JPH08181449A - Connection electrode for electronic circuit board and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] An electronic device that can obtain a highly reliable electrical connection through a brazing material even if there is a non-contact portion due to a step or the like between the metal surfaces of the connection electrodes of the electric circuit board initially. A connection electrode for a circuit board and a method for manufacturing the same. [Composition] A connecting electrode of an electronic circuit board covers a surface of a material having good wettability with a brazing material and a material having good wettability with a brazing material on the substrate, and an opening is provided in a part thereof and the surface thereof is provided. Is covered with a brazing material, and further, among the adhesives for adhering between the substrates, only the adhesive layer on the connection electrode surface is removed to form a window opening of the pad portion. The manufacturing method is to form a connection electrode by forming an opening in a part of the surface of a composite film formed by depositing a brazing material, a material having good wettability and a material having poor wettability, and covering the opening with a brazing material having a diameter larger than the opening diameter. Then, only the adhesive layer on the connection electrode surface is removed in advance before the thermocompression bonding in the next step to open the window of the pad portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting electrode for an electronic circuit board and a method for manufacturing the connecting electrode, and in particular, even if there is a non-contact portion due to a step or the like between the metal surfaces of the connecting electrode of the electric circuit board initially. The present invention relates to a connection electrode of an electronic circuit board suitable for obtaining a highly reliable electrical connection through a brazing material and eliminating a connection failure due to a conventional adhesive, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a multilayer wiring board, a wiring pattern is formed on a polyimide sheet, an adhesive is applied to the polyimide sheet on which the wiring pattern is formed, and the polyimide sheet coated with the adhesive is used. A method of laminating a large number of the above on a substrate and integrating them under pressure and heating (for example, JP-A-4-162589) has been used. In this method, as a method for connecting the sheets, a wiring pattern using gold was formed on both surfaces of the polyimide sheet, and a polyimide precursor varnish of about 0.1 μm was applied on the wiring pattern, and thermocompression bonding was performed.

This method is expected to electrically connect the connection electrodes on the polyimide sheet by solid-phase diffusion of gold and gold, and the temperature required for the connection must be 350 ° C. or higher, and In order to ensure solid-phase diffusion, it was necessary to clean the surface of gold and apply contact pressure.

[0004]

However, the above-mentioned Japanese Unexamined Patent Application Publication No.
When the method as disclosed in Japanese Patent Laid-Open No. 162589/1989 is used, the reliability of the connection may be impaired due to the following two points. The first point is that it is expected that the polyimide precursor varnish for adhering between the sheets is applied by 0.1 μm and then thermocompression-bonded, and the polyimide precursor varnish can be removed from the gold surface by flow. With the method, it is difficult to reliably remove the polyimide varnish from the surface of the connection electrode, and a part of the polyimide varnish may be sandwiched between the electrodes, resulting in poor connection. The second point is that when trying to manufacture a large-scale circuit board, the number of connection points becomes 10,000 or more, and it is difficult for all points to make reliable contact even if the applied pressure is increased. It was difficult to make connections by mutual diffusion reliably at all points.

Further, if the thickness of the adhesive is limited to about 0.1 μm, it is not possible to make it smooth with the step adhesive of the wiring conductor. For example, when the wiring conductor has a thickness of 5 μm or more, an adhesive layer thickness equal to or larger than the conductor layer thickness is required to smooth the step. Therefore, in such a case, it is almost impossible to expect that the adhesive can be removed from the connection electrode surface by pressurization, which may cause a connection failure. For the above reasons, it has been difficult to reliably electrically connect the connection electrodes between the sheets by the conventional method.

The present invention has been made in view of the above problems of the prior art.
Even if there is a non-contact part due to a step or the like between the metal surfaces of the connection electrodes of the electric circuit board initially, a reliable electrical connection can be obtained through the brazing material, and a connection failure due to the conventional adhesive can be prevented. It is an object of the present invention to provide a connection electrode structure of an electric circuit board which can be solved and can be used even if the thickness of the adhesive layer is significantly thicker than in the past.

