JPH10341079A - Multilayered wiring board and inspection thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable inspection of conduction state, etc., of intermediate layers in a wiring board consisting of a multiplicity of wiring sheets. SOLUTION: A multiplicity of wiring sheets 2 to 7 having conductive parts 4a to 7a provided on their main surfaces are stacked. The front layer wiring sheets 2 and/or back layer wiring sheets 3 are formed with inspection conductive parts 8 to 11 which are electrically connected with their conductive layers via through-holes 12 to 16 which are insulated from the conductive parts of the other wiring sheets as associated with the intermediate layer wiring sheets 4 to 7. The inspection conductive parts 9 to 11 can be electrically isolated as associated with the intermediate layer wiring sheets 4 to 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board formed by laminating a large number of wiring boards each having a conductor portion formed on a main surface, and a method for inspecting the multilayer wiring board.

[0002]

2. Description of the Related Art In general, a multilayer wiring board is formed by laminating a predetermined number of wiring boards in which conductor parts such as circuit patterns are formed by subjecting a copper-clad board to etching or the like, and forming through holes between conductor parts of each layer. It is electrically connected as appropriate.
The through hole is formed by making the hole wall conductive by a method such as electrolytic copper plating, electroless copper plating, or printing of a conductive paste with respect to the through hole formed in each wiring board.

[0003] In the case of wiring boards, especially when high density is to be achieved, problems such as short-circuiting or disconnection of conductors caused by production accuracy or migration, or disconnection in through-holes have become extremely important.
Conduction inspection and reliability evaluation of each conductor portion and through hole are performed. A continuity inspection device having a large number of contact probes is generally used for the continuity inspection of the wiring board, and a voltage is applied in a state where the contact probes are in contact with appropriate portions of the conductor portion formed on the wiring board, and the voltage is applied. This is performed by measuring the conduction resistance value and the insulation resistance value.

In order to evaluate the reliability of the wiring board, a test pattern which enables measurement of the conduction resistance of through holes and conductors and the insulation resistance between patterns, between layers or between through holes is prepared. Environmental conditions in the pattern,
The measurement is performed by applying an electromechanical stress and measuring a conduction resistance value or an insulation resistance value. On the other hand, in the case of a multilayer wiring board, it is not possible to directly conduct a continuity test or a reliability evaluation with the continuity test device described above on a wiring board constituting each intermediate layer. For this reason, the continuity inspection and reliability evaluation of the multilayer wiring board are performed by electrically connecting the conductor portion of the wiring board constituting the intermediate layer to an appropriate portion of the surface layer or the back surface layer through a through hole. I was going. In the multilayer wiring board, since the state of the wiring board forming the intermediate layer cannot be visually confirmed, a defective portion cannot be specified.

[0005] The conventional multilayer wiring board 50 employs, for example, a structure as shown in FIG. 4 in order to perform the above-described first inspection. That is, as shown in FIG. 1B, the multilayer wiring board for through-hole inspection 50 includes a first-layer wiring board 51 having a predetermined circuit pattern or the like formed on each main surface.
The sixth to sixth layer wiring boards (lowest layer wiring boards) 56 are laminated and integrated in the thickness direction. In the multilayer wiring board 50, the first through hole 57a and the second through hole 57 penetrate through the first to lowermost wiring boards 51 to 56.
b is formed.

As shown in FIG. 1A, the first-layer wiring board 51 and the lowermost-layer wiring board 56 have first inspection terminal conductors 58a, 59a and second Inspection terminal conductor portions 58b and 59b are formed. The first inspection terminal conductors 58a, 59a and the first through hole 57a are electrically connected by connection conductors 58c, 59c, respectively. Similarly, the second inspection terminal conductors 58b, 59b and the second through hole 57
b is electrically connected to each other by connection conductors 58d and 59d.

The first through hole 57a is formed as a clearance hole that is insulated from the conductors 52a to 55a formed on the main surfaces of the second to fifth wiring boards 52 to 55. Further, the second second through holes 57b are formed in the second to fifth wiring boards 52 to 55, respectively.
Are formed through-holes electrically connected to the conductors 52a to 55a formed on the main surface of the.

[0008] The multilayer wiring board 50 constructed as described above.
Are the first inspection terminal conductors 58 mounted on the continuity inspection device and formed on the first layer wiring board 51 and the lowermost layer wiring board 56.
a, 59a and the second inspection terminal conductors 58b, 59b, a voltage V1 is applied, and the measuring device measures the conduction resistance or the insulation resistance. For example, when there is a break in the first through hole 57a, the contact resistance between the first inspection terminal conductors 58a and 59a becomes infinite, and the multi-layer wiring board 50 has a predetermined conduction resistance by the measuring device. A conduction resistance value greater than the value is measured. In addition, when the conductor parts 52a to 55a to be kept insulated from the first through hole 57a cause an improper short circuit due to migration or the like, the multilayer wiring board 50 has a predetermined conduction resistance value by a measuring device. A smaller contact resistance value is measured. Note that the multilayer wiring board 50 can obtain an inspection result opposite to that of the first through hole 57a for the first through hole 57b.

The conventional multilayer wiring board 60 employs, for example, a structure as shown in FIG. 5 in order to perform the above-described second inspection. That is, as shown in FIG. 1B, for example, as shown in FIG. 3B, the multilayer wiring board for intermediate layer inspection 60 includes a first wiring board 61 to a sixth wiring board (lowermost wiring board).
A first through-hole 67 and a second through-hole 68 penetrating through 66 are formed. Then, the first layer wiring board 61
As shown in FIG. 1A, a first inspection terminal conductor portion 69 and a second inspection terminal conductor portion 70 are formed on the main surface thereof. Also, as shown in FIG. 3A, a third inspection terminal conductor portion 71 and a fourth inspection terminal conductor portion 72 are formed on the main surface of the lowermost wiring board 66.

The first inspection terminal conductor 69 and the first through hole 67 are electrically connected via a first connection conductor 69 a formed on the main surface of the first-layer wiring board 61. .
Second inspection terminal conductor 70 and second through hole 68
Is electrically connected via a second connection conductor portion 70a formed on the main surface of the first-layer wiring board 61. Similarly, the third
The inspection terminal conductor portion 71 and the first through hole 67 are electrically connected via a third connection conductor portion 71b formed on the main surface of the lowermost wiring board 66. The fourth inspection terminal conductor portion 70b and the second through hole 68 are electrically connected via a fourth connection conductor portion 72b formed on the main surface of the lowermost wiring board 66. In other words, the first inspection terminal conductor 69 and the third inspection terminal conductor 71 are electrically connected to each other via the first through hole 67. Further, the second inspection terminal conductor 70 and the fourth inspection terminal conductor 70b are electrically connected to each other through the second through hole 68.

As shown in FIG. 5B, the first through hole 67 is formed in the conductor portion 62a of the even-numbered second-layer wiring board 62.
In addition, it is electrically short-circuited with the conductor portion 64a of the fourth-layer wiring board 64, and the third-layer wiring board 63 and the fifth-layer wiring board 65 of the odd-numbered layers form clearance holes to maintain insulation. Therefore, the first inspection terminal conductor 69 and the third inspection terminal conductor 71 constitute an inspection terminal conductor of the second layer wiring board 62 and the fourth wiring board 64. As shown in FIG. 5B, the second through-hole 68 is formed between the conductor portion 63a of the odd-numbered third-layer wiring board 63 and the fifth through-hole.
The conductor portion 65a of the layer wiring board 65 is electrically short-circuited, and the even-numbered second-layer wiring board 62 and the fourth-layer wiring board 64 form a clearance hole to maintain insulation. Therefore, the second inspection terminal conductor 70 and the fourth inspection terminal conductor 72 form an inspection terminal conductor of the third layer wiring board 63 and the fifth wiring board 65.

