JP2003046222A - Bonding material and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new bonding material which is suitably used for bonding an electronic component to a wiring pattern formed on a board in an electronic component mounting process. SOLUTION: Charged particles which are each composed of a metal particle and first coating layer that coats the metal particle are used as bonding material, and the first coating layer contains a charge control agent and an silane coupling agent. The charged particles can be fed to the prescribed spots of a wiring pattern provided on a board, taking advantage of the principle of an electrophotographic method, and thereafter the board where electronic component are arranged is subjected to a thermal treatment, by which the wiring pattern and the electronic components can be electrically and physically bonded together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting process for forming an electronic circuit board, in order to join a wiring pattern and an electronic component, more specifically, electrical and physical (or mechanical, And the like) and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, in the process of manufacturing an electronic circuit board used for electronic equipment or the like, in order to mount electronic parts on the board, more specifically, electrodes (or leads, terminals or terminals) of the electronic parts and the board are to be mounted. Reflow soldering is one of the methods used to electrically and physically bond the land of the formed wiring pattern. Reflow soldering is generally performed by supplying a bonding material containing solder onto lands of a wiring pattern formed on a substrate, then appropriately placing electronic components on the lands, and then heat treating the substrate. The electrode of the electronic component and the wiring pattern are soldered.

In this reflow soldering, cream solder has been conventionally used as a joining material,
A screen printing method is usually used to supply cream solder, which is a bonding material, onto lands of a wiring pattern formed on a substrate. Such a conventional method will be described below. First, a metal mask (or a screen plate) having a thickness of 80 to 150 μm, in which openings having a predetermined shape are provided at predetermined positions so as to correspond to the lands on the substrate, The substrates are arranged so as to be in contact with each other. Then, cream solder (bonding material) is supplied near one end of the metal mask arranged on the substrate. Next, the squeegee is moved in parallel with the substrate surface to smooth out the cream solder on the metal mask, thereby filling the opening provided in the metal mask with the bonding material. Then, the metal mask is separated from the substrate, and the metal mask and the cream solder on the metal mask are removed from the substrate. At this time, the cream solder filled in the opening passes through the metal mask, that is, "plate-out", and remains on the land of the wiring pattern on the substrate, which causes the cream solder to land on the land of the wiring pattern. Supplied. In general, a plurality of lands to which the bonding material is to be supplied are present on the substrate and form a predetermined land pattern, so that the bonding material is supplied on the land pattern as a bonding pattern corresponding to the land pattern. .

The cream solder used in the screen printing method is usually formed by mixing a solder powder containing tin and lead as main components and having a diameter of 10 to 40 μm with a flux composed of rosin, an activator and a solvent.

[0005]

In recent years, in response to a demand for miniaturization and high functionality of portable electronic equipment such as a mobile phone, the electronic circuit board is mounted on a substrate in order to achieve higher integration. The miniaturization of electronic parts and the narrowing of the pitch between electrodes of electronic parts are progressing. Along with this, further miniaturization of lands for mounting electronic components is required, and a bonding material for bonding electronic components is supplied onto smaller lands, in other words, bonding made of bonding material. Further miniaturization of patterns is required.

For example, in order to mount a CSP (chip scale package) component of 0.4 mm pitch,
It is required to reduce the size of the land to a diameter of about 0.2 mm. Also, 0402 parts (0.4 mm x 0.2
In order to mount a chip component (mm size), it is required to reduce the size of the land to 0.2 mm × 0.2 mm.

However, the conventional screen printing method using a metal mask is not sufficiently satisfactory to form a fine bonding pattern by supplying cream solder as a bonding material onto such a minute land. Absent. In order to accurately supply the cream solder onto the land and to secure a sufficient solder amount for joining the electronic parts (more specifically, conductive connection), the metal mask should have a certain thickness, for example, 1 mm. It is necessary to secure a thickness of about 1.2 mm. However, when a metal mask having such a thickness is used, the cream solder may remain in the opening of the metal mask without being removed from the plate, which causes a problem of printing failure.

The present invention has been made to solve the above conventional problems, and an object of the present invention is to bond a wiring pattern formed on a substrate to an electronic component in mounting the electronic component. Another object of the present invention is to provide a novel bonding material that is preferably used for electrical and physical bonding (or conductive connection), and a manufacturing method thereof.

[0009]

In the conventional general electronic component mounting process, as described above, the bonding material for bonding the wiring pattern formed on the substrate and the electronic component is formed by the screen printing method. It is printed on a substrate (more specifically, it is supplied on a predetermined portion of a wiring pattern, for example, on a land), and cream solder is used as a bonding material printed by such a method. On the other hand, in the manufacturing process of the multilayer laminate, there is a method of printing a circuit forming material on a green sheet by an electrophotographic method, and the circuit forming material printed by the electrophotographic method includes charged particles. The granular material (or chargeable powder) is used.

For example, in Japanese Unexamined Patent Publication No. 11-251718, chargeable powder (chargeable particles) is printed on a green sheet in a predetermined pattern by an electrophotographic method, and the obtained green sheets are laminated and fired. It is described that a multilayer wiring board is manufactured by doing so. The chargeable particles used as the circuit forming material are obtained by heat-melt kneading a mixture of conductive metal particles, a heat-meltable resin, a charge control agent and an adhesion enhancer, and crushing and classifying the mixture. The obtained chargeable particles have a structure in which conductive metal particles, a charge control agent and an adhesion enhancer are dispersed in a hot melt resin. The chargeable particles as described above correspond to so-called toner used in the printing technique by electrophotography, and generally have a particle size similar to that of the toner. For example, Japanese Patent Laid-Open No. 11-251718
The publication describes that the chargeable particles may have an average particle size of about 3 to 20 μm, and the conductive metal particles dispersed in the heat-meltable resin component in the chargeable particles are, of course, The particle size is smaller than the particle size of the charged particles. The conductive metal particles used for the circuit-forming material are made of a metal material having a relatively high melting point such as copper that is generally used as a circuit material (hereinafter, the conductive metal particles used for the circuit-forming material are simply referred to as Cu. Also called particles).

In order to print a bonding material for electrically and physically bonding the wiring pattern formed on the substrate and the electronic component on the substrate, the present inventors have replaced the screen printing method with an electrophotographic method. We examined the use of the principle. Conventionally, cream solder that has been used as a bonding material is not suitable for printing by electrophotography. Also,
If the circuit-forming material composed of the above-mentioned chargeable powder is used as it is, it is impossible to electrically and physically bond the wiring pattern formed on the substrate and the electronic component. Therefore, it is necessary to develop a novel bonding material that can be printed by the electrophotographic method and that can electrically and physically bond the wiring pattern formed on the substrate and the electronic component.

In order to print the bonding material by electrophotography, it is considered necessary to use a granular material composed of charged particles such as toner as the material. Further, in order to electrically and physically bond the wiring pattern and the electronic component, as the metal particles present in the chargeable particles, instead of the Cu particles as described above, a solder material having a relatively low melting point is used. It is considered preferable to use the particles (hereinafter, also simply referred to as solder particles). Therefore, the present inventors have attempted to realize a new bonding material, heat-melt and knead the solder particles together with the heat-meltable resin, and pulverize the solid mixture obtained at room temperature to obtain the new charged particles. (Or granular material) was made. However, although it is possible to print the charged particles thus obtained on the substrate by an electrophotographic method, it was found that accurate printing on the substrate with a fine pattern is not always sufficient. did. This is partly because the chargeable particles obtained by using the solder particles may be exposed without being completely covered with the resin when the mixture containing the solder particles and the resin is pulverized. It is believed that there is.

The Cu particles used for the charged particles that are the above-mentioned circuit-forming material may be manufactured by a precipitation method or the like so as to have a sufficiently small particle size, for example, a particle size of about 1 μm or less. It is possible. Therefore, in the above-mentioned charged particles (material for forming a circuit) using Cu particles as the metal particles, the average particle diameter of the Cu particles used is set to the above-mentioned value so that the Cu particles are not exposed and are sufficiently covered with the resin component. It can be appropriately selected according to the average particle size of the target charged particles in the range of about 3 to 20 μm.

On the other hand, solder particles cannot be manufactured by a precipitation method because they are composed of a solder material which is an alloy. Generally, they are manufactured by atomizing a molten solder material and solidifying it as it is. To be done. Therefore, it is difficult to obtain solder particles having a particle size as small as Cu particles due to the manufacturing method, and the particle size of commercially available solder particles is currently about 10 μm at the minimum. Therefore, when the solder particles are used as the metal particles instead of the Cu particles to produce the above-described new chargeable particles, the available particle diameter of the metal particles is larger than that when the Cu particles are used as the metal particles. However, there is no choice but to use solder particles having a relatively large particle size, and metal particles are often exposed without being completely covered with resin. If the metal particles are at least partially exposed, when the charged particles are charged, the charged charge escapes to the exposed metal particles, so that the charged particles cannot be uniformly charged, and therefore printing is performed. It can be considered that the accuracy is reduced.

As a result of further earnest studies, the present inventors have solved the above-mentioned problems, and utilize the principle of electrophotography without using a screen printing method to print a substrate (for example, a substrate to be printed). It has come to realize a novel bonding material capable of accurately printing a desired pattern on a body). still,
The bonding material obtained by the present invention described below is used for physically and electrically bonding an electronic component to a substrate (more specifically, a wiring pattern formed on the substrate) (in other words, conductive bonding or conductive bonding). As long as the electronic components can be physically and electrically bonded to the substrate by some treatment, it can be used before the bonding (for example, when printing by electrophotography). It should be noted that it does not necessarily have to be electrically conductive.

According to one aspect of the present invention, there is provided a joining material for joining a wiring pattern formed on a substrate and an electronic component, the joining material comprising metal particles and a first coat layer for covering the metal particles. A bonding material is provided that includes particles having a first coating layer that includes a charge control agent and a silane coupling agent. As described above, the particles in which the metal particles are covered with the first coating layer containing the charge control agent and the silane coupling agent can be charged, and thus have a charge property, and thus such particles are charged in the present invention. Let us call them particles. The chargeable particles may have charging characteristics similar to those of so-called toner particles used for toner in electrophotography, so that the charged particles are charged and charged with the principle of electrophotography. By transferring the particles to the substrate, the charged particles can be supplied onto the substrate (more specifically, the wiring pattern, and so on).

As is generally known, the silane coupling agent is an organosilicon compound and has an organic functional group and a hydrolyzable group in the same molecule. Since such a silane coupling agent is easily bonded to an inorganic material such as a metal due to its hydrolyzable group, it is more compatible with the inorganic material than the resin material (that is, has high wettability to the inorganic material) and has a high bonding force. Binds with inorganic materials. Therefore, when the silane coupling agent is used in the first coat layer for coating the metal particles as in the present invention, the metal particles can be completely coated with the first coat layer without exposing the metal particles to the surface of the charged particles, It is possible to uniformly charge the charged particles. This makes it possible to arrange (or supply) such charged particles on a substrate accurately (or with high precision) in a fine pattern using the principle of electrophotography. It should be noted that the present invention does not necessarily require that the metal particles be coated with the first coat layer in all the charged particles contained in the bonding material.

The bonding material of the present invention as described above may be a granular material composed of only charged particles, in which case the bonding material composed of charged particles is accurately printed as a desired bonding pattern on the substrate. be able to. Further, the bonding material of the present invention may contain other materials in addition to the charged particles, such as an external additive referred to in electrophotography,
In this case, the bonding material containing the charged particles and the external additive can be accurately printed as a desired bonding pattern on the substrate. A bonding material composed of or containing such charged particles will be understood as a toner equivalent in electrophotography. Hereinafter, for ease of understanding, the bonding material of the present invention will be simply referred to as the charged particles of the present invention, but it should be noted that the bonding material of the present invention may include something other than the charged particles. It should be.

Further, the charged particles (bonding material) of the present invention
May be used alone to be printed by a so-called one-component developing method, or may be used by being mixed with a carrier or the like in the electrophotographic method, so-called a two-component developing method or a 1.5-component developing method. It may be printed. A mixture in which charged particles are mixed with a carrier (however, in the case of a one-component developing system, it is composed of only charged particles) is understood as being equivalent to a developer in the field of electrophotography.

In the charged particles of the present invention, as the metal particles, particles (or powders) made of a metal material having a relatively low melting point, for example, a melting point of about 300 ° C. or less, preferably about 1 are used.
Particles composed of solder material or the like having a melting point of 00 to 250 ° C. may be used. By using particles made of a metal material having a relatively low melting point as described above, the charged particles of the present invention are arranged (printed) on a substrate in a desired pattern by an electrophotographic method and then contacted with the charged particles. The electronic component can be bonded to the substrate by arranging the electronic component on the base body and subjecting the obtained substrate to heat treatment. this is,
The heat treatment heats the metal material of the metal particles to a temperature above its melting point to melt it once, and then cools or cools it to solidify it. ) Is based on the fact that it can be electrically and physically joined to and from. However, the present invention is not limited to this, and the electronic component and the wiring pattern of the substrate may be joined by other means, and the electrical joining and the physical joining are realized by using different materials. You may do it.