[0007]

In order to achieve the above object, the connection electrode of the electronic circuit board of the present invention has a plurality of boards having an electric circuit pattern laminated through an adhesive layer,
In the connection electrodes of the electronic circuit board in which the electrical connection between the electrodes of each board is performed by thermocompression bonding of the board, on the board surface,
Consists of a brazing material having a predetermined connection electrode diameter and a conductive material having good wettability, a brazing material having an opening in the central portion covering the surface of the conductive material having good wettability, and a conductive material having poor wettability The connection electrode formed by the composite film and the brazing material plated on the composite film to a predetermined thickness has a structure in which only the adhesive layer on the connection electrode surface is removed from the adhesive layers for adhesively laminating the substrates. This is a structure in which the opening of the window of the pad portion is formed.

In the method of manufacturing the connection electrodes of the electronic circuit board, a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and the electrical connection between the electrodes of each board is performed by thermocompression bonding of the boards. In the method for producing a connection electrode of an electronic circuit board performed according to (i), a composite film made of a conductive material is formed on a substrate in the order of a material having good wettability with a brazing material and a material having poor wettability, ( ii) A resist pattern is formed on the surface of the formed composite film, a material having poor wettability with the brazing material is partially removed by etching, and an opening is provided at the center of a position where a connection electrode is formed. ) After removing the resist, a connection electrode formed on the removed surface of the removed surface is larger than the opening diameter and similar to the opening so as to straddle the surface of the material having poor wettability with the brazing material. A lens with an opening corresponding to the diameter Stroke pattern is newly formed, and the brazing material is plated to a predetermined thickness by electroplating using the resist pattern as a plating mask. (Iv) The newly formed resist pattern is removed, and the plated brazing material is masked. As a result, the composite film is removed by etching to form a connection electrode, and (v) an adhesive layer is applied to the formed connection electrode and substrate surface and dried, and then only the adhesive layer on the connection electrode surface is subjected to the next step. Before heating and pressure bonding, the pad is opened beforehand to open the window of the pad.

Further, in the connection electrode of another electronic circuit board of the present invention, a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and the electrical connection between the electrodes of each board is performed by heating the board. In a connection electrode of an electronic circuit board, which is performed by pressure bonding, a connection electrode formed of a conductive material having a good wettability with a brazing material on a substrate surface, and adhesion between the substrate formed excluding the connection electrode upper surface and An adhesive layer made of an insulating material for preventing the wetting and spreading of the brazing material, and a brazing material formed on the connection electrode so as to have a diameter larger than the diameter of the connection electrode so as to extend over the surface of the adhesion layer. It is configured.

Further, in the above-mentioned method for manufacturing a connecting electrode of an electronic circuit board according to the present invention, a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and the electric connection between the electrodes of each board is made. In the method for manufacturing a connection electrode of an electronic circuit board, which is performed by thermocompression bonding of the board, (i) on the board,
A composite film made of an electrically conductive material is formed in the order of a material for improving the adhesiveness to the substrate, a brazing material and a material having good wettability, and (ii) connecting to the surface of the formed composite film. A resist pattern is formed by removing the other resist leaving only the resist in the shape of the electrode, and (iii) the composite film is etched through the formed resist pattern, and then the resist pattern is removed to form a connection electrode. And (iv) after forming an adhesive layer made of an insulating material for adhesion between the substrates and preventing the wetting and spreading of the brazing material on the surfaces of the formed connection electrode and substrate, only the adhesive layer on the connection electrode surface Is removed to open the pad portion, and (v) a brazing material is formed on the connection electrode by overlapping a metal mask having a diameter larger than that of the connection electrode so as to extend over the surface of the adhesive layer. The one You.

The adhesive layer may be an adhesive material having a flow starting temperature higher than the melting point of the brazing material in the connection electrode.

Further, the range of the melting point of the brazing material is 200
It is preferable that the temperature is not lower than 400 ° C. and not higher than 400 ° C. Further, in the connection electrode of the other electronic circuit board of the present invention and the manufacturing method thereof, the brazing material is formed by any one of vapor deposition, electroless plating and printing. Should be done by.

[0013]

With the above structure, the polyimide precursor varnish is removed by laser light irradiation or the like at the portion where the connection electrode is present, and a clean surface free of polyimide can be obtained on the surface of the connection electrode. When the substrates are stacked and heated, the brazing materials are likely to diffuse into each other.

