JPH02159090A - Connection of circuit board - Google Patents

Abstract

PURPOSE:To prevent shortcircuiting and leak and to improve reliability of connection greatly by connecting electrodes mutually by an interposed object which is held by a holding layer between a first circuit board and a second circuit board. CONSTITUTION:A thermosetting resin adhesive is applied all over a substrate 1 whereon an electrode 2 and a surface protecting layer 3 are formed in advance, to form an adhesive layer 8a. Ultraviolet rays are irradiated through a mask 9. A conductive particle 5 is attached to the adhesive layer 8a formed as a fine patter. A projecting electrode is formed by attaching the conductive particle 5 selectively only to a region whereon the electrode 2 is formed in this way. A surface whereon a projecting electrode of a semiconductor device 6 is formed and a surface whereon a wiring electrode 13 of a liquid crystal display plate 12 is formed are opposed, and the conductive particle 5 and the wiring electrode 13 are registered. An adhesive 14 which cures at a relatively low temperature is injected and filled between substrate 1, 12. Pressure is applied until a distance between the electrodes 2 and 13 becomes a specified distance l1. The adhesive layer 14 is hardened in this state to mount the semiconductor device 6 on the liquid crystal display plate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to an IC (Integrated C1rcu)
The present invention relates to a circuit board connection method suitably implemented for electrically connecting a circuit board on which a semiconductor element such as .

2. Description of the Related Art Conventionally, circuit boards have been connected mainly by soldering R-T or by using an anisotropic conductive sheet. In the case of the soldering method, a solder layer was formed on the electrodes of one circuit board by plating or printing, and this solder layer was heated and melted to connect to the electrodes of the local circuit board. In addition, in the 1% method using an anisotropic conductive sheet, an anisotropic conductive sheet is pasted on the electrode of one circuit board, and after mutually aligning with the corresponding electrode of the local circuit board, both The circuit board was pressurized and heated to electrically connect both electrodes.

In the soldering method, Au and C are used as electrode materials in advance.
It is necessary to use parent solder metals such as u and Ni. In addition, when connecting a circuit board such as a liquid crystal display board, ITO (Indium Tin 0
Since it is difficult to melt and bond directly to solder metal, it is necessary to separately form a new parent solder metal layer on ITOl, resulting in high cost. Furthermore, since the two electrodes are connected by heating and melting the solder, there is a pressure between adjacent terminals that tends to cause a short circuit when the pitch of the electrodes to be connected is fine.

In a method using an anisotropic conductive sheet, the anisotropic conductive sheet, which has conductive particles dispersed in a resin, connects opposing electrodes well up to a pinch width of about 150 μm. However, in electrodes with smaller pinches than this, conductive particles dispersed in the sheet create a state of conductivity between adjacent electrode terminals, causing short circuits.

Furthermore, in the method using one inch of solder and an anisotropic conductive sheet, heating at 150 to 250° C. is required when connecting the electrodes. In addition, especially in the case of anisotropic conductive sheets, the connecting circuit boards are approximately 20 kg/c
A pressurization of rn 2 is required. Therefore, for example, when connecting a flexible substrate to the above-mentioned liquid crystal display panel, an undesirable situation may occur in which the substrate itself is damaged due to thermal stress and pressurizing force.

When connecting a semiconductor circuit board such as an IC to another circuit board, WB (Wire Bonding) is usually used.
Method, T A B (Tape AuLomaLed
Bonding) method, FC (F I i p C It
ip) method etc. are used. In recent years, attention has been paid to the FC method, which is advantageous in terms of reducing mounting surface precision, shortening connection time, and shortening connection length.

In the FC method, to which the connection method in this case applies, generally the IC
Protruding electrodes made of solder metal etc. are provided on a semiconductor circuit board such as, and the protruding electrodes made of solder metal are heated and melted while facing another circuit board and connected to the electrodes of the other circuit board. .

