WO2020090684A1

WO2020090684A1 - Method for manufacturing connected body, anisotropic bonding film, and connected body

Info

Publication number: WO2020090684A1
Application number: PCT/JP2019/042035
Authority: WO
Inventors: 朋之石松; 智幸阿部; 青木　正治
Original assignee: デクセリアルズ株式会社
Priority date: 2018-10-31
Filing date: 2019-10-25
Publication date: 2020-05-07

Abstract

Provided are a method for manufacturing a connected body that is capable of bonding electronic components having fine-pitch electrodes, an anisotropic bonding film, and a connected body. An anisotropic bonding material which comprises solder particles, a flux compound, and at least one solid resin selected from among a thermoplastic resin, a solid radically polymerizable resin, and a solid epoxy resin that are solid at normal temperature and have a melt flow rate of 10 g/10 min or more measured under the condition of a temperature of 190°C and a load of 2.16 kg is interposed between an electrode of a first electronic component and an electrode of a second electronic component in a thickness that is 50 to 300% of the average particle size of the solder particles, and the electrode of the first electronic component and the electrode of the second electronic component are heat-bonded with no load.

Description

Method for manufacturing connected body, anisotropic bonding film, connected body

The present invention relates to a method for manufacturing a connection body for mounting a semiconductor chip (element) such as an LED (Light Emitting Diode), an anisotropic bonding film, and a connection body. This application is based on Japanese Patent Application No. 2018-206058 filed on October 31, 2018 and Japanese Patent Application No. 2019-194479 filed on October 25, 2019 in Japan. Claims priority and is incorporated herein by reference.

Flip-chip mounting is one of the methods for mounting semiconductor chips (elements) such as LEDs. Flip-chip mounting can reduce the mounting area compared to wire bonding, and can mount a small and thin semiconductor chip.

However, since flip-chip mounting is performed by thermocompression bonding, for example, when a large number of semiconductor chips are bonded to a large substrate, very high pressure is required or parallelism needs to be adjusted. Sex is difficult.

JP-A-2009-102545

Patent Document 1 describes that a solder paste containing solder particles, a thermosetting resin binder, and a flux component is used, and a plurality of components are collectively mounted on a wiring board or the like by reflow.

However, the solder paste of Patent Document 1 contains a large amount of solder particles in order to melt and integrate the solder particles, and it is difficult to join electronic components having fine pitch electrodes.

FIG. 8 is a micrograph of an LED mounting body manufactured using a conventional solder paste, in which a solder joint state on the board side after peeling off the LED chip is observed. As shown in FIG. 8, in a general solder paste, when self-alignment in which solder particles are melted and integrated occurs, the solder particles agglomerate between adjacent terminals to form a bridge A, which may cause a short circuit. there were.

The present technology has been proposed in view of such conventional circumstances, and provides a method for manufacturing a connector, an anisotropic bonding film, and a connector capable of bonding an electronic component including fine-pitch electrodes. To do.

As a result of earnest studies, the inventors of the present application have used an anisotropic bonding material containing a solid resin that is solid at room temperature and has a predetermined melt flow rate, and solder the thickness of the anisotropic bonding material between electrodes by soldering. The inventors have found that the above-mentioned object can be achieved by setting a predetermined value with respect to the average particle diameter of the particles, and have completed the present invention.

That is, the method for producing a connector according to the present invention is a solid resin at room temperature, a thermoplastic resin having a melt flow rate of 10 g / 10 min or more measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg, solid radical polymerization. Of an anisotropic bonding material containing at least one solid resin selected from a conductive resin and a solid epoxy resin, a solder particle, and a flux compound is used as an electrode of a first electronic component and an electrode of a second electronic component. And 50% or more and 300% or less of the average particle diameter of the solder particles, and the electrodes of the first electronic component and the electrodes of the second electronic component are heat-bonded with no load.

Further, the anisotropic bonding film according to the present invention is a solid at room temperature, a thermoplastic resin having a melt flow rate of 10 g / 10 min or more measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg, solid radical polymerization. Resin, and at least one solid resin selected from solid epoxy resins, solder particles, and a flux compound, and the thickness is 50% or more and 300% or less of the average particle diameter of the solder particles.

The connection body according to the present invention is formed by joining the electrodes of the first electronic component and the electrodes of the second electronic component by using the anisotropic bonding film described above.

According to the present invention, the solid resin is melted by heating and the solder particles are sandwiched between the electrodes and melted, so that an electronic component having fine pitch electrodes can be joined.

FIG. 1 is a cross-sectional view schematically showing a part of the joining process. FIG. 2 is a cross-sectional view showing a configuration example of the LED mounting body. FIG. 3 is a cross-sectional view schematically showing a part of the anisotropic bonding film to which the present technology is applied. FIG. 4 is a photomicrograph of the solder bonding state on the substrate side after peeling off the LED chip of Example 1-1. FIG. 5 is a photomicrograph of the solder bonding state on the substrate side after peeling off the LED chip of Comparative Example 1-1. FIG. 6 is a photomicrograph of the solder bonding state on the substrate side after peeling off the LED chip of Comparative Example 1-2. FIG. 7 is a photomicrograph when observing the solder joint state on the substrate side after peeling off the LED chip of Comparative Example 1-3. FIG. 8 is a micrograph of an LED mounting body manufactured using a conventional solder paste, in which a solder joint state on the substrate side after the LED chip is peeled off is observed.

Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings.
1. 1. Method of manufacturing connected body Anisotropic bonding film (anisotropic bonding material)
3. Example

<1. Manufacturing method of connection body>
The method for producing a connector in the present embodiment is a thermoplastic resin that is solid at room temperature and has a melt flow rate of 10 g / 10 min or more measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg, and a solid radical-polymerizable resin. An anisotropic bonding material containing at least one solid resin selected from a resin and a solid epoxy resin, solder particles, and a flux compound is used for an electrode of a first electronic component and an electrode of a second electronic component. The thickness of the solder particles is 50% or more and 300% or less of the average particle diameter of the solder particles, and the electrodes of the first electronic component and the electrodes of the second electronic component are heat-bonded with no load.

In the present specification, the melt flow rate is a value measured under the conditions of 190 ° C. and 2.16 kg load, which is specified in JIS K7210: 1999 for determining the melt flow rate of thermoplastics. Also called mass flow rate (MFR). Further, the room temperature is a range of 20 ° C. ± 15 ° C. (5 ° C. to 35 ° C.) specified by JISZ8703. Further, the connection body is one in which two materials or members are electrically connected. Moreover, joining means joining two materials or members. Further, no load means a state in which no mechanical pressure is applied.

The average particle size is N = 50 or more, preferably N = 100 or more, more preferably N = 200 or more in an observation image using a metallographic microscope, an optical microscope, an electron microscope such as an SEM (Scanning Electron Microscope). It is the average value of the major axis diameters of the particles measured in 1., and when the particles are spherical, it is the average value of the particle diameters. In addition, the observed image is measured using a known image analysis software (WinROOF, Mitani Shoji Co., Ltd.) and an image type particle size distribution measuring device (for example, FPIA-3000 (Malvern)). The measured value (N = 1000 or more) may be used. The average particle diameter obtained from an observation image or an image type particle size distribution measuring device can be an average value of the maximum length of particles. When producing an anisotropic bonding material, the particle diameter (D50) and the arithmetic mean diameter (volume basis) at which the cumulative frequency in the particle size distribution obtained by the laser diffraction / scattering method becomes 50% simply. Manufacturer values such as (preferably)) can be used.

