JP2002090465A - Production method for radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method which enables stable and inexpensive production of a radiation detector with a less risk of shortcircuiting by accomplishing the detection of position accurately. SOLUTION: An anode is formed as cylindrical via post or a conical bump simultaneously with or immediately after the production process of a both sides continuity means in the course of producing the radiation detector to allow stable production of the radiation detector at a less cost. Especially, when the anode and the both sides continuity means are formed simultaneously in the via post or the bump, the process can be shortened thereby contributing to a less cost and a higher reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a radiation detector, and more particularly to a method for manufacturing a radiation detector used for detecting an incident position of radiation such as X-rays.

[0002]

2. Description of the Related Art A radiation detector for irradiating a crystal with radiation such as X-rays for analyzing a crystal structure and measuring secondary electrons in a gas atmosphere is known, and is also called a radiation gas amplification detector. . Such a radiation detector is also referred to as MSGC (Micro Strip Gas Chamber) because it has a minute strip-shaped (strip) electrode in a gas-sealed case.

The structure of a conventional radiation detector will be described with reference to FIG. 13A is a plan view, and FIGS. 13B and 13B are a cross-sectional view taken along the line PP ′ and a line QQ ′ of FIG. 13A, respectively.

As shown in these figures, a conventional radiation amplifier has a plurality of backstrips 2 having a width of, for example, 160 .mu.m on a ceramic substrate 1 having a thickness of, for example, 1 mm.
m, and an insulating layer 3 is formed thereon.
An anode strip 4 having a width of 10 μm and a width of 100 μm are formed on the insulating layer 3 so as to be orthogonal to the backstrip 2.
m cathode strips 5 are alternately arranged at a pitch of 200 μm.

[0005] In such a radiation detector, a high voltage is applied between the anode strip 4 and the cathode strip 5, and depending on which anode strip 4 or backstrip 5 current flows when radiation is incident. , The radiation incident position is detected.

[0006]

However, in such a conventional radiation detector, when radiation is incident so as to overlap in the direction in which the anode strip runs, one radiation detector is required.
There is a problem that only dimensional coordinates can be read.

Further, as described above, since the anode strip 4 is applied with a high voltage in spite of its very narrow width, the anode strip 4 may be blown, and this blowing may cause one of the anode strips to be opened. Or there is a problem that the wiring piece at the time of fusing may cause a short circuit with the adjacent pattern.

Further, since the conventional radiation detector uses the expensive ceramic substrate 1, the manufacturing process becomes longer,
Was raising costs.

The present invention has been made to solve such a problem, and a manufacturing method capable of accurately detecting a position and stably and inexpensively manufacturing a radiation detector which is less likely to cause a short circuit. The purpose is to provide.

[0010]

According to a first aspect of the present invention, a step of forming a conductive pump on a first conductive plate serving as an inner layer, and a step of forming a conductive pump on the first conductive plate serving as an inner layer. Performing a press by stacking conductive plates, patterning the first conductive plate to form an inner layer, fixing the patterned first conductive plate on a base material, Selectively removing the conductive plate corresponding to the planned anode, and forming an opening in the insulating plate to reach the first conductive plate; and patterning the second conductive plate to form a surface layer serving as a cathode. And a step of forming a conductive bost serving as an anode in the opening by metal plating in the opening.

According to a second aspect of the present invention, a step of forming a conductive pump on the first conductive plate serving as an inner layer at the planned front and back conductive portion and the planned anode is provided. Pressing a second conductive plate to be a surface layer, pressing the first conductive plate, fixing the patterned first conductive plate on a base material, Selectively removing the second conductive plate from the anode portion and its surrounding portion to obtain an exposed pump as an anode and a patterned second conductive plate as a cathode. Is done.

According to a third aspect of the present invention, a step of patterning the first conductive layer of an insulating plate having first and second conductive layers in a lower layer and an upper layer, respectively, into an inner layer pattern; Fixing the second conductive layer on the base material, opening the second conductive layer corresponding to the front and back conductive portions and the anode portion, and further forming an opening that passes through the insulating plate and reaches the first conductive layer. A method for manufacturing a radiation detector, comprising: a step of forming a surface layer serving as a cathode by patterning the second conductive layer; and a step of forming a post-shaped conductor by metal plating in the opening. Is done.

The first and second layers are respectively provided in the lower layer and the upper layer.
Forming a through-hole corresponding to the front / back conductive portion of the insulating plate having the conductive layer, forming a metal plating layer in the through-hole to obtain a through-hole, and forming the first conductive layer into an inner layer pattern. Patterning, fixing the insulating plate on a base material, opening the second conductive layer corresponding to the anode portion, and further penetrating the insulating plate to the first conductive layer. A radiation detector comprising: a step of forming an opening that reaches; a step of patterning the second conductive layer to form a surface layer serving as a cathode; and a step of forming a post-shaped conductor by metal plating in the opening. Is provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1A is a plan view showing the configuration of a radiation detector 100 manufactured by applying the first embodiment of the method according to the present invention, and FIG. FIG. 1C is a sectional view taken along the line BB of FIG.

The copper foil pattern 10 of the inner layer is
1 'is formed, and an apost 126 is provided to penetrate the polyimide resin layer 103 formed thereon, and is connected to the lower layer pattern 101'. On the other hand, on the front side, the surface copper foil pattern 104 ′ has a circular opening separated from the via post 126 by a certain distance.
Is provided.

Such a radiation detector includes a via post 1
26 functions as an anode, and the surface layer pattern 104 'functions as a cathode. However, since the via posts are columnar and have no directionality, accurate position detection can be performed.

FIGS. 2 to 4 are sectional views showing the steps of a method for manufacturing the radiation detector shown in FIG. 1 according to the first embodiment of the present invention.

First, an 18 μm-thick copper foil 10 serving as an inner layer
A silver paste is selectively printed on the top 1 in correspondence with the front and back conductive portions. As a result, a substantially conical silver bump 102 remains on the copper foil 101 (FIG. 2A).

Next, a polyimide resin 103 serving as an insulating layer is placed on the copper foil 101 and the silver bumps 102, and another copper foil 104 (18 μm thick) is placed thereon and pressed. The configuration shown in FIG. That is, the silver bump 102 penetrates the insulating layer 103 and is in contact with the upper copper foil 104. The upper copper foil 104 becomes a surface layer, and the surface layer and the inner layer are connected by silver bumps.

Next, the copper foil 101 on the inner layer side is patterned through exposure and development steps to form an inner layer pattern 101 '.
Is formed (FIG. 2C).

Next, a base material 110 such as a glass fiber reinforced epoxy plate is prepared, and the laminate prepared in the previous step is placed on the surface of the base material with the prepreg 111 interposed therebetween, and pressed in a heated state (FIG. 2 (d)). As a result, the prepreg 111 is melted to fix the laminate and the base material 110 together.

Next, a resist 120 is applied on the entire surface, and is patterned by exposure and development so that an area where an anode is to be formed is opened (FIG. 2E). Etch to make hole 12 with a diameter of 50 μm
1 (FIG. 3A).

Next, by irradiating the entire surface with a carbon dioxide laser beam 122 (FIG. 3B), the polyimide resin 103 corresponding to only the etched portion of the copper foil is removed, and the hole 123 reaching the inner layer 101 '. Is formed.

Subsequently, the resist 120 is once removed (FIG. 3
(C)) A new resist 124 for forming a surface layer pattern is applied (FIG. 3 (d)), and this is patterned by photolithography. The surface layer 104 is patterned using the patterned resist 124 to obtain a surface layer pattern 104 '(FIG. 3E), and the resist 124 is peeled off (FIG. 4A).

Next, in order to form a via post in the already formed hole 123, a plating resist 125 is selectively formed so that only a portion corresponding to the hole 123 is exposed (FIG. 4B). The hole is filled with copper by electrolytic copper plating to obtain a via post 126 (FIG. 4C. The plating resist 125 is removed to obtain a configuration as shown in FIG. 4D.

In the case of a radiation amplifier having a size of 3 cm × 3 cm as a whole, via posts are arranged at a pitch of 400 μm, for example, in a vertical direction of 75 μm.
And 5625 pieces, 75 pieces in the horizontal direction.

In this embodiment, since silver bumps are used to connect the surface layer and the inner layer, variations in height can be suppressed.

FIGS. 5 and 6 are cross-sectional views showing a manufacturing method according to the second embodiment of the present invention, in which the connection between the surface layer and the inner layer is formed by via posts.

First, a resin plate 201 made of polyimide or the like having copper foil on the front and back is prepared, and the lower layer is patterned to obtain an inner layer pattern 202 (FIG. 5A).

Next, a substrate 210 such as a glass fiber reinforced epoxy plate is prepared, and a double-sided copper-clad laminate 201 having an inner layer pattern formed on the surface thereof in the previous step is prepreg 211
And press it in a heated state (see FIG. 5).
(B)). As a result, the prepreg 211 melts and fixes the double-sided copper-clad laminate and the base 210.

Next, a resist 220 is applied on the entire surface, and is patterned by exposure and development so that the front and back conductive portions and the region where the anode is to be formed are opened (FIG. 5C). The outer layer copper foil 220 is etched to form a hole 221 having a diameter of 50 μm using FIG.
(D)).

Next, by irradiating the entire surface with a carbon dioxide gas laser beam 222, the polyimide resin 201 corresponding to only the etched portion of the copper foil is removed, and a hole 223 reaching the inner layer 202 is formed (FIG. 5 ( e)).

Subsequently, the resist 220 is once removed (FIG. 5)
(F)), a new resist 224 for forming a surface layer pattern is applied, and this is patterned by photolithography (FIG. 6A). Using the patterned resist 224, the surface layer 203 is patterned to obtain a surface layer pattern 203 '(FIG. 6B), and the resist 224 is peeled off (FIG. 6C).

Next, in order to form a via post in the already formed hole 223, a plating resist 225 is selectively formed so that only a portion corresponding to the hole 223 is exposed (FIG. 6D). , Copper by electro copper plating
3 to obtain via posts 226 (FIG. 6).
(E)). After removing the plating resist 225, FIG.
Is obtained.

In the case of this embodiment, the formation of the front and back conductive wires and the anode are simultaneously formed by the via posts formed by electroplating, so that the process is shortened and the cost can be reduced.

FIGS. 7 to 9 are sectional views showing steps in a third embodiment of the method according to the present invention. In this embodiment, the front and back connection wiring is formed as a through hole.

First, a double-sided copper-clad resin plate 301 made of polyimide having copper foils 302 and 303 on the front and back sides is prepared, and holes are drilled at portions where conductive portions on the front and back sides are to be formed (FIG. 7).
(A)). Subsequently, a thin copper film is formed in the through hole by chemical plating, and normal electroplating is further performed to form a copper plating layer 304 in the through hole, on the surface copper foil 303, and on the inner copper foil 302. (FIG. 7 (b)).

In this state, the copper foil 302
Then, the copper plating layer 304 is patterned to form an inner layer pattern 305 (FIG. 7C).

Next, a substrate 310 such as a glass fiber reinforced epoxy plate is prepared, and the resin plate 3 having the through-hole plating and the inner layer pattern 305 formed on the surface thereof in the previous step.
01 is placed with the prepreg 311 interposed therebetween, and pressed in a heated state (FIG. 7D). As a result, the prepreg 311 melts, and the double-sided copper-clad resin plate 301 and the base 210 are melted.
Is fixed.

Next, a resist 320 is applied on the entire surface, and is patterned by exposure and development so that a region where an anode is to be formed is opened (FIG. 7 (e)). The copper foil 302 and the copper plating layer 304 are etched to form a hole 321 having a diameter of 50 μm (FIG. 7F).

Next, by irradiating the entire surface with a carbon dioxide laser beam 322, the polyimide resin corresponding to only the etched portion of the copper foil is removed, and the inner layer pattern 305 is removed.
Is formed (FIG. 8A).

Subsequently, the resist 320 is once removed (FIG. 8)
(B)) A new resist 324 for forming a surface layer pattern is applied and is patterned by photolithography (FIG. 8C). Using the patterned resist 324, the surface copper foil 303 and copper plating 304 are patterned to obtain a surface layer pattern 306 (FIG. 8D), and the resist 324 is peeled off (FIG. 8E).

Next, in order to form a via post in the hole 323 already formed, a plating resist 325 is selectively formed so that only a portion corresponding to the hole 323 is exposed (FIG. 9A, Hole 323 with copper by electrolytic copper plating
To obtain via posts 326 (FIG. 9B. The plating resist 325 is removed to obtain a configuration as shown in FIG. 9C.

In this embodiment, since the front and back continuity is formed by a reliable through hole, stable operation can be expected.

FIG. 10 shows a configuration of a radiation detector manufactured by applying the method according to the fourth embodiment of the present invention, and corresponds to FIG. That is, FIG. 10A is a plan view, and FIG.
10C is a sectional view taken along the line DD ′ of FIG. 10, and the difference from the radiation detector shown in FIG. 1 is that in the configuration of FIG. The point is that it is formed as a silver bump in the configuration.

FIGS. 11 and 12 are sectional views showing steps for obtaining the structure shown in FIG.

First, an 18 μm thick copper foil 40 serving as an inner layer
1. A silver paste is selectively printed on the front and back conductive portions and the anode forming portions on the surface 1. Thus, substantially conical silver bumps 402 and 405 remain on the copper foil 401 (FIG. 11A).

Next, a polyimide resin 403, which is an insulating layer, is placed on the copper foil 401 and the silver bump 402, and another copper foil 404 (18 μm in thickness) is further pressed. The configuration shown in FIG. That is, the silver bump 402 penetrates through the insulating layer 403 and is in contact with the upper copper foil 404. The upper copper foil 404 becomes a surface layer, and the surface layer and the inner layer are connected by silver bumps. In the case of this embodiment, a silver bump serving as an anode is also included.

Next, the first copper foil 401 on the inner layer side is patterned through exposure and development steps to form an inner layer pattern 4.
01 ′ is formed (FIG. 11C).

Next, a substrate 410 such as a glass fiber reinforced epoxy plate is prepared, and the laminate prepared in the previous step is placed on the surface thereof with the prepreg 411 interposed therebetween, and is pressed while being heated (FIG. 11 (d)). As a result, the prepreg 411 melts and fixes the laminate and the base 410.

Next, a resist 420 is applied on the entire surface, and is patterned by exposure and development so that the anode part and its surrounding area are opened (FIG. 12).
(A)), the outer copper foil 404 in the opening is etched to expose the top of the silver bump 405 serving as an anode and the surface of the polyimide plate 404 around the top (FIG. 1).
2 (b)).

Finally, the resist 420 is peeled off and FIG.
The state of (c) is obtained.

In the radiation detector manufactured in this manner, the anode is formed of silver bumps as in the case of the front and back conductive portions, so that it can be manufactured stably at low cost.

[0055]

As described above, according to the present invention, in the process of manufacturing the radiation detector, the anode is formed as a cylindrical via post or a conical bump at the same time as or immediately after the manufacturing process of the front / back conduction means. Therefore, a radiation detector can be stably manufactured at low cost.

In particular, when the anode and the front / back conduction means are simultaneously formed by via posts or bumps, the steps can be shortened, which can contribute to cost reduction and high reliability.

[Brief description of the drawings]

FIG. 1 is a plan view and a sectional view of a radiation detector manufactured according to a first embodiment of the present invention.

FIGS. 2A and 2B are cross-sectional views illustrating a method of manufacturing the radiation detector according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view for each step, following FIG. 2;

FIG. 4 is a cross-sectional view illustrating another step following FIG. 3;

FIG. 5 is a cross-sectional view illustrating a method of manufacturing the radiation detector according to the second exemplary embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a step subsequent to FIG. 5;

FIG. 7 is a cross-sectional view illustrating a method of manufacturing the radiation detector according to the third exemplary embodiment of the present invention.

FIG. 8 is a cross-sectional view by a step following FIG. 7;

FIG. 9 is a cross-sectional view illustrating another step subsequent to FIG. 8;

FIG. 10 is a plan view and a cross-sectional view of a radiation detector manufactured according to a fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view illustrating a method of manufacturing the radiation detector according to the fourth exemplary embodiment of the present invention. .

FIG. 12 is a cross-sectional view showing a step subsequent to FIG. 11;

FIG. 13 is a plan view and a cross-sectional view of a conventional radiation detector.

[Explanation of symbols]

100, 200, 300, 400 Radiation detector 101, 104, 202, 203, 302, 303, 4
01, 404 Copper foil, 102, 402, 405 Silver bump 103, 201, 301 Insulating plate 110, 210, 310, 410 Base material 111, 211, 311, 411 Prepreg 120, 124, 125, 220, 224, 225, 3
20, 325, 420 Resist 121, 221, 321, Opening 122, 222, 322 Laser Light 123, 223, 323 Hole 126, 226, 326 Via Post 304 Plating Layer 305 Inner Layer Pattern

Claims (5)

[Claims] A step of forming a conductive pump on a first conductive plate serving as an inner layer; a step of pressing an insulating plate and a second conductive plate serving as a surface layer on each other; Patterning a conductive plate to form an inner layer; fixing the patterned first conductive plate on a substrate; and selectively removing the second conductive plate corresponding to a predetermined anode position Forming an opening reaching the first conductive plate in the insulating plate; patterning the second conductive plate to form a surface layer serving as a cathode; and forming an anode by metal plating in the opening. Forming a conductive bost. 2. A step of forming conductive pumps on a first conductive plate serving as an inner layer at a portion where a front and back conductive portion is to be formed and at a portion where an anode is to be formed. Stacking and pressing; patterning the first conductive plate; fixing the patterned first conductive plate on a base material; Selectively removing the surrounding portion to obtain an exposed pump as an anode and a patterned second conductive plate as a cathode. 3. A first layer and a second layer, respectively, in a lower layer and an upper layer.
Patterning the first conductive layer of the insulating plate having the conductive layer into an inner layer pattern, fixing the insulating plate on a base material, and applying the second conductive layer to the front and back conductive portions and the anode portion. Corresponding to the first opening, and further penetrating the insulating plate.
Forming an opening reaching the conductive layer, forming a surface layer serving as a cathode by patterning the second conductive layer, and forming a post-shaped conductor by metal plating in the opening. Manufacturing method of radiation detector. 4. A method according to claim 1, wherein the first and second layers are provided in a lower layer and an upper layer, respectively.
Forming a through-hole corresponding to the front / back conduction portion of the insulating plate having the conductive layer of the above, forming a metal plating layer in the through-hole to obtain a through-hole, and forming the first conductive layer into an inner layer pattern. Patterning; fixing the insulating plate on a substrate; opening the second conductive layer in correspondence with the anode portion;
A step of forming an opening reaching the first conductive layer through the insulating plate; a step of patterning the second conductive layer to form a surface layer serving as a cathode; Forming a conductor in the form of a conductor. 5. The radiation detector according to claim 1, wherein the step of fixing the first conductive plate on the substrate is a step of heating the prepreg with the prepreg sandwiched therebetween. Method.