For this reason, when the connection electrodes and the adhesive layer formed on the substrate are opposed to each other so that the connection electrodes are vertically paired and heated to a temperature higher than the melting point of the brazing material, a material having poor wettability with the brazing material. The brazing material supplied to the surface gathers in the brazing material in the central part of the connecting electrode and the conductive material part with good wettability so as to be repelled, increasing the thickness of the brazing material layer, and between the upper and lower connecting electrodes, The state where they are not in contact with each other in the initial stage of just making them face each other in a pair of upper and lower sides is changed to the state where they are in contact with each other through the molten brazing material. When the upper and lower substrates are pressure-bonded to each other and the temperature is lowered in this contact state, the upper and lower substrates are laminated with the connecting electrodes facing each other securely connected through the brazing material, and electrical connection of all the connecting electrodes on the substrate is performed. It will be possible to get a connection.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view of a connection electrode forming process, FIG. 2 is a view showing an example of forming a multilayer electronic circuit board by using a large number of connection electrodes shown in FIG. 1, and FIG. 3 is a connection formed in FIG. FIG. 4 is a view showing a side surface and a plane for explaining the shape change of the electrode before and after heating, and FIG. 4 is a perspective view showing an example in which an LSI and an input / output terminal are attached to the electronic circuit board shown in FIG. 2 to form a circuit module. .

In FIG. 1, FIG. 1A shows a lower layer Cr1 on a polyimide sheet (hereinafter, simply referred to as a substrate) 101.
02, Cu layer 103 and Cr / Cu in the upper Cr 104
The / Cr composite film is sputter-deposited in a thickness of 0.05 μm / 5 μm / 0.05 μm. 1 (b) is shown in FIG.
A state in which a resist 105 is applied onto the upper layer Cr 104 shown in (a) and the resist is partially removed by exposure and development, and then the upper layer Cr 104 is partially removed by etching using the resist 105 Show.

Next, the resist 105 shown in FIG.
After removing the resist, a resist 106 is newly applied to the removed surface as shown in FIG.
The resist 106 having an area similar to the opening from which the upper layer Cr 104 is removed by etching in the step (b) and larger than the area of the opening, that is, an area corresponding to the diameter of the connection electrode.
Is removed. Then, using the resist 106 as a plating mask, the brazing filler metal 107 is supplied by an electroplating method to plate to a uniform thickness of, for example, 20 μm.

Next, the resist 106 shown in FIG.
Is removed, and the upper layer Cr10 is formed using the brazing material 107 as a mask.
4, the Cu layer 103 and the lower layer Cr 102 are removed by etching to form the connection electrode 109 shown in FIG.

Next, the adhesive layer 108 between the substrates made of a polyimide precursor varnish is applied to the surfaces of the substrate 101 and the connecting electrode 109 shown in FIG. Only the body varnish 108 is removed in advance before the thermocompression bonding in the next step, and a clean pad portion where the polyimide precursor varnish 108 does not remain is opened on the surface of the connection electrode 109, and the state shown in FIG. Form. Here, the removal of the polyimide precursor varnish 108 on the connection electrode 109 is performed by, for example, laser light irradiation.

Then, the connection electrodes 109 and the adhesive layer 108 formed on the substrate 101 shown in FIG. 1 (e) are opposed to each other so that the connection electrodes 109 form a pair, and are heated at a predetermined temperature described later. The connecting electrodes 109 formed by the above process by this heating gather in the central portion of the brazing filler metal 107 due to the action to be described later to increase the thickness of the brazing filler metal 107, and the upper and lower connecting electrodes 109 are opposed to the upper and lower pair. As shown in FIG. 1 (f), the molten brazing filler metal 10
7 are in contact with each other. When the upper and lower substrates 101 are pressure-bonded to each other and the temperature is lowered in this contact state, the upper and lower substrates 101 are laminated in a state where the opposing connection electrodes 109 are securely connected via the brazing material 107.

In the process shown in FIG. 1, the connecting electrode 10 is used.
Although only one pair of 9 is enlarged and described, it is common that a multi-layer wiring board has a large number of connection electrodes 109 in each layer. In reality, a large number of connection electrodes 109 are provided in the state shown in FIG. The individual connection electrodes are multilayered by thermocompression bonding at the same time and laminated in the state shown in FIG. An example of laminated electronic circuit boards is shown in FIG. In FIG. 2, 201 is a substrate, 208 is an adhesive layer, and 209 is a connection electrode.

Although a polyimide sheet is used for the substrate 101 in the above-mentioned embodiment, a glass epoxy substrate, a ceramics substrate, a silicon wafer or the like may be used as the substrate material. Further, a Cr / Cu / Cr laminated film is used as a base film of the connection electrode 109, but the lower layer Cr 102 immediately above the substrate 101 is used to secure the adhesive strength with the substrate 101 and is not always necessary. Any material that can maintain the adhesive strength with the substrate 101 such as Ti can be used.

Next, in the above embodiment, the connection electrode 10
Although the Cu layer 103 was used as the second layer of the base film of No. 9,
This is a material that is well wetted with the brazing material 107 and secures the connection strength, and Ni or the like may be used instead of Cu. Here, the brazing material 107 and the material having good wettability means a material that does not form a strong oxide film on the surface and can be alloyed with the brazing material 107. Further, the third layer of the base film needs to be a material that does not wet the brazing material 107 in order to serve as a plating electrode capable of supplying the brazing material 107 by electroplating and to prevent the wetting and spreading of the brazing material 107. Is. At present, the most suitable material as such a material is C
Although it is r, metals such as aluminum and stainless steel can also be used.

Although a thermoplastic polyimide resin is used as the adhesive layer 108 between the substrates, an adhesive such as an epoxy resin or an acrylic resin may be used depending on the application. However, when the substrate is thermocompression bonded, the brazing material 107
When the flow of the adhesive layer 108 starts at a temperature lower than the melting point of
Before the brazing is completed, the adhesive enters between the connection electrodes 109 to cause defective bonding, and therefore the type of the adhesive needs to be selected in relation to the melting point of the brazing material 107. That is, the flow starting temperature of the adhesive (the glass transition temperature may be used as a guide) is the brazing material 107 in the connection electrode 109.
Above the melting point of. As an example, the substrate 1
When the eutectic alloy of 62Sn-38Pb is used as the brazing material 107 for connecting the electronic components mounted outside the substrate 101, the heat resistance of 01 is required to be 200 ° C. or higher. The heat resistance of the organic material forming the substrate 101 is 400 ° C.
Since most of the cases below are possible, the brazing filler metal 107 can be firmly connected to the connection electrode 109 and has a melting point range of 2 or less.
It is necessary that the temperature is not lower than 00 ° C and not higher than 400 ° C. Therefore, the heating temperature in the state shown in FIG.
It is selected in the range of 200 ° C or higher and 400 ° C or lower.

A material satisfying the above conditions is 96.5S.
n-3.5Ag alloy (melting point: 221 ° C), 100Sn
(Melting point: 232 ° C.), 20Sn-80Au (melting point: 28
Materials such as 0 ° C.) and 100 Pb (melting point: 327 ° C.) can be used.

The adhesive layer 10 on the connection electrode 109 is also provided.
As the removing method of 8, the method of irradiating the surface of the connection electrode 109 with a laser to decompose and remove it after applying the polyimide precursor varnish is most useful. In addition to this, a method of developing using a photosensitive material, a dry method It is also possible to use a method by etching or a method in which an adhesive is supplied only at a necessary portion by printing. As a method of supplying the adhesive, application of varnish is useful, but a method of forming the adhesive into a sheet shape in advance and sandwiching and bonding the same can also be used.

Next, the change in shape of the brazing filler metal 107 shown in FIG. 1 (f) before and after heating will be described with reference to FIG. In the figure, the same symbols as those in FIG. 1 indicate the same components.

In the structure of the connecting electrode, the layer having wettability with the brazing material 107, that is, the electrode diameter of the Cu layer 103 is d, and the layer having no wettability with the brazing material 107, that is, the upper layer Cr.
Assuming that the diameter of 104 is n times that of n, the area ratio is n ²
Double. Now, as shown in FIG. 3A, the entire upper surface of the upper layer Cr 104 having no wettability is covered with a layer of a brazing filler metal 107 having a thickness t, and the temperature of the brazing filler metal 107 is raised to its melting point. Upper layer Cr1 which melts 107 and has no wettability
The brazing material 107 on 04 is attracted to the electrode diameter d portion of the Cu layer 103 that is wettable as if it was repelled by the surface tension, and is collected in the central portion of the electrode. As a result, the thickness of the brazing filler metal 107 increases depending on what was originally in the electrode diameter d portion and what was gathered in the electrode central portion, and its shape has the surface tension as shown in FIG. 3 (b). To make it almost spherical. The height H of this spherical shape is H on average.
= N ² t.

As an example, d = 100 μm, n = 2, t
In the case of = 20 μm, the height of the electrode after heating is about 60 μm higher than that before heating, and the height H of the electrode formed in a substantially spherical shape is about 80 μm.
Therefore, when two electrodes of this dimension example are connected to each other, it is possible to connect even if the gap between the electrodes is 120 μm at maximum, considering that the height of the electrodes rises up and down by about 60 μm after heating. Become.

Even if a gap of about 120 μm is formed between the connecting electrodes, the brazing material 107 on the connecting electrode 109 from which the adhesive layer 108 has been removed from the surface by thermocompression bonding above the melting point of the brazing material 107, The thickness dimension is automatically increased by the surface tension of the brazing filler metal 107, and the connecting electrode pair, which was not in sufficient contact at the initial stage of simply laminating the substrates, is contacted with the molten brazing filler metal 107, Ensure electrical connection between the two. Therefore, in the conventional connection electrode structure, when a large number of layers of substrates are connected to connect a large number of electrodes, it is not always possible to adhere all the electrodes due to the unevenness of the pattern, steps, etc., causing a connection failure. It became possible to solve the problem.

By appropriately selecting the ratio n of the electrode diameter d and the thickness t of the brazing filler metal 107, it is possible to arbitrarily change the size of the gap between the connectable connecting electrodes.

FIG. 4 shows an example of a circuit module to which the connection electrode structure according to the first embodiment is applied. In the figure, 10 is an LSI, 11 is the circuit board shown in FIG.
A plurality of LSIs 10 are mounted on a circuit board 11 via solder joints 13. Reference numeral 12 is an input / output pin provided on the back surface of the circuit board 11, and is configured to be connected to an external circuit via the input / output pin 12.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram of a process of forming a connection electrode when a vapor deposition method is used to supply the brazing material.

In the first embodiment, since the electroplating method is used to supply the brazing material, the conductive material is required as the material for suppressing the wetting and spreading of the brazing material. However, in addition to the electroplating method, there are methods for supplying the brazing material, such as electroless plating method, vapor deposition method, and printing method. When these methods are used, the wetting and spreading of the brazing material is suppressed. It is also possible to use an insulating material as a material for this. In the second embodiment, an example in which a vapor deposition method is used for supplying the brazing material will be shown.

In FIG. 5, FIG. 5A shows a Cr layer 302 and a Ni layer 30 on a substrate 301 made of polyimide.
3 shows a state in which the Cr / Ni composite film of No. 3 is formed by sputtering.
FIG. 5B shows a state in which a resist is applied on the Ni layer 303 shown in FIG. 5A, the resist 305 having a shape to be a connection electrode is left by exposure and development, and the other resist is removed.

Next, the resist 305 shown in FIG.
Is used to etch the Ni layer 303 and the Cr layer 302,
After the etching, the resist 305 is removed to remove the resist, as shown in FIG.
The connection electrode 309 shown in is formed in, for example, a circular shape.

Then, an adhesive layer between the substrates made of a polyimide precursor varnish and an adhesive layer 308 serving as a wetting and spreading preventing layer for the brazing material are applied to the surfaces of the substrate 301 and the connection electrode 309 shown in FIG. 5C. Dry and connect electrode 309
Only the upper polyimide precursor varnish is removed and the window of the pad portion is opened to form the state shown in FIG. Here, the removal of the polyimide precursor varnish on the connection electrode 309 is performed by laser light irradiation, for example.

Next, the connection electrode 309 shown in FIG.
A metal mask having a diameter larger than that of the connection electrode 309 is superposed on the surface of, and a brazing material 307 is vapor-deposited to form the state shown in FIG.