As the first electronic component, a chip (element) such as an LED (Light Emitting Diode) or a driver IC (Integrated Circuit) is suitable, and as the second electronic component, particularly if a wiring is provided, There is no limitation, and any substrate that can be broadly defined as a substrate (so-called printed wiring board: PWB) provided with an electrode on which the first electronic component can be mounted may be used. Examples thereof include a rigid substrate, a glass substrate, a flexible printed circuit (FPC), a ceramic substrate, and a plastic substrate. Electrodes (electrode array, electrode group) provided on each of the first electronic component and the second electronic component are provided so as to face each other and are anisotropically connected, and the plurality of first electronic components are provided. The electrodes (electrode array, electrode group) may be provided so that the components are mounted on one second electronic component. As the first electronic components, in addition to LEDs (Light Emitting Diodes), chips such as driver ICs (Integrated Circuits) (for example, semiconductor elements), flexible substrates (FPC: Flexible Printed Circuits, resin molded components, wiring, etc.) The second electronic component is not particularly limited as long as it is provided with terminals that at least partially correspond to the terminals of the first electronic component. It is sufficient if it can be broadly defined as a substrate (so-called printed wiring board: PWB) provided with electrodes on which electronic components can be mounted, and the same components may be laminated and connected. There is no particular limitation as long as it does not hinder the connection.The same applies to the case where a large number of different kinds of components are laminated. Electrodes (electrode arrangements) provided on the first electronic component and the second electronic component, respectively. The electrode group) is provided so as to face and be anisotropically connected, and the electrodes (electrode array, electrode group) are arranged so that the plurality of first electronic components are mounted on one second electronic component. It is desirable that the above electronic component has heat resistance in the reflow process.

The anisotropic bonding material is solid at room temperature and has a MFR of 10 g / 10 min or more, a solid resin made of one kind selected from a thermoplastic resin, a solid radically polymerizable resin, and a solid epoxy resin, and solder particles, And a flux compound. The flux compound is preferably a carboxylic acid. As a result, good solder connection can be obtained, and when an epoxy resin is mixed, it can function as a curing agent for the epoxy resin. Further, the flux compound is preferably a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether. This makes it possible to control the temperature at which the flux effect and the curing agent function are exhibited.

The resin flow amount of the anisotropic bonding material may be 1.3 to 2.5, and it may be preferable to set it to less than 1.3. By setting the resin flow amount to these values, it is possible to perform heat bonding without load, as described later. The resin flow amount can be measured according to the measuring method described in JP-A-2016-178225. First, the anisotropic bonding film is cut into a width of 2.0 mm, and the cut anisotropic bonding film is sandwiched by non-alkali glass (thickness 0.7 μm) and passed through a reflow process. This may be the same as the condition used for connection. Then, the amount of resin spread before and after reflow is measured, and the value obtained by dividing the maximum value B of the width of the anisotropic bonding film after pressurization by the width A (= 2.0 mm) before pressurization is taken as the resin flow amount. be able to. Further, it is more preferable that the anisotropic bonding material is placed without being sandwiched by the non-alkali glass and is subjected to the reflow step to obtain the above numerical values. When the resin flow amount of the anisotropic bonding material is small, the resin melting does not proceed without a load in the reflow process, and there is a possibility that the sandwiching between the solder particles and the electrode may be hindered. Since this technology does not apply a load when heat-curing the binder resin, it has a higher meltability than the binder resin designed on the premise of applying a load (pressing with a tool like general anisotropic connection). It is desirable to do.

The anisotropic bonding material may be a film-shaped anisotropic bonding film or a paste-shaped anisotropic bonding paste. Further, the anisotropic bonding paste may be formed into a film at the time of connection, or may have a form close to a film by mounting components.

In the case of the anisotropic bonding paste, it is sufficient that a predetermined amount can be uniformly applied onto the substrate. For example, a coating method such as dispensing, stamping, screen printing or the like can be used, and it may be dried if necessary. .. The anisotropic bonding film is particularly preferable because not only the amount of the anisotropic bonding material can be made uniform by the film thickness but also the substrate can be laminated on the substrate at one time and the tact time can be shortened. Further, since it is easy to handle by forming it in a film shape in advance, it can be expected that the work efficiency is improved.

The lower limit of the thickness of the anisotropic bonding material between the electrode of the first electronic component and the electrode of the second electronic component is 50% or more, preferably 80% or more, and more preferably the average particle size of the solder particles. 90% or more. If the thickness of the anisotropic bonding material is too thin, the solder particles can be easily sandwiched between the electrodes, but the difficulty in forming a film may increase. In addition, the upper limit of the thickness of the anisotropic bonding material between the electrode of the first electronic component and the electrode of the second electronic component is 300% or less, preferably 200% or less of the average particle diameter of the solder particles. It is preferably 150% or less. If the anisotropic bonding material is too thick, the bonding may be hindered.

A method for manufacturing an LED mounting body will be described below as a specific example of a method for manufacturing a connection body. The manufacturing method of an LED mounting body is a step of providing an anisotropic bonding material having a thickness of 50% to 300% of an average particle diameter of solder particles on a substrate, and mounting an LED element on the anisotropic bonding material. There is a mounting process and a bonding process for heating and bonding the electrode of the LED element and the electrode of the substrate with no load.

The step of providing the anisotropic bonding material may be a step of forming a film of the anisotropic bonding paste on the substrate before connection, and as in the conventional anisotropic conductive film, it is anisotropic. It may be a temporary attaching step of attaching the sexual bonding film to the substrate at low temperature and low pressure, or a laminating step of laminating the anisotropic bonding film on the substrate.

When the process of providing the anisotropic bonding material is a temporary bonding process, the anisotropic bonding film can be provided on the substrate under known use conditions. In this case, since there is only a minimum change such as a tool change from the conventional device, an economic advantage can be obtained.

When the process of providing the anisotropic bonding material is a laminating process, the anisotropic bonding film is laminated on the substrate using, for example, a pressure laminator. The laminating temperature is preferably 40 ° C or higher and 160 ° C or lower, more preferably 50 ° C or higher and 140 ° C or lower, and further preferably 60 ° C or higher and 120 ° C or lower. The laminating pressure is preferably 0.1 MPa or more and 10 MPa or less, more preferably 0.5 MPa or more and 5 MPa or less, and further preferably 1 MPa or more and 3 MPa or less. The laminating time is preferably 0.1 sec or more and 10 sec or less, preferably 0.5 sec or more and 8 sec or less, and more preferably 1 sec or more and 5 sec or less. Further, it may be a vacuum pressure type laminate. If the conventional anisotropic conductive film is temporarily attached using a heating and pressing tool, the width of the film is restricted by the tool width, but in the laminating process, the heating and pressing tool is not used, so it is relatively wide. It can be expected that the width can be installed at once. Also, one anisotropic bonding film may be laminated on one substrate. Accordingly, since the vertical movement of the thermocompression bonding tool and the conveyance of the anisotropic bonding film are not performed a plurality of times, the time for providing the anisotropic bonding material can be shortened.

In the mounting process, for example, multiple LED elements are arranged and mounted on an anisotropic bonding film. In the present technology, since self-alignment due to solder particles cannot be expected, it is preferable to accurately align the LED element in the mounting process. Each LED element has, for example, a first conductivity type electrode and a second conductivity type electrode on one surface, and is arranged on the electrodes of the substrate 30 corresponding to the first conductivity type electrode and the second conductivity type electrode.

In the step of providing the anisotropic conductive bonding material described above, the thickness of the anisotropic bonding material between the electrode of the LED element and the electrode of the substrate is set to be close to the average particle diameter of the solder particles. The present invention is not limited to this, and the thickness of the anisotropic bonding material may be approximated to the average particle diameter of the solder particles by pressing (for example, temporary compression bonding) in the mounting process. In this pressurizing step, for example, the thickness of the anisotropic bonding material between the electrode of the LED element and the electrode of the substrate is applied by applying pressure from the side of the first electronic component mounted on the second electronic component. Is approximated to the average particle size of the solder particles. Here, if the thickness of the anisotropic bonding material is too large, the pressurization may be hindered, so it can be said that it is preferable to set the thickness to the upper limit described above. Approximate to the average particle size means that theoretically the maximum diameter of the solder particles becomes the thickness of the anisotropic connecting material after this pressing step, so the thickness of the anisotropic connecting material is the maximum diameter of the solder particles. It may be considered to be equivalent, and if the thickness variation is taken into consideration, the maximum diameter of the solder particles may be 130% or less, preferably 120% or less. Further, the lower limit of the pressure in the pressurizing step is preferably 0.2 MPa or more, more preferably 0.4 MPa or more, and the upper limit of the pressure in the pressurizing step may be 2.0 MPa or less, preferably 1. It is 0 MPa or less, more preferably 0.8 MPa or less. The upper and lower limits may vary depending on the specifications of the apparatus, and are not limited to the above numerical range as long as the purpose of pushing the resin to the solder particle size can be achieved. This pressurization (temporary compression) step is performed in order to bring the electrodes and the solder particles closer to each other without melting the solder particles.

FIG. 1 is a sectional view schematically showing a part of the joining process. In the joining step, the

electrodes

11 and 12 of the LED element 10 and the

electrodes

21 and 21 of the substrate 20 are heated and joined with no load. Examples of the method of heat-bonding without load without mechanical pressure include atmospheric pressure reflow, vacuum reflow, atmospheric pressure oven, autoclave (pressurizing oven), and the like. It is preferable to use a vacuum reflow, an autoclave, or the like that can eliminate bubbles. Since there is no load, unnecessary resin flow does not occur as compared with anisotropic conductive connection using a general heating / pressurizing tool, and therefore an effect of suppressing entrainment of bubbles can be expected.

The solid resin is melted by heating, the solder particles 31 are sandwiched between the electrodes by the self-weight of the LED element 10, the solder particles 31 are melted by the main heating that is the solder melting temperature or higher, the solder wets and spreads on the electrodes, and the LED is cooled by cooling. The electrode of the element 10 and the electrode of the substrate 20 are bonded. In the joining step, as an example, the main heating is preferably performed at a temperature of 200 ° C. or higher and 300 ° C. or lower, more preferably 220 ° C. or higher and 290 ° C. or lower, and further preferably 240 ° C. or higher and 280 ° C. or lower. As a result, the electrode of the LED element 10 and the electrode of the substrate 20 are bonded to each other, and thus excellent conductivity, heat dissipation and adhesiveness can be obtained. Since no load is applied in the joining step, the amount of movement of the solder particles is reduced, and it is expected that the solder particle capturing efficiency is high. In addition, the content of solder particles is such that self-alignment cannot be expected, and since many solder particles contained in the anisotropic bonding film are not integrated in the bonding process, multiple solder particles can be used in one electrode. There is a joint. Here, the solder joining refers to melting and connecting the respective electrodes of the electronic components facing each other.

FIG. 2 is a sectional view showing a configuration example of an LED mounting body. In this LED mounting body, the LED element 10 and the substrate 20 are connected using an anisotropic bonding film in which solder particles 31 are dispersed in a solid resin. That is, the LED mounting body has the LED element 10, the substrate 20, and the solder particles 31, and is anisotropically joined by connecting the

electrodes

11 and 12 of the LED element 10 and the

electrodes

21 and 22 of the substrate 20. A film 32 is provided, the

electrodes

11 and 12 of the LED element 10 and the

electrodes

21 and 22 of the substrate 20 are joined by a solder joint 33, and the solid resin is filled between the LED element 10 and the substrate 20. It has been done.

The LED element 10 includes a first conductivity type electrode 11 and a second conductivity type electrode 12, and when a voltage is applied between the first conductivity type electrode 11 and the second conductivity type electrode 12, carriers are generated in an active layer in the element. Are concentrated and recombine to generate light. The distance between the spaces between the first conductivity type electrode 11 and the second conductivity type electrode 12 is, for example, 100 μm or more and 200 μm or less, 100 μm or more and 50 μm or less, or 20 μm or more and 50 μm or less depending on the element size. is there. The LED element 10 is not particularly limited, but for example, a blue LED having a peak wavelength of 400 nm to 500 nm can be preferably used.

The substrate 20 has a first electrode 21 and a second electrode 22 on the base material at positions corresponding to the first conductivity type electrode 11 and the second conductivity type electrode 12 of the LED element 10, respectively. Examples of the substrate 20 include a printed wiring board, a glass substrate, a flexible substrate, a ceramic substrate and a plastic substrate. The electrode height of the printed wiring board is, for example, 10 μm or more and 40 μm or less, the electrode height of the glass substrate is, for example, 3 μm or less, and the electrode height of the flexible substrate is, for example, 5 μm or more and 20 μm or less.

The anisotropic bonding film 32 is a film made of an anisotropic bonding material after the bonding process, and the

electrodes

11 and 12 of the LED element 10 and the

electrodes

21 and 22 of the substrate 20 are bonded at the solder bonding portion 33. Along with metal bonding, an anisotropic bonding material is filled between the LED element 10 and the substrate 20.

As shown in FIG. 2, in the LED mounting body, the terminals (electrodes 11 and 12) of the LED element 10 and the terminals (electrodes 21 and 22) of the substrate 20 are metal-bonded to each other by the solder joint portion 33. A solid resin is filled between 20 and the substrate 30. As a result, it is possible to prevent water and the like from entering between the LED element 10 and the substrate 20.

<2. Anisotropic Bonding Film (Anisotropic Bonding Material)>
FIG. 3 is a cross-sectional view schematically showing a part of the anisotropic bonding film to which the present technology is applied. As shown in FIG. 3, the anisotropic bonding film 30 contains a solid resin, solder particles 31, and a flux compound. Further, in the anisotropic conductive film 30, the first film may be attached to the first surface and the second film may be attached to the second surface, if necessary. The anisotropic bonding film is formed by forming an anisotropic bonding material into a film.

The lower limit of the film thickness is 50% or more, preferably 80% or more, more preferably 90% or more of the average particle diameter of the solder particles. When the film thickness is too thin, the sandwiching of the solder particles between the electrodes becomes easy, but the difficulty in forming the film may increase. The upper limit of the film thickness is 300% or less, preferably 200% or less, more preferably 150% or less of the average particle diameter of the solder particles. If the film is too thick, there is a risk that it will interfere with the joining. The film thickness can be measured using a known micrometer or digital thickness gauge (eg Mitutoyo Corporation: MDE-25M, minimum display amount 0.0001 mm) capable of measuring 1 μm or less, preferably 0.1 μm or less. .. The film thickness may be obtained by measuring 10 or more points and averaging them. However, when the film thickness is smaller than the particle size, a contact-type thickness measuring instrument is not suitable, so it is preferable to use a laser displacement meter (eg, Keyence Corporation, spectral interference displacement type SI-T series, etc.). .. Here, the film thickness is the thickness of only the resin layer and does not include the particle diameter.

[Solid resin]
The solid resin is solid at room temperature and has an MFR of 10 g / 10 min or more measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg. The upper limit of MFR is preferably 5000 g / 10 min or less, more preferably 4000 g / 10 min or less, still more preferably 3000 g / 10 min or less. If the MFR is too large, it becomes difficult to fill the solid resin between the first electronic component and the second electronic component.

The thermoplastic resin is solid at room temperature and is not particularly limited as long as it satisfies the above MFR, and examples thereof include ethylene vinyl acetate copolymer resin, ethylene acrylic acid copolymer resin, polyamide resin, and polyester resin. Good. When the solid resin is a thermoplastic resin, the electrodes of the first electronic component and the electrodes of the second electronic component are metal-bonded to each other by hot melt, so that sufficient bonding strength can be obtained. In addition, since the thermoplastic resin does not undergo a reaction, it is not necessary to care about the pot life (the product life is longer than that using a curable resin and a curing agent (reaction initiator)), and handling is easy. become. Further, since the thermoplastic resin is a solid at room temperature, the resin does not melt at the time of use, but when it melts, a filler may be added to prevent melting.

The solid radical polysynthetic resin is not particularly limited as long as it is a radical polymerizable resin that is solid at room temperature, satisfies the above MFR, and has one or more unsaturated double bonds in the molecule. It may be unsaturated polyester (also called vinyl ester), epoxy-modified or urethane-modified (meth) acrylate. Thereby, the film shape can be maintained.

The solid epoxy resin is not particularly limited as long as it is a solid at room temperature, satisfies the above MFR, and has one or more epoxy groups in the molecule, and examples thereof include bisphenol A type epoxy resin and biphenyl. Type epoxy resin or the like may be used. Thereby, the film shape can be maintained.

The anisotropic bonding film may further contain a liquid radical polymerizable resin which is liquid at room temperature and a polymerization initiator. The liquid radical polymerizable resin is not particularly limited as long as it is liquid at room temperature, and may be, for example, acrylate, methacrylate, unsaturated polyester, or urethane-modified. By using a liquid radically polymerizable resin, tackiness can be imparted to the anisotropic bonding film, and not only the laminate property to the adherend is improved but also the fluidity of the entire binder at the time of mounting is improved. be able to.

The blending amount of the liquid radical-polymerizable resin is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and further preferably 70 parts by mass or less with respect to 100 parts by mass of the solid resin. If the blending amount of the liquid radically polymerizable resin increases, it becomes difficult to maintain the film shape.

The polymerization initiator is preferably an organic peroxide such as diacyl peroxide. Further, the reaction initiation temperature of the polymerization initiator is preferably higher than the melting point of the solder particles. As a result, curing starts after the solid resin flows, so that good solder joint can be obtained.

Further, the anisotropic bonding film may further contain a liquid epoxy resin and a curing agent at room temperature. The liquid epoxy resin is not particularly limited as long as it is liquid at room temperature, and may be, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, or urethane modified epoxy resin. Absent.

The blending amount of the liquid epoxy resin is preferably 160 parts by mass or less, more preferably 100 parts by mass or less, and further preferably 70 parts by mass or less based on 100 parts by mass of the solid resin. When the blending amount of the liquid epoxy resin is large, it becomes difficult to maintain the film shape.

The curing agent is not particularly limited as long as it is a thermal curing agent that starts to cure by heat, and examples thereof include anionic curing agents such as amine and imidazole, and cationic curing agents such as sulfonium salts. Further, the curing agent may be microencapsulated so as to obtain resistance to the solvent used when forming a film.

Further, the curing agent may be a carboxylic acid or a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether. That is, the curing agent may be a flux compound.

[Solder particles]
The solder particles may be randomly kneaded and dispersed in the anisotropic bonding film, or may be arranged in a plan view. The arrangement of the entire solder particles in a plan view of the anisotropic bonding film may be regular arrangement or random arrangement. Examples of the regular arrangement include a lattice arrangement such as a square lattice, a hexagonal lattice, an orthorhombic lattice, and a rectangular lattice, and there is no particular limitation. Further, as a mode of the random arrangement, it is preferable that the solder particles exist without contacting each other in a plan view of the film, and the solder particles also exist in the film thickness direction without overlapping each other. Further, it is preferable that 95% or more of all the solder particles in the anisotropic bonding film are not in contact with other solder particles and are independent. This can be confirmed by using a known metallographic microscope or optical microscope to arbitrarily extract 5 or more areas of 1 mm ² or more in a plane view of the film and observe 200 or more, preferably 1000 or more solder particles. You can Further, when the solder particles are arranged in the anisotropic bonding film in a plan view, the solder particles may be aligned at the same position in the film thickness direction.

Also, the solder particles may be arranged as an aggregate of a plurality of particles. In this case, the arrangement of the agglomerates in a plan view of the anisotropic bonding film may be a regular arrangement or a random arrangement, similar to the arrangement of the solder particles described above. Further, it is preferable that the agglomerates exist without contacting each other in a plan view of the film, and the agglomerates also exist in the film thickness direction without overlapping with each other. The average particle size of the individual solder particles of the aggregate can be measured in the same manner as the above-mentioned average particle size.

The average particle diameter of the solder particles is preferably ⅓ or less of the distance between the spaces of the electrodes of the semiconductor element which is the adherend, more preferably ¼ or less, and further preferably ⅕ or less. is there. When the average particle diameter of the solder particles is larger than 1/3 of the distance between the spaces of the electrodes of the semiconductor element, the possibility of short circuiting increases. The specific particle diameter of the solder particles is preferably 1 μm or more and 30 μm or less. If the average particle diameter is smaller than 1 μm, a good solder joint state with the electrode cannot be obtained, and reliability tends to deteriorate. Further, in order to keep the coating thickness of the film constant, the lower limit of the average particle diameter of the solder particles is preferably 3 μm or more, more preferably 5 μm or more. If the average particle size of the solder particles is 30 μm or more, fine pitch connection becomes difficult. The upper limit of the average particle diameter of the solder particles is 30 μm or less, preferably 25 μm or less, and more preferably 20 μm or less. Depending on the object to be connected, the upper limit of the average particle diameter of the solder particles is preferably 15 μm or less. In the case of an aggregate of a plurality of solder particles, the size of the aggregate may be equal to the average particle diameter of the solder particles described above. In the case of forming an aggregate, the average particle size of the solder particles may be smaller than the above value. The size of each solder particle can be determined by observing with an electron microscope.

The solder particles are, for example, Sn-Pb type, Pb-Sn-Sb type, Sn-Sb type, Sn-Pb-Bi type, Bi-Sn type, Sn-Cu type, and Sn-Cu type specified in JIS Z3282-1999. It can be appropriately selected from Sn-Pb-Cu-based, Sn-In-based, Sn-Ag-based, Sn-Pb-Ag-based, Pb-Ag-based, etc. depending on the electrode material, connection conditions and the like. The melting point of the solder particles is preferably 110 ° C. or higher and 180 ° C. or lower, more preferably 120 ° C. or higher and 160 ° C. or lower, and further preferably 130 ° C. or higher and 150 ° C. or lower. Further, in the solder particles, a flux compound may be directly bonded to the surface for the purpose of activating the surface. By activating the surface, metal bonding with the electrode part can be promoted.

The lower limit of the mass ratio range of the blending amount of the solder particles is preferably 20 wt% or more, more preferably 30 wt% or more, further preferably 40 wt% or more, and the lower limit of the mass ratio range of the blending amount of the solder particles is preferably It is 80 wt% or less, more preferably 70 wt% or less, and further preferably 60 wt% or less. Further, the lower limit of the volume ratio range of the blending amount of the solder particles is preferably 5 vol% or more, more preferably 10 vol% or more, further preferably 15 vol% or more, the upper limit of the volume ratio range of the blending amount of the solder particles, It is preferably 30 vol% or less, more preferably 25 vol% or less, and further preferably 20 vol% or less. When the blending amount of the solder particles satisfies the above mass ratio range or volume ratio range, excellent conductivity, heat dissipation and adhesiveness can be obtained. When the solder particles are present in the binder, the volume ratio may be used, and when manufacturing the anisotropic conductive bonding material (before the solder particles are present in the binder), the mass ratio may be used. .. The mass ratio can be converted into a volume ratio from the specific gravity of the compound or the compounding ratio. If the blending amount of the solder particles is too small, excellent conductivity, heat dissipation and adhesiveness cannot be obtained, and if the blending amount is too large, anisotropy is impaired and excellent conduction reliability cannot be obtained.

[Flux compound]
The flux compound removes foreign matters and oxide film on the electrode surface, prevents oxidation on the electrode surface, and lowers the surface tension of the molten solder. As the flux compound, for example, carboxylic acids such as levulinic acid, maleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and sebacic acid are preferably used. As a result, good solder connection can be obtained, and when an epoxy resin is mixed, it can function as a curing agent for the epoxy resin.

Also, it is preferable to use a blocked carboxylic acid having a carboxyl group blocked with an alkyl vinyl ether as the flux compound. This makes it possible to control the temperature at which the flux effect and the curing agent function are exhibited. Further, since the solubility in the resin is improved, it is possible to improve the mixing and coating unevenness when forming a film. The dissociation temperature at which the blocking is released is preferably equal to or higher than the melting point of the solder particles. As a result, good solder connection can be obtained, and when the epoxy resin is blended, curing is started after the epoxy resin flows, so that good solder joint can be obtained.

[Other additives]
In addition to the above-mentioned solid resin, solder particles, and flux compound, various additives can be added to the anisotropic bonding film within a range that does not impair the effects of the present invention. For example, the anisotropic bonding film may contain an inorganic filler, an organic filler, a metal filler, a coupling agent, a leveling agent, a stabilizer, a thixotropic agent and the like. The particle size of the inorganic filler, the organic filler, and the metal filler is smaller than the average particle size of the solder particles from the viewpoint of connection stability. For example, a nanofiller of 10-1000 nm, a microfiller of 1-10 μm, or the like is used. ..

Examples of the inorganic filler include silica, aluminum oxide, aluminum hydroxide, titanium oxide, aluminum hydroxide, calcium hydroxide, calcium carbonate, talc, zinc oxide, zeolite, etc., and silica is added for the purpose of improving moisture absorption reliability. Alternatively, titanium oxide may be added for the purpose of improving light reflection, or aluminum hydroxide, calcium hydroxide, or the like may be added for the purpose of preventing corrosion by acid.

As the organic filler, acrylic resin, carbon, core shell particles and the like can be mentioned. By adding the organic filler, effects such as blocking prevention and light scattering can be obtained.

Examples of the metal filler include Ni, Cu, Ag and Au, and alloys of these may be used. For example, the Cu filler forms a complex with an acid and therefore can prevent corrosion of the electrodes and the like. The metal filler may or may not contribute to conduction, and the compounding amount of the metal filler, including the solder particles, may be adjusted so as not to cause a short circuit.

Further, the above-mentioned anisotropic bonding film is prepared by, for example, mixing solid resin, solder particles, and a flux compound in a solvent, and applying this mixture by a bar coater to a predetermined thickness on a release-treated film. Then, it can be obtained by drying and volatilizing the solvent. Further, in order to enhance the dispersibility of the solder particles, it is preferable to apply a high share in a state of containing a solvent. For example, a known batch type planetary stirring device can be used. It may be one that can be performed in a vacuum environment. The amount of residual solvent in the anisotropic bonding film is preferably 2% or less, more preferably 1% or less.

<3.1 First Example>
In the first example, an LED mounting body was produced using an anisotropic bonding film containing a thermoplastic resin, and the forward voltage, die shear strength, and bonding state of the LED mounting body were evaluated.

[Measurement of melt flow rate of solid resin]
According to JIS K7210: 1999 method for determining the melt flow rate of plastic plastics, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Seiki Seisaku-sho, Ltd.), temperature 190 ° C., load 2.16 kg The melt flow rate of the thermoplastic resins AE was measured by.
A: Polyester resin, Primalloy A1500 (Mitsubishi Chemical Corporation), MFR = 11 g / 10 min
B: ethylene vinyl acetate copolymer resin, Evaflex EV205WR (Mitsui DuPont Chemical Co., Ltd.), MFR = 800 g / 10 min
C: ethylene acrylic acid copolymer resin, Nucrel N1050H (DuPont Co., Ltd.), MFR = 500 g / 10 min
D: Polyamide resin, Grillex D1666A (EMS GRIVORY Co., Ltd.), MFR = 130 g / 10 min
E: Phenoxy resin, Phenothote YP70 (Nippon Steel & Sumitomo Metal Corporation), MFR = 1g / 10min

[Production of LED mounting body]
LED chip (LED chip for evaluation of Dexerials, size 45 mil, If = 350 mA, Vf = 3.1 V, Au-Sn pad, P electrode and N electrode of pad size 300 μm × 800 μm are provided respectively, and the distance between pads (P (Distance between electrodes and N electrode) 150 μm), and a substrate (ceramic substrate for Dexerials evaluation, 18 μm thick Cu pattern, Ni—Au plating, space between patterns (50 μm)) were prepared. The anisotropic bonding film was laminated on the substrate under the condition of 80 ° C.-2 MPa-3 sec, the LED chip was aligned and mounted, and then the LED chip was mounted by reflow (peak temperature 260 ° C.).

[Measurement of forward voltage]
A rated current If = 350 mA was passed through the LED chip through the pattern of the substrate, and the forward voltage value Vf of the LED chip was measured. The case where reading was not possible due to overvoltage was designated as "OPEN".

[Measurement of die shear strength]
The die shear strength of the LED chip was measured at a measurement speed of 20 μm / sec using a bonding tester (product number: PTR-1100, manufactured by Reska Co.).

[Observation of bonding state]
After measuring the die shear strength, that is, the solder bonding state on the substrate side after peeling off the LED chip was observed with an optical microscope.

[Measurement of film thickness]
The film thickness was measured at 10 or more points using a digital micrometer, and the average was taken as the film thickness.

<Example 1-1>
As shown in Table 1, thermoplastic resin A, flux compound (glutaric acid (1,3-propanedicarboxylic acid), Wako Pure Chemical Industries, Ltd.), solder particles (42Sn-58Bi, Type 6, melting point 139 ° C, average particle) A diameter of 10 μm, Mitsui Kinzoku Co., Ltd., and titanium oxide (average particle size 0.21 μm, CR-60, Ishihara Sangyo Co., Ltd.) were mixed in a predetermined mass part to prepare an anisotropic bonding film.

After the solder particles are dispersed in a toluene solution in which a thermoplastic resin A, a flux compound, and titanium oxide are mixed and dissolved, a PET (PET-02-BU) PET (PET-02-BU) is peeled off with a gap coater so that the thickness after drying is 20 μm. , Shikoku Tohcello Co., Ltd.). Toluene was dried at 80 ° C. for 10 minutes. The measured film thickness after drying was 20 μm.

Table 1 shows the measurement results of the forward voltage and the die shear strength of the LED mounting body manufactured using the anisotropic bonding film. The forward voltage was 3.1 V and the die shear strength was 40 N / chip.

FIG. 4 is a photomicrograph when observing the solder joint state on the substrate side after peeling off the LED chip of Example 1-1. The solder was wet and spread on the LED chip side and the substrate side, and was in a good solder joint state. It was also confirmed that there were a plurality of solder joints in one electrode.

<Example 1-2>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the thermoplastic resin B was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V and a die shear strength of 45 N / chip.

<Example 1-3>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the thermoplastic resin C was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.0 V and a die shear strength of 43 N / chip.

<Example 1-4>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the thermoplastic resin D was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.0 V and a die shear strength of 46 N / chip.

<Example 1-5>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the thickness of the anisotropic bonding film was 30 μm. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.1 V and a die shear strength of 47 N / chip.

<Comparative Example 1-1>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the thermoplastic resin E was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had an open forward voltage and a die shear strength of 19 N / chip.

FIG. 5 is a photomicrograph of the solder bonding state on the substrate side after peeling off the LED chip of Comparative Example 1-1. Since the melt flow rate of the thermoplastic resin E was 1 g / 10 min, the resin hardly flowed and the solder particles did not contact the pad of the LED chip or the pattern of the substrate and were not melted.

<Comparative Example 1-2>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the flux compound was not added. The LED package manufactured using the anisotropic bonding film had an open forward voltage and a die shear strength of 18 N / chip.

FIG. 6 is a photomicrograph when observing the solder joint state on the substrate side after peeling off the LED chip of Comparative Example 1-2. Since no flux compound was added, the solder particles did not melt.

<Comparative Example 1-3>
As shown in Table 1, an anisotropic bonding film was produced in the same manner as in Example 1-1, except that the thickness of the anisotropic bonding film was 40 μm. The LED mounting body produced using the anisotropic bonding film had an open forward voltage and a die shear strength of 25 N / chip.

FIG. 7 is a photomicrograph of the solder bonding state on the substrate side after peeling off the LED chip of Comparative Example 1-3. Since the thickness of the anisotropic bonding film is as thick as 40 μm, the sandwiching of the solder particles between the electrodes is insufficient, the solder bonding becomes insufficient, and the wetting and spreading of the solder particles occurs only on the LED chip side and only on the substrate side. The spot was seen.

In Comparative Example 1-1, since the thermoplastic resin E having a melt flow rate of 1 g / 10 min was used, the fluidity of the resin was poor, the solder particles did not melt, and the electrodes of the adherend were not joined. Therefore, the forward voltage could not be measured. Further, the resin did not flow sufficiently and the solder joint was not formed, so that the adhesion of the LED chip was weak and the die shear strength was low.

In Comparative Example 1-2, since the flux compound was not mixed, the solder particles did not melt and the forward voltage could not be measured.

In Comparative Example 1-3, since the anisotropic bonding film having a thickness of 40 μm, which is four times as thick as the average particle size of the solder particles, was used, solder bonding was not formed and the forward voltage could not be measured. .. The die shear strength was also low.

On the other hand, in Examples 1-1 to 1-5, the thermoplastic resins A to D having a melt flow rate of 1 g / 10 min or more were used, and the thickness of the solder particles was 2-3 times as large as the average particle diameter of 10 μm. Since the anisotropic bonding film having a thickness of 20 to 30 μm was used, the resin melted and flowed, and the solder particles were solder-bonded between the electrodes of the adherend, and a value close to the rated voltage of 3.1 V could be obtained. The die shear strength was also good.

<3.2 Second Example>
In the second example, an LED mounting body was prepared using an anisotropic bonding film containing a radically polymerizable resin, and the forward voltage, the insulating property and the die shear strength of the LED mounting body were evaluated. The manufacturing of the LED mounting body, the measurement of the forward voltage of the LED mounting body, and the measurement of the die-shake strength are the same as those in the first embodiment, and thus the description thereof is omitted here.

[Measurement of melt flow rate of solid resin]
According to JIS K7210: 1999 method for determining the melt flow rate of plastic plastics, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Seiki Seisaku-sho, Ltd.), temperature 190 ° C., load 2.16 kg The melt flow rates of the thermoplastic resins AC and E and the solid radically polymerizable resin were measured by.
A: Polyester resin, Primalloy A1500 (Mitsubishi Chemical Corporation), MFR = 11 g / 10 min
B: ethylene vinyl acetate copolymer resin, Evaflex EV205WR (Mitsui DuPont Chemical Co., Ltd.), MFR = 800 g / 10 min
C: ethylene acrylic acid copolymer resin, Nucrel N1050H (DuPont Co., Ltd.), MFR = 500 g / 10 min
E: Phenoxy resin, Phenothote YP70 (Nippon Steel & Sumitomo Metal Corporation), MFR = 1g / 10min
Solid radical polymerizable resin: vinyl ester resin, Lipoxy VR-90, Showa Denko KK, MFR = 100g / 10min

[Evaluation of insulation]
A reverse current of 0.1 μA was applied to the LED chip through the pattern of the substrate, and the evaluation when the current did not flow was “OK”, and the evaluation when the current flowed was “NG”.

<Example 2-1>
As shown in Table 2, a thermoplastic resin A, a liquid radical polymerizable resin (hydrogenated bisphenol A diglycidyl ether, Epolite 4000, Kyoeisha Chemical Co., Ltd.), an initiator (diacyl peroxide, Perhexa 25B, NOF CORPORATION) )), Flux compound A (glutaric acid (1,3-propanedicarboxylic acid), Wako Pure Chemical Industries, Ltd.), solder particles (42Sn-58Bi, Type6, melting point 139 ° C., average particle size 10 μm, Mitsui Kinzoku Co., Ltd.) ) And titanium oxide (average particle size 0.21 μm, CR-60, Ishihara Sangyo Co., Ltd.) were mixed in a predetermined mass part to prepare an anisotropic bonding film.

Thermoplastic resin A and liquid radical-polymerizable resin are mixed and dissolved in toluene, flux compound A and titanium oxide are added thereto, and the mixture is dispersed with three rolls (three passes with a gap of 10 μm) and then started. A resin solution was obtained by dispersing the agent and the solder particles. This resin solution was applied to a peeled PET (PET-02-BU, Shikoku Tocello Co., Ltd.) with a gap coater so that the thickness after drying with toluene was 20 μm. Toluene was dried at 80 ° C. for 10 minutes.

As shown in Table 2, the LED mounting body manufactured using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 42 N / chip.

<Example 2-2>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the thermoplastic resin B was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 46 N / chip.

<Example 2-3>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the thermoplastic resin C was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 41 N / chip.

<Example 2-4>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the solid radically polymerizable resin was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 47 N / chip.

<Example 2-5>
As shown in Table 2, the anisotropic bonding film was the same as in Example 2-1 except that flux compound B (blocked carboxylic acid, Santacid G, NOF Corporation) was used in place of flux compound A. Was produced. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 46 N / chip.

<Example 2-6>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the thickness of the anisotropic bonding film was 30 μm. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 49 N / chip.

<Comparative Example 2-1>
As shown in Table 2, the thermoplastic resin E was dissolved with a reactive diluent (tetrahydrofurfuryl acrylate, biscoat # 150, Osaka Organic Chemical Industry Co., Ltd.), and then the radical polymerizable resin, the initiator and the flux compound A were dissolved. An anisotropic bonding paste was prepared by mixing, dispersing, titanium oxide, and solder particles.

LED chip (LED chip for Dexerials evaluation, size 45 mil, If = 350 mA, Vf = 3.1 V, Au-Sn pad, pad size 300 μm × 800 μm, distance between pads 200 μm), substrate (Dexerials evaluation ceramic substrate, 18 μm thickness) A Cu pattern, Ni—Au plating, and space (space between patterns) of 50 μm) were prepared. The anisotropic bonding paste was applied onto the substrate using a mask having a thickness of 30 μm, the LED chips were mounted by alignment, and then the LED chips were mounted by reflow (peak temperature of 260 ° C.).

As shown in Table 2, the LED mounting body produced using the anisotropic bonding paste had a forward voltage of 3.0 V, an insulating property of NG, and a die shear strength of 45 N / chip.

<Comparative Example 2-2>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the thermoplastic resin E was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 19 N / chip.

<Comparative Example 2-3>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the flux compound was not added. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 19 N / chip.

<Comparative Example 2-4>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 2-1 except that the thickness of the anisotropic bonding film was 40 μm. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 26 N / chip.

In Comparative Example 2-1, since the paste resin anisotropic bonding material was applied using the thermoplastic resin E having a melt flow rate of 1 g / 10 min, a short circuit due to solder bonding occurred between the adjacent terminals of the substrate.

In Comparative Example 2-2, since the thermoplastic resin E having a melt flow rate of 1 g / 10 min was used, the fluidity of the resin was poor, the solder particles did not melt, and the electrodes of the adherend were not joined. Therefore, the forward voltage could not be measured. Further, the resin did not flow sufficiently and the solder joint was not formed, so that the adhesion of the LED chip was weak and the die shear strength was low.

In Comparative Example 2-3, since the flux compound was not mixed, the solder particles did not melt and the forward voltage could not be measured.

In Comparative Example 2-4, since the anisotropic bonding film having a thickness of 40 μm, which is four times the thickness of the solder particles having an average particle diameter of 10 μm, was used, solder bonding was not formed and the forward voltage could not be measured. .. The die shear strength was also low.

On the other hand, in Examples 2-1 to 2-5, the thermoplastic resins A to D having a melt flow rate of 1 g / 10 min or more were used, and the thickness was 2-3 times as large as the average particle diameter of the solder particles of 10 μm. Since the anisotropic bonding film having a thickness of 20 to 30 μm was used, the resin melted and flowed, and the solder particles were solder-bonded between the electrodes of the adherend, and a value close to the rated voltage of 3.1 V could be obtained. The die shear strength was also good.

<3.3 Third Example>
In the third example, an LED mounting body was prepared using an anisotropic bonding film containing an epoxy resin, and the forward voltage, the insulating property and the die shear strength of the LED mounting body were evaluated. The production of the LED mounting body, the measurement of the forward voltage of the LED mounting body, and the dieche strength are the same as those in the first embodiment, and the evaluation of the insulating property of the LED mounting body is the same as that in the second embodiment. The description is omitted here.

[Measurement of melt flow rate of solid resin]
According to JIS K7210: 1999 method for determining the melt flow rate of plastic plastics, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Seiki Seisaku-sho, Ltd.), temperature 190 ° C., load 2.16 kg The melt flow rates of the thermoplastic resins AC and E and the solid epoxy resin were measured by.
A: Polyester resin, Primalloy A1500 (Mitsubishi Chemical Corporation), MFR = 11 g / 10 min
B: ethylene vinyl acetate copolymer resin, Evaflex EV205WR (Mitsui DuPont Chemical Co., Ltd.), MFR = 800 g / 10 min
C: ethylene acrylic acid copolymer resin, Nucrel N1050H (DuPont Co., Ltd.), MFR = 500 g / 10 min
E: Phenoxy resin, Phenothote YP70 (Nippon Steel & Sumitomo Metal Corporation), MFR = 1g / 10min
Solid epoxy resin: Bisphenol A type epoxy resin, 1001, Mitsubishi Chemical Co., MFR = 2600g / 10min

<Example 3-1>
As shown in Table 3, thermoplastic resin A, liquid epoxy resin (bisphenol A type epoxy resin, YL980, Mitsubishi Chemical Corporation), curing agent A (anion curing agent, microcapsule type imidazole curing agent, HX3941HP, Asahi Kasei ( Co., Ltd.), flux compound A (glutaric acid (1,3-propanedicarboxylic acid), Wako Pure Chemical Industries, Ltd.), solder particles (42Sn-58Bi, Type 6, melting point 139 ° C., average particle size 10 μm, Mitsui Kinzoku Co., Ltd. )) And titanium oxide (average particle size 0.21 μm, CR-60, Ishihara Sangyo Co., Ltd.) were mixed in a predetermined mass part to prepare an anisotropic bonding film.

The thermoplastic resin A and the liquid epoxy resin are mixed and dissolved in toluene, and the flux compound A and titanium oxide are added thereto and dispersed by a three-roll (three passes with a gap of 10 μm), and then a curing agent A. A resin solution was obtained by dispersing the solder particles. This resin solution was applied to a peeled PET (PET-02-BU, Shikoku Tocello Co., Ltd.) with a gap coater so that the thickness after drying with toluene was 20 μm. Toluene was dried at 80 ° C. for 10 minutes.

As shown in Table 3, the LED package manufactured using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 43 N / chip.

<Example 3-2>
As shown in Table 3, an anisotropic bonding film was produced in the same manner as in Example 3-1 except that the thermoplastic resin B was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 46 N / chip.

<Example 3-3>
As shown in Table 3, an anisotropic bonding film was produced in the same manner as in Example 3-1 except that the thermoplastic resin C was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 41 N / chip.

<Example 3-4>
As shown in Table 3, an anisotropic bonding film was produced in the same manner as in Example 3-1 except that a solid epoxy resin was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 47 N / chip.

<Example 3-5>
As shown in Table 3, except that the curing agent B (cationic curing agent, sulfonium salt, San-Aid SI-80L, manufactured by Sanshin Chemical Co., Ltd.) was used in place of the curing agent A and the mixing ratio of the liquid epoxy resin was adjusted. An anisotropic bonding film was produced in the same manner as in Example 3-1. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 46 N / chip.

<Example 3-6>
As shown in Table 3, the anisotropic bonding film was the same as in Example 3-1 except that flux compound B (blocked carboxylic acid, Santacid G, NOF Corporation) was used in place of flux compound A. Was produced. The LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 44 N / chip.

<Example 3-7>
As shown in Table 3, an anisotropic bonding film was produced in the same manner as in Example 3-1, except that the thickness of the anisotropic bonding film was 30 μm. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 49 N / chip.

<Comparative Example 3-1>
As shown in Table 3, an anisotropic bonding paste was prepared by mixing and dispersing a liquid epoxy resin, a curing agent A, a flux compound A, titanium oxide, and solder particles.

As shown in Table 3, the LED mounting body manufactured using the anisotropic bonding paste had a forward voltage of 3.0 V, an insulating property of NG, and a die shear strength of 45 N / chip.

<Comparative Example 3-2>
As shown in Table 2, an anisotropic bonding film was produced in the same manner as in Example 3-1 except that the thermoplastic resin E was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 19 N / chip.

<Comparative Example 3-3>
As shown in Table 3, an anisotropic bonding film was produced in the same manner as in Example 3-1 except that the flux compound was not added. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 19 N / chip.

<Comparative Example 3-4>
As shown in Table 3, an anisotropic bonding film was produced in the same manner as in Example 3-1 except that the thickness of the anisotropic bonding film was 40 μm. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 26 N / chip.

In Comparative Example 3-1, since the liquid epoxy resin was used and the paste-like anisotropic bonding material was applied, a short circuit due to solder bonding occurred between the adjacent terminals of the substrate.

In Comparative Example 3-2, since the thermoplastic resin E having a melt flow rate of 1 g / 10 min was used, the fluidity of the resin was poor, the solder particles did not melt, and the electrodes of the adherend were not joined. Therefore, the forward voltage could not be measured. Further, the resin did not flow sufficiently and the solder joint was not formed, so that the adhesion of the LED chip was weak and the die shear strength was low.

In Comparative Example 3-3, since the flux compound was not mixed, the solder particles did not melt and the forward voltage could not be measured.

In Comparative Example 3-4, since the anisotropic bonding film having a thickness of 40 μm, which is four times the thickness of the solder particles having an average particle diameter of 10 μm, was used, solder bonding was not formed and the forward voltage could not be measured. .. The die shear strength was also low.

On the other hand, in Examples 3-1 to 3-7, the thermoplastic resin A-D having a melt flow rate of 1 g / 10 min or more was used, and the thickness of the solder particles was 2-3 times the average particle diameter of 10 μm. Since the anisotropic bonding film having a thickness of 20 to 30 μm was used, the resin melted and flowed, and the solder particles were solder-bonded between the electrodes of the adherend, and a value close to the rated voltage of 3.1 V could be obtained. The die shear strength was also good. Also, good results could be obtained by using the blocked flux compound in which the carboxyl group was blocked by the vinyl ether of Example 3-6.

<3.4 Fourth Embodiment>
In the fourth example, an LED mounting body was prepared using an anisotropic bonding film containing a carboxylic acid as a flux compound, and the forward voltage, insulation and die shear strength of the LED mounting body were evaluated. Since the manufacturing of the LED mounting body, the measurement of the forward voltage of the LED mounting body, and the die shear strength are the same as those in the first embodiment, the evaluation of the insulating property of the LED mounting body is the same as that in the second embodiment. The description is omitted here.

