KR20210043655A - Connection body manufacturing method, anisotropic bonding film, connection body - Google Patents

Abstract

It provides a manufacturing method of a connection body, an anisotropic bonding film, and a connection body capable of bonding an electronic component provided with a fine pitch electrode. At least one solid resin selected from a thermoplastic resin, a solid radical 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 conditions of 190° C. and a load of 2.16 kg, and , The anisotropic bonding material containing the solder particles and the flux compound is interposed between the electrode of the first electronic component and the electrode of the second electronic component at a thickness of 50% or more and 300% or less of the average particle diameter of the solder particles, and the first electron The electrode of the component and the electrode of the second electronic component are heat-bonded without load.

Description

Connection body manufacturing method, anisotropic bonding film, connection body

The present invention relates to a method of manufacturing a connection body for mounting semiconductor chips (elements) such as LED (Light Emitting Diode), an anisotropic bonding film, and a connection body. This application claims priority in Japan 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, This application is incorporated herein by reference.

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

However, in the case of bonding a large number of semiconductor chips and a large substrate, for example, in order to heat-press the flip chip mounting, a very high pressure is required or parallelism adjustment is required, making mass production difficult.

Japanese Unexamined Patent Publication No. 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 Literature 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 microscopic photograph of an LED mounting body fabricated using a conventional solder paste, when the state of solder bonding on the substrate side after peeling 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, solder particles agglomerate between adjacent terminals to form a bridge A, thereby causing a short circuit.

The present technology has been proposed in view of such a conventional situation, and provides a method of manufacturing a connection body, an anisotropic bonding film, and a connection body capable of bonding electronic components provided with fine pitch electrodes.

As a result of careful examination, the inventor of the present invention used an anisotropic bonding material containing a solid resin that is solid at room temperature and has a predetermined melt flow rate, and the thickness of the anisotropic bonding material between electrodes is determined with respect to the average particle diameter of the solder particles. By setting it as the value of, it found out that the object mentioned above can be achieved, and came to complete this invention.

That is, the manufacturing method of the connecting body according to the present invention is a thermoplastic resin having a melt flow rate of 10 g/10 min or more, which is solid at room temperature and a temperature of 190° C. and a load of 2.16 kg, and a solid radical polymerizable resin, and An anisotropic bonding material containing at least one solid resin selected from solid epoxy resins, solder particles, and flux compounds is used between the electrode of the first electronic component and the electrode of the second electronic component. The electrode of the first electronic component and the electrode of the second electronic component are heat-bonded with no load, with a thickness of 50% or more and 300% or less.

In addition, the anisotropic bonding film according to the present invention is a thermoplastic resin, a solid radical polymerizable resin, and a solid epoxy having a melt flow rate of 10 g/10 min or more, which is solid at room temperature and a temperature of 190°C and a load of 2.16 kg. It contains at least one type of solid resin selected from resins, solder particles, and a flux compound, and has a thickness of 50% or more and 300% or less of the average particle diameter of the solder particles.

In addition, the connection body according to the present invention is formed by bonding the electrode of the first electronic component and the electrode of the second electronic component using the anisotropic bonding film described above.

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

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

Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings.

1. Manufacturing method of connection body

2. Anisotropic bonding film (Anisotropic bonding material)

3. Examples

<1. Connection body manufacturing method>

The manufacturing method of the connection body in this embodiment is a thermoplastic resin, a solid radical polymerizable resin, and a melt flow rate of 10 g/10 min or more, which is solid at room temperature, and has a melt flow rate of 10 g/10 min or more measured under conditions of a temperature of 190°C and a load of 2.16 kg, and 50 of the average particle diameter of the solder particles between the electrode of the first electronic component and the electrode of the second electronic component by using at least one solid resin selected from solid epoxy resins, a solder particle, and an anisotropic bonding material containing a flux compound. The electrode of the first electronic component and the electrode of the second electronic component are heat-bonded without load by interposing with a thickness of not less than% and not more than 300%.

In the present specification, the melt flow rate is a value measured under conditions of 190°C and a load of 2.16 kg, specified in the method for determining the melt flow rate of a thermoplastic plastic in JIS K7210:1999, and is also referred to as a melt mass flow rate (MFR). I call it. In addition, normal temperature is a range of 20°C ± 15°C (5°C to 35°C) specified in JIS Z 8703. In addition, a connection body is a thing in which two materials or members are electrically connected. In addition, bonding is a connection of two materials or members. In addition, no load means a state in which there is no mechanical pressure.