The metal particles have, for example, about 0.01 to 40 μm.
Particle size of about 0.01 to 10 μm, preferably about 0.01 to 10 μm. Also, the metal particles can have any suitable shape, such as spherical, spheroidal, and amorphous. The metal particles, for example, by using the atomization method, a metal ingot made of a predetermined metal material is heated to a temperature equal to or higher than its melting point to be completely melted, and the melted metal material is dispersed in a droplet form by spraying, and the like by air or the like. Powdered (or granular) by cooling and solidifying
It is obtained by classifying as necessary. However, the invention is not so limited and the metal particles may be produced by any other suitable method. In particular, metal particles made of a solder material having a particle size of 10 μm or less are not easy to manufacture by the atomizing method as described above, but it is not always impossible. Generally, particles obtained by spraying a molten solder material by an atomizing method are distributed around a particle size of about 30 μm, and particles having a particle size of 10 μm or less are also compared to the entire particles. It exists, albeit in a small amount. Therefore, by classifying the particles thus obtained, the particle size is 10 μm or less, for example, 0.
Only particles with a particle size of 01-10 μm can be obtained. However, it is not limited to this, and 1
It would be possible to produce solder particles of 0 μm and smaller.

The chargeable particles of the present invention in which such metal particles are covered with the first coat layer have a particle size of the metal particles which is the first.
It can have a particle size equal to the thickness of the coating layer plus, for example, a particle size of about 10-400 μm, preferably 10-100 μm (of course larger than the particle size of the metal particles).

Throughout the present specification, the "particle size" of the metal particles and the chargeable particles means the number average particle size of the granules of the particles obtained on the assumption that the particles have a spherical shape. .

The solder material that can be used for the metal particles in the present invention generally contains tin as a main component and contains lead, silver, copper,
1 selected from the group consisting of bismuth and indium
Contains at least one metal element. For example, Sn-Pb system, Sn
-Ag system, Sn-Cu system, Sn-Ag-Cu system, Sn-
There are solder materials such as Ag-Bi-Cu based and Sn-Ag-Bi-In based. Considering the influence on the environment, it is preferable to use a so-called lead-free solder material that does not contain lead, but the present invention is not limited to this.

The silane coupling agent contained in the first coat layer is, for example, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane,
β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane,
γ-methacryloxypropylmethyldimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ-
Methacryloxypropylmethyldiethoxysilane, γ-
Methacryloxypropyltriethoxysilane, N-β
(Aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-
Aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane,
γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine hydrolyzate, etc. Can be used, and vinyltrichlorosilane, vinyltrimethoxysilane, and vinyltriethoxysilane are preferable.

In the chargeable particles of the present invention, the charge control agent plays a role of charging the surface of the chargeable particles and controlling the charge amount. Examples of materials for the charge control agent include styrene / acrylic copolymers, polyesters (eg, chlorinated polyesters, polyesters having excess acid groups), polystyrenes, amine-based metal compounds, azo-based compounds, chlorine-based paraffins, and copper phthalocyanine sulfonyls. Amine naphthenic acid metal salts, fatty acid metal salts, resin acid soaps, and mixtures of two or more thereof are used, and preferably styrene / acrylic copolymers and polyesters. The charge control agent generally has a very fine powdery morphology as compared with metal particles.

According to another aspect of the present invention,
A bonding material for bonding a wiring pattern formed on a substrate to an electronic component, comprising metal particles, a first coat layer covering the metal particles, and a second coat layer covering the first coat layer. A bonding material is provided, which comprises particles having a first coating layer containing a silane coupling agent, and a second coating layer containing a charge control agent and a resin component. Thus, the particles in which the metal particles are covered with the first coat layer containing the silane coupling agent and further covered with the second coat layer containing the charge control agent and the resin component are also referred to in electrophotography. It is a chargeable particle having a charging property similar to that of a toner particle used in a toner, and the bonding material of the present invention containing such a chargeable particle is also understood to correspond to a toner in electrophotography. Will be done. In the present specification, the above-mentioned chargeable particles in which metal particles are covered only by the first coat layer are referred to as one-layer type, and the metal particles are covered by the first coat layer and the second coat layer. The functional particles are called a two-layer type. Also in the two-layer type chargeable particles of the present invention, the same silane coupling agent, metal particles and charge control agent as those in the one-layer type chargeable particles of the present invention can be used, and description thereof will be omitted. I shall.

The resin component used in the present invention functions so as to cover the metal particles and the first coat layer to give the morphology of the particles, and the term "resin component" means
Containing a resin material as a main component (however, including a resin material alone without other subcomponents)
Say The resin component may include, for example, an activator in addition to the resin material. As the resin material used for the two-layer type chargeable particles of the present invention, a heat-meltable resin material such as rosin and styrene / acrylic copolymer can be used.

Such a two-layer type chargeable particle of the present invention has a particle diameter equal to the particle diameter of the metal particle plus the thickness of the first coat layer and the second coat layer, for example, about 1
It may have a particle size of 0 to 400 μm, preferably 10 to 100 μm (of course larger than the particle size of the metal particles).

According to the two-layer type chargeable particles of the present invention as described above, even when the second coat layer containing the resin component cannot completely cover the surface of the chargeable particles, the metal particles contain the silane coupling agent. Since it is covered with the first coat layer containing the metal particles, the metal particles are not exposed on the surface of the charged particles. Therefore, even with such a bonding material containing the two-layer type charged particles of the present invention, the above-mentioned bonding material of the present invention 1
The effect similar to that of the bonding material containing the layer-type charged particles can be obtained, and the bonding material can be used in mounting electronic components.

Further, according to the two-layer type charged particles of the present invention, since the first coat layer containing the silane coupling agent is covered with the second coat layer containing the resin component, the flux as the resin component is By using the same components, the same effect as that obtained by the flux in the conventional cream solder can be obtained. Specifically, when a resin containing rosin as a main component and an activator such as an amine halogen salt such as ethylamine hydrochloride is used as the resin component of the second coat layer, metal particles made of a solder material are used. Can be effectively prevented, and thus, the melting of the metal particles when joining the wiring pattern and the electronic component can be assisted (or the wettability of the metal obtained by melting the metal particles can be improved). .

When a resin material that can also function as a charge control agent is used as the resin component, such as a styrene / acrylic copolymer, the second coat layer is separate from the resin material (resin component). The charge control agent may not be included.

The two-layer type chargeable particles of the present invention as described above are also brought into contact with the chargeable particles after the chargeable particles are arranged (printed) on a substrate by electrophotography in a desired pattern. The electronic component can be bonded to the substrate by simply disposing the electronic component on the base body and subjecting the obtained substrate to heat treatment. This is also similar to the one-layer type charged particles of the present invention, in that the electronic component and the wiring pattern (for example, land) of the substrate are electrically and physically joined with a molten and solidified metal material. It is based on the fact that

In the bonding material of the present invention as described above, both the one-layer type and the two-layer type chargeable particles may include one metal particle, but the present invention is not limited to this and the chargeability is not limited thereto. The particles may include more than one metal particle. Further, when the chargeable particles include two or more metal particles, these metal particles may be in contact with each other or fused to each other, or may be separated from each other.

In addition, in the bonding material of the present invention as described above, in addition to the metal particles and the charge control agent (and the resin component), any type of charged particles can be added to a trace amount of other components such as charged particles. A release agent such as polypropylene may be included in order to improve the adhesion of the charged particles to the substrate when transferring.

According to another aspect of the present invention, the metal particles are soaked in a liquid material containing a silane coupling agent and a charge control agent so that the metal particles form a first coating layer containing the silane coupling agent and the charge control agent. There is provided a method of manufacturing charged particles, which comprises obtaining covered charged particles, and therefore a method of manufacturing a bonding material for bonding a wiring pattern formed on a substrate to an electronic component, the method comprising: Provided is a method of manufacturing a bonding material including a conductive particle. By such a manufacturing method, the bonding material containing the single-layer type charged particles of the present invention as described above can be obtained.

The charge control agent may be added to the chargeable particles by using a liquid material in which the charge control agent is previously dispersed as in the above-mentioned type of production method of the present invention. Forming a first coating layer containing a silane coupling agent around the metal particles by immersing the metal particles in a liquid containing but not containing the charge control agent, and then mixing the obtained particles with the charge control agent Alternatively, the charge control agent may be attached to the first coat layer on the surface of the chargeable particles, or the charge control agent may be added to the first coat layer.

According to another aspect of the present invention, the metal particles are dipped in a liquid containing a silane coupling agent, and the metal particles are covered with a first coating layer containing the silane coupling agent.
The obtained metal particles are kneaded with a mixture obtained by mixing a charge control agent and a resin component and pulverized, whereby the metal particles are coated with a first coating layer containing a silane coupling agent,
Provided is a method for producing chargeable particles, which comprises obtaining a chargeable particle in which a coat layer is covered with a second coat layer containing a charge control agent and a resin component. Therefore, a wiring pattern and an electronic component formed on a substrate are provided. A method for manufacturing a bonding material for bonding, comprising: providing a bonding material containing the charged particles. By such a manufacturing method, the bonding material containing the above-mentioned two-layer type charged particles of the present invention can be obtained.

In such a manufacturing method, the charge control agent may be mixed with the metal particles and the resin component, but the charge control agent is not mixed with the metal particles and the resin component, and the metal particles contain the silane coupling agent. After obtaining the chargeable particles coated with the first coat layer and the first coat layer being coated with the second coat layer containing a resin component, a charge control agent is provided on the surface of the second coat layer of the obtained particles, For example, they may be fixed by applying a mechanical impact force.

In the method for producing a bonding material containing charged particles of any type of the present invention, the liquid material containing the silane coupling agent may or may not contain a solvent. When the liquid contains a solvent and the silane coupling agent is diluted with the solvent, the metal particles soaked in the liquid are dried or heated as necessary to adhere to the metal particles together with the silane coupling agent. It is preferable to vaporize and remove the solvent.

Further, in any type of production method of the present invention, the obtained charged particles may be classified if necessary, and / or surface modification known in the field of granulation technology (for example, Heat treatment).

According to the present invention as described above, there is provided a novel joining material which is preferably used as a material for joining a wiring pattern and an electronic component in mounting an electronic component, and a manufacturing method thereof. The bonding material of the present invention is applied to the substrate (more specifically, a predetermined portion of the wiring pattern formed on the substrate, for example, a land) by transfer by applying the principle of electrophotography without using the screen printing method. It can be accurately supplied in a desired pattern, and furthermore, the electronic component can be bonded to the base body (more specifically, a predetermined portion of the wiring pattern, for example, a land).

Therefore, if an electronic circuit board is manufactured using the bonding material of the present invention, the bonding material (charged particles) can be reliably and productively arranged at a predetermined position on the substrate, for example, a fine land pattern. Therefore, it is possible to sufficiently cope with high integration and narrow pitch of the electronic circuit board.

In the present specification, the term "base" means a substrate on which a wiring pattern is formed and on which a bonding material for bonding the wiring pattern and the electronic component is to be arranged. Therefore, the term "base" includes, but is not limited to, a sheet-like form (for example, a circuit board), and a wiring pattern is formed, and an electronic component is provided at a predetermined position of the wiring pattern. Any form (for example, housing) may be used as long as it requires joining. For example, a circuit board and a multilayer laminated board (such as a build-up board) in which a wiring pattern is formed on a base made of paper phenol-based material, glass epoxy-based material, polyimide film-based material, ceramic-based material, metal-based material, etc. It can be used in the present invention.

The wiring pattern (including lands) formed on such a substrate may be made of a material such as copper, gold, aluminum and solder. The wiring pattern can have any suitable width.

The bonding material of the present invention can be preferably used when the substrate is a circuit board on which a circuit is formed by a wiring pattern. For example, according to the invention, a width of 50-5
00 μm, preferably 60 to 200 μm, more preferably 80 to 150 μm, each having a pitch of 0.1 to 1.0 μm, preferably 0.12 to 0.4 μm.
The charged particles of the bonding material of the present invention can also be supplied onto a land pattern of m, more preferably 0.16 to 0.3 μm. The term "land" is a part of the wiring pattern, and the part or place on which the bonding material (chargeable particles in the present invention) is arranged, the term "width" is
The shortest length of one land, the term "pitch", refers to the pitch of a plurality of lands associated with the same electronic component (ie, corresponding to the pitch of the electrodes of the electronic component).

Electronic parts to be joined to a wiring pattern using the present invention include semiconductor parts (for example, so-called QFP).
(Quad flat package) components, CSP (chip scale package) components, and SOP (single outside package) components), chip components (eg resistors, capacitors, transistors, inductors, etc.), and connectors Etc. are included. The bonding material of the present invention is particularly suitable for electronic components having a narrow pitch, such as QFP components having an electrode pitch of 0.4 mm, 0.3 mm or less and 0.65 mm, 0.5 mm.
CSP with an electrode pitch of 0.4 mm or less
It is also suitably used for a fine land pattern for joining components and the like to a circuit board.

As described above, the charged particles of the present invention are used as a bonding material. However, it is of course possible to use the charged particles of the present invention as a material for forming a circuit. In this case, it is not necessary to bond the electronic component to the substrate, and the chargeable particles of the present invention are printed by an electrophotographic method on the substrate on which a circuit pattern such as a green sheet is to be formed. A circuit pattern of particles can be formed. Thus, when the charged particles of the present invention are used as a material for forming a circuit, particles made of a metal material having a relatively high melting point such as copper, gold and silver can be used as the metal particles. Such high melting point metallic material may have a particle size of, for example, about 0.01 to 10 μm, and may have, for example, a spherical shape,
It may have any suitable shape, such as spheroid, and amorphous, and may be manufactured by any suitable method such as atomization and precipitation.

Even when the charged particles of the present invention are used as the circuit-forming material as described above, the metal particles are completely covered with the first coating layer containing the silane coupling agent, as in the case of using the bonding material. Therefore, it is possible to obtain the effect that the principle of electrophotography can be used to accurately arrange (or supply) a fine pattern on a substrate.

When the chargeable particles of the present invention are used as a material for forming a circuit, various appropriate treatments may be applied as necessary in consideration of the fixability of the chargeable particles to the substrate. The particles may be fixed to the substrate with a stronger fixing force. For example, after the charged particles are printed on the substrate, the substrate is subjected to a heat treatment, or the charged particles having a surface layer containing a fixing agent are used to fix the charged particles to the substrate with a stronger fixing force. You can Further, when the charged particles of the present invention are used as a material for forming a circuit, a multilayer laminated plate may be formed by stacking and firing a substrate such as a green sheet on which a circuit pattern of charged particles is formed. It is possible.

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, two embodiments of the present invention and usage forms thereof will be described with reference to the drawings.

(Embodiment 1) The bonding material of this embodiment is
The metal particles 1 as shown in FIG. 1 are composed of the charged particles 10 coated with the first coat layer 2. First coat layer 2
Is composed of a silane coupling agent 3 and a charge control agent 4 dispersed therein.

The metal particles 1 are, for example, Sn--Pb type, Sn
-Ag system, Sn-Cu system, Sn-Ag-Cu system, Sn-
It may be made of a solder material such as Ag-Bi-Cu based or Sn-Ag-Bi-In based, and may be manufactured by, for example, an atomizing method and have a particle size of about 0.01 to 10 μm.

Silane coupling agent 3 for first coat layer 2
Can be any suitable material as described above, for example vinyltrichlorosilane, vinyltrimethoxysilane or vinyltriethoxysilane.
Further, as the charge control agent 4, any suitable material as described above can be used, but styrene acrylic can be used, for example. The thickness of the first coat layer 2 is, for example, about 0.01 to 10
can be μm and is generally smaller than the particle size of the metal particles.

The bonding material composed of the chargeable particles 10 as described above can be manufactured by a so-called wet method by immersing the metal particles 1 in the silane coupling agent 3 in which the charge control agent 4 is dispersed and taking it out. Silane coupling agent 3
Is generally a liquid at room temperature, and when the metal particles 1 are dipped in and taken out, the surfaces of the metal particles 1 are completely covered with the silane coupling agent 3. At this time, since the silane coupling agent 3 is bonded to the metal particle 1 by the hydrolyzable group, it cannot be easily removed from the surface of the metal particle 1,
The surface of the metal particles 1 is covered with a sticky liquid material. The charge control agent 4 may be dispersed in the silane coupling agent 3 in advance, but the metal particles 1 are dipped in the silane coupling agent 3 not containing the charge control agent 4 and taken out, and then the obtained particles are charged. The charged particles 10 can also be obtained by attaching or adding the charge control agent 4 to the silane coupling agent 3 by attaching the control agent 4 (for example, simply “spraying” the charge control agent 4). Charged particles 1
0 is, for example, about 10 to 400 μm, preferably 10 to 1
It has a particle size of 00 μm (which is naturally larger than the particle size of the metal particles 1).

In the obtained bonding material (granular material) composed of the charged particles 10, the metal material of the metal particles 1, the silane coupling agent 3 and the charge control agent 4 are each about 50 to 50 on the basis of the entire bonding material. 90% by weight, about 5-4
It is present in proportions of 9.5% by weight and about 0.5-5% by weight, provided that their sum does not exceed 100.

The bonding material of the present embodiment composed of the charged particles as described above is preferably used as a material for bonding the wiring pattern and the electronic component in mounting the electronic component. The bonding material of the present embodiment is applied to the substrate (more specifically, the wiring formed on the substrate by transfer using the principle of electrophotography without using the screen printing method, as in the usage pattern described later). It can be supplied in a desired pattern on a predetermined portion of the pattern, for example, on a land). The chargeable particles of the bonding material of the present embodiment are completely covered with the metal particles by the silane coupling agent and are not exposed on the surface of the chargeable particles, so that the chargeable particles can be uniformly charged and the chargeable particles can be charged. The particles can be accurately supplied onto the substrate in a fine pattern.

The charged particles of the bonding material of the present embodiment are dispersed in the silane coupling agent in a small amount of other components such as a release agent (polypropylene, etc.) in the first coat layer. May be included. Further, the bonding material of the present embodiment may include, for example, an external additive (such as silica) in addition to the above-mentioned charged particles. Furthermore,
In the present embodiment, the chargeable particles are described as including one metal particle, but the present invention is not limited to this, and as long as the metal particle is coated with the silane coupling agent, one chargeable particle is included. Or it may contain more metal particles.

(Embodiment 2) The bonding material of this embodiment is
The metal particles 1 as shown in FIG. 2 are composed of the charged particles 11 covered with the first coat layer 2 and the second coat layer 6. The first coat layer 2 is composed of a silane coupling agent 3, and the second coat layer 6 is composed of a resin component 5 and a charge control agent 4 dispersed therein. Note that, in FIG. 2, the same members as those of the charged particles of the embodiment of FIG.

The metal particles 1, the silane coupling agent 3 and the charge control agent 4 can be made of the same materials as those in the first embodiment, and the metal particles 1 and the charge control agent 4 have the same dimensions as those in the first embodiment. Can have. In addition, the first coat layer 2 is
It may have the same thickness as in the first embodiment.

As the resin material which is the main component of the resin component 5 of the second coat layer 6, for example, a heat-melting resin such as rosin or styrene / acryl copolymer is used, and preferably styrene / acryl copolymer. . The resin component 5 may include an activator and the like in addition to such a resin material. Second coat layer 6
Can have a thickness of, for example, about 0.01 to 10 μm, and is generally smaller than the particle size of the metal particles. The charged particles 11 are also, for example, about 10 to 400 μm, preferably 10 to 1 μm.
It has a particle size of 00 μm (which is naturally larger than the particle size of the metal particles 1).

In the obtained bonding material (granular material) consisting of the charged particles 11, the metal material of the metal particles 1, the silane coupling agent 3, the charge control agent 4 and the resin component 5 are
50-85% by weight, 5-44.5% by weight, 0.5-5% by weight and 5-
10% by weight (however, the total of these does not exceed 100)
Exist in the ratio of.

The bonding material composed of the charged particles 11 as described above is manufactured as follows. First, in the same manner as in Embodiment 1 except that the charge control agent 4 is used without being dispersed in the silane coupling agent 3, the first coating layer 2 made of the silane coupling agent 3 is used to form the metal particles 1 by a so-called wet method. To cover. The metal particles 1 covered with the first coat layer 2 thus obtained are mixed with the charge control agent 4 and the resin component 5, and the temperature of the resin component 5 is equal to or higher than the softening point of the heat-meltable resin, for example, about 100. Hot melt kneading at ~ 200 ° C. After that, the obtained mixture is pulverized by a cutter mill or the like to obtain a granular material. At this time, depending on how the shearing force is applied to the mixture, the resin component 5 may be partially peeled from the particles. However, between the metal particles 1 and the first coating layer 2 composed of the silane coupling agent 3. Since the bonding force is sufficiently strong, the first coat layer 2 remains bonded to the metal particles 1 and the metal particles 1 can be prevented from being exposed. Then, if necessary, the obtained granules are classified with a sieve, and the classified granules are subjected to surface modification known in the field of granulation technology (for example, heat treatment or treatment using a ball mill and a mixer). Is added, and an external additive such as silica is added to and mixed with the external additive for external treatment. Thereby, the bonding material containing the charged particles in which the metal particles are coated with the first coating layer containing the silane coupling agent and the first coating layer is coated with the second coating layer containing the charge control agent and the resin component is manufactured. Can be done.

Like the first embodiment, the bonding material of the present embodiment composed of charged particles as described above is also suitably used as a material for bonding the wiring pattern and the electronic component in mounting the electronic component. As in the case of the first embodiment, the bonding material of the present embodiment does not use the screen printing method and is transferred onto the substrate (more specifically, the substrate by applying the principle of the electrophotographic method as in the usage pattern described later). (On a predetermined part of the wiring pattern formed above, for example, on a land)
Can be supplied in any desired pattern. The chargeable particles of the bonding material of the present embodiment, at least the metal particles are completely covered with the silane coupling agent and are not exposed to the surface of the chargeable particles, so that the chargeable particles can be uniformly charged and charged. It is possible to accurately supply the functional particles in a fine pattern onto the substrate.

The chargeable particles of the bonding material of the present embodiment contain a slight amount of other components such as a release agent (polypropylene, etc.) in the second coat layer in a state of being dispersed in the resin component. You may stay. Further, the bonding material of the present embodiment is the same as in the first embodiment, in addition to the charged particles as described above,
For example, it may contain an external additive (such as silica). Further, also in the present embodiment, as in the first embodiment,
Although the charged particles are described as including one metal particle, the present invention is not limited thereto, and the charged particle may be one or more metal particles as long as the metal particles are coated with the silane coupling agent. May be included.

(Usage Mode) Hereinafter, the bonding material (chargeable particles) in the above-described embodiment of the present invention is used in the mounting process of the electronic component to bond the wiring pattern formed on the substrate to the electronic component. The method for doing so will be described separately with reference to the drawings, "1. Supply of charged particles onto a substrate" and "2. Bonding of electronic component and wiring pattern using charged particles".

1. Supply of Chargeable Particles to Substrate (Formation of Bonding Pattern) As described below in detail, first, chargeable particles of a bonding material as in the above-described embodiment are bonded to a bonding pattern forming apparatus as shown in FIG. 20 is used to supply a desired pattern on the substrate 29 to form a bonding pattern (or a charged particle pattern) composed of the charged particles 27.

The bonding pattern forming apparatus 20 shown in FIG. 3 is provided with a rotary drum composed of a cylindrical rotary drum body 21 and a conductive film 22 provided on the surface of the cylinder. A photoconductor 23 is provided on the top. This rotary drum is rotatable in the direction indicated by arrow 31 in the figure. Around the rotating drum, an initialization device 24 for initializing the surface of the photoconductor 23, and an electric charge are supplied to the surface of the initialized photoconductor 23 so that the surface of the photoconductor 23 is first moved. Charger 25 for uniformly charging the electric potential
And a light irradiation device 26 for irradiating light onto a predetermined region of the surface of the photoconductor 23 charged to the first potential so as to form a latent image pattern (not shown) on the photoconductor 23, and a second potential. A charged particle supply device 28 for supplying the charged particles 27 charged to the surface of the photoconductor 23 is provided. In addition, a transfer device 30 that transfers the bonding pattern, which is composed of the charged particles 27 attached to the surface of the photoconductor 23, to the substrate 29 is disposed on the back side of the transfer surface of the substrate 29. The initialization device 24, the charger 25, the light irradiation device 26, the charged particle supply device 28, and the transfer device 30 are each connected to a control device 36. The substrate 29 is a transfer device 30.
And a rotary drum provided with the photoconductor 23 (that is, the rotary drum body 21 and the conductive film 22), an arrow 3
2 is conveyed at a substantially constant speed in the direction indicated by 2, and the arrow 33
Is taken out in the direction of.

The bonding pattern forming method using the bonding pattern forming apparatus 20 shown in FIG. 3 is continuously carried out as in the process flow shown in FIG. Generally, a step of initializing the photoconductor, a step of charging the photoconductor, a step of forming a latent image pattern, a step of attaching chargeable particles,
The step of transferring the charged particles and one step is continuously repeated. Hereinafter, the method for forming the bonding pattern will be described more specifically. 5 to 9 are schematic diagrams in each process, and all show the center of the rotating drum downward.

I. Step of Initializing Photoconductor As shown in FIG. 5, first, an initialization device 24 is used to irradiate the photoconductor 23 with light to remove charges on the surface of the photoconductor 23 and to perform photoconduction. The photoconductor 23 is initialized by leaving the body substantially uncharged. At this time, charged particles (not shown) that may remain on the surface of the photoconductor 23 in the previous cycle may be removed by using a brush or a blade (not shown). Photoconductor 23
Becomes insulative (that is, a state in which electric charges do not pass) when the light irradiation in this initialization step is completed, and the surface of the photoconductor 23 can be made uniform.

II. Step of charging the photoconductor On the surface of the photoconductor 23 initialized as described above,
As shown in FIG. 6, a charger 25 is used to supply an electric charge,
The surface of the photoconductor 23 is uniformly charged to the first potential. The charger 25 is, for example, a tungsten wire (not shown) arranged apart from the surface of the photoconductor 23, and is made of a metal such as aluminum so as not to scatter corona ions other than a predetermined charged region of the photoconductor 23. It can be configured as a shield. By applying an appropriate voltage to this wire, the positive (possibly negative) ions generated thereby are applied to the surface of the photoconductor 23, whereby the photoconductor 2
The surface of 3 can be charged to a predetermined first potential.

III. Step of Forming Latent Image Pattern Next, as shown in FIG. 7, a light irradiation device (for example, a laser beam generator) 26 is used to apply light (for example, light) to the photoconductor 23 with a negative pattern that is the reverse of the desired bonding pattern. Laser light)
Irradiate. Since the photoconductor 23 has the property of becoming conductive and releasing charged charges when irradiated with light,
The charged charges existing in the light irradiation region 34 are transferred to the photoconductor 2
3 escapes from the light-irradiated portion (hatched portion in the figure) to the lower conductive film 22. The conductive film 22 is grounded through the rotary drum body 21. On the other hand, since the photoconductor 23 located in the non-light-irradiated region 35 having the positive pattern is kept as an insulating material, the non-light-irradiated region 35 is
A charged electric charge remains in. This makes it possible to form a latent image pattern composed of charged charges in the same positive pattern as the desired bonding pattern.

The light irradiation device 26 is not particularly limited as long as it makes the photoconductor 23 conductive and has sufficient strength and image formation degree to obtain a desired bonding pattern. A device using a light emitting diode, a fluorescent lamp, or a halogen lamp as a light source can be used. With such a device, for example, while scanning the light on the drum surface in the axial direction, the light is modulated or controlled by a shutter to irradiate a predetermined area on the surface of the photoconductor 23 with the light. obtain.

IV. Step of Attaching Chargeable Particles As shown in FIG. 8, a chargeable particle supply device 28 containing the chargeable particles (bonding material and optionally an external additive) of the embodiment of the present invention described above is used in advance. , The charged particles 27 charged to the second potential are supplied to the surface of the photoconductor 23 charged to the first potential having a polarity opposite to the second potential. For example, the chargeable particles 27 (in some cases, the chargeable particles 27 and the external additive) that form the bonding material are mixed with stirring inside a chargeable particle supply device 28 together with a carrier such as ferrite, and charged from the carrier surface. By transferring an electric charge to the chargeable particles 27, the chargeable particles 27 can be charged to the second potential, and the charged chargeable particles 27 can be supplied to the surface of the photoconductor 23 by a magnetic brush method or the like. . Here, for example, an electron donating coat resin can be used as the carrier, and in this case, the carrier can impart electrons to the chargeable particles 27 to negatively charge the chargeable particles 27. As described above, the charged particles 27 are coated with the coating layer containing the silane coupling agent, and thus are uniformly charged.

Charged to a second potential having a polarity opposite to the first potential,
The chargeable particles 27 supplied to the surface of the photoconductor 23 adhere to the non-light-irradiated flow region 35 by the electrostatic attraction between the chargeable particles 27 and the charged charges remaining in the non-light-irradiated region 35.
On the other hand, there is no charge that attracts the charged particles 27 in the light irradiation area 34, and the charged particles 27 do not adhere to the light irradiation area 34. As a result, a bonding pattern composed of the charged particles 27 can be formed on the surface of the photoconductor 23 in the same pattern as the latent image pattern composed of the charged charges.

V. Then, as shown in FIG. 9, the transfer device 30 transfers the substrate 29 between the transfer device 29 and the rotating drum at a synchronized speed equal to the peripheral speed of the rotating drum. The charged particles 2 formed on the surface of the photoconductor 23 using
The bonding pattern consisting of 7 is transferred onto the substrate 29. For example, an electric field is generated between the photoconductor 23 and the base 29, and the electrostatic attraction induced by the electric field causes the charged particles 27 to move from the photoconductor 23 to the space between the photoconductor 23 and the base 29. It flies toward the base body 29 and adheres to the base body 29. As a result, the charged particles 2 forming the bonding pattern
It is possible to transfer the charged particles 27 (bonding pattern) to the substrate 29 while the photoconductor 7 and the photoconductor 23 and the substrate 29 are not simultaneously in contact with each other (that is, in a non-contact manner). Alternatively, the bonding pattern composed of the charged particles 27 formed on the surface of the conductor 23 can be transferred to the substrate 29 by a contact method by pressure bonding or the like.

As described above, the charged particles of the bonding material as in the above-described embodiment can be printed (supplied) on the substrate in a desired pattern, so that the desired bonding pattern (or charged particle pattern) can be obtained. ) Can be formed. The bonding pattern can be formed more accurately and reliably on the substrate because the charged particles of the above-described embodiment are uniformly charged and transferred. Since the charged particles are used for joining the wiring pattern formed on the base and the electronic component, they are supplied onto the wiring pattern, more specifically, onto a predetermined portion of the wiring pattern. For example, the charged particles are supplied so as to be located on the land of the wiring pattern, and thus the bonding pattern is formed corresponding to the land pattern.

After the bonding pattern made of charged particles is formed on one substrate as described above, the rotary drum is further rotated to return to the step of initializing the photoconductor, and the photoconductor is initialized again. A desired bonding pattern can be formed on the substrate.

In the above description, the first potential is the positive potential and the second potential is the negative potential, but it may be the negative potential in some cases. Further, it can be appropriately selected depending on the transcription mode (forward transcription or reverse transcription).

2. Joining of electronic component and wiring pattern using charged particles Next, a method of joining a wiring pattern and an electronic component using charged particles accurately supplied in a desired pattern on the substrate as described above Will be described.