Therefore, the wiring of the other circuit board to which the semiconductor circuit board is connected needs to be made of parent solder metal, resulting in high costs. In addition, the connection requires heating above the melting point of the solder metal, which limits the number of circuit boards to be used and the electronic components mounted on the board. Furthermore, when this solder metal is heated and melted to make a connection, because there is a difference in the coefficient of thermal expansion between the semiconductor circuit board and the other circuit board, the thermal stress generated during heating remains and the connection is made. There are problems such as causing breakage.

An attempt to solve the above problems was made in JP-A-63-1
No. 3337. In this method, protruding electrodes are provided on the electrodes of one circuit board, and these are pressed together while being aligned with the electrodes of the other circuit board, and a room-temperature curing adhesive is applied between each circuit board in advance. It is fixed with.

This protruding electrode is usually made of Au, Cu, Ni, r'b
A metal material such as -s port is used, and the protruding electrodes are formed by plating, vapor deposition, or transfer.

The plating method is a method of forming protruding electrodes on the electrode body by electroplating. In the plating method, for example, when using the lift-off method, a resist is formed for lift-off, a barrier metal layer is formed on the entire surface to prevent metal diffusion, and then the parts not to be plated are covered with the resist. Did you mask it? The supports shall be electroplated. Therefore, in such a plating method, there is a problem that the working process becomes unnecessarily complicated.

In the vapor deposition method, a metal mask with through holes formed in it corresponding to the positions where protruding electrodes are to be formed is placed on the circuit board, a metal layer is formed in this state by sputtering or electron beam evaporation, and this metal layer is formed by sputtering or electron beam vapor deposition. This is a method of forming protruding electrodes using the following method. In this vapor deposition method, it is necessary to vapor-deposit the metal for forming the protruding electrodes again through a metal mask over the area where the barrier metal layer has been formed. This not only complicates the work process, but also requires a large amount of materials and requires the creation of a precise metal mask, resulting in high costs.

In addition, in the transfer method, protrusions of gold (A 11 >) are formed at predetermined positions on the temporary substrate by, for example, plating,
This temporary substrate is heated and pressed while being laminated on a circuit board on which protruding electrodes are to be formed. As a result, the gold protrusions are thermally transferred to the circuit board, forming protruding electrodes.

In such a transfer method, metals other than metal cannot be used as the material for forming the protrusions.

Therefore, the cost is high. Furthermore, the conditions for plating gold, as well as the temperature and pressure conditions for performing thermal transfer to form these gold protrusions as protruding electrodes on a circuit board, are severe. Therefore, there is a problem in that it is difficult to form a protruding electrode in a desired shape.

Even if metal protruding electrodes are formed on one circuit board using the various methods described above and both circuit boards are connected according to the above-mentioned Japanese Patent Application Laid-Open No. 6113337, the difference between the metal of these protruding electrodes and the room-temperature curing adhesive There is a difference in thermal expansion coefficient between it and polymers. Therefore, when the external environment changes thermally, the connection state becomes unstable. For example, at relatively high temperatures, the thermal expansion of the adhesive is larger than that of the protruding electrodes, resulting in mutual positional deviation. This may cause connection failures to occur. Therefore, it must be said that such a connection method is inferior in reliability.

It is believed that the above problems can be solved by using a gono-shaped elastic body whose surface is coated with a conductive material as a protruding electrode, as disclosed in JP-A No. 61-259548. It will be done. However, in this method, Todofol-resist is applied at least twice: when forming a silicone layer, which is an elastic member, on the electrode of a circuit board, and when forming a gold conductive layer on the surface of the silicone layer. A process such as exposure through a mask is required. Therefore, there is a problem that the process of forming the protruding electrode becomes unnecessarily complicated.

Moreover, the adhesion between silicone and conductive layers such as gold is poor. Therefore, for example, silicone gono,
An undesirable situation may occur in which the conductive layer peels off from the surface and the protruding electrodes no longer function to electrically connect the two circuit boards.