The multilayer wiring board 60 constructed as described above
Is loaded in the continuity inspection device, and the first
A voltage V20 is applied between the inspection terminal conductor 69 and the third inspection terminal conductor 71 of the lowermost wiring board 66, and the measuring device measures the conduction resistance therebetween. The multilayer wiring board 60 is provided in the first through hole 67 and in the second layer wiring board 6.
2 conductor part 62a and conductor part 64a of fourth layer wiring board 64
When there is a disconnection in the terminal, a measuring device measures a conduction resistance value larger than a predetermined conduction resistance value. In the multilayer wiring board 60, the migration resistance of the conductor 62a of the second wiring board 62 or the conductor 64a of the fourth wiring board 64 is measured based on the conduction resistance value measured by the measuring instrument.

In the multilayer wiring board 60, a voltage V30 is applied between the second inspection terminal conductor 70 of the first wiring board 51 and the fourth inspection terminal conductor 72 of the lowermost wiring board 66. The measuring device measures the conduction resistance value therebetween. The multi-layered wiring board 60 is formed in the second through hole 68, the conductor portion 63 a of the third-layer wiring board 63 and the conductor portion 65 of the fifth-layer wiring board 65.
When there is a disconnection in a, the measuring device measures a conduction resistance value larger than a predetermined conduction resistance value. In the multilayer wiring board 60, the migration resistance of the conductor 63a of the third wiring board 63 or the conductor 65a of the fifth wiring board 65 is measured based on the conduction resistance value measured by the measuring instrument.

[0014]

In the above-described conventional multilayer wiring boards 50 and 60, a continuity test is performed to determine the overall insulation resistance value of each of the layer wiring boards 51 to 56 and 61 to 66 constituting the wiring board. It is possible to measure migration resistance. However, the conventional multilayer wiring board 5
At 0 and 60, since it is not possible to directly conduct a continuity test or to evaluate the reliability of each of the wiring boards 52 to 55 and 62 to 65 constituting the intermediate layer, the occurrence of an improper short-circuit or disconnection, etc. occurring in these boards is not possible. It was extremely difficult to identify the location where the defect occurred.

For example, in the conventional manufacturing process of a multilayer wiring board, when the occurrence of an entire defect is confirmed by the above-described continuity test, a continuity test is performed on each individual wiring board, which is extremely troublesome. Work is performed.
Of course, in the manufacturing process of the multilayer wiring board, an inspection is performed on each individual wiring board at a stage prior to the multilayering process, but the manufacturing efficiency is reduced and, for example, the occurrence of defects is caused by the multilayering process. In such a case, there is a problem that a troublesome response must be taken because confirmation by a preliminary inspection cannot be performed.

Accordingly, the present invention has been proposed with the object of providing a multilayer wiring board capable of easily specifying a defective portion when an insulation resistance and migration resistance failure occurs in each individual wiring board, and an inspection method therefor. It is a thing.

[0017]

According to the present invention, there is provided a multilayer wiring board which achieves the above object, comprises a surface layer wiring board and / or a rear layer wiring board, each of which corresponds to each wiring board constituting an intermediate layer. Inspection terminal conductor portion electrically connected to each conductor portion through a through hole insulated from the conductor portion of the intermediate layer wiring board and electrically separateable for each intermediate layer wiring board Is formed. The multilayer wiring board has a second inspection terminal conductor portion electrically connected to the surface layer wiring board and the back layer wiring board via a through hole insulated from the conductor portion of each intermediate layer wiring board. Are formed respectively.

According to the multilayer wiring board of the present invention configured as described above, a voltage is applied to the inspection terminal conductor portion, the insulation resistance and the anti-magnation property are measured by a measuring device, and / or the through-hole is measured. A continuity test such as a short circuit or disconnection of the conductor of the intermediate layer wiring board is performed. When a predetermined measurement value is not obtained by the first inspection, it is confirmed that a defective portion exists in any of the respective intermediate-layer wiring boards, and the multilayer wiring board corresponds to each of the intermediate-layer wiring boards. By cutting off the inspection terminal conductors and applying a voltage to them sequentially and performing the second inspection, the intermediate layer wiring board where the failure occurs is easily specified.

In the above-described method for inspecting a multilayer wiring board according to the present invention, the surface layer wiring board and / or the rear layer wiring board may include other intermediate layer wiring corresponding to each wiring board constituting the intermediate layer. A multilayer wiring board is used in which test terminal conductors are formed which are electrically connected to the conductors via through holes insulated from the conductors of the board. In a method for inspecting a multilayer wiring board, a voltage is applied to the inspection terminal conductor to measure insulation resistance and anti-magnation properties and / or to conduct a continuity inspection such as a short circuit or disconnection between the through hole and the conductor of the wiring board. In the overall measurement step, when a predetermined measurement value was not obtained by the overall measurement step and it was confirmed that a defective portion was present in any of the intermediate layer wiring boards, the intermediate layer wiring board corresponded to each of these intermediate layer wiring boards, respectively. An individual measurement step of selecting an individual inspection terminal conductor portion, sequentially applying a voltage, measuring insulation resistance and anti-magnation properties, and / or conducting a continuity inspection such as a short-circuit or disconnection between the through-hole and the conductor portion of the wiring board. The process is performed to identify the intermediate layer wiring board where the failure occurs.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. The multilayer wiring board 1 shown in FIGS. 1 to 3 as an embodiment has a structure in which a second layer wiring board (front layer wiring board) 2 and a sixth layer wiring board (backside layer wiring board) 3 6 formed by integrally laminating four intermediate-layer wiring boards composed of wiring boards 4 to 5 to each other in the thickness direction
It is a multilayer wiring board having a layer configuration. Each of the wiring boards 2 to 7 is etched on a copper-clad board formed by bonding a copper foil to a main surface of a board obtained by infiltrating an epoxy resin or a phenol resin using paper, glass fiber, or the like as a material and solidifying by pressing. Conductor portions 2a to 7a of appropriate circuit patterns etc.
Is formed. The multilayer wiring board 1 is formed by sandwiching the intermediate layer wiring boards 4 to 7 between the surface layer wiring board 2 and the rear layer wiring board 3 so as to be integrated with each other. Predetermined circuit patterns are electrically connected to each other.

The multilayer wiring board 1 is composed of wiring boards 2 to 7
Is constituted by a so-called single-sided wiring board having a conductor portion such as a circuit pattern formed on one main surface, but may be constituted by a double-sided wiring board having conductor portions formed on both front and back main surfaces. Further, in the multilayer wiring board 1, the intermediate wiring boards 4 to 7 may be configured by multilayer wiring boards. The basic configuration of the multilayer wiring board 1 is the same as that of a generally used multilayer wiring board. Of course, the multilayer wiring board 1 is not limited to the six-layer structure, but is formed by laminating an appropriate number of wiring boards, and furthermore, a chip component or the like is mounted on the circuit pattern.

In the multilayer wiring board 1, an inspection terminal conductor is formed, for example, in a peripheral area where a circuit pattern or the like is not formed. A first inspection terminal conductor 8 and a second inspection terminal conductor 9 are formed on the surface layer wiring board 2. Also, the first inspection terminal conductor portion 8 is provided on the back layer wiring board 3.
And a third inspection terminal conductor 10 electrically connected to the second inspection terminal conductor 9 via a first through hole 12 to be described later, and a second through fifth through hole 16 to be described later. And a fourth inspection terminal conductor 11 electrically connected to the fourth inspection terminal conductor 11.

As shown in FIG. 2, the first inspection terminal conductor 8 and the land 12a of the first through hole 12 are electrically connected through the connection conductor 8a. The third inspection terminal conductor portion 10 and the land 12b of the first through hole 12
Are also electrically connected via the connection conductor 10a. The first inspection terminal conductor 8 is formed while maintaining electrical insulation from the second inspection terminal conductor 9. Similarly, the third inspection terminal conductor 10 is formed while maintaining electrical insulation from the fourth inspection terminal conductor 11.

As shown in FIG. 1, the second to fifth wiring boards 4 to 7 constituting the intermediate wiring board layer are formed on the respective main surfaces with respect to the first through holes 12. The conductor portion 4a to the circuit conductor portion 7a constitute a clearance hole in which insulation is maintained. Therefore, the first
The through hole 12 penetrates through the second to fifth wiring boards 4 to 5 to the first inspection terminal conductor part 8 of the surface layer wiring board 2 and the third inspection terminal conductor part 10 of the back layer wiring board 3. Only electrically connected.

As shown in FIG. 1, the second to fifth wiring boards 4 to 7 constituting the intermediate wiring board layer have respective circuit boards with respect to the second through holes 13 to fifth through hole 16, respectively. The conductor is selectively connected. That is, in the second-layer wiring board 4, the circuit land 4 a is electrically connected to the second through-hole 13 by forming the connection land 25 around the through-hole forming the second through-hole 13. ing. Thereby, the second through hole 13
Are electrically connected to the second inspection terminal conductor 9 of the front layer wiring board 2, the fourth inspection terminal conductor 11 of the back layer wiring board 3, and the circuit conductor 4 a of the second layer wiring board 4. Also, the third
The circuit conductor 5a of the layer wiring board 5 is electrically connected to the third through-hole 14 by forming the connection land 26 around the through-hole constituting the third through-hole 14. Thereby, the third through hole 14 is formed.
Are electrically connected to the second inspection terminal conductor 9 of the surface layer wiring board 2, the fourth inspection terminal conductor 11 of the back layer wiring board 3, and the circuit conductor 5 a of the third layer wiring board 5.

Similarly, in the fourth-layer wiring board 6, the connection land 27 is formed around the through hole constituting the fourth through-hole 15, so that the circuit conductor 6a is electrically connected to the fourth through-hole 15. Connected. Thus, the fourth through hole 15 is formed between the second inspection terminal conductor 9 of the front layer wiring board 2, the fourth inspection terminal conductor 11 of the back layer wiring board 3, and the circuit conductor 6 a of the fourth layer wiring board 6. It is electrically connected. Further, the fifth-layer wiring board 7 has connection lands 28 around the through holes constituting the fifth through holes 16.
Is formed, the circuit conductor portion 7a is electrically connected to the fifth through hole 16. As a result, the fifth through-hole 16 is formed between the second inspection terminal conductor 9 of the front layer wiring board 2, the fourth inspection terminal conductor 11 of the rear layer wiring board 3, and the circuit conductor 7 a of the fifth layer wiring board 7. It is electrically connected.

By the way, the second inspection terminal conductor 9 corresponds to FIG.
As shown in the figure, the first individual inspection terminal conductor 17 corresponding to the second through hole 13, the second individual inspection terminal conductor 18 corresponding to the third through hole 14, and the fourth individual inspection terminal conductor 18 corresponding to the fourth through hole 15. Third individual inspection terminal conductor 19 corresponding to third individual inspection terminal conductor 19 and fifth through hole 16
Are electrically connected integrally via the connection conductors 29 to 31 respectively. These connecting conductors 2
9 to the connection conductor portion 31 are configured to be cuttable,
The first to fourth individual inspection terminal conductors 17 to 20 are configured as individual inspection terminal conductors.

The first individual inspection terminal conductor 17 is connected to the land 13a of the second through hole 13 via the connection conductor 17a.
Is electrically connected to Further, the second individual inspection terminal conductor 18 is electrically connected to the land 14a of the third through hole 14 via the connection conductor 18a. Third
The individual inspection terminal conductor 19 is electrically connected to the land 15a of the fourth through hole 15 via the connection conductor 19a. Further, the fourth individual inspection terminal conductor 20 is electrically connected to the land 16a of the fifth through hole 16 via the connection conductor 20a.

Similarly, the fourth inspection terminal conductor portion 11 is
As shown in FIG. 5, the first individual inspection terminal conductor 21 corresponding to the second through-hole 13, the second individual inspection terminal conductor 22 corresponding to the third through-hole 14, and the fourth individual inspection terminal conductor 22 corresponding to the fourth through-hole 15. Third individual inspection terminal conductor portion 24 corresponding to third individual inspection terminal conductor portion 23 and fifth through hole 16
Are electrically and integrally connected via the connection conductor portions 32 to 34, respectively. These connecting conductors 3
The second to connection conductors 34 are configured to be cuttable,
The first individual inspection terminal conductor 21 to the fourth individual inspection terminal conductor 24 are configured as individual inspection terminal conductors.

The first individual inspection terminal conductor 21 is connected to the land 13b of the second through hole 13 via the connection conductor 21a.
Electrically connected to the first individual inspection terminal conductor 17 on the surface layer wiring board 2 side. The second individual inspection terminal conductor 22 is electrically connected to the land 14b of the third through hole 14 via the connection conductor 22a, and is connected to the second individual inspection terminal conductor 18 on the surface layer wiring board 2 side. Make a pair. Further, the third individual inspection terminal conductor portion 23 includes a connection conductor portion 23a.
And is electrically connected to the land 15b of the fourth through hole 15 via the third through hole 15, and forms a pair with the third individual inspection terminal conductor 19 on the surface layer wiring board 2 side. Furthermore, the fourth individual inspection terminal conductor portion 24 is electrically connected to the land 16b of the fifth through hole 16 via the connection conductor portion 24a, and the fourth individual inspection terminal conductor portion 20 on the surface layer wiring board 2 side. Pair with.

The multilayer wiring board 1 configured as above is
As shown in FIG. 3, the first inspection terminal conductor portion 8 of the surface layer wiring board 2 and the third inspection terminal
A voltage V1 is applied between the test terminal conductor portion 10 and the measuring device measures the conduction resistance. The multilayer wiring board 1
When there is a break in the through-hole 12, the contact resistance between the first inspection terminal conductor 8 and the third inspection terminal conductor 10 becomes infinite, so that the measurement device has a predetermined conduction resistance. A larger conduction resistance value is measured. Further, in the multilayer wiring board 1, the conductors 4a to 7a of the wiring boards 4 to 7 constituting the intermediate layer to be kept insulated from the through-holes 12 cause an improper short circuit due to migration or the like. In this case, a contact resistance value smaller than a predetermined conduction resistance value is measured by the measuring instrument.

On the other hand, the multilayer wiring board 1 is measured by applying a voltage V2 between the second inspection terminal conductor 9 of the front layer wiring board 2 and the fourth inspection terminal conductor 11 of the back layer wiring board 3. The continuity resistance value is measured by the device. The multilayer wiring board 1 is provided with a predetermined conduction by a measuring device when an improper short circuit or the like occurs due to migration or the like in each of the circuit conductors 4a to 7a of each of the wiring boards 4 to 7 constituting the intermediate layer. A contact resistance value smaller than the resistance value is measured. Therefore,
It is confirmed that the multilayer wiring board 1 has a defective portion in any of the wiring boards 4 to 7 constituting the intermediate layer. The multilayer wiring board 1 is determined to be non-defective when a predetermined conduction resistance value is measured by a measuring device.

When it is confirmed by the above-described first inspection that any of the wiring boards 4 to 7 constituting the intermediate layer has a defective portion, the multilayer wiring board 1 An individual inspection is performed on the circuit boards 4 to 7. The multilayer wiring board 1 has a first individual inspection terminal conductor portion 17 to a fourth individual inspection terminal conductor portion 20 constituting the second inspection terminal conductor portion 9 and a first individual inspection constituting the fourth inspection terminal conductor portion 11. Terminal conductor 21 to fourth individual inspection conductor 24
However, the connection conductors 29 to 31 and the connection conductors 32 to 34 are cut and electrically separated from each other.

As shown in FIG. 3, the multilayer wiring board 1 is formed by a first individual inspection terminal conductor 17 of the separated front layer wiring board 2 and a first individual inspection terminal conductor 21 of the back layer wiring board 3. During this time, the voltage V3 is applied and the measuring device measures the conduction resistance value. The multilayer wiring board 1 is composed of the circuit conductor 4 of the second layer wiring board 4.
a, a contact resistance value smaller than a predetermined conduction resistance value is measured by a measuring device when an illegal short circuit or the like occurs due to migration or the like in the second wiring board 4.
It is confirmed that a defective portion exists.

Similarly, the multilayer wiring board 1 comprises a surface layer wiring board 2
Of the second individual inspection terminal conductor portion 18 and the second
A voltage V4 is applied between the conductor 22 and the individual inspection terminal conductor portion 22, and the continuity resistance value is measured by the measuring instrument. In addition, the multilayer wiring board 1 is provided with the third individual inspection terminal conductor 19 of the surface layer wiring board 2.
A voltage V5 is applied between the third individual inspection terminal conductor portion 23 of the back surface wiring board 3 and the conduction resistance value is measured by the measuring instrument. Further, in the multilayer wiring board 1, the voltage V6 is applied between the fourth individual inspection terminal conductor section 20 of the front layer wiring board 2 and the fourth individual inspection terminal conductor section 24 of the back layer wiring board 3, and the measuring instrument is used. The conduction resistance is measured. With this inspection, the multilayer wiring board 1 is quickly identified by non-destructive inspection as to whether a defective portion exists in any of the second to fifth wiring boards 4 to 5.

In the multilayer wiring board 1 described above,
First inspection terminal conductor 8 and third inspection terminal conductor 10 and second inspection conductor 9 and fourth inspection terminal conductor 11 forming a pair with front surface wiring board 2 and back surface wiring board 3. However, for example, a common terminal conductor is formed in another portion of the surface layer wiring board 2 or the back layer wiring board 3, and the common terminal conductor and the first inspection terminal conductor 8 or the second inspection terminal conductor 8 are formed. The inspection voltage may be applied between the inspection conductors 9 of the above.

In the multilayer wiring board 1, the second inspection conductor 9 and the fourth inspection terminal conductor 11 can be separated from each other by the connection conductors 29 to 31 and the connection conductors 32 to 34. Although the individual test terminal conductors 17 to 20 and the individual test terminal conductors 21 to 24 are integrally formed, they may be formed independently of each other. In this case, the multilayer wiring board 1 is subjected to the short-circuit inspection and the cut inspection by the first inspection terminal conductor portion 8 and the third inspection terminal conductor portion 10 to inspect the presence or absence of the entire defective portion.

[0038]

As described above in detail, according to the multilayer wiring board of the present invention, the inspection terminal conductor of each wiring board constituting the intermediate layer is formed on the surface layer wiring board and / or the back layer wiring board. Since it is formed, it is possible to measure the insulation resistance and the anti-magnation property of each intermediate-layer wiring board via these inspection terminal conductors, thereby making it possible to extremely easily identify a defective portion. It becomes possible.

Further, according to the method for inspecting a multilayer wiring board according to the present invention, the inspection terminal conductor of each wiring board constituting the intermediate layer is formed on the surface layer wiring board and / or the rear layer wiring board. Is used to measure the insulation resistance and the anti-magnation property of the intermediate layer wiring board through each inspection terminal conductor part. Can be identified.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a multilayer wiring board shown as an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the multilayer wiring board.

FIG. 3 is an explanatory view of an inspection method of the multilayer wiring board.

4A and 4B show a conventional multilayer wiring board, FIG. 4A is a plan view of a main part, and FIG. 4B is a longitudinal sectional view of a main part.

5A and 5B show another conventional multilayer wiring board. FIG. 5A is a plan view of a main part, and FIG. 5B is a longitudinal sectional view of the main part.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 multilayer wiring board, 2 surface layer wiring board, 3 back layer wiring board, 4 to 7 wiring board, 8 to 11 inspection terminal conductor,
12 to 16 through hole, 17 to 24 individual inspection terminal conductor

Claims (6)

[Claims] 1. A multilayer wiring board comprising a plurality of wiring boards each having a conductor portion formed on a main surface thereof, wherein the intermediate layer is formed on a surface layer wiring board and / or a rear layer wiring board. A test terminal conductor portion is formed corresponding to each wiring board and electrically connected to each conductor portion through a plurality of through holes insulated from the conductor portion of another wiring board. The multilayer wiring board, wherein the terminal conductor portions are electrically separable from each other corresponding to the respective intermediate-layer wiring boards. 2. The method according to claim 1, wherein the surface layer wiring board and the back layer wiring board have:
The second inspection terminal conductor portion electrically connected to a conductor portion of each wiring board constituting the intermediate layer via a through hole insulated from the conductor portion is formed, respectively. The multilayer wiring board as described. 3. The inspection terminal conductor section includes a plurality of individual inspection terminal conductor sections formed on the surface layer wiring board and / or the back layer wiring board corresponding to each wiring board constituting the intermediate layer. The multilayer wiring board according to claim 1, wherein: 4. A front-layer wiring board and / or a back-layer wiring board, corresponding to each wiring board constituting the intermediate layer, via through holes insulated from conductor portions of wiring boards of other layers. A multi-layer wiring board on which a test terminal conductor portion electrically connected to each conductor portion is formed, and a voltage is applied to the test terminal conductor portion to measure insulation resistance and anti-magnation property and / or The whole measurement step of conducting a continuity test such as a short circuit or a disconnection between the through hole and the conductor part of the wiring board, and the whole measurement step confirms that a defective portion exists in any of the wiring boards constituting the intermediate layer. In this case, a voltage is sequentially applied after separating the inspection terminal conductors corresponding to each of the intermediate layer wiring boards, to measure insulation resistance and anti-magnation property, and / or to measure the through hole and the intermediate layer. Wiring board Shorting of the conductive portion, the inspection method for a multilayer wiring board and performing a specific failure point through a separate measurement step of performing a continuity test such as disconnection. 5. The front-side wiring board and the back-side wiring board,
Second inspection terminal conductors electrically connected to the conductors of the respective wiring boards constituting the intermediate layer via insulated through holes are formed, respectively, between the second inspection terminal conductors. 5. The method according to claim 4, wherein a voltage is applied to the conductor to measure insulation resistance and anti-magnation property and / or conduct a continuity test such as a short circuit or a disconnection between the through hole and the conductor of the intermediate wiring board. Inspection method for multilayer wiring boards. 6. A front-layer wiring board and / or a back-layer wiring board, which correspond to each wiring board constituting an intermediate layer, through through holes insulated from conductors of wiring boards of other layers. By applying a voltage to each of the individual inspection terminals and applying a voltage to each of the intermediate inspection layers, the multilayer wiring board having a plurality of individual inspection terminals electrically connected to the respective conductors is inspected. A method for inspecting a multilayer wiring board, comprising measuring insulation resistance and anti-magnation properties and / or conducting a continuity test such as a short circuit or disconnection of a conductor portion thereof.