In addition, the average particle diameter is N = 50 or more, preferably N = 100 or more, and more preferably N = 200 in an observation image using an electron microscope such as a metallurgical microscope, an optical microscope, or a SEM (Scanning Electron Microscope). It is the average value of the major axis diameters of the particles measured as described above, and when the particles are spherical, it is the average value of the particle diameters. In addition, the observation image was measured using a known image analysis software (WinROOF, Mitani Corporation), and a measurement value measured using an image-type particle size distribution measuring device (for example, FPIA-3000 (Malburn)) ( N = 1000 or more). The average particle diameter calculated|required from an observation image or an image-type particle size distribution measuring apparatus can be made into the average value of the maximum length of a particle. In addition, when producing an anisotropic bonding material, such as the particle diameter (D 50) at which the cumulative frequency in the particle size distribution determined by the simple laser diffraction/scattering method becomes 50%, the arithmetic mean diameter (preferably on a volume basis), etc. Maker value can be used.

The first electronic component is preferably a chip (element) such as an LED (Light Emitting Diode) and a driver IC (Integrated Circuit), and the second electronic component is not particularly limited as long as a wiring is formed, and the first electronic component A substrate (so-called printed wiring board: PWB) on which an electrode on which can be mounted is formed, as long as it can be defined in a broad sense. For example, a substrate such as a rigid substrate, a glass substrate, a flexible substrate (FPC: Flexible Printed Circuits), a ceramic substrate, and a plastic substrate may be mentioned. The electrodes (electrode array, electrode group) formed on each of the first electronic component and the second electronic component are formed to be anisotropically connected to each other, and electrodes ( Electrode array, electrode group) may be formed. As the first electronic component, in addition to LED (Light Emitting Diode), chips such as driver IC (Integrated Circuit) (for example, semiconductor devices), flexible substrates (FPC: Flexible Printed Circuits, resin molded parts, etc., wiring ( The second electronic component is not particularly limited as long as a terminal corresponding to at least a part of the terminal of the first electronic component is formed, and the substrate on which the electrode on which the first electronic component can be mounted is formed ( A so-called printed wiring board: PWB) may be defined in a broad sense, and the same components may be laminated and connected, and the number of these laminates is not particularly limited as long as it does not interfere with the connection. The same applies even if it is laminated. The electrodes (electrode array, electrode group) formed on each of the first electronic component and the second electronic component are formed so as to be anisotropically connected to each other, and the plurality of first electronic components is a single second electronic component. Electrodes (electrode array, electrode group) may be formed so as to be mounted on the electronic component, and it is preferable that the electronic component has heat resistance in the reflow process.

The anisotropic bonding material is solid at room temperature and contains a solid resin composed of one type selected from a thermoplastic resin having an MFR of 10 g/10 min or more, a solid radical polymerizable resin, and a solid epoxy resin, and a solder particle and a flux compound. It is preferable that the flux compound is a carboxylic acid. Thereby, a good solder connection can be obtained, and when an epoxy resin is blended, it can function as a curing agent for the epoxy resin. Moreover, it is preferable that the flux compound is a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether. Thereby, the temperature at which the flux effect and the curing agent function are exhibited can be controlled.

Moreover, the amount of the resin flow of an anisotropic bonding material may be 1.3-2.5, and it may be preferable to set it as less than 1.3. When the amount of the resin flow becomes these values, heat bonding can be performed without load as described later. The amount of resin flow can be measured in accordance with the measurement method described in Japanese Unexamined Patent Application Publication No. 2016-178225. First, the anisotropic bonding film is cut to a width of 2.0 mm, and the cut anisotropic bonding film is sandwiched between non-alkali glass (thickness 0.7 µm) and passed through a reflow process. This should be the same as the conditions used for connection. And the amount of resin diffusion 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 can be taken as the amount of resin flow. Moreover, it is more preferable that the anisotropic bonding material is mounted and passed through a reflow process without sandwiching between the non-alkali glasses to obtain the above numerical value. When the amount of resin flow of the anisotropic bonding material is small, resin melting does not proceed without load in the reflow process, and there arises a fear that the pinch between the solder particles and the electrode is hindered. In the present technology, since no load is applied during heat curing of the binder resin, it is preferable to make the meltability higher than the design of the binder resin on the premise of applying a load (pressing with a tool like a general anisotropic connection).

The anisotropic bonding material may be any of an anisotropic bonding film or a paste-like anisotropic bonding paste. In addition, the anisotropic bonding paste may be used at the time of connection, or may be formed close to a film by mounting a component.