Then, the substrate 301, the connection electrode 309 and the adhesive layer 308 formed in the state shown in FIG.
The connection electrodes 309 are opposed to each other so as to form a pair and are heated at a predetermined temperature. Here, since the diameter of the brazing filler metal 307 is made larger than the diameter of the connecting electrode 309 as described above, the portion of the brazing filler metal 307 protruding from the diameter of the connecting electrode 309 due to the heating is melted and wet by the surface tension. Which is attracted onto the Ni layer 303 having the property of
03 and those attracted by the surface tension increase the thickness of the brazing material 307 on the connection electrode 309. Therefore, the brazing material 3 on the connection electrode 309 that was not in contact with the pair of upper and lower parts at the beginning is not in contact with each other.
As shown in FIG. 5 (f), 07 is vertically integrated at the upper part of the connection electrode 309, and is in a metal-bonded state. At the same time, the adhesive layer 308 is also melted. The upper and lower substrates 30 in this state
When 1s are pressure-bonded to each other and the temperature is lowered, the upper and lower substrates 301 are laminated via the adhesive layer 308 in a state where the opposing connection electrodes 309 are surely connected via the brazing material 307.

The process shown in FIG. 5 is described by enlarging only one pair of the connection electrodes 309 similarly to the process shown in FIG. 1, and in practice, a large number of connection electrodes are simultaneously heat-pressed in multiple layers. To form a multilayer wiring board.

In the second embodiment, a glass epoxy substrate, a ceramics substrate, a silicon wafer or the like may be used for the substrate 301 in addition to the polyimide sheet, and a Cr / Ni composite film is used as a base film of the connection electrode 309. Although a film is used, the Cr layer 302 directly on the substrate 301 is the substrate 30.
It is used to secure the adhesive strength with the substrate 1 and is not always necessary, and it can be used as long as it can maintain the adhesive strength with the substrate 301 such as Ti. As with the first embodiment, as the adhesive layer 308, an adhesive such as an epoxy resin or an acrylic resin can be used in addition to the thermoplastic polyimide resin depending on the application.

As with the first embodiment, it is necessary to select the type of adhesive in relation to the melting point of the brazing filler metal 307, and the flow starting temperature of the adhesive (as a guide, the glass transition temperature is set). (Which may be used) is required to be higher than the melting point of the brazing filler metal 307 in the connection electrode 309. Therefore, the heating temperature in the state shown in FIG. 5E is 200 ° C. as in the first embodiment. As mentioned above, it is selected in the range of 400 ° C. or lower.

The brazing material 307 shown in FIG.
The diameter may be larger than the diameter of the connection electrode 309 according to the unevenness of the pattern, the step, etc. on the electronic circuit board, and the interval between the connection electrodes can be arbitrarily changed by selecting the ratio of the two diameters. It is possible to make contact, and even if there is a non-contact portion between the connection electrodes in the electronic circuit board, electrical connection of the non-contact portion can be surely obtained.
It has become possible to solve the problems that were the cause of the conventional connection failure.

[0044]

As described above, according to the present invention, even if there is a non-contact portion due to a step or the like between the metal surfaces of the connection electrodes of the electric circuit board at the beginning, reliability is improved by applying a temperature to the brazing material. A high electrical connection is obtained, and the adhesive between the substrates is surely removed from the surface of the connection electrodes before the thermocompression bonding of the substrates. This has the effect of eliminating defects and enabling the use of adhesive layers having a significantly thicker thickness than before.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a process of forming a connection electrode according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example in which a multilayer electronic circuit board is formed by using a large number of connection electrodes shown in FIG.

3A and 3B are diagrams showing a side surface and a plane for explaining a change in shape of a connection electrode formed in FIG. 1 before and after heating.

4 is a perspective view showing an example in which an LSI and input / output terminals are attached to the electronic circuit board shown in FIG. 2 to form a circuit module.

FIG. 5 is an explanatory diagram of a process of forming a connection electrode according to the second embodiment of the present invention.

[Explanation of symbols]

101, 201, 301 ... Substrate, 102 ... Lower layer Cr, 1
03 ... Cu layer, 104 ... Upper layer Cr, 105, 106, 3
05 ... Resist, 107 ... Brazing material, 108, 208, 3
08 ... Adhesive layer, 109, 209 ... Connection electrode, 302 ... C
r layer, 303 ... Ni layer, 307 ... brazing material, 309 ... connection electrode, 10 ... LSI, 11 ... circuit board, 12 ... input / output pin, 13 ... solder joint.