Problem to be Solved by the Invention An object of the present invention is to solve the above-mentioned technical problems and to provide a method for connecting circuit boards that is simple, easy, low cost, and highly reliable. .

Means for Solving the Problems The present invention provides a method for interconnecting a first circuit board on which an electrode is formed and a second circuit board on which an electrode is formed at a position corresponding to the first circuit board. An intervening body having conductivity and having a thickness greater than the thickness of the holding layer is buried and held in a holding layer formed on the electrode of the substrate, and the first circuit board and the second circuit board are faced to each other, Pressure is applied to the first and second circuit boards while their corresponding electrodes are connected to each other via the intervening body, and the adhesive, which is cured at a relatively low temperature, that has been filled between each circuit board is cured. This is a method for connecting a circuit board, characterized in that the circuit board is connected by the following steps.

Function: In the circuit board connection method of the present invention, a retaining layer is formed on the electrode of the first circuit board, and an intervening body having conductivity and having a thickness larger than the retaining layer is embedded in the retaining layer. is retained. This holding layer may be electrically conductive or non-conductive.

With the electrodes to be connected mutually aligned, the first circuit board and the second circuit board are wetted with an adhesive that hardens at a relatively low temperature and is filled between the circuit boards in advance. Ru. This adhesive filling may be performed before or after the circuit boards are faced. At this time, pressure is applied so that the mutually corresponding electrodes of the first and second circuit boards are electrically connected through the intervening body or the intervening body and its holding layer, and in this pressurized state, each circuit board The adhesive filled in between is hardened.

As the adhesive used, it is possible to use various adhesives such as room temperature hardening, anaerobic, light hardening, and reaction hardening adhesives as long as they harden at relatively low temperatures. .

According to the invention, the electrical connection between the electrodes of the first and second circuit boards is made by the intervening body or the intervening body and its holding layer. As a result, it is not necessary to provide a protruding electrode as conventionally formed, and the complicated process required to form a protruding electrode can be omitted. Further, by using an elastic body as the conductive intervening body, a more stable connection state can be achieved without being affected by thermal influences from outside the connected circuit board.

Furthermore, since the conductive intervening body is selectively arranged on the electrodes of each circuit board, it is possible to make connections that correspond to the miniaturization of the electrode pitch of the circuit boards. In addition, if an adhesive that hardens at room temperature is used, it is sufficient to simply fix the two circuit boards together and cure the adhesive, which hardens at room temperature.There is no need for high-temperature heating, and the circuit board can be cured by heating. Adverse effects such as thermal stress occurring or remaining on the substrate can be prevented.

Embodiment FIG. 1 is a sectional view of circuit boards 6 and 12 connected according to the circuit board connection method of the present invention, and FIG. 2 is an enlarged sectional view showing the details of FIG. 1 in detail. FIG. 3 is a sectional view of a liquid crystal display device 10 in which a semiconductor device 6 is mounted on one liquid crystal display panel 12 according to the present invention. Therefore, FIG. 1 is a cross-sectional view of the liquid crystal display device 10 shown in FIG. 3 taken along the section line II.

Referring to FIG. 3, the wiring electrode 13 and the counter electrode f
A pair of liquid crystal display panels 12.1 each having an i16 formed thereon.
1 are bonded together via a sealing resin 15, and a liquid crystal 17 is sealed between them. In this liquid crystal display device 10, the wiring electrode 13 extends on the liquid crystal display board 12 toward the right side of the drawing, and is connected to the voltage [2] of the semiconductor device 6 mounted to drive the display of the liquid crystal display device 10. .

Referring to FIGS. 1 and 2, a semiconductor device 6, which is a first circuit board, has a diffusion layer formed on a wafer of silicon or gallium arsenide, and a large number of transistors, diodes, etc. are formed by this. , has a function of driving the display of the liquid crystal display device 10. The semiconductor device 6 includes a substrate 1, an electrode 2 formed on the top layer of the substrate 1, and a surface protection layer 3 made of, for example, SiN, PSG (glass), or polyimide. The electrode 2 is made of, for example, AN-3i, Ni, Ti, or W.

Also, the wiring electrode 13 of the liquid crystal display board 12 which is the second circuit board
is, for example, tin-doped indium oxide (Indiun+TinOxid) formed on a surface such as soda glass.
e, hereinafter abbreviated as ``rlTo'') or nickel-plated ITO, usually with a thickness of 100 to 20 O
It is about rr rn.

The semiconductor device 6 and the liquid crystal display board 12 are connected to each other by an adhesive layer 8 which is a holding layer so that a predetermined distance 11 is maintained between the electrodes 8i 213.
a, 14, and conductive particles 5 as intervening bodies. As the adhesive layer 8a1t1, various adhesives such as an anaerobic adhesive, a reactive curable adhesive, a photocurable adhesive, or a thermosetting adhesive can be used.

In particular, in this embodiment, since the liquid crystal display panel 12 is made of glass, which is a light-transmitting material, the adhesive layer 14 can use a photocurable adhesive that can be bonded at high speed.

Conductive particles 5 are arranged at the boundary between the adhesive layer 8a and the adhesive N14. The conductive particles 5 are elastic members 5L+
The surface is coated with one metal layer 5a, or with two or more layers for the purpose of ensuring adhesion to the elastic member 5b, and has a uniform particle size distribution. The elastic members 5b, which are embedded and bonded at least one per connection part with the adhesive layer 8a, are made of rubbers such as silicone rubber and urethane rubber, and elastic polymers such as synthetic resins. Approximately spherical particles made of material are used.As the metal layer 5a, AL1,
Metals such as Ag, Ni, C, Cu, Pd, Pb, Sn, or Irr, or metal plates of these metals are used.

Only a portion of the conductive particles 5 is embedded in the adhesive layer 8a, the remaining portion is in contact with the adhesive layer 14, and one end thereof penetrates through the adhesive layer 14 and is in contact with the surface of the wiring electrode 13. . The ends of the conductive particles 5 may be in direct contact with the surface of the electrode 2, or may be connected to the electrode 2 via a conductive first adhesive layer 8a, as shown in the examples described later. It may also be possible to connect the

The structure shown in FIG. 1 can be molded with a protective resin or the like, or can be mechanically protected by IR in order to further improve moisture resistance. Although it is possible to use spherical particles made of a single metal or an alloy similar to that used for metal R5a, when using the elastic member 5b whose surface is coated with metal Jl 5a, sexual particle 5 is electrode 1
Variations in height on the surface in contact with the electrode 13 surface can be absorbed by elastic deformation of the elastic member 5b, and surface contact with the electrode 13 surface can be maintained at all times, so that a stable connected layer can be maintained.

FIG. 4 is a cross-sectional view showing a manufacturing process for obtaining a connection between the semiconductor device 6 and the liquid crystal display panel 12 as shown in FIG. As shown in FIG. 4(1), in the substrate 1 on which the electrodes 2 and the surface protective layer 3 are formed in advance, a spin cord or roll coat, for example, is applied above the electrodes 2 and the surface protective layer 3. The adhesive layer 8a is formed by applying a photocurable adhesive over the entire surface by the method described in (a). At this time, the thickness N of the adhesive M8a is made sufficiently thinner than the particle size of the conductive particles 5 so that only a portion of the conductive particles 5 is embedded in the adhesive N8a.

In this state 1, in order to prevent the adhesive layer 8a from flowing out and the conductive particles 5 from dispersing when removing unnecessary conductive particles 5, which will be described later, the entire surface is irradiated with moderate ultraviolet rays and bonded in stages. The adhesiveness can also be improved by hardening the agent layer 8a and increasing the viscosity. In addition, the adhesive with high viscosity is diluted with a solvent to adjust the viscosity to an appropriate level, and the adhesive coated by the above-mentioned spin cord or roll coating method is hardened in stages by evaporating the solvent and then conductive. particle 5
may be attached.

Furthermore, in the case 6 where a thermosetting adhesive is used as the material for the adhesive layer 8a, a low viscosity adhesive is applied by the above method and then heated to harden in stages to increase the viscosity. It is also possible to attach the conductive particles 5 after that.

The substrate 1 on which the adhesive layer 8a has been formed as described above is irradiated with ultraviolet light indicated by the arrow 20 through the mask 9, as shown in FIG. 4(2). The mask 9 is formed with a blocking portion 9it that blocks ultraviolet rays 20 and a through hole 9b that allows ultraviolet rays 20 to pass through. The irradiation with the ultraviolet rays 20 is performed when the Kt region of the substrate 1 where the surface protection film 3 is formed is aligned with the through hole 9b. As a result, only the adhesive JI8b in the area where the surface protection M3 is formed is selectively cured. On the other hand, the adhesive layer 8a in the area where the electrode 2 is formed, where the ultraviolet rays 20 are blocked by the blocking portion 9a, remains uncured and remains sticky. In this way, the sticky adhesive layer 8a can be formed in an rR fine pattern.

Next, as shown in FIG. 4(3), conductive particles 5 are attached to the adhesive layer 8a formed as a fine pattern. As explained in FIG. 4(2), the adhesive layer 8a
Adhesive N8b has UV 20
is irradiated and hardened and loses its tackiness. Therefore, although the conductive particles 5 adhere to the sticky adhesive layer 8a, they do not adhere to other areas such as the adhesive J18b.

Further, unnecessary conductive particles 5 that have adhered to the pond area due to electrostatic force or the like are removed by air blowing or by using a brush or the like. Further, although it is preferable to attach the conductive particles 5 in a single layer to the adhesive layer 8a, it is preferable that the conductive particles 5 be attached in multiple layers at the stage of the manufacturing process in which the semiconductor device 6 is pressed against the liquid crystal display panel 12, as will be described later. There may be two or more layers as long as the conductive particles 5 move to form m layers.

In this way, a protruding electrode can be formed by selectively depositing one inch of the conductive particles 5 only on the region where the electrode 2 is formed.

After forming the protruding electrodes made of conductive particles 5 as described above, the adhesive layer 8a having adhesiveness is cured,
Therefore, handling of the semiconductor device 6 becomes easier, and operability in the manufacturing process of the semiconductor device 6 is improved. Furthermore, as mentioned above, when molding such a semiconductor device 6 with an adhesive after connecting it to a circuit board, the adhesive layer 8 is applied in the same process as the adhesive for molding.
It is also possible to harden a.

No. 411m(4) is a cross-sectional view in which the adhesive layer 8b is further selectively removed from the substrate 1 on which protruding electrodes are formed by the above-described manufacturing process. Although the step of removing the adhesive layer 8b is not particularly necessary in this embodiment, as shown in other embodiments described later, the adhesive layer 8'rt is removed using a particularly conductive adhesive. PS to form
In some cases, it is necessary to selectively etch and remove the adhesive layer 8b by photolithography or the like so that the electrodes 2 adjacent to each other through the adhesive layer 8b are not electrically short-circuited. .

Further, the adhesive layer 8 rt can also be selectively formed on the electrode 2 by a printing method such as screen printing or offset printing. According to the printing method, the adhesive layer 8a
It is easy to form a pattern, and it also eliminates the need for unnecessary adhesives, especially when using conductive adhesives.
[118b] No removal is necessary, simplifying the manufacturing process.

FIG. 4(5) is a cross-sectional view for explaining the process of connecting the semiconductor device 6 on which the protruding electrodes are formed as described above to the liquid crystal display panel 12. The surface of the semiconductor device W6 on which the protruding electrodes are formed is opposed to the surface on which the wiring electrodes 13 (of the liquid crystal display panel 12f) are formed, and the conductive particles 5 and the wiring electrodes 13 are aligned. An adhesive 14 that hardens at a relatively low temperature is injected and filled between the substrates 112 aligned in this manner using a metering device such as a dispenser. In this state, the semiconductor device 6 is attached to the liquid crystal display board 12 through the adhesive layer 14 in the direction of the arrow 19, and the electrodes 2, 13
Pressure is applied until the distance between them reaches a predetermined distance r1. By curing the adhesive layer 14 in this pressurized state, the semiconductor device 6 is mounted on the liquid crystal display board 12.

Another method for filling the adhesive 14 between the substrates 1 and 12 is to fill the adhesive 14 between the substrates 1 and the liquid crystal display panel 12 before aligning the electrodes 2 13 of the substrate 1 and the liquid crystal display panel 12 with each other.
It is also possible to apply the adhesive 1.1 in advance to one or both surfaces by a method such as printing.

Through the manufacturing process explained above, the substrate 1 and the liquid crystal display panel 1 are
The two electrodes 2 and 13 are electrically connected, and the semiconductor device 6 is mounted on the liquid crystal display board 12 with the connection structure shown in FIG. In this mounted state, as shown in FIG. 2, the conductive particles 5 are elastically deformed in the pressing direction shown by arrow 1 in FIG. fixed between.

In this letter, the gold R layer 5a on the surface of the conductive particles 5 is
In addition to serving as an electrical connection between 12 and 13,
Even if the substrates 1 and 12 are deformed such as warping or waviness due to external thermal or fulltiJ influence, the conductive particles 5 deform and follow the elasticity of the conductive particles 5, causing a gap between the electrodes 2 and 13. electrical connection is maintained at all times. In particular, the elastic member 5b of the conductive particles 5 and the adhesive layer 8
=t, 14 is made of materials with similar coefficients of thermal expansion as mentioned above, so it is connected due to the difference in coefficient of thermal expansion! This prevents D from becoming unstable. Therefore, the reliability of the connection is improved.

Moreover, the metal layer 5rL coated on the surface of the conductive particles 5 is
Further, the surface is molded with the adhesive layer 14. As a result, the space between the substrates 1 and 12 is sealed by the adhesive 111, and outside air is prevented from entering. Further, even if the adhesion of the metal layer 5a to the elastic member 5b is somewhat poor, undesirable simplexes such as peeling of the metal layer 5a from the surface and poor electrical connection are prevented, and the reliability of the connection is improved.

FIG. 5 is a cross-sectional view of the conductive particles 4 as an example of a pond. The conductive particles 4 of this example are contained in elastic polymeric materials such as rubbers such as silicone rubber and urethane rubber, and synthetic resins such as Au, Ag, Ni, C, and C.
The conductive attachment 4 is made of a metal such as Ll, P(1, Pb, Sr+, or Irr), or a mixture of these metals with fine gold particles.

Therefore, the conductive particles 4 have elasticity and also have conductivity due to the gold R fine particles contained in the formed resin. By using the conductive particles 4 instead of the conductive particles 5 used in the previous embodiment, it is possible to electrically connect the semiconductor device 6 and the liquid crystal display panel 12. Especially when using this conductive particle = 1,
A metal layer 5a coated on the surface of the conductive particle 5
The reliability of the connection is further improved, since the possibility of undesired deviations, such as separation during the manufacturing process, is completely eliminated.

Furthermore, although not shown, as the conductive particles 5, A
ll, Ag, CLI, Ni, C, Pd, In, S
Single metals such as n and pb or alloys thereof can also be used.

No. 6 [2I] is a cross-sectional view of a semiconductor device 18 in which a protruding electrode is formed, which is another embodiment of the present invention. Note that the first [2
The same reference numerals are used for parts corresponding to those in the embodiment shown in FIG. In the configuration shown in FIG. 6, the adhesive layer 7 is made of a conductive adhesive. The material f of the adhesive layer 7: 1 is acrylic resin, polyester resin,
Various synthetic resins such as urethane resin, epoxy resin, or silicone resin are used, and in this adhesive layer 7a, for example, Au, Ag, Cu, Ni, C, Pd,
Fine particles 7 made of a conductive material such as pb, S rt or I rt or an alloy of these conductive materials
Mix b to give 11 conductivity. This adhesive N7,
The conductive particles 5 are selectively formed on the surface of the electrode 12 by the method explained in connection with FIG. 4, and the conductive particles 5 are deposited one by one on the surface to form a protruding electrode.

In the semiconductor device 18 in which the protruding electrodes are formed in this way, since the adhesive layer 7 itself has conductivity,
Even if the other end of the conductive particles 5 embedded in the surface thereof is not necessarily in contact with the surface of the electrode 2, the metal N5EL is in contact with the wiring conductor 113 of the liquid crystal display board 12 via the conductive adhesive layer 7. and electrode 2 are electrically connected. Also in this example, instead of the conductive particles 5, conductive particles 4 shown in FIG. 5 or Au, Ag, Cu, Ni
It is possible to use particles made of metals such as , C, P (1, I rt , S rl, Pb, or alloys thereof.

In this embodiment, a t% electrode is described in which protruding electrodes are formed on the substrate 1 of the semiconductor devices 6 and 18 and connected to the liquid crystal display panel 12. However, it is not necessary to limit the connection to circuit boards related to semiconductor devices, and it is not necessary to electrically connect electrodes of circuit boards on which other electronic components are mounted, such as printed circuit boards, glass boards, flexible boards, ceramic boards, etc. It is also possible to implement the present invention wherever there is.

Effects of the Invention According to the present invention, the electrodes are electrically connected to each other by the intervening body held by the holding layer between the first circuit board and the second circuit board. Therefore, even when connecting electrodes having a fine pitch, situations such as short circuits and leakage are prevented, and the reliability of the connection is significantly improved.

Further, according to the present invention, an adhesive that hardens at a relatively low temperature is used to bond the circuit boards together. Therefore, there is no need to perform high-temperature heat treatment to connect each circuit board.
There is no possibility of thermal fatigue or damage to each component due to thermal stress, and productivity is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
Enlarged sectional view showing details of the figure, No. 3I2! is a cross-sectional view of a liquid crystal display device 10 in which a semiconductor device 6 is mounted according to the present invention, FIG. 4 is a cross-sectional view showing the manufacturing process f) for obtaining the connection shown in FIG. 1, and FIG. A cross-sectional view of the sexual particle 4,
FIG. 6 is a sectional view showing a semiconductor device 18 according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Electrode, 3... Surface protective layer, 4
．． 5 conductive particles, 6,18...semiconductor device, 7.814
...Adhesive layer, 10...Liquid crystal display device, 11.12
...Liquid crystal display board, 13...Wiring electrode, 16...Counter electrode, one...Pressure direction, 20...Ultraviolet agent
Patent Attorney Keibu Saikyo

Claims (1)

[Claims] A method for interconnecting a first circuit board on which electrodes are formed and a second circuit board on which electrodes are formed at positions corresponding to the electrodes, comprising: An intervening body having electrical conductivity and having a thickness greater than that of the retaining layer is buried and held in the formed retaining layer, and the first circuit board and the second circuit board are faced to each other, and the intervening body is inserted through the intervening body. Pressure is applied to the first and second circuit boards while their corresponding electrodes are connected to each other, thereby curing the adhesive which is cured at a relatively low temperature and which has been filled between each circuit board in advance. A circuit board connection method characterized by: