JPH11101841A - Conductive paste through hole type double-sided printed wiring board and its electric characteristics inspection equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electric characteristics inspection equipment which enables simultaneously the open-short inspection of a conductive paste through hole type double-sided printed wiring board and the electric continuity resistance inspection of a through hole. SOLUTION: This equipment 30 inspects electric characteristics of a conductive paste through hole type double-sided printed wiring board which has printed wirings 72A, 72B on both surfaces of an insulating board 70, and makes electric continuity between the printed wirings 72A and 72B on both surfaces of the board, via a conductive paste layer 76 buried in a through hole 74 of the board 70. This equipment 30 is provided with an open-short inspection part 32 inspecting the open-short state of the printed wirings 72A, 72B, and an electric continuity resistance inspection part 34 measuring the electric continuity resistance value of the conductive paste through hole 74.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for testing electrical characteristics of a conductive paste through-hole type double-sided printed wiring board (hereinafter, simply referred to as a double-sided printed wiring board).
More specifically, the present invention relates to an electrical characteristic test apparatus capable of simultaneously performing an open / short inspection and a conduction resistance inspection of a double-sided printed wiring board, and further has a configuration suitable as a test object of the electrical characteristic test apparatus. And a double-sided printed wiring board.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conductive paste through-hole type double-sided printed wiring board (hereinafter simply referred to as a double-sided printed wiring board) 69 is provided on both sides of an insulating substrate 70 and a substrate 70. In addition, printed wirings 72A, B made of metal foil, for example, copper foil, and printed wirings 72A, B on both sides via through holes 74 provided in substrate 70.
Since it is a mounting substrate having a conductive paste layer that allows electrical conduction between each other, for example, a silver paste layer 76, and can mount electric and electronic elements in a compact manner, it is widely used in various electric and electronic products in recent years. In FIG. 5, reference numeral 78 denotes a printed wiring circuit of the double-sided printed wiring board 69, and 79 denotes an electrode of the printed wiring circuit 78. Those using silver paste,
It is called a silver paste through-hole type double-sided printed wiring board, and one using a copper paste is called a copper paste through-hole type double-sided printed wiring board. Silver or copper paste, in which silver metal particles or copper metal particles are dispersed as a conductor in a low-temperature curable resin, respectively, is fed in a fluid state, fills through holes, is cured, and is used as a conductive wire. .

Conventionally, for a double-sided printed wiring board, only an open / short inspection for a printed wiring has been performed using a two-terminal open / short inspection apparatus applied to a general single-sided printed wiring board. As shown in FIG. 5, a conventional two-terminal open / short inspection apparatus 80 is used for inspecting a large number of pairs (only one pair is simply shown in FIG. 5) supported by a pin board 90. A probe pin 82A, B (hereinafter simply referred to as a probe pin), a battery 84 provided between the probe pins 82A, B, a voltmeter 86 for measuring the electromotive force of the battery 84,
An ammeter 88 is provided for measuring a current flowing between the probe pins 82A and 82B. Normally, the pin board 90 is
As shown in the figure, there are two upper and lower boards, and the double-sided printed circuit board 69 is supported between the upper and lower boards with the probe pins 82 interposed therebetween. When performing the open / short inspection, as shown in FIG. 6, the double-sided printed wiring board 69 is moved by the two upper and lower pin boards 90 of the open / short inspection apparatus 80.
As shown in FIG. 5, the probe pins 82A and B are sandwiched between the probe pins 82 and the probe pins 82A and
9, the current is measured by an ammeter 88 so as to measure the open state or the short-circuit state of the double-sided printed circuit board 69.

The manufactured double-sided printed wiring board product 69
As shown in FIG. 6, all of the printed wiring boards are sequentially supplied from the substrate supply apparatus and transferred to the open / short inspection apparatus 80, where the open / short state of the printed wiring is inspected. Non-defective products and short defective products are distinguished and stored in respective storage locations by the substrate storage device. In the open / short inspection of the double-sided printed wiring board, if the measured resistance value of the double-sided printed wiring board product is within the predetermined range, it is judged as good, and if it is higher than the predetermined resistance value, it is judged that it is in open mode and the open defective product On the other hand, when it is almost zero, it is determined that the short mode is set, and it is determined that the short-circuit is defective.

[0005]

The electrical characteristics of the printed wiring on a double-sided printed wiring board are, for example, open-circuited.
In addition to short-circuit inspection, the conduction resistance of through-holes (hereinafter simply referred to as through-holes) embedded with conductive paste is one of the important factors in evaluating the reliability of double-sided printed wiring boards. . Also, the conduction resistance of the through-hole is a factor that needs to be strictly controlled for each double-sided printed wiring board, for example, because it tends to change due to thermal history. However, the conduction resistance of the through hole is
Conventionally, only a lot-by-lot management is performed by a continuity inspection performed by a double-sided printed circuit board manufacturer before shipment, and mounting and assembly are performed using a double-sided printed circuit board, and final components and Users are not fully managed. Furthermore, on the user side,
Despite having a thermal history on conduction resistance due to heat treatment during the component mounting process and after the component mounting process, it is possible to manage the conduction resistance of through holes at the time of product shipment and after product shipment and record the history. Couldn't be efficient. This is a problem in quality control of the double-sided printed wiring board.

[0006] Despite performing open / short inspection on all double-sided printed wiring board products,
One of the major reasons for not conducting the continuity resistance test, which is important as a reliability factor, is that open / short tests and through-hole continuity resistance tests cannot be performed simultaneously in one test process using conventional testing equipment. Because. The measurement limit of the conventional open / short inspection apparatus is a resistance of about 10 to 1000Ω in the open failure mode. on the other hand,
Even if the conductive resistance of the paste has tended to increase due to the abnormality of the conductive paste material, the conductive resistance per through hole is at most 200.
mΩ or less, in this case, since the conduction resistance value is below the lower limit of measurement of the conventional open / short inspection device,
This is because it was difficult to inspect the conduction resistance of the through hole. The second reason is that it is not always easy to strictly perform the post-management of the through-hole conduction resistance due to the structural limitation of the conventional double-sided printed wiring board.

For the above reasons, a first object of the present invention is to
A second object of the present invention is to provide an electrical property testing apparatus capable of simultaneously performing an open / short test of a conductive paste through-hole type double-sided printed wiring board and a conductive resistance test of a through-hole. An object of the present invention is to provide a double-sided printed circuit board having a configuration suitable for a device under test.

[0008]

In order to achieve the first object, an apparatus for testing electrical characteristics of a conductive paste through-hole type double-sided printed wiring board according to the present invention (hereinafter referred to as a first apparatus).
Is a conductive paste through-hole type double-sided printed wiring that has printed wiring on both surfaces of an insulating substrate and conducts the printed wiring on both surfaces of the substrate through a conductive paste layer that fills through holes in the substrate. An apparatus for testing electrical characteristics of a substrate, comprising: an open / short inspection section for inspecting an open / short state of a printed wiring; and a conduction resistance inspection section for measuring a conduction resistance value of a conductive paste through hole. It is characterized by: In the present invention, a known open / short inspection apparatus used for an open / short inspection of a double-sided printed wiring board and a continuity resistance inspection apparatus for a conductive paste through hole are incorporated in the same fixture, so that an open / short circuit is provided. The short-circuit inspection and the conduction resistance inspection are performed at the same time, and the productivity of the inspection work of the electric characteristics can be improved.

Preferably, the open / short inspection section and the continuity resistance inspection section are configured as a two-terminal method inspection apparatus and a four-terminal method inspection apparatus, respectively, and each probe pin is provided on a common pin board. I have. By configuring the continuity resistance inspection unit as a four-terminal method inspection device, when determining the continuity resistance, the effect of the voltage drop due to the resistance of the ammeter is eliminated, and the potential difference and the weak current are accurately measured. As a result, Since accurate conduction resistance can be obtained, inspection accuracy can be improved.

A conductive paste through-hole type double-sided printed wiring board according to the present invention (hereinafter referred to as a second invention)
Is a conductive paste through-hole type double-sided printed wiring board having printed wiring on both surfaces of an insulating substrate and conducting printed wiring on both surfaces of the substrate through a conductive paste layer filling the through holes of the substrate, It has a product substrate portion composed of a substrate region used as a product and a discarded substrate portion composed of a substrate region not used as a product. The discarded substrate portion has a dummy conductive paste through hole and a dummy conductive paste through hole. And a test coupon including a dummy electrode connected to the test coupon. Preferably, a display surface for displaying predetermined items is provided on the substrate surface of the discarded substrate portion, or on both the discarded substrate portion and the product substrate portion.

With the above configuration, since the conductive paste through-hole type double-sided printed wiring board of the present invention is provided with the test coupon, the conduction resistance test by the electric characteristic testing apparatus according to the present invention is facilitated. By displaying the required information such as board manufacturing date, manufacturing lot, part number, etc. on the display surface as symbol silk-screen printing, users of double-sided printed wiring boards can control the quality of through-hole conduction resistance. -Defect tracking can be performed easily.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment 1 This embodiment is an embodiment of the first invention,
1 is an example of a system for testing the electrical characteristics of a double-sided printed wiring board using the electrical characteristic testing apparatus according to the present invention. FIG. 1 is a conceptual diagram showing a basic configuration of an electric characteristic test system of the present embodiment using an electric characteristic test apparatus according to the present invention. The electrical characteristic test system 10 includes a substrate supply device 12 and an electrical characteristic test device 1 for a double-sided printed wiring board according to the present invention.
4 (hereinafter, simply referred to as an electrical characteristic test device 14) and a substrate storage device 16. As shown in FIG. 1, the electrical characteristic test apparatus 14 has an open-circuit of a known configuration.
Short inspection unit 18 and through-hole conduction resistance inspection unit 2
0, and a pin board section 22 common to both inspection sections, so that the open / short inspection and the through-hole conduction resistance of the double-sided printed wiring board can be inspected simultaneously.

The pin board section 22 includes upper and lower two pin boards 26A and 26B which are freely approached and separated from each other, and an open board.
Short inspection section 18 and through-hole continuity resistance inspection section 2
0 and the probe pins 24 provided on opposing surfaces of the pin boards 26A and 26B. As a result, the pin board unit 22 includes, as a fixture, a double-sided pin board mechanism that sandwiches the double-sided printed wiring board 28 with an appropriate pressure between the probe pins 24 of the opposing pin boards 26A and 26B. The manufactured double-sided printed wiring board product is shown in FIG.
As shown in (1), they are sequentially supplied from the substrate supply device 12 and transferred to the electrical characteristic test device 14. The electrical characteristic test apparatus 14 holds the double-sided printed wiring board 28 by holding the double-sided printed wiring board 28 from both sides of the double-sided printed wiring board 28 with appropriate pressure using the probe pins 24.
The probe pin 24 is brought into contact with the electrode 8 (not shown)
Perform open / short inspection and through-hole continuity inspection at the same time. The quality of the double-sided printed circuit board 28 is determined by the electrical property tester 14, separated into a good product, an open defective product, a short defective product, and a defective through-hole conduction product, and accommodated in the respective accommodation locations by the substrate accommodation unit 16. .

In the open / short inspection performed by the open / short inspection section 18, it is possible to detect an open / short defect due to copper foil etching failure, paste bleeding or blurring due to printing mistake of the conductive paste, etc. Since the disconnection detection lower limit of the unit 18 is 10Ω, the open / short inspection unit 18 cannot detect a conduction resistance value that greatly affects the reliability of the through hole. Therefore, in this embodiment,
The conduction resistance value is measured by the conduction resistance inspection unit 20 provided in parallel with the short inspection unit 18.

Embodiment 2 This embodiment is another embodiment of the first invention, and shows a configuration of an apparatus for testing the electrical characteristics of a double-sided printed wiring board according to the present invention. FIG. 2 is a conceptual diagram showing the configuration of the electrical characteristic test device of the present embodiment. As shown in FIG. 2, an electrical characteristic test apparatus 30 for a double-sided printed wiring board (hereinafter, simply referred to as an electrical characteristic test apparatus 30) of the present embodiment,
A known two-terminal open / short inspection unit 32;
And a through-hole continuity resistance testing unit 34 of the terminal method. The through-hole continuity resistance inspection unit 34 (hereinafter simply referred to as the continuity resistance inspection unit 34) includes a pin board 36 that moves up and down. Further, the continuity resistance inspection unit 34 is provided on the pin board 36 and includes a pair of probe pins 38A and 38B that contact the electrodes of the double-sided printed wiring board, and a voltmeter 40 provided between the pair of probe pins 38A and 38B. A pair of probe pins 42A provided on the pin board 36 and in contact with the electrodes of the double-sided printed wiring board;
B, and an ammeter system having an ammeter 44 and a battery 46 provided in series between the pin boards 42A and 42B. Normally, as shown in FIG. 1, the pin board 36 is composed of two upper and lower pin boards which are freely approached to and separated from each other, and supports the double-sided printed wiring board 28 between the probe pins 38 and 42 therebetween. Alternatively, the two pin boards 36 may be arranged at fixed positions, and the probe pins 38 and 42 may freely expand and contract to hold the double-sided printed circuit board 28. The continuity resistance inspection unit 34 is configured as the inspection mechanism of the four-terminal method as described above. Like the short-circuit inspection device 80, the potential difference between the probe pins 82A and 82B measured by the voltmeter 86
Is not affected by the resistance value, there is no error in the calculation of the conduction resistance value. Thereby, the conduction resistance value can be accurately measured.

The configuration of the open / short inspection section 32 is as follows.
The configuration of the conventional open / short inspection apparatus 80 shown in FIG. 5 is the same as that of the conventional open / short inspection apparatus 80, except that a large number of pairs (only one pair is simply shown in FIG. 2) of the probe pins 82A and B and the probe pins 82A and B A battery 84 provided therebetween, a voltmeter 86 for measuring the electromotive force of the battery 84, and probe pins 82A and 82B
The probe pins 82A and 82B are supported by a pin board 36 common to the continuity resistance testing unit 34.

The double-sided printed wiring board 28 measured by the electrical characteristics test apparatus 30 has the same configuration as the double-sided printed wiring board 69 shown in FIG. 5, and as shown in FIG. Printed wirings 72A, B made of metal foil, for example, copper foil, provided on both sides of
And a silver paste layer 76 that conducts between the wirings on both sides via a through hole 74 provided in the substrate. In FIG. 2, 78
Denotes a printed wiring circuit of the double-sided printed wiring board 69, and 79 denotes an electrode of the printed wiring circuit 78.

In the inspection of the conduction resistance, a first embodiment is described.
In the same manner as described above, the double-sided printed wiring board 28 is sandwiched between the probe pins 38 and 42 of the upper and lower two pin boards 36 of the continuity resistance inspection unit 34, and the probe pins 38 and 42 are printed on both sides as shown in FIG. The electrode 79 of the printed wiring circuit 78 of the wiring board 28 is brought into contact, the current value is measured by the ammeter 44, the voltage between the probe pins 42 is measured by the voltmeter 40, and the conduction resistance of the silver paste layer 76 is measured. Ask. Preferably, a test coupon in which dummy through holes are connected in series is arranged at an appropriate position on a double-sided printed wiring board, electrodes are pulled out from both ends of the test coupon, and probe pins 38A, B and 42A, B are brought into contact with the electrodes, Thereby, the conduction resistance is measured by the four-terminal method. The open / short inspection is performed by the open / short inspection unit 32 in the same manner as in the related art.

With the above configuration, the electrical characteristic test apparatus 3
At 0, the probe board 82A, B, 38A, B, and 4
By pressing while contacting 2A and 2B, the open / short inspection and the through-hole continuity inspection of the double-sided printed wiring board 28 can be performed simultaneously.

Inspection devices for measuring the conduction resistance of 70 to 80% of the total number of through holes of a double-sided printed wiring board have conventionally existed, but the inspection devices and fixtures are expensive and expensive. Since the measurement took time, productivity was poor. Inspection of conduction resistance was also performed manually, but it was difficult to obtain accurate conduction resistance because the contact pressure of the probe pins varied depending on the operator. On the other hand, as described above, the electrical property test device 30 of the present embodiment can accurately measure the conduction resistance of all the through holes.

EXPERIMENTAL EXAMPLE In order to evaluate the performance of the electrical characteristic testing apparatus for a double-sided printed wiring board according to the present invention, the electrical characteristic testing apparatus 30 shown in the second embodiment was used to evaluate the electrical performance shown in the first embodiment. The electrical characteristics test of the copper paste through-hole double-sided printed wiring board was performed by the characteristic test system 10. A copper paste through-hole double-sided printed wiring board in which four through-holes were arranged in series was prepared as a sample, and an open / short inspection and a through-hole conduction resistance were inspected. In the through-hole conduction resistance test, the total conduction resistance of four through-holes was measured by a four-terminal method. In this experiment, the inspection of the through-hole conduction resistance can be performed simultaneously with the open / short inspection in 4 seconds, and it is possible to stably detect that the total conduction resistance of the four through-holes is 10 to 400 mΩ. did it.

Embodiment 3 This embodiment is an embodiment of the second invention,
1 shows a configuration of a conductive paste through-hole type double-sided printed wiring board suitable as a device under test of the electrical property test apparatus of the first invention. FIG. 3 is a plan view of the conductive paste through-hole type double-sided printed wiring board of the present embodiment. Conductive paste through-hole type double-sided printed wiring board 50
(Hereinafter simply referred to as double-sided printed wiring board 50)
It is composed of a product substrate portion 52 used as a product substrate and a discarded substrate portion 54 not used as a product substrate, and a dividing line is provided at a boundary so that the product substrate portion 52 and the discarded substrate portion 54 can be easily separated. A dividing perforation 56 and a slit 58 are provided. A V-cut or a U-cut may be used instead of the perforation provided on the dividing line. Discard substrate part 5
4 is separated from the double-sided printed wiring board 50 by a dividing line at the time of shipment, and is stored as future tracking data.

A single or a plurality of dummy conductive paste through-holes 60 are provided on the substrate surface of the discarded substrate portion 52 (four dummy conductive paste through-holes are shown in FIG. 3).
Are connected in series by a wiring 61 on the front surface and a wiring 62 on the rear surface. At both ends of the test coupon 64, copper foil electrodes 66A and 66B are provided as four-terminal method conduction resistance measuring terminals for measuring the conduction resistance of the test coupon 64, and a probe of a conduction resistance inspection device is provided on each copper foil land. Touch the pins. Further, as shown in FIG. 3, a display surface 68 is provided near the test coupon 64 on the board surface of the discarded board section 52, and the board manufacturing date, board manufacturing lot, part number, and imposition are printed by symbol silk printing. Display the location. Further, the same display may be provided on the product substrate section 52.

Referring to FIG. 4, a method for inspecting the conduction resistance of the double-sided printed wiring board 50 will be described. FIG. 4 shows the continuity resistance inspection unit 3 of the electrical characteristic test apparatus 30 according to the second embodiment.
4 and a double-sided printed wiring board 50 as a device under test. In testing the conduction resistance, the second embodiment
In the same manner as described above, the double-sided printed wiring board 28 is sandwiched between the probe pins 38 and 42 of the two upper and lower pin boards 36 of the conduction resistance inspection unit 34, and the probe pins 38 and 42 are printed on both sides as shown in FIG. The electrode 79 of the printed wiring circuit 78 of the wiring board 50 is brought into contact with the electrode 79, the current value is measured by the ammeter 44, the voltage between the probe pins 42 is measured by the voltmeter 40, and the conduction resistance value of the silver paste layer 76 is measured. Ask.

In this embodiment, information on the date of manufacture of the board, the lot number of the board, the part number, and the imposition location are displayed on both the product board 52 and the discarded board 54 provided with the test coupon 64. I have. Accordingly, even if the product substrate shipped after the thermal history load due to the mounting of the electronic component has an abnormal conduction resistance value, the stored discarded substrate portion 54 can be traced to analyze the trend failure. And lot tracking can be easily performed. Further, in the present embodiment, when a conduction resistance abnormality occurs in a certain product, the defective portion of the product of the same lot is analyzed by analyzing the test coupon of the discarded substrate unit 54 stored in the same lot as the product. Can be tracked. On the other hand, with a conventional double-sided printed wiring board, it is difficult to perform such a follow-up survey.

[0026]

According to the structure of the first aspect of the present invention, the open / short inspection and the conduction resistance inspection of the double-sided printed wiring board can be performed simultaneously, so that the efficiency of the work for inspecting the electrical characteristics of the double-sided printed wiring board can be improved. high. In addition, the electrical characteristic test apparatus does not need to include a continuity inspection apparatus in a conventional open / short inspection apparatus, so that the equipment cost does not increase. Also, by incorporating both into one test apparatus, the electrical property test apparatus can be reduced in size and the equipment space efficiency can be improved.

According to the configuration of the second aspect of the present invention, since the test coupon for the conduction resistance test is provided in advance, in the double-sided printed wiring board, the through-hole conduction resistance test cannot be performed, but the defect of the conductive paste material itself is not possible. In addition, it is possible to easily detect a tendency of variation in paste firing conditions. Also, by storing the discarded substrate part, the user of the double-sided printed wiring board can easily perform the lot management of the conduction resistance. Since the destructive inspection and analysis of the test coupon on the discarded substrate can be performed, failure analysis is easy. In addition, since the display performed on the display surface of the double-sided printed wiring board is performed by the symbol silk display for displaying the components, no additional cost is generated.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a basic configuration of an electric property test system of an embodiment using an electric property test apparatus according to the present invention.

FIG. 2 is a conceptual diagram illustrating a configuration of an electrical characteristic test apparatus according to a second embodiment.

FIG. 3 is a plan view of a conductive paste through-hole type double-sided printed wiring board according to Embodiment 3;

FIG. 4 is a diagram illustrating a main part of a continuity resistance inspection unit of an electrical characteristic testing apparatus according to a second embodiment and a double-sided printed wiring board according to a third embodiment as a device under test, and illustrating a continuity resistance inspection method.

FIG. 5 is a conceptual diagram showing a configuration of a conventional open / short inspection apparatus.

FIG. 6: Using a conventional open / short inspection device,
It is a figure explaining the open-short inspection method of a double-sided printed wiring board.

[Explanation of symbols]

Reference Signs List 10 ... Electrical characteristic test system, 12 ... Substrate supply device, 14 ... Electrical characteristic test device for double-sided printed wiring board according to the present invention, 16 ... Substrate storage device, 18 ... Open / short inspection unit, 20 ... ... Through-hole continuity resistance inspection part, 22 ... Pin board part, fixture, 24 ...
Probe pins, 26 pin board, 28 double-sided printed wiring board, 30 double-sided printed wiring board electrical characteristic testing apparatus of Embodiment 2, 32 open-short inspection section 32 of the two-terminal method, 34: a through-hole continuity resistance testing unit of the four-terminal method, 36: a pin board, 38A,
B: Probe pin, 40: Voltmeter, 42A, B ...
A pair of probe pins, 44 ... Ammeter, 46 ... Battery, 5
0: double-sided printed wiring board of Embodiment 3;
Product substrate part, 54 ... Discard substrate part, 56 ... Perforation for dividing, 58 ... Slit, 60 ... Dummy conductive paste through hole, 61 ... Back wiring, 62 ... Front wiring, 64 ... ... test coupon, 66A, B ... copper foil electrode, 68 ... display surface, 70 ... insulating substrate, 72A, B
Printed wiring, 74: through-hole, 76: silver paste, 78: printed wiring circuit, 79: electrode, 80
…… Conventional two-terminal open / short inspection device, 8
2A, B: pair of probe pins, 84: battery, 86:
... voltmeter, 88 ... ammeter, 90 ... pin board.

Claims (4)

[Claims] 1. A conductive paste through-hole type double-sided printed wiring board having printed wiring on both surfaces of an insulating substrate and conducting printed wiring on both surfaces of the substrate through a conductive paste layer filling through holes in the substrate. An apparatus for testing electrical characteristics, comprising: an open / short inspection section for inspecting an open / short state of a printed wiring; and a conduction resistance inspection section for measuring a conduction resistance value of a conductive paste through hole. Characteristic testing equipment for conductive paste through-hole type double-sided printed wiring boards. 2. An open / short inspection unit and a continuity resistance inspection unit are respectively configured as a two-terminal inspection device and a four-terminal inspection device, and each probe pin is provided on a common pin board. The electrical characteristics test apparatus for a conductive paste through-hole type double-sided printed wiring board according to claim 1, wherein: 3. A conductive paste through-hole type double-sided printed wiring board having printed wiring on both surfaces of an insulating substrate and conducting printed wiring on both surfaces of the substrate through a conductive paste layer filling through holes in the substrate. There is a product substrate part comprising a substrate area used as a product,
A discarded substrate portion comprising a substrate region not used as a product, the discarded substrate portion being provided with a dummy conductive paste through hole and a test coupon having a dummy electrode connected to the dummy conductive paste through hole. A conductive paste through-hole type double-sided printed wiring board. 4. The display device according to claim 3, wherein a display surface for displaying predetermined items is provided on a substrate surface of the discarded substrate portion or on both substrate surfaces of the discarded substrate portion and the product substrate portion. , Conductive paste through-hole type double-sided printed wiring board.