JP2002314219A - Substrate embedded with through conductor and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide a substrate in which a through conductor is embedded and a method of manufacturing the same, to manufacture a substrate in which a through conductor is embedded at a high density in a simple process with high accuracy and at low cost. SOLUTION: A conductor 3 is inserted into a through-hole 2 having a diameter of 2 mm or less provided in a substrate 1, and a gap between the through-hole 2 and the conductor 3 is filled with an insulating resin 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate having a through conductor embedded therein and a method of manufacturing the same, and more particularly to an inspection of a structure suitable for mounting on a printed wiring board or a wiring inspection apparatus for inspecting a printed wiring board. The present invention relates to a substrate in which a through conductor having a feature in the configuration and insertion method of a through conductor constituting a probe and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a wiring inspection board used for inspecting a printed wiring board has an inspection probe for contacting a desired portion of a wiring on a printed wiring board attached to a substrate base portion. And pressed against the printed wiring board.

In this inspection apparatus, a contact terminal of an inspection probe is pressed against a wiring pattern of a printed wiring board to detect a disconnection or short circuit of a wiring pattern formed on a printed wiring board.

As a method of manufacturing such a wiring inspection plate,
A method of forming a fine hole in a substrate base portion and filling the fine hole with a conductive material to form a conductive hole (through via) has been used. As a method of filling such a conductive material, plating is used. And a method of penetrating a conductive wire.

[0005] In the case of such a method of metallizing the through holes by plating or a method of forming through vias by penetrating conductive wires, crosstalk or short circuit between adjacent through vias through the substrate is prevented. To do
It is necessary to use an insulating substrate as the substrate.

The above-mentioned method is also used as a means for manufacturing a wiring board. For a wiring board, in particular, for a high-density mounting board, for example, glass which can obtain extremely high smoothness when polished is used. Are used as insulating substrates.

In this case, a through-hole is formed in the glass serving as a substrate by laser processing, or a conductive material serving as a through-conductor is plated in a portion of the through-hole using a glass having a through-hole provided in advance, such as photosensitive glass. The wiring board is manufactured by filling with such as.

[0008]

However, there are several problems with the above-described method of manufacturing a through via. For example, when the plating method is used, there are problems that the cost is high due to the long process and that the type of the conductor that can be plated is restricted.

Further, with the recent demand for higher density integration of IC chips, it is necessary to provide wiring at a fine pitch of 100 μm or less. However, depending on a base material such as glass, such a fine pitch is required. In some cases, it is difficult to form a through hole while preventing breakage.

On the other hand, in the case of a method in which a conductive wire is penetrated without using a plating method, a means used for filling a tolerance between the conductive wire and a through hole provided in a substrate base is limited to heat treatment. In addition, there is a problem that the combination of the conductive wire, the base material constituting the substrate, and the heat treatment atmosphere is limited by the heat treatment.

Accordingly, an object of the present invention is to manufacture a substrate in which through conductors are embedded at high density with a simple process, with high accuracy, and at low cost.

[0012]

FIG. 1 is an explanatory view of the principle configuration of the present invention. Referring to FIG. 1, means for solving the problems in the present invention will be described. See FIG. 1 In order to achieve the above-described object, the present invention relates to a substrate 1 in which a conductor is embedded in a through-hole 2 having a diameter of 2 mm or less provided in the substrate 1.
The gap between the conductor and the conductor is buried with an insulating resin.

As described above, by filling the gap between the conductor 3 and the through hole 2 provided in the substrate 1 with the insulating resin 4, there is no restriction to use an insulating substrate as the substrate 1.
Since it is easy to form the through hole 2 having a small diameter, it is possible to increase the density and reduce the cost. In addition, since the damaged material of the insulating resin 4 does not permeate, the wiring and the like may swell. Can be prevented.

In this case, by making the length of the conductor 3 longer than the thickness of the substrate 1 and projecting from one surface of the substrate 1, the protrusion of the conductor 3 is inclined with respect to the normal line of the substrate 1. By peeling, it may be used as a contact terminal part of the probe,
With a simple configuration, a wiring inspection board with high pitch accuracy can be configured.

The conductor 3 may have a length substantially equal to the thickness of the substrate 1 to form the through-via substrate 1. The conductor 3 does not protrude from the main surface of the substrate 1 and is flat. In addition, the formation of electrodes and wiring layers becomes easy.

When manufacturing the substrate 1 in which such a through conductor is embedded, it is desirable to insert the conductor 3 previously coated with the insulating resin 4, whereby the substrate 1
It is possible to satisfactorily insulate and insert into the device.

Before the conductor 3 is inserted, the substrate 1
It is desirable to form an insulating resin layer on one surface of the conductor 3, thereby displacing the conductor 3 caused by the disappearance of the insulator provided between the inserted conductor 3 and the through hole 2. Short circuit and crosstalk due to contact between conductors can be prevented.

In the step of inserting the conductor 3 into the through hole 2, a plurality of conductors 3 are provided on one main surface of the substrate 1.
By carrying out suction from the other main surface side of the substrate 1 in a state where the substrate 3 is placed, the conductor 3 can be inserted into the through hole 2 without requiring high-precision alignment. In this case, suction may be performed from the air inlet 6 provided in the jig 5 while the substrate 1 is held by the jig 5.

At the time of suction, it is desirable to vibrate the jig 5 and hence the substrate 1, so that the conductor 3 can be more smoothly inserted into the through hole 2.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A manufacturing process according to a first embodiment of the present invention will now be described with reference to FIGS. Referring to FIG. 2A, first, a silicon substrate 11 having a thickness of, for example, 550 μm
After applying epoxy resin which is a thermosetting resin on top,
By heat curing, the thickness is, for example, 50 μm
The epoxy resin layer 12 is formed.

Next, by irradiating the silicon substrate 11 with a laser beam 13 at a predetermined interval using a YAG laser, a through hole 14 having a diameter of, for example, 1 mm is formed, for example, at 1.27.
It is formed at a pitch of mm.

Referring to FIG. 2C, on the other hand, for example, an Au wire 16 having a diameter of 0.95 mm, for example.
Epoxy resin layer 1 having a thickness of, for example, 25 μm
7, after applying and curing, a predetermined length, for example, 4
The plurality of conductors 15 are formed by cutting the conductors 15 mm.

Next, as shown in FIG. 2D, the silicon substrate 11 having the through-holes 14 is placed on a jig base 18 provided with an intake port 19, and the holding member 20 is used to hold and hold the silicon substrate 11. Fix it. Although not shown, an O-ring is provided at a contact portion of the jig base 18 and the pressing member 20 with the silicon substrate 11 in order to prevent mechanical damage of the silicon substrate 11 and to enhance confidentiality in a peripheral portion. It is interposed.

Next, in such a state, the silicon substrate 1
A large number of conductors 15 made of Au wires 16 covered with an epoxy resin layer 17 are randomly placed on the surface provided with one epoxy resin layer 12, and provided on a jig base 18 while vibrating the jig. By conducting vacuum suction through the suction port 20, the conductor 15 is sucked and inserted into the through hole 14 serving as a suction port.

In this case, since the jig is vibrated, the conductor 15 will eventually move and be sucked into the through-hole 14 near the through-hole 14 through which the conductor 15 is not inserted. By conducting vibration and suction, the conductor 15 can be inserted into all the through holes 14. In this case, the length of the conductor protruding from the through hole 14 is defined by the distance between the silicon substrate 11 and the jig base 18 and is aligned at a substantially constant length.

Next, although not shown, a thermoplastic epoxy resin is previously applied to the entire surface of the epoxy resin layer 12 side to fill the gap between the through hole 14 and the conductor 15 and then heat-treated. Through hole 14 and conductor 1
5 can be eliminated.

Next, as shown in FIG. 3 (e), the exposed portions of the epoxy resin layer 12 and the epoxy resin layer 17 covering the Au wires 16 are removed by performing ashing using O ₂ plasma on the entire surface.

Next, one protruding portion of the Au wire 16 is bent at a predetermined angle with respect to the silicon substrate 11 so as to be Au.
One protruding portion of the wire 16 is set as the contact terminal portion 21 so as to match the pitch of the terminals of the substrate to be measured. In the figure, four Au wires 16 are shown as one set for simplicity of illustration, but in practice many Au wires 16 are divided into many sets, and in each set, FIG. ).

Next, after a Ni plating layer 22 having a thickness of, for example, 10 μm is formed on the surface of the terminal contact portion 21 by an electroless plating method, the thickness is reduced by, for example, an electrolytic plating method. 5μ
An Au plating layer 23 of m m is formed. This Au plating layer 2
By forming 3, the contact with the substrate to be inspected is softened, and the life of the probe can be extended.

Next, referring to FIG. 3 (h), the other end of the Au wire 16 is polished and flattened by polishing the protruding portion in a state where the contact terminal portion 21 is protected. By using an electrolytic plating method, a wiring layer 25 connected to the buried conductor portion 24 is formed, thereby completing a basic configuration of a wiring test board having a test probe. Note that the wiring layer 25 serves as a lead electrode for guiding a measurement signal to the measurement device.

As described above, in the first embodiment of the present invention, since the conductor penetrating the substrate is previously coated with the epoxy resin which is an insulator, the silicon substrate 11 having conductivity is used as the substrate. It can be used and there are fewer constraints on the substrate.

Since the gap between the through hole 14 and the Au wire 16 is necessarily filled with the epoxy resin layer 17,
Moisture and the like do not seep into the through-holes, so that there is no problem such as the wiring layer 25 or the like swelling, so that the reliability is improved.

Further, before forming the through hole 14, since the surface of the silicon substrate 11 is provided an epoxy resin layer 12, during the ashing by O ₂ plasma, epoxy resin layer 12 is ashed, epoxy resin layer 17 Ashing of the portion inside the through-hole 4 by the O ₂ plasma can be suppressed,
It is possible to prevent the Au wire 16 from being displaced or bent.

Next, a second embodiment of the present invention will be described with reference to FIG. 4. However, only the direction in which the Au wire is bent is different, and the other configuration is different from that of the first embodiment. The description is simplified since it is completely the same. Referring to FIG. 4A, the bare Au wires 16 are projected from both surfaces of the silicon substrate 11 through exactly the same steps as in FIGS. 2A to 3E of the first embodiment. Is obtained.

4 (b) and 4 (c). Next, one protruding portion of the Au wire 16 is bent at a predetermined angle with respect to the silicon substrate 11 toward the inside of the silicon substrate 11, and the Au wire 16 is bent. One protruding portion of the wire 16 is referred to as a contact terminal portion 21. FIG. 4 (c)
Shows a cross section along a direction orthogonal to FIG. 4B, and the contact terminal portions 21 arranged in a line are bent at the same angle in the same direction.

Next, after a Ni plating layer 22 having a thickness of, for example, 10 μm is formed on the surface of the terminal contact portion 21 by an electroless plating method, the thickness is reduced by an electrolytic plating method.
For example, a 5 μm Au plating layer 23 is formed.

Next, with the contact terminal portion 21 protected, the other end of the Au wire 16 is polished and flattened to form the buried conductor portion 24. By using an electrolytic plating method, a wiring layer 25 connected to the buried conductor portion 24 is formed, thereby completing a basic configuration of a wiring test board having a test probe.

As described above, in the second embodiment of the present invention, since the contact terminal portion 21 is bent inward, the area of the silicon substrate 11 can be made larger than the area of the substrate to be measured. This facilitates the conductor insertion step.

Next, a manufacturing process according to a third embodiment of the present invention will be described with reference to FIGS. 5 (a) and 5 (b) First, the thickness of the sintered ceramic is, for example, 2 mm.
The AlN substrate 31 is prepared, and then the AlN substrate 31 is irradiated with laser beams 32 in a matrix at predetermined intervals using a YAG laser to form a through hole 33 having a diameter of, for example, 1 mm.

Referring to FIG. 5C, on the other hand, an epoxy resin layer 36 having a thickness of, for example, 25 μm is formed on the surface of the W wire 35 having a diameter of, for example, 0.95 mm.
After applying and curing, a predetermined length, for example, 4m
The plurality of conductors 34 are formed by cutting the conductors so as to have a width of m.

Next, the AlN substrate 31 having the through-hole 33 formed thereon is placed on a jig base 37 provided with an air inlet 38, and the holding member 39 is used to hold and hold the AlN substrate 31. Fix it.
Although not shown, the AlN substrate 3 is also used in this case.
An O-ring is interposed at the contact portion between the jig base 37 and the pressing member 39 with the AlN substrate 31 in order to prevent mechanical damage of 1 and to enhance the confidentiality in the peripheral portion.

Next, in this state, the AlN substrate 31
Wire 35 covered with an epoxy resin layer 36 on the upper surface
A large number of conductors 34 are randomly placed, and while the jig is vibrated, vacuum suction is performed through an intake port 39 provided in the jig base 37 so that the conductor 34 is inserted into the through hole 33 serving as a suction port. It will be sucked and inserted.

In this case, since the jig is vibrated, the conductor 34 moves and is attracted to the through hole 33 near the through hole 33 where the conductor 34 is not inserted. By conducting vibration and suction, the conductor 34 can be inserted into all the through holes 33.

Next, although not shown, after removing the AlN substrate 31 from the jig, an epoxy resin is applied to fill the gap between the through hole 33 and the conductor 34, and then heat-treated. Through hole 33 and conductor 3
4 so as to eliminate the gap.

Next, as shown in FIG. 6E, the exposed portion of the epoxy resin layer 16 covering the W wire 35 is removed by performing ashing using O ₂ plasma on the entire surface.

Next, as shown in FIG. 6F, the buried conductor 40 is formed by polishing both surfaces of the AlN substrate 31 to remove and flatten the protrusions of the W wires 35 protruding from the AlN substrate 31. .

Next, as shown in FIG. 6 (g), the embedded conductor 4 is formed by a normal selective electrolytic plating method.
The basic structure of the wiring board having a multilayer structure is completed by repeating the steps of forming the wiring layer 41 to be connected to zero and the step of forming the interlayer insulating layer as necessary.

As described above, in the third embodiment of the present invention, the conductor penetrating the substrate is previously covered with the epoxy resin which is an insulator, so that the restriction on the base material used as the substrate is reduced. Although the heat treatment temperature can be reduced as compared with the conventional method of penetrating a conductive wire, the restriction on the substrate, the wire, or the atmosphere for the heat treatment can be reduced although the heat curing of the resin is used. Can be.

Also, in the third embodiment,
Since the substrate is polished and flattened after inserting the conductor,
The electrodes and wiring layers connected to the buried conductor 40 can be formed accurately and easily.

In the third embodiment,
To facilitate the manufacturing process, the diameter of the through-hole is made as large as 1 mm, but it is possible to make it about 100 μm, which makes it difficult to use a conventional glass substrate. Also, it becomes possible to form through vias at a minute pitch.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configuration described in the embodiments, and various modifications are possible. For example, in the above-described first embodiment, the contact terminal portion is divided into a plurality of sets, and the sets are bent in the same manner between the sets.
The whole contact terminal portions arranged in a line may be bent toward the center with the center contact terminal portion as the center.

However, in this case, since the height of the contact terminals after bending is not uniform, the cross-sectional shape of the bottom of the jig base where the suction port is provided is triangular with the center being higher and inserted. In this state, the length of the projecting portion of the conductor may be increased in the peripheral portion.

Further, the contact terminal portion may be bent toward the center of the contact terminal portion arranged in a line and also toward the center portion of the substrate, whereby the pogo constituting the measuring device may be formed. The difference between the terminal pitch of the seat and the terminal pitch of the substrate to be measured can be adjusted.

In each of the above embodiments, the conductor is inserted into the through hole, and then epoxy resin is applied to fill the gap between the conductor and the through hole. This is not always necessary when the outer diameter of the conductor is substantially equal.

In each of the above embodiments, the conductor is formed by coating the metal wire with the epoxy resin in a long state and then cutting the metal wire to a predetermined length. After being cut to length, it may be covered with an epoxy resin.

In the probe substrates of the first and second embodiments, a silicon substrate is used as the substrate, and the through-via substrate of the third embodiment is formed of AlN.
Although a substrate is used, the substrate is not limited as described above, and an AlN substrate may be used as the probe substrate, and a silicon substrate may be used as the through via substrate. Although it is difficult to form a through via hole, a glass substrate may be used, and in any case, the cost can be reduced by using the method of the present invention.

In the first and second embodiments, the conductor is made of a soft and easily bendable Au wire. However, the conductor is not limited to the Au wire, but is made of a conductive material like Au. A soft Cu wire having good properties may be used.

In the third embodiment, the W wire is used to form the through via. However, the present invention is not limited to the W wire, and other conductors such as an Au wire may be used. Is also good.

In each of the above embodiments, the epoxy resin is used as the resin. However, the resin is not limited to the epoxy resin, and another thermosetting resin may be used. Alternatively, a photocurable resin may be used.

In the above description, a probe substrate or a through-via substrate is assumed, but the present invention is not limited to such a probe substrate or a through-via substrate, but may be applied to various substrates provided with through conductors. For example, when an LSI chip is mounted on a mounting wiring board, the present invention is also applied to an interposer type capacitor board inserted between the mounting wiring board and the LSI chip.

Here, the detailed features of the present invention will be described with reference to FIG. 1 again. See FIG. 1 (Supplementary Note 1) In a substrate 1 in which a through conductor is embedded, a conductor 3 is inserted into a through hole 2 having a diameter of 2 mm or less provided in the substrate 1, and between the through hole 2 and the conductor 3. Wherein the gap is filled with an insulating resin 4. (Supplementary Note 2) The length of the conductor 3 is longer than the thickness of the substrate 1, and the conductor 3 protruding from one surface of the substrate 1 constitutes a contact terminal portion of a probe, and the contact terminal portion 3. The substrate according to claim 1, wherein a center line of the substrate is inclined with respect to a normal line of the substrate 1. (Supplementary Note 3) The conductor 3 does not protrude from the main surfaces on both sides of the substrate 1, and the conductor 3 is electrically connected to a wiring layer provided on the substrate 1 on at least one main surface. Supplementary note 1 characterized in that the connection is made
A substrate in which the described through conductor is embedded. (Supplementary Note 4) The substrate according to any one of Supplementary Notes 1 to 3, wherein the substrate 1 is one of a conductive substrate and an insulating substrate. (Supplementary Note 5) A step of forming a through hole 2 having a diameter of 2 mm or less in the substrate 1, a step of inserting a conductor 3 having a smaller diameter than the through hole 2 and previously coated with an insulating resin 4 into the through hole 2,
A step of bending the conductor (3) projecting from one surface of the substrate (1) constituting a contact terminal portion of a probe at a predetermined angle with respect to a normal line of the substrate (1); The method of manufacturing the substrate. (Supplementary Note 6) A step of forming a through hole 2 having a diameter of 2 mm or less in the substrate 1, a step of inserting a conductor 3 having a smaller diameter than the through hole 2 and coated with an insulating resin 4 in advance through the through hole 2,
A method of manufacturing a substrate having embedded through conductors, comprising a step of polishing the conductor 3 and the insulating resin 4 projecting from both surfaces of the substrate 1 to smooth the substrate 1. (Supplementary Note 7) The through conductor according to Supplementary Note 5 or 6, wherein an insulating resin layer is formed on one surface of the substrate 1 before the step of forming the through hole 2 in the substrate 1. Substrate manufacturing method. (Supplementary Note 8) In the step of inserting the conductor 3 into the through-hole 2, the plurality of conductors 3 are placed on one main surface of the substrate 1 and the other main surface of the substrate 1 is 8. The method of manufacturing a substrate in which a through conductor is embedded according to any one of supplementary notes 5 to 7, wherein suction is performed. (Supplementary Note 9) The method for producing a substrate with embedded through conductors according to supplementary note 8, wherein the substrate 1 is vibrated in the step of performing suction from one main surface side of the substrate 1.

[0062]

According to the present invention, since the conductor coated in advance with the insulating resin is inserted through the through-hole formed in the substrate, the substrate material is not restricted and the wire material and the heat treatment conditions are also restricted. As a result, the cost can be reduced and the density can be increased. In addition, since no inconvenience occurs due to the infiltration of moisture or the like into the through-holes, the reliability can be improved. It greatly contributes to higher performance.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process partway through the first embodiment of the present invention.

FIG. 3 is an explanatory view of a manufacturing process of the first embodiment of the present invention after FIG. 2;

FIG. 4 is an explanatory diagram of a manufacturing process according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a manufacturing process partway through a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a manufacturing process of the third embodiment of the present invention after FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 substrate 2 through hole 3 conductor 4 insulating resin 5 jig 6 suction port 11 silicon substrate 12 epoxy resin layer 13 laser beam 14 through hole 15 conductor 16 Au wire 17 epoxy resin layer 18 jig base 19 suction port 20 press Member 21 Contact terminal part 22 Ni plating layer 23 Au plating layer 24 Embedded conductor part 25 Wiring layer 31 AlN substrate 32 Laser beam 33 Through-hole 34 Conductor 35 W wire 36 Epoxy resin layer 37 Jig base 38 Inlet 39 Holding member 40 embedded conductor 41 wiring layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/50 H01L 23/50 Y F term (Reference) 2G011 AA02 AA15 AB06 AB07 AC00 AE01 AF06 AF07 5F067 AA19 BC01 BC12 CC07

Claims (5)

[Claims] In a substrate having a through conductor embedded therein, a conductor is inserted into a through hole having a diameter of 2 mm or less provided in the substrate, and a gap between the through hole and the conductor is filled with an insulating resin. A substrate having a through conductor embedded therein. 2. The length of the conductor is longer than the thickness of the substrate, and the conductor protruding from one surface of the substrate constitutes a contact terminal portion of a probe, and a center line of the contact terminal portion. 2. The substrate according to claim 1, wherein the substrate is inclined with respect to a normal line of the substrate. 3. The electric conductor does not protrude from main surfaces on both sides of the substrate, and the electric conductor is electrically connected to a wiring layer provided on the substrate on at least one main surface side. A substrate in which the through conductor according to claim 1 is embedded. 4. A step of forming a through hole having a diameter of 2 mm or less in a substrate, a step of inserting a conductor having a diameter smaller than that of the through hole and previously coated with an insulating resin into the through hole, and forming a contact terminal portion of the probe. A method of manufacturing a substrate in which a through conductor is embedded, the method including a step of bending the conductor projecting from one surface of the substrate to be formed at a predetermined angle with respect to a normal line of the substrate. 5. A step of forming a through hole having a diameter of 2 mm or less in a substrate, a step of inserting a conductor having a smaller diameter than the through hole and previously coated with an insulating resin into the through hole, and both surfaces of the substrate. And polishing the conductor and insulating resin projecting from the substrate to smooth the substrate.