JPH03226604A - Detecting method of pin hole of ceramic green sheet - Google Patents

Abstract

PURPOSE:To correctly detect a pin hole by a method wherein the surface of a ceramic green sheet peeled from a carrier tape where a conductive pattern is formed is brought into contact with the surface of a conductor and a voltage is impressed between the sheet surface and the conductive surface from the rear of the sheet surface. CONSTITUTION:A green sheet 2 is peeled off from the surface of a carrier tape as the surface of the sheet 2 where a conductive pattern 22 is formed is attracted to the surface of an adhesive roll 5. Thereafter, a voltage is impressed between a pin hole detector 20 and the roll 5. The presence or absence of a pin hole in the sheet 2 is detected by the leakage of electricity from the gap. If a pin hole 23 is present at a part of the sheet 2, whether or not it is the part where the pattern 22 is printed, a high voltage discharged from the detector 20 flows to the side of the roll 5 through the pin hole 23. Accordingly, the presence of the pin hole 23 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting pinholes in ceramic green sheets produced during the manufacturing process of multilayer capacitors and multilayer wiring boards.

[Prior Art] In the production of multilayer ceramic capacitors and multilayer wiring boards, ceramic green sheets C, hereinafter referred to as "green sheets", are insulating plates on which electrodes and circuit wiring are printed in a predetermined pattern using conductive paste. ) is cut into a predetermined shape (for example, a rectangle), and a plurality of these are laminated.

An example of the manufacturing process for such a green sheet is shown in Figure 4 (
To explain in terms of a) and (b), a green sheet 2 with a conductor pattern printed on its upper surface is placed on a long carrier tape l made of polyethylene terephthalate film or the like.
The green sheet 2 is fed out from the supply roll 3 while being held on top of the carrier tape 1 , passed through a tensidine roll 4 for tension adjustment, and then peeled off from the carrier tape 1 by a suction roll 5 . The carrier tape 1 passes through another Tensilon roll 6 and is wound onto a take-up roll 7. Also, carrier tape
The green sheet 2 peeled off from the carrier belt 8
The sheet is placed on top of the sheet, and is cut along the cutting line a using the cutting cutters 11, 11. After that, green sheet 2
is adsorbed to the bottom surface of the suction unit) 12 and separates into another lamination area 1.
3 and are stacked. The remaining blank sheet 2a is then stored in the blank container IO.

FIG. 5 shows the structure of a multilayer semiconductor capacitor 100 as an example of a product manufactured from green sheets cut and stacked as described above.

[Problem to be solved by the invention] When forming such a green sheet into a sheet, pinholes may occur in the sheet. When manufacturing a laminated semi-condenser or a multilayer wiring board, electrical characteristics such as withstand voltage properties are lower than expected values in the design. Therefore, it is necessary to detect pinholes in the sheet and remove these pinholes.

However, in the conventional manufacturing process for laminated substrates, it is very difficult to detect pinholes in green sheets. That is, although a conductive pattern is preprinted on the surface of the green sheet, the printed portion of the conductive pattern is hidden by the printed conductive pattern, making it difficult to detect the presence or absence of pinholes underneath. On the other hand, the back surface is attached to the carrier tape, and pinholes cannot be detected from above.

Therefore, in view of the problems in the prior art described above, the present invention provides the following advantages:
The purpose is to provide a pinhole detection method that can reliably detect pinholes at any position on a green sheet.

[Means for Solving the Problems] In other words, the gist of the means employed to achieve the above-mentioned object of the present invention is to print a conductive pattern on the surface, form it in a layer on a carrier tape, and supply it. In a method for detecting pinholes in a ceramic green sheet, after peeling the ceramic green sheet from the carrier tape, a conductive surface is formed on the side of the ceramic green sheet on which the conductive pattern is formed. A voltage is applied between the back side of the green sheet where the conductor pattern is not formed and the conductor surface, and the presence or absence of pinholes in the ceramic green sheet is detected by the current leaking from the back side to the conductor surface. This is a method for detecting pinholes in ceramic green sheets.

[Function] In the method for detecting pinholes in a ceramic green sheet described above, a conductive surface is brought into contact with the surface of the ceramic green sheet on which the conductive pattern is formed, which has been peeled off from the carrier tape, and the gap on the conductive surface is By applying a voltage to the green sheet, when there are no pinholes in the green sheet, the insulating properties of the green sheet prevent current from leaking from the back surface to the front conductor surface. On the other hand, if there is a pinhole in the part of the green sheet where the conductor pattern is printed, the insulation of that part of the green sheet is partially low, so the conductor can be passed from the back side through the conductor pattern. Current flows to the surface. Also, when pinholes grow in areas where the conductor pattern is not printed on the green sheet,
Current flows directly from the back surface to the conductor surface. This results in
The presence or absence of pinholes can be detected.

[Embodiments] Examples of the present invention will be described below with reference to the drawings.

FIG. 3 shows the manufacturing process of a laminated substrate configured to carry out the method for detecting pinholes in ceramic green sheets according to the present invention.

In the figure, a green sheet 2 is placed on a long carrier tape l made of polyethylene terephthalate film, etc.
The two-layer tape on which is formed is fed out from a supply roll 3, passed through a tension roll 4 for tension adjustment, and then the green sheet 2 is peeled off from the carrier tape 1 by a suction roll 5. Thereafter, the carrier tape 1 passes through another tension roll 6 and is wound onto a take-up roll 7. On the other hand, the green sheet 2 peeled off from the carrier tape 1 is placed on the carrier belt 8, and is cut here by cutting cutters 11, 11. Thereafter, the green sheets 2 cut into a predetermined shape are adsorbed to the lower surface of the suction machine 12 and conveyed to another stacking area 13 where they are stacked.

Then, the blank sheet 2a after being cut is stored in the blank container IO.

In the present invention, after the green sheet 2 is peeled off from the carrier tape l by the suction roll 5, a roller having conductivity is applied to the ω11 surface of the green sheet 2 on which the conductive patterns 22, 22... are formed. etc., and the pinhole detector 20 detects the presence or absence of a pinhole from the back side.

To explain this more specifically, the suction roll 5 is
As shown in FIG. 1, the roller is made of a conductive material formed into a cylindrical shape, or the surface thereof is coated with a conductive material such as Ni by plating or the like. Moreover, on the outer peripheral surface of this suction roll 6, there are many small holes 21, 21, .
· are opened, air is sucked through these small holes 2L21, and the green sheet 2 is adsorbed to its surface by its back pressure. The back side of this green sheet 2 (
For example, a high-voltage discharge type pinhole detector (for example, high-voltage discharge type pinhole detector TRD type manufactured by Sancora Electronic Research Institute, etc.) 20 is placed opposite the suction roll 5 (lower part in the figure). is located.

As shown in FIG. 2, the green sheet 2 for detecting the presence or absence of pinholes is attached to the carrier tape while the surface on which the conductor patterns 22, 22... are formed is adsorbed to the adsorption surface of the adsorption roll 5. peeled off from the surface of 1.

After that, the pinhole detector 20 and the suction roll 5
A voltage is applied between them, and the presence or absence of pinholes in the green sheet 2 is detected by the leakage of electricity between them. and,
As already mentioned, if the pinhole 23 exists in the part where the green sheet 2 is formed, it will cause the conductor pattern 22
Regardless of whether it is a printed part or not, the high voltage discharged from the pinhole detector 20 flows through this pinhole to the suction roll 5 side, and thereby the presence of a pinhole can be detected. .

In the above embodiment, pinholes in the green sheet are detected at the position of the suction roll 5, but the present invention is not limited to this. The pinhole detection may be carried out after the green sheet 2 is peeled off from the carrier tape l. For example, the green sheet 2 may be cut into a predetermined shape using a cutting cutter, and this may be adsorbed to the bottom of a suction unit. During transportation, the bottom surface of the suction unit may be made conductive and a voltage may be applied from the back surface for detection.

[Effects of the Invention] As is clear from the above description, according to the present invention, regardless of whether the conductor pattern is printed on the part or not,
It is possible to reliably detect pinholes in ceramic green sheets.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a pinhole detection device for explaining a method for detecting pinholes in a ceramic green sheet according to an embodiment of the present invention, and FIG. 2 is a perspective view for explaining the detection operation of the pinhole detection device. A partially enlarged sectional view, FIG. 3 is a diagram showing the manufacturing process of a laminated board configured to carry out the above-mentioned pinhole detection method, and FIGS. 4(a) and (b) are conventional manufacturing steps of a laminated board. FIG. 5 is a sectional view showing the structure of a multilayer semiconductor capacitor manufactured by the multilayer substrate manufacturing process according to the prior art.

Claims (1)

[Claims] In a method for detecting pinholes in a ceramic green sheet, which prints a conductor pattern on the surface and detects pinholes in a ceramic green sheet supplied in layers on a carrier tape, the ceramic green sheet is peeled from the carrier tape. After that, a conductive surface is brought into contact with the surface of the ceramic green sheet on which the conductive pattern is formed, and a voltage is applied between the back surface of the green sheet on which the conductive pattern is not formed and the conductive surface. A method for detecting pinholes in a ceramic green sheet, characterized in that the presence or absence of pinholes in the ceramic green sheet is detected by a current leaking from the back side to the conductor surface.