First, the electronic component is arranged at a predetermined position on the substrate so that the bonded portion of the electronic component comes into contact with the charged particles on the substrate. At this time, in the single-layer type chargeable particle as in the first embodiment, the silane coupling agent functions to temporarily fix the electronic component to the base due to its adhesiveness.
In addition, in the two-layer type chargeable particle as in the second embodiment, before the electronic component is placed on the substrate, it is subjected to a heat treatment for a very short time at a temperature equal to or higher than the softening point of the heat melting resin material of the resin component. Then, the heat-fusible resin material is softened or partially melted, and then the electronic component is arranged at a predetermined position on the substrate so that the bonded portion of the electronic component comes into contact with the charged particles on the substrate. Therefore, it is preferable to temporarily fix the electronic component to the base to such an extent that the electronic component does not move easily.

After that, the substrate on which the electronic parts are arranged is passed through a reflow furnace and the heat-resistant temperature of the electronic parts (for example, about 300 ° C.,
Further, the temperature is lower than about 250 ° C.) or higher than the melting point of the metal material (solder material) of the metal particles, for example, 210 to 240 ° C., preferably 220 to 230 ° C. to melt the metal particles at least partially, The metal particles of are fused together to connect the bonded part of the electronic component and the land of the wiring pattern, and then cooled or allowed to cool to room temperature, and the molten metal material is bonded to the bonded part of the electronic component and the land of the wiring pattern. Solidify while connecting.

In this reflow step, the silane coupling agent and the charge control agent are in a molten state in both cases of the one-layer type charged particles of the first embodiment and the two-layer type charged particles of the second embodiment. Collected outside the metallic material. The resin material of the resin component present in the bonding material in the case of the two-layer type charged particles of the second embodiment is generally a metal material of metal particles when a heat-meltable resin is used as the resin material. Since it has a lower melting point, it melts before the metal particles melt, and then separates from the metal particles in a molten state and solidifies in a state mixed with a silane coupling agent or the like.

As a result, the electronic component and the wiring pattern on the substrate are physically and electrically bonded by the metal material of the metal particles, and sufficient bonding strength and conductivity are secured.

As described above, when the bonding material of this embodiment is used, the principle of electrophotography is applied, and the chargeability is given to a predetermined position (for example, on the land pattern) on the substrate on which the wiring pattern is formed. The particles can be accurately and reliably supplied, and electronic components can be bonded to the substrate using the charged particles.

In the above-described usage form, the case where the bonding material is composed of only charged particles has been described, but the present invention is not limited to this. For example, if the bonding material includes an external additive or the like in addition to the charged particles, the external additive is also printed on the substrate together with the charged particles, and the desired bonding material containing the charged particles and the external additive is formed on the substrate. Those skilled in the art will readily understand that the bonding pattern can be formed.

[0087]

According to the present invention, there is provided a novel joining material which is preferably used for joining a wiring pattern formed on a substrate to an electronic component in mounting the electronic component, and a method for producing the same. The bonding material of the present invention can be applied in a desired pattern on a substrate by transfer by applying the principle of electrophotography without using a screen printing method. The chargeable particles of the bonding material of the present invention are such that the metal particles are coated with the silane coupling agent and are not exposed to the surface of the chargeable particles, so that the chargeable particles can be uniformly charged, and the chargeable particles are Therefore, the bonding material can be accurately supplied onto the base in a fine pattern.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of charged particles constituting a bonding material according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of charged particles constituting a bonding material according to another embodiment of the present invention.

FIG. 3 is a schematic view of a bonding pattern forming apparatus used in the application mode of the present invention.

FIG. 4 is a process flow diagram for continuously forming a bonding pattern in the application form of the present invention.

FIG. 5 is a schematic process diagram illustrating a method for forming a bonding pattern according to a mode of use of the present invention.

FIG. 6 is a schematic process diagram illustrating a method for forming a bonding pattern according to the usage mode of the present invention.

FIG. 7 is a schematic process diagram illustrating a method for forming a bonding pattern according to a usage mode of the present invention.

FIG. 8 is a schematic process diagram illustrating a method for forming a bonding pattern according to the application mode of the present invention.

FIG. 9 is a schematic process diagram illustrating a method for forming a bonding pattern according to a usage mode of the present invention.

[Explanation of symbols]

1 metal particles 2 First coat layer 3 Silane coupling agent 4 Charge control agent 5 resin components 6 Second coat layer 10, 11, 27 charged particles 20 Bonding pattern forming device 21 Rotating drum body 22 Conductive film 23 Photoconductor 24 Initialization device 25 charger 26 Light irradiation device 28 Chargeable Particle Supply Device 29 base 30 transfer device 31, 32, 33 arrows 34 Light irradiation area 35 Non-light irradiation area 36 Controller

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akio Furusawa             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5E319 BB01 CC33 CD29 GG15                 5E343 BB54 BB78 DD72 FF02 GG08                       GG11                 5F044 LL01

Claims (9)

[Claims] 1. A bonding material for bonding a wiring pattern formed on a substrate and an electronic component, comprising metal particles,
A bonding material comprising: charged particles having a first coat layer covering metal particles, the first coat layer containing a charge control agent and a silane coupling agent. 2. A bonding material for bonding a wiring pattern formed on a substrate to an electronic component, comprising metal particles,
A first coat layer that covers the metal particles; and a second coat layer that covers the first coat layer.
A bonding material in which the coating layer contains a silane coupling agent, and the second coating layer contains a charge control agent and a resin component. 3. The bonding material according to claim 1, wherein the resin component contains one or more materials selected from rosin and styrene / acrylic copolymer. 4. The bonding material according to claim 1, wherein the metal particles are made of a solder material. 5. The bonding material according to claim 4, wherein the solder material comprises tin and one or more metal elements selected from the group consisting of lead, silver, copper, bismuth and indium. 6. The bonding material according to claim 1, wherein the metal particles have a particle size of 0.01 to 40 μm. 7. The bonding material according to claim 1, wherein the chargeable particles have a particle size of 10 to 400 μm. 8. The method for producing a bonding material according to claim 1, which is used for bonding a wiring pattern formed on a substrate and an electronic component, wherein a liquid material containing a silane coupling agent and a charge control agent is added to a metal. A method of making a bonding material comprising dipping particles. 9. The method for producing a bonding material according to claim 2, which is used for bonding a wiring pattern formed on a substrate and an electronic component, wherein metal particles are dipped in a liquid material containing a silane coupling agent. A method for producing a bonding material, which comprises covering the metal particles with a first coating layer containing a silane coupling agent, and kneading and pulverizing the mixture of the obtained metal particles, the charge control agent and the resin component.