JP2014212181A - Multilayer substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the stability of measurement by stably contacting a testing probe to electrode portions.SOLUTION: A multilayer substrate having electrode portions with which a testing probe is electrically in contact includes a plurality of insulating layers each having a through hole, and a plurality of conductor layers each provided on each insulating layer. The conductor layers are alternately provided with the insulating layers and each include an electrode portion. Each electrode portion is formed on a peripheral portion of each through hole. In a plan view viewed from a normal direction of a primary surface of the insulating layers, each through hole of the plurality of insulating layers is provided in a concentric circular shape. Each size of the through holes of the plurality of insulating layers decreases in the depth direction.

Description

  The present invention relates to a multilayer substrate having an electrode part for inspection.

  2. Description of the Related Art Conventionally, as electric circuits are highly integrated and complicated, tests for inspecting the operation of electric circuits are also important. As one of the methods, there is a method of providing a test point in a part of the wiring pattern of the electric circuit. For example, in Patent Document 1, when an electric circuit using a multilayer substrate is operating, an inspection probe is brought into electrical contact with an electrode serving as a test point, a signal flowing through the wiring pattern of the electric circuit, its voltage value, etc. Measure.

JP 2004-6933 A

  However, in general, in an electric circuit, a test point is formed by partially removing a resist layer provided on a conductor layer on which a wiring pattern is formed and exposing a part of the wiring pattern. . When measurement is performed by bringing the tip of the inspection probe into contact with such a test point, the contact area between the test point and the inspection probe is narrow, and the contact position of the inspection probe tends to shift. For this reason, when the probe for inspection comes into contact with the test point in an insufficient state, the measurement value may become unstable and accurate measurement may not be possible. Also, if the operator holds the probe for inspection during measurement and performs another operation such as changing the setting of the measuring instrument, the probe for inspection will be removed from the test point and measurement will need to be repeated. There is.

  Further, in Patent Document 1, an electrode serving as a test point is provided on two opposing side walls inside a rectangular probe contact hole, and the test probe is brought into contact with the electrode via the probe contact hole when measuring the test point. ing. However, since the inspection probe is in point contact with the electrode, the contact area with the electrode is small. Further, the inspection probe is likely to be displaced in a direction parallel to the opposing side wall in the probe contact hole. For this reason, if the operator holds the probe for inspection during measurement and performs another operation such as changing the setting of the measuring instrument, the contact state between the probe for inspection and the electrode may deteriorate, There is a risk of falling off the test point.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a multilayer substrate capable of stably bringing a probe for inspection into contact with an electrode portion and improving measurement stability. To do.

  In order to achieve the above object, a multilayer substrate according to one aspect of the present invention is a multilayer substrate having an electrode portion with which an inspection probe is in electrical contact, and includes a plurality of insulating layers in which through holes are formed. A plurality of conductor layers provided on the insulating layer, wherein the conductor layers are alternately provided with the insulating layers and include electrode portions, and the electrode portions are formed at the peripheral portions of the through holes. In a plan view viewed from the normal direction of the surface, the through holes of the plurality of insulating layers are provided concentrically, and the sizes of the through holes of the plurality of insulating layers decrease in the depth direction.

  According to the said structure, the electrode part which the probe for a test | inspection electrically contacts is formed in the peripheral part of the through-hole of a some insulating layer. Each through-hole is provided concentrically in plan view, and its size decreases in the depth direction. Therefore, when the inspection probe is brought into electrical contact with the electrode portion, the probe is inserted into each through-hole and comes into contact with each electrode portion. Accordingly, it is possible to make it difficult for the probe to be detached from the through hole. In addition, the contact area between the probe and the electrode portion increases. Therefore, it is possible to stably bring the inspection probe into contact with the electrode portion and improve the measurement stability.

  Furthermore, since the reliability of the measurement value can be improved and the occurrence of measurement errors can be suppressed, the time required for the measurement work can be reduced.

  In the above configuration, a conductive path electrically connected to the electrode portion may be formed on the inner wall of the through hole.

  According to this configuration, the electrical connection area between the probe and the electrode portion is substantially increased by the probe coming into contact with the conductive path formed on the inner wall of the through hole. Therefore, the electrical contact state between the probe and the electrode part can be improved.

  Moreover, in the said structure, each through-hole may have a cylindrical shape.

  According to this configuration, since the shape of the through hole is simple, the through hole can be easily formed in each insulating layer. Therefore, the manufacturing process is not complicated and the cost can be suppressed.

  In the above configuration, each through hole may have a tapered shape whose size decreases in the depth direction.

  According to this configuration, since the probe easily comes into contact with the inner wall of the through hole, the position of the probe is difficult to shift. Therefore, it is possible to make it difficult for the probe to be removed from the through-hole or to be separated from the electrode portion. Therefore, the probe can be brought into contact with the electrode portion more stably.

  In the above configuration, an internal conductive path that electrically connects the electrode portion of the conductor layer on one main surface side and the electrode portion of the conductor layer on the other main surface side is formed inside the insulating layer. Also good.

  According to this configuration, the internal conductive path is not exposed inside the through hole. Therefore, there is no fear that the internal conductive path is worn by contact with the probe, and deterioration of the internal conductive path (for example, oxidation, corrosion, etc.) due to the atmosphere in the through hole can be suppressed.

  Or in the said structure, each size of a through-hole may reduce according to the shape of the front-end | tip of a probe.

  According to this configuration, since each size of the inner peripheral edge of the electrode part formed at the peripheral part of the through hole also changes according to the shape of the tip of the probe, the inspection probe is in electrical contact with the plurality of electrode parts. Can be made. Accordingly, since the contact area between the probe and the electrode portion increases, the measurement stability can be improved and the reliability of the measurement value can be further improved.

  ADVANTAGE OF THE INVENTION According to this invention, the multilayer probe which can make the probe for an inspection contact the electrode part stably, and can improve stability of a measurement can be provided.

It is a perspective view of the multilayer substrate concerning a 1st embodiment. 1 is a cross-sectional view of a multilayer substrate according to a first embodiment. 1 is a top view of a multilayer substrate according to a first embodiment. It is sectional drawing which shows the structure of the electrode part periphery of the multilayer substrate in a 1st comparative example. It is sectional drawing which shows the structure of the electrode part periphery of the multilayer substrate in a 2nd comparative example. It is a perspective view of the multilayer substrate concerning a 2nd embodiment. It is sectional drawing of the multilayer substrate which concerns on 2nd Embodiment. It is sectional drawing of the multilayer substrate which concerns on 3rd Embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking as an example a multilayer substrate having a test point with which an inspection probe is in electrical contact. In the following, of both the main surfaces of the multilayer substrate, the main surface on the side where the probe is inserted is referred to as the upper surface, and the main surface on the side where the probe is not inserted is referred to as the back surface. In the drawings referred to below, the X direction and the Y direction are parallel to one main surface of the multilayer substrate, and the Z direction is parallel to the normal direction of the main surface. Further, the X direction, the Y direction, and the Z direction are orthogonal to each other.
<First Embodiment>

  FIG. 1 is a perspective view of a multilayer substrate according to the first embodiment. FIG. 2 is a cross-sectional view of the multilayer substrate according to the first embodiment. FIG. 3 is a top view of the multilayer substrate according to the first embodiment. As shown in FIGS. 1 and 2, the multilayer substrate 1 includes first to third insulating layers 2a to 2c, first to fourth conductor layers 3a to 3d, and first and second resist layers 4a and 4b. It is a four-layer board | substrate comprised including. The multilayer substrate 1 is provided with a through hole 6. When an electrical signal (or voltage value or voltage value) of a wiring pattern (not shown) in the multilayer substrate 1 is measured, an inspection is performed during operation of an electrical circuit (not shown) using the multilayer substrate 1. The probe 8 is inserted into the through hole 6. The probe 8 is in electrical contact with a test point (first to fourth electrode portions 31a to 31d described later). The through hole 6 will be described later.

  The first to third insulating layers 2a to 2c and the first to fourth conductor layers 3a to 3d are alternately provided. The first conductor layer 3a is provided on the main surface on the upper surface side (the upper side in FIG. 1) of the first insulating layer 2a, and the second conductor layer 3b is provided between the first and second insulating layers 2a and 2b. The third conductor layer 3c is provided between the second and third insulating layers 2b and 2c, and the fourth conductor layer 3d is provided on the main surface on the back surface side (lower side in FIG. 1) of the third insulating layer 2c. ing. Furthermore, the first resist layer 4a is provided on the main surface on the upper surface side of the first conductor layer 3a, and the second resist layer 4b is provided on the main surface on the lower surface side of the second conductor layer 3b.

  The first to third insulating layers 2a to 2c are formed using an electrically insulating material. Cylindrical first to third through holes 21a to 21c are formed in the first to third insulating layers 2a to 2c, respectively. In addition, first to third conductive paths 22a to 22c are formed on the inner walls of the first to third through holes 21a to 21c, respectively. The first to third conductive paths 22a to 22c are formed using a conductive material, and electrically connect first to fourth electrode portions 31a to 31d described later. For example, the first conductive path 22a is formed on the inner wall of the first through hole 21a and electrically connects the first and second electrode portions 31a and 31b. The second conductive path 22b is formed on the inner wall of the second through hole 21b and electrically connects the second and third electrode portions 31b and 31c. The third conductive path 22c is formed on the inner wall of the third through hole 21c, and electrically connects the third and fourth electrode portions 31c and 31d.

  The first to fourth conductor layers 3a to 3d have wiring patterns (not shown) including the first to fourth electrode portions 31a to 31d, respectively. These first to fourth electrode portions 31a to 31d are test points for measuring an electric signal flowing through the wiring pattern. The 1st electrode part 31a is formed along the peripheral part of the opening end of one side (upper side of Drawing 1) of the 1st penetration hole 21a formed in the 1st insulating layer 2a. The 2nd electrode part 31b is formed along the peripheral part of one open end (upper side of Drawing 1) of the 2nd penetration hole 21b formed in the 2nd insulating layer 2b. Further, the third and fourth electrode portions 31c and 31d are formed along the peripheral edge portions of the respective opening ends (upper and lower sides in FIG. 1) of the third through hole 21c formed in the third insulating layer 2c. Has been.

  First and second openings 41a and 41b are formed in the first and second resist layers 4a and 4b, respectively. As shown in FIG. 2, in the plan view seen from the Z direction, the peripheral edge portion of the first opening 41a is located between the inner peripheral edge and the outer peripheral edge of the first electrode portion 31a. Similarly, the peripheral edge portion of the second opening 41b is located between the inner peripheral edge and the outer peripheral edge of the second electrode portion 31b. Therefore, as shown in FIG. 3, the first to third electrode portions 31a to 31c are exposed on the upper surface side of the multilayer substrate 1 through the first opening 41a. The fourth electrode portion 31d is exposed on the back surface side of the multilayer substrate 1 through the second opening 41b.

  The first to third through holes 21a to 21c, the first to third conductive paths 22a to 22c, the first to fourth electrode portions 31a to 31d, and the first and second openings 41a and 41b described above are through. Hall 6 is formed.

  Moreover, as shown in FIG. 3, the 1st-3rd through-holes 21a-21c and the 1st-4th electrode parts 31a-31d are formed concentrically in planar view seen from the Z direction. The sizes of the opening ends of the first to third through holes 21a to 21c and the inner peripheral edges of the first to third electrode portions 31a to 31c are reduced in the depth direction. The size of the opening end of the first through hole 21a is larger than the size of the opening end of the second through hole 21b, and the size of the opening end of the second through hole 21b is larger than the size of the opening end of the third through hole 21c. ing. The size of the inner periphery of the first electrode portion 31a is larger than the size of the inner periphery of the second electrode portion 31b, and the size of the inner periphery of the second electrode portion 31b is the inner size of the third and fourth electrode portions 31c and 31d. It is larger than the size of the periphery.

  The sizes of the open ends of the first and second through holes 21a and 21b and the inner peripheral edges of the first and second electrode portions 31a and 31b are sizes that allow the tip of the probe 8 to be inserted when measuring the test points. If it is. For example, when the probe 8 is inserted deepest into the through hole 6, the probe 8 comes into contact with the third electrode portion 31c. At this time, the sizes of the opening end of the first through hole 21a and the inner peripheral edge of the first electrode portion 31a are larger than the cross-sectional size of the probe 8 on the XY plane including the inner peripheral edge of the first electrode portion 31a. That's fine. It is preferable that each size of the opening end of the inner periphery of the second through hole 21b and the second electrode portion 31b is the same.

  If it carries out like this, when measuring at a test point, the probe 8 inserted in the through hole 6 can be made to contact the 1st-3rd electrode parts 31a-31c. Therefore, it is possible to prevent the probe 8 from being displaced and to be easily removed from the through hole 6. Further, the contact area between the probe 8 and the first to third electrode portions 31a to 31c also increases. Therefore, the signal can be measured in a more stable state, and the reliability of the measured value can be improved. In addition, since measurement errors can be made less likely to occur, the time required for measurement work can be further reduced.

  Further, the sizes of the opening ends of the first and second through holes 21a and 21b and the inner peripheral edges of the first and second electrode portions 31a and 31b are reduced in the depth direction according to the shape of the tip of the probe 8. It is preferable to do. For example, when the probe 8 is inserted deepest into the through hole 6, the size of the inner peripheral edge of the first electrode portion 31a is substantially the same as the cross-sectional size of the probe 8 in the XY plane including the inner peripheral edge. Is preferred. It is preferable that the size of the opening end of the inner periphery of the second through hole 21b and the second electrode portion 31b is the same.

  If it carries out like this, when measuring at a test point, the probe 8 inserted in the through-hole 6 can be made to contact over the perimeter of each inner periphery of the 1st and 2nd electrode parts 31a and 31b. Therefore, the probe 8 can be substantially fixed and held in the through hole 6, and the contact area between the probe 8 and the first to third electrode portions 31a to 31c can be maximized. Therefore, since a stable measurement value can be obtained in a substantially fixed state, the reliability of the measurement value can be improved, and the time required for the measurement operation can be greatly reduced.

Next, in order to make it easier to understand the advantages of the operation and effect of the multilayer substrate 1 of the present embodiment, two comparative examples will be described.
(First comparative example)

  FIG. 4 is a cross-sectional view showing the structure around the electrode portion of the multilayer substrate in the first comparative example. As shown in FIG. 4, in the multilayer substrate 501 of the first comparative example, first to third insulating layers 502a to 502c and first to fourth conductor layers 503a to 503d are alternately provided in the Z direction. In addition, first and second resist layers 504 a and 504 b are formed on both main surfaces of the multilayer substrate 510. An electrode portion 531 is formed in the first conductor layer 503a, and an opening portion 541 is formed in the first resist layer 504a. The electrode portion 531 exposed to the outside through the opening 541 is used as a test point.

When performing measurement using such an electrode portion 531 as a test point, an operator needs to keep holding the probe 8 pressed against the electrode portion 531 during the measurement operation. Further, when the worker performs another work (for example, changing the setting of the measuring device), the probe 8 may be detached from the electrode portion 531. In such a case, the measurement needs to be repeated. Further, since the tip of the test probe 8 is in point contact with the electrode portion 531, the contact area between the probe 8 and the electrode portion 531 is small. For this reason, since the measurement value becomes unstable, the reliability of the measurement value becomes low, and the time required for the measurement work becomes relatively long.
(Second comparative example)

  FIG. 5 is a cross-sectional view showing the structure around the electrode portion of the multilayer substrate in the second comparative example. As shown in FIG. 5, in the multilayer substrate 511 of the second comparative example, solder 532 is provided on the electrode portion 531 exposed through the opening 541. Other than that is the same as the first comparative example.

  Thus, even when measurement is performed using the solder 532 as a test point, the same problem as in the first comparative example occurs. Furthermore, in the second comparative example, since the solder 532 swells outside the multilayer substrate 1, the tip of the probe 8 is easily slipped on the upper surface of the solder 532. For this reason, the probe 8 is not easily held in a state of being pressed against the solder 532 and is easily detached from the solder 532 (test point). Therefore, the measurement becomes unstable.

  The first embodiment has been described above. The multilayer substrate 1 of the first embodiment includes first to fourth electrode portions 31a to 31d with which the inspection probe 8 is in electrical contact. The multilayer substrate 1 includes first to third insulating layers 2a to 2c in which first to third through holes 21a to 21c are formed, and first to first insulating layers 2a to 2c provided on the first to third insulating layers 2a to 2c. 4 conductor layers 3a-3d. The first to fourth conductor layers 3a to 3d are alternately provided with the first to third insulating layers 2a to 2c, and include first to fourth electrode portions 31a to 31d. The 1st-4th electrode parts 31a-31d are formed in the peripheral part of the 1st-3rd through-holes 21a-21c. The through holes 21a to 21c of the first to third insulating layers 2a to 2c are provided concentrically in a plan view as viewed from the normal direction of the main surfaces of the first to third insulating layers 2a to 2c. Moreover, each size of the 1st-3rd through-holes 21a-21c of the 1st-3rd insulating layers 2a-2c reduces in the depth direction.

  If it carries out like this, the 1st-4th electrode parts 31a-31d which the probe 8 for an inspection will contact electrically will be the periphery of the 1st-3rd through-holes 21a-21c of the 1st-3rd insulating layers 2a-2c. Formed in the part. Each through-hole 21a-21c is provided concentrically in planar view, and each of those sizes decreases in the depth direction. Therefore, when the inspection probe 8 is brought into electrical contact with the first to fourth electrode portions 31a to 31d, the probe 8 is inserted into the first and second through holes 21a and 21b, and the first to third electrode portions. Contact with 31a to 31c. Therefore, it is possible to make it difficult for the probe 8 to be detached from the first and second through holes 21a and 21b. Further, the contact area between the probe 8 and the first to third electrode portions 31a to 31c increases. Therefore, the inspection probe 8 can be stably brought into electrical contact with the first to third electrode portions 31a to 31c, and the measurement stability can be improved.

  Furthermore, since the reliability of the measurement value can be improved and the occurrence of measurement errors can be suppressed, the time required for the measurement work can be reduced.

  Moreover, according to the multilayer substrate 1 of 1st Embodiment, the 1st-3rd electrically connected to the inner wall of the 1st-3rd through-holes 21a-21c with the 1st-4th electrode parts 31a-31d. Conductive paths 22a to 22c are formed. If it carries out like this, the probe 8 and the 1st-4th electrode part 31a will contact by the probe 8 contacting the 1st-3rd conductive path 22a-22c formed in the inner wall of the 1st-3rd through-holes 21a-21c. The electrical connection area with ~ 31d is substantially increased. Therefore, the electrical contact state between the probe 8 and the first to fourth electrode portions 31a to 31d can be improved.

  Moreover, according to the multilayer substrate 1 of 1st Embodiment, each through-hole 21a-21c has a cylindrical shape. If it carries out like this, since the shape of the 1st-3rd through-holes 21a-21c is simple, the 1st-3rd through-holes 21a-21c can be easily formed in each insulating layer 2a-2c. Therefore, the manufacturing process is not complicated and the cost can be suppressed.

According to the multilayer substrate 1 of the first embodiment, the sizes of the first to third through holes 21 a to 21 c may be reduced according to the shape of the tip of the probe 8. By doing so, the sizes of the inner peripheral edges of the electrode parts 31a to 31c formed at the peripheral parts of the first to third through holes 21a to 21c also change according to the shape of the tip of the probe 8, The probe 8 can be brought into electrical contact with the first to third electrode portions 31a to 31c. Therefore, the contact area between the probe 8 and the first to third electrode portions 31a to 31c increases, so that the measurement stability can be improved and the reliability of the measurement value can be further improved.
Second Embodiment

  Next, a second embodiment will be described. In the second embodiment, the inner walls of the first and second through holes 21a and 21b are tapered. The rest is the same as in the first embodiment. In the following, the second embodiment will be described with respect to items different from the first embodiment. Moreover, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description may be abbreviate | omitted.

  FIG. 6 is a perspective view of the multilayer substrate according to the second embodiment. FIG. 7 is a cross-sectional view of the multilayer substrate according to the second embodiment. As shown in FIGS. 6 and 7, in the second embodiment, the first and second through holes 21a and 21b formed in the first and second insulating layers 2a and 2b are reduced in size in the depth direction. It is formed to have a tapered shape. Moreover, in each through-hole 21a, 21b, the size of the opening end on the upper surface side is larger than the size of the opening end on the back surface side. The third through hole 21c formed in the third insulating layer 2c has a cylindrical shape parallel to the Z direction, and the size of each open end on the upper surface side and the back surface side of the third through hole 21c is second. It is the same as the opening end on the back surface side of the through hole 21b.

  The tapered shape of the first and second through holes 21a and 21b is preferably close to the shape of the tip of the probe 8. In this way, when measuring at the test point, the probe 8 is brought into contact with at least a part of the first and second conductive paths 22a and 22b formed in the inner walls of the first and second through holes 21a and 21b. Can do. Therefore, the probe 8 is held more stably in the through hole 6, and the contact area between the first to fourth electrode portions 31a to 31d and the first and second conductive paths 22a and 22b is also increased. Therefore, since the signal can be measured in a more stable state, the reliability of the measured value can be improved. In addition, since measurement errors can be made less likely to occur, the time required for measurement work can be further reduced.

  Furthermore, it is further desirable that the tapered shape of the first and second through holes 21 a and 21 b is substantially the same as the shape of the tip of the probe 8. In this way, when performing measurement at the test point, the probe 8 inserted into the through hole 6 is connected to the first and second conductive paths 22a and 22b formed on the inner walls of the first and second through holes 21a and 21b. Surface contact can be made on almost the entire surface. Therefore, the probe 8 can be held in a substantially fixed manner in the through hole 6, and the contact area with the first to fourth electrode portions 31a to 31d and the first and second conductive paths 22a and 22b is maximized. be able to. Therefore, since a stable measurement value can be obtained in a substantially fixed state, the reliability of the measurement value can be improved, and the time required for the measurement operation can be greatly reduced.

The second embodiment has been described above. According to the multilayer substrate 1 of the second embodiment, the first and second through holes 21a and 21b have a tapered shape whose size decreases in the depth direction. If it carries out like this, since it becomes easy for the probe 8 to contact the inner wall of the 1st and 2nd through-holes 21a and 21b, the position of the probe 8 becomes difficult to shift | deviate. Therefore, it is possible to make it difficult for the probe 8 to be detached from the first and second through holes 21a and 21b, and to make it difficult to separate from the first and second electrode portions 31a and 31b. Therefore, the probe 8 can be brought into contact with the first and second electrode portions 31a and 31b more stably.
<Third Embodiment>

  Next, a third embodiment will be described. In the third embodiment, first to third internal conductive paths 23a to 23c for electrically connecting the electrode portions 31a to 31c are formed in the first to third insulating layers 2a to 2c. The rest is the same as in the first and second embodiments. In the following, the third embodiment will be described with respect to items different from the first and second embodiments. Moreover, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description may be abbreviate | omitted.

  FIG. 8 is a cross-sectional view of the multilayer substrate according to the second embodiment. As shown in FIG. 8, in the third embodiment, a first internal conductive path 23a for electrically connecting the first and second electrode portions 31a and 31b in the first insulating layer 2a. Is formed. Further, in the second insulating layer 2b, a second internal conductive path 23b for electrically connecting both is formed between the second and third electrode portions 31b and 31c. Further, in the third insulating layer 2c, a third internal conductive path 23c for electrically connecting the third and fourth electrode portions 31c and 31d is formed. By so doing, the first to third internal conductive paths 23 a to 23 c are not exposed to the inside of the first to third through holes 21 a to 21 c and do not contact the atmosphere around the multilayer substrate 1. Therefore, wear or damage due to contact with the probe 8 and deterioration of the atmosphere (for example, oxidation or corrosion) can be suppressed.

  The form of the first to third internal conductive paths 23a to 23c is not particularly limited. The first to third internal conductive paths 23a to 23c may be through holes filled with a conductive material, or may be through holes in which conductive paths are formed on the inner wall.

  As described above, according to the multilayer substrate 1 of the third embodiment, inside the first to third insulating layers 2a to 2c, the electrode portion 31 of the conductor layer 3 on one main surface side and the other main surface. First to third internal conductive paths 23a to 23c that electrically connect the electrode portion 31 of the side conductor layer 3 are formed. In this way, the first to third internal conductive paths 23a to 23c are not exposed inside the through holes 21a to 21c. Therefore, there is no possibility that the first to third internal conductive paths 23a to 23c are worn by contact with the probe 8. Moreover, deterioration (for example, oxidation, corrosion, etc.) of the 1st-3rd internal conductive paths 23a-23c by the atmosphere in the 1st-3rd through-holes 21a-21c can also be suppressed.

  The embodiment of the present invention has been described above. Note that the above-described embodiment is an exemplification, and various modifications can be made to each component and combination of processes, and it will be understood by those skilled in the art that they are within the scope of the present invention.

  For example, in the first to third embodiments, a four-layer substrate is described as an example, but the scope of application of the present invention is not limited to this example. The multilayer substrate 1 may be an n-layer substrate (n is a positive integer of 2 or more).

  In the first to third embodiments, the probe 8 is inserted into the first and second through holes 21a and 21b and is not substantially inserted into the third through hole 21c when measuring the test point. However, the scope of application of the present invention is not limited to this example. When measuring the test point, the probe 8 may be inserted into the first to third through holes 21a to 21c.

  Moreover, in 1st-3rd embodiment, although each through-hole 21a-21c is formed in all the 1st-3rd insulating layers 2a-2c, the application range of this invention is not limited to this illustration. The through holes may not be formed in one or more insulating layers counted from the back surface side of the multilayer substrate 1. As an example, for example, a configuration in which the third through hole 21c is not formed in the third insulating layer 2c in the first to third embodiments can be exemplified.

DESCRIPTION OF SYMBOLS 1,501,511 Multilayer substrate 2a-2d, 502a-502d Insulating layer 21a-21c, 521a-521c Through-hole 22a-22c, 522a-522c Conductive path 23a-23c Internal conductive path 3a-3c, 503a-503c Conductive layer 31a ˜31c, 531 Electrode portion 532 Solder 4a, 4b, 504a, 504b Resist layer 41a, 41b, 541 Opening 6 Through hole 8 Probe

Claims (6)

A multilayer substrate having an electrode part with which an inspection probe is in electrical contact;
A plurality of insulating layers in which through-holes are formed, and a plurality of conductor layers provided on the insulating layer,
The conductor layer is provided alternately with the insulating layer, and includes the electrode portion,
The electrode portion is formed at the peripheral edge of the through hole,
In a plan view seen from the normal direction of the main surface of the insulating layer, each through hole of the plurality of insulating layers is provided concentrically,
The multilayer substrate, wherein each size of the through holes of the plurality of insulating layers decreases in the depth direction.   The multilayer substrate according to claim 1, wherein a conductive path electrically connected to the electrode portion is formed on an inner wall of the through hole.   The multilayer substrate according to claim 1, wherein each through hole has a cylindrical shape.   The multilayer substrate according to claim 1, wherein each through hole has a tapered shape whose size decreases in the depth direction.   An internal conductive path for electrically connecting the electrode portion of the conductor layer on one main surface side and the electrode portion of the conductor layer on the other main surface side is formed inside the insulating layer. The multilayer substrate according to any one of claims 1 to 4.   6. The multilayer substrate according to claim 1, wherein each size of the through hole decreases according to a shape of a tip of the probe.