Claims (7)

[Claims] 1. A connection electrode of an electronic circuit board, wherein a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and the electric connection between the electrodes of each board is performed by thermocompression bonding of the boards. A conductive material having good wettability with a brazing material having a predetermined connection electrode diameter, a brazing material having an opening in the center covering the surface of the conductive material having good wettability, and a conductive material having poor wettability A connecting electrode formed of a composite film consisting of and a brazing material plated to a predetermined thickness on the composite film, of the adhesive layers for bonding and laminating between substrates, only the adhesive layer on the connecting electrode surface. A connection electrode of an electronic circuit board, wherein the connection electrode of the electronic circuit board is formed by removing a window opening of a pad portion. 2. A method of manufacturing a connection electrode of an electronic circuit board, wherein a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and the electric connection between the electrodes of each board is performed by thermocompression bonding of the boards. In (i), a composite film made of a conductive material is formed on a substrate in the order of a material having good wettability with a brazing material and a material having poor wettability, and (ii) a resist pattern on the surface of the formed composite film. To form an opening in the central portion of the position where the connection electrode is formed by partially etching away the material having poor wettability with the brazing material, and (iii) removing the resist and then removing the surface of the removed surface. A resist pattern is newly formed on the opening, which has an opening larger than the opening diameter and similar to the opening and having a diameter corresponding to the diameter of the connection electrode so as to extend over the surface of the material having poor wettability with the brazing material. And the resist pattern The brazing material is plated by electroplating to a predetermined thickness as a plating mask, (iv) the newly formed resist pattern is removed, and the composite film is etched away using the plated brazing material as a mask to form a connection electrode. After forming and (v) applying an adhesive layer to the surface of the connecting electrode and the substrate thus formed and drying, only the adhesive layer on the surface of the connecting electrode is removed in advance before the thermocompression bonding in the next step, and the window of the pad portion is formed. A method of manufacturing a connection electrode of an electronic circuit board, characterized by performing the dawn. 3. A connection electrode of an electronic circuit board, wherein a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and the electric connection between the electrodes of each board is performed by thermocompression bonding of the boards. A circular connecting electrode made of an electrically conductive material having good wettability with the brazing material, and an insulating material for preventing adhesion and adhesion between the substrates formed excluding the upper surface of the connecting electrode and preventing the wetting and spreading of the brazing material. A connection of an electronic circuit board, which is formed by an adhesive layer formed of and a brazing material formed on the connection electrode so as to extend over the surface of the adhesion layer and has a diameter larger than the diameter of the connection electrode. electrode. 4. A method for manufacturing a connection electrode of an electronic circuit board, wherein a plurality of boards having an electric circuit pattern are laminated via an adhesive layer, and electrical connection between the electrodes of each board is performed by thermocompression bonding of the boards. In (i), a composite film made of a conductive material is formed on the substrate in the order of a material for improving the adhesiveness with the substrate and a material having good wettability with the brazing material, and (ii) On the surface of the formed composite film, a resist pattern is formed by removing the other resist while leaving only the resist in the shape of the connection electrode, and (iii) after etching the composite film through the formed resist pattern, After removing the resist pattern to form connection electrodes, (iv) after forming an adhesion layer made of an insulating material for adhesion between the substrates and prevention of wetting and spreading of the brazing material on the surfaces of the formed connection electrodes and the substrate , Connection Only the adhesive layer on the pole surface is removed to open the pad window, and (v) a metal mask having a diameter larger than the diameter of the connection electrode is laid over the connection electrode so as to extend over the surface of the adhesion layer. A method of manufacturing a connecting electrode of an electronic circuit board, characterized in that a brazing material is formed. 5. The connection electrode for an electronic circuit board according to claim 1, 2, 3 or 4, and a method for manufacturing the connection electrode, wherein the adhesion layer is made of an adhesion material having a flow starting temperature higher than a melting point of a brazing material in the connection electrode. . 6. The connection electrode for an electronic circuit board according to claim 1, 2, 3 or 4, and a method for manufacturing the same, wherein a melting point range of the brazing material is 200 ° C. or higher and 400 ° C. or lower. 7. A connection electrode for an electronic circuit board according to claim 3, wherein the brazing material is formed by any one of vapor deposition, electroless plating, and printing, and a method of manufacturing the same.