[Measurement of melt flow rate of solid resin]
According to JIS K7210: 1999 method for determining the melt flow rate of plastic plastics, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Seiki Seisaku-sho, Ltd.), temperature 190 ° C., load 2.16 kg The melt flow rates of the thermoplastic resins A and E and the solid epoxy resin were measured by.
A: Polyester resin, Primalloy A1500 (Mitsubishi Chemical Corporation), MFR = 11 g / 10 min
E: Phenoxy resin, Phenothote YP70 (Nippon Steel & Sumitomo Metal Corporation), MFR = 1g / 10min
Solid epoxy resin: Bisphenol A type epoxy resin, 1001, Mitsubishi Chemical Co., MFR = 2600g / 10min

<Example 4-1>
As shown in Table 4, thermoplastic resin A, liquid epoxy resin (bisphenol A type epoxy resin, YL980, Mitsubishi Chemical Corporation), flux compound A (glutaric acid (1,3-propanedicarboxylic acid), Wako Pure Chemical Industries, Ltd. Co., Ltd.), solder particles (42Sn-58Bi, Type 6, melting point 139 ° C., average particle size 10 μm, Mitsui Metals Co., Ltd.), titanium oxide (average particle size 0.21 μm, CR-60, Ishihara Sangyo Co., Ltd.) Was blended in a predetermined mass part to prepare an anisotropic bonding film.

The thermoplastic resin A and the liquid epoxy resin are mixed and dissolved in toluene, and the flux compound A and titanium oxide are put therein, and dispersed by three rolls (three passes with a gap of 10 μm), and then the solder particles are dispersed. A resin solution was obtained by dispersing. This resin solution was applied to a peeled PET (PET-02-BU, Shikoku Tocello Co., Ltd.) with a gap coater so that the thickness after drying with toluene was 20 μm. Toluene was dried at 80 ° C. for 10 minutes.

As shown in Table 4, the LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 44 N / chip.

<Example 4-2>
As shown in Table 4, an anisotropic bonding film was produced in the same manner as in Example 4-1 except that a solid epoxy resin was used instead of the thermoplastic resin A. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 45 N / chip.

<Example 4-3>
As shown in Table 4, the anisotropic bonding film was the same as in Example 4-1 except that flux compound B (blocked carboxylic acid, Santacid G, NOF CORPORATION) was used in place of flux compound A. Was produced. The LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.0 V, an insulating property of OK, and a die shear strength of 44 N / chip.

<Example 4-4>
As shown in Table 4, an anisotropic bonding film was produced in the same manner as in Example 4-1, except that the thickness of the anisotropic bonding film was 30 μm. The LED package manufactured using the anisotropic bonding film had a forward voltage of 3.1 V, an insulating property of OK, and a die shear strength of 48 N / chip.

<Comparative Example 4-1>
As shown in Table 4, an anisotropic bonding paste was prepared by mixing and dispersing a liquid epoxy resin, a curing agent A, a flux compound B, titanium oxide, and solder particles.

As shown in Table 4, the LED mounting body produced using the anisotropic bonding paste had a forward voltage of 3.0 V, an insulating property of NG, and a die shear strength of 45 N / chip.

<Comparative Example 4-2>
As shown in Table 4, an anisotropic bonding film was produced in the same manner as in Example 4-1 except that the thermoplastic resin E was used instead of the thermoplastic resin A. The LED mounting body produced using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 19 N / chip.

<Comparative Example 4-3>
As shown in Table 4, an anisotropic bonding film was produced in the same manner as in Example 4-1 except that the flux compound was not added. The LED package manufactured using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 18 N / chip.

<Comparative Example 4-4>
As shown in Table 4, an anisotropic bonding film was produced in the same manner as in Example 4-1 except that the thickness of the anisotropic bonding film was 40 μm. The LED package manufactured using the anisotropic bonding film had a forward voltage of OPEN, an insulating property of OK, and a die shear strength of 25 N / chip.

In Comparative Example 4-1, since the solid resin was not mixed and the paste-like anisotropic bonding material was applied, a short circuit due to solder bonding occurred between the adjacent terminals of the substrate.

In Comparative Example 4-2, since the thermoplastic resin E having a melt flow rate of 1 g / 10 min was used, the fluidity of the resin was poor, the solder particles did not melt, and the electrodes of the adherend were not joined. Therefore, the forward voltage could not be measured. Further, the resin did not flow sufficiently and the solder joint was not formed, so that the adhesion of the LED chip was weak and the die shear strength was low.

In Comparative Example 4-3, since the flux compound was not mixed, the solder particles did not melt and the forward voltage could not be measured.

In Comparative Example 4-4, since an anisotropic bonding film having a thickness of 40 μm, which is four times as thick as the average particle diameter of solder particles of 10 μm, was used, solder bonding was not formed and forward voltage could not be measured. .. The die shear strength was also low.

On the other hand, in Examples 4-1 to 4-4, the thermoplastic resin A or the solid epoxy resin having a melt flow rate of 1 g / 10 min or more was used, and the average particle diameter of the solder particles was 10 to 2 times 2-3 times. Since an anisotropic bonding film with a thickness of 20-30 μm was used, the resin melted and flowed, and solder particles were used to solder bond between the electrodes of the adherend, and a value close to the rated voltage of 3.1 V could be obtained. It was The die shear strength was also good. Further, in Example 4-3, good results could be obtained even when the flux compound was used as the curing agent.

Although the film-shaped anisotropic bonding material was used in the above-mentioned examples, it is considered that the same result can be obtained by adjusting the paste-shaped anisotropic bonding material to a predetermined thickness.

DESCRIPTION OF SYMBOLS 10 LED element, 11 1st conductivity type electrode, 12 2nd conductivity type electrode, 20 board | substrate, 21 1st electrode, 22 2nd electrode, 30 anisotropic bonding film, 31 solder particle, 32 anisotropic conductive film , 33 Solder joint

Claims

At least one selected from a thermoplastic resin, a solid radically polymerizable resin, and a solid epoxy resin, which is solid at room temperature and has a melt flow rate of 10 g / 10 min or more measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg. Of the anisotropic bonding material containing the solid resin, the solder particles, and the flux compound between the electrodes of the first electronic component and the electrodes of the second electronic component, the average particle size of the solder particles being 50 % And 300% or less in thickness,
A method for manufacturing a connection body, in which an electrode of the first electronic component and an electrode of the second electronic component are heat-bonded without load.
The method for producing a connector according to claim 1, wherein the anisotropic bonding material is an anisotropic bonding film having a thickness of 50% or more and 300% or less of an average particle diameter of the solder particles.
The second electronic component is a substrate,
The method for manufacturing a connector according to claim 2, wherein the anisotropic bonding film is laminated on the substrate, a plurality of the first electronic components are mounted on the anisotropic bonding film, and heat bonding is performed.
The method for manufacturing a connector according to any one of claims 1 to 3, wherein the flux compound is a carboxylic acid.
The method for producing a connector according to any one of claims 1 to 3, wherein the flux compound is a blocked carboxylic acid having a carboxyl group blocked with an alkyl vinyl ether.
At least one selected from a thermoplastic resin, a solid radically polymerizable resin, and a solid epoxy resin, which is solid at room temperature and has a melt flow rate of 10 g / 10 min or more measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg. Containing a solid resin, solder particles, and a flux compound,
An anisotropic bonding material having a thickness of 50% or more and 300% or less of the average particle diameter of the solder particles.
The anisotropic bonding material according to claim 6, wherein the flux compound is a carboxylic acid.
The anisotropic bonding material according to claim 6, wherein the flux compound is a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether.
The anisotropic bonding material according to any one of claims 6 to 8, which further contains a liquid radical polymerizable resin that is liquid at room temperature and a polymerization initiator.
The anisotropic bonding material according to any one of claims 6 to 8, which further contains a liquid epoxy resin at room temperature and a curing agent.
The anisotropic bonding material according to claim 10, wherein the curing agent is a carboxylic acid or a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether.
An anisotropic bonding film in which the anisotropic bonding material according to any one of claims 6 to 11 is in the form of a film.
An electrode for a first electronic component and an electrode for a second electronic component, using the anisotropic bonding material according to claim 6 or the anisotropic bonding film according to claim 12. A connection body made by joining and.