 13, and an approximate position of the electrical contact 15. A scale plate 16 for measuring the distance, a detection circuit for detecting the presence or absence of contact between the electrical contact 15 and the conductor pattern (not shown), and a position signal of the electrical contact and a detection code are sent to the drive control circuit of the drill to drive the drill to the inner layer. It is composed of a drilling position control circuit for moving the reference hole to the drilling position and a code reading circuit. Reference numeral 17 indicates an index of the scale plate, and reference numeral 18 indicates an electrode for supplying a detection voltage to the conductor pattern.

In this detection device 8, first, the multilayer circuit board 3 is positioned by having one side abutted against the stoppers 9, and then is suctioned and fixed to the vacuum suction cup 11.

Next, the electrode 18 is brought into contact with any position other than the code area of the conductor pattern of the multilayer circuit board 3, and the fluid cylinder 13 is actuated to connect the electric contact 15 at the tip of the piston 14 to the multilayer circuit board 19 as shown in FIG. It is moved along each side of the multilayer circuit board 19 while being in contact with the exposed conductor pattern 1b.

As a result, discontinuity points P _X and P _Y are detected from the electrical discontinuity between the electrode 18 and the electrical contact 15, and the contents of the code are read from the code area.

After the positions of the discontinuous points on each side are determined in this way and the contents of the code are read, the distances X and Y read from the code area from the discontinuous points P _X and P _Y in FIG. The position moved by this amount is determined to be the position of the inner layer reference hole.

In Figure 9, an 8-bit code area is provided at the outer edge of the conductor pattern, and a notch C' is formed in the copper foil within this area to code.In the example shown in Figure 9, 16 It is marked as 4AH in base number.

Further, FIG. 10 shows an example in which three types are directly discriminated, and the discrimination is made by the position of the notch C'.

Note that the number of electrical contacts for reading may be one as shown in FIG. 6;
As shown in Figure 0, the number of contacts corresponding to the number of bits may be used. In this case, the electrical contact need not be roller-shaped.

Therefore, by positioning the drill based on this position data and drilling, an inner layer reference hole can be drilled at a predetermined position.

In addition, if the position of the interior reference hole provided along the side is completely parallel to the side, the interior reference hole will be drilled just by detecting a discontinuity point between two orthogonal sides as described above. However, if necessary, discontinuous points may also be detected on other sides and used as a reference. Furthermore, the position of the interior reference hole may be determined based on the position of the notch in the code area instead of the discontinuity point described above.

Furthermore, it is possible to automatically position the drill based on the position data of this discontinuous point, but if necessary, the position of the discontinuous point can be marked on the multilayer circuit board and the inner layer reference hole can be drawn by drawing. It is also possible to determine the position of and manually drill an inner layer reference hole at this position.

Further, according to the present invention, since the type of multilayer circuit board can be identified in any process, it is also possible to automatically process this and use it as management data for process management.

[Effects of the Invention] As explained above, according to the present invention, the inner layer reference hole of a multilayer circuit board can be easily drilled in one step, and the position detection and drilling of the inner layer reference hole can be performed without relying particularly on acquisition. Since the process can be performed without any steps, it is possible to automate the entire system.

Furthermore, since the type of multilayer circuit board can be identified, it is also possible to automatically process this to streamline process management.

[Brief explanation of drawings]

Fig. 1 is an enlarged cross-sectional view conceptually showing a multilayer circuit board, Fig. 2 is a cross-sectional view showing a counterbore hole drilled up to the inner layer reference hole, and Fig. 3 is a vinyl chloride film used in other conventional methods. An enlarged cross-sectional view of a multilayer circuit board in which a small piece of resin is embedded, FIG. 4 is a plan view showing an inner layer reference hole that appears at the bottom of a counterbore in the conventional method, and FIG. 5 is a plan view conceptually showing a multilayer circuit board. 6 is a plan view showing an inner layer reference hole detection device used in an embodiment of the present invention, and FIG. 7 is a side view thereof.
FIG. 8 is a front view showing the electrical contacts and their contact positions on the multilayer circuit board, and FIGS. 9 and 10 are plan views showing the coded conductor patterns. 1a...1n...conductor pattern layer, 2a, 2b...
...Insulating layer, 3...Multilayer circuit board, 4...Counterbore drill, 5...Counterbore hole, 6...Inner layer reference hole, 7
...Small piece of vinyl chloride resin film, 8...Inner layer reference hole detection device, 9...Stopper, 11...Vacuum sucker, 12...Discontinuity point detection device, 13...Fluid cylinder, 14...Piston, 15 ...Electrical contacts, P _X , P _Y ... Discontinuous points.

Claims (1)

[Scope of Claims] 1 (A) The intermediate layer conductor pattern is formed on the sides of the multilayer circuit board to have a specific length and/or in accordance with the type of the multilayer circuit board and other necessary information regarding the multilayer circuit board. (B) detecting the exposed length and/or spacing of the outer edge of the conductor pattern in the code area to determine the type of this multilayer circuit board and other types of this multilayer circuit; A method for identifying a multilayer circuit board, comprising the step of reading necessary information about the board.