In the case of the anisotropic bonding paste, it is sufficient to uniformly apply a predetermined amount on the substrate. For example, application methods such as dispensing, stamping, and screen printing may be used, and may be dried as necessary. In the case of an anisotropic bonding film, it is particularly preferable because not only the amount of the anisotropic bonding material can be uniformized depending on the film thickness, but also can be laminated together on a substrate and the tact can be shortened. Moreover, by setting it as in advance, it becomes easy to handle, and an improvement in work efficiency can also be expected.

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 90% or more of the average particle diameter of the solder particles. If the thickness of the anisotropic bonding material is too thin, it becomes easy to pinch the solder particles between the electrodes, but there is a concern that the difficulty in forming a film form increases. 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, more preferably 150% or less of the average particle diameter of the solder particles. to be. If the thickness of the anisotropic bonding material is too thick, there is a concern that it may interfere with bonding.

Hereinafter, a method of manufacturing an LED mounting body will be described as a specific example of the manufacturing method of the connected body. The manufacturing method of the LED mounting body includes a step of forming an anisotropic bonding material having a thickness of 50% or more and 300% or less of the average particle diameter of the solder particles on a substrate, a mounting step of mounting an LED element on an anisotropic bonding material, and an LED element. It has a bonding step of heating and bonding the electrodes of the substrate and the electrodes of the substrate under no load.

The process of forming the anisotropic bonding material may be a process of forming an anisotropic bonding paste on a substrate prior to connection, or, as used in a conventional anisotropic conductive film, temporary attachment of affixing an anisotropic bonding film on a substrate at low temperature and low pressure. It may be a process, and a lamination process of laminating an anisotropic bonding film on a board|substrate may be sufficient.

When the process of forming the anisotropic bonding material is a temporary attachment process, an anisotropic bonding film can be formed on the substrate under known conditions of use. In this case, an economic advantage is obtained because only the minimum change, such as a change of a tool in the conventional device, is performed.

When the process of forming the anisotropic bonding material is a lamination process, an anisotropic bonding film is laminated on a substrate using, for example, a pressurized laminator. The lamination temperature is preferably 40°C or more and 160°C or less, more preferably 50°C or more and 140°C or less, and still more preferably 60°C or more and 120°C or less. Moreover, the lamination pressure becomes like this. Preferably it is 0.1 MPa or more and 10 MPa or less, More preferably, it is 0.5 MPa or more and 5 MPa or less, More preferably, it is 1 MPa or more and 3 MPa or less. Further, the lamination 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. Moreover, vacuum pressurization type lamination may be sufficient. If the conventional anisotropic conductive film is temporarily attached using a heating and pressing tool, the width of the film is limited by the tool width, but in the case of a lamination process, since the heating and pressing tool is not used, a relatively wide width can be mounted at once. You can expect to be there. Moreover, you may laminate one anisotropic bonding film with respect to one substrate. Thereby, since there is no case where the vertical motion of the heat-pressing tool and the conveyance of the anisotropic bonding film are carried out a plurality of times, the time of the step of forming the anisotropic bonding material can be shortened.

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

In addition, in the step of forming 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 approximated to the average particle diameter of the solder particles, but the mounting process is not limited thereto. WHEREIN: You may make the thickness of the anisotropic bonding material approximate to the average particle diameter of a solder particle by pressurization (for example, temporary compression bonding). In this pressing step, for example, by pressing from the side of the first electronic component mounted on the second electronic component, the thickness of the anisotropic bonding material between the electrode of the LED element and the electrode of the substrate is approximated to the average particle diameter of the solder particles. . Here, when the thickness of the anisotropic bonding material is too large, it may be said that it is preferable to set the thickness of the upper limit described above, since there is a possibility that it may interfere with pressing. The approximation to the average particle diameter means that the maximum diameter of the solder particles becomes the thickness of the anisotropic connection material in theory after this pressing process, so the thickness of the anisotropic connection material may be considered to be equal to the maximum diameter of the solder particles, and the thickness deviation is considered. If so, it may be 130% or less, preferably 120% or less of the maximum diameter of the solder particles. In addition, the lower limit of the pressure in the pressurization step is preferably 0.2 MPa or more, more preferably 0.4 MPa or more, and the upper limit of the pressure in the pressurization step may be 2.0 MPa or less, preferably 1.0 MPa or less, more Preferably it is 0.8 MPa or less. Since the upper and lower limits may fluctuate depending on the specifications of the device, as long as the purpose of pushing the resin to the solder particle diameter can be achieved, it is not limited to the above numerical range. This pressurization (temporary pressure bonding) step is performed in order to bring the electrode and the solder particles closer together without melting the solder particles.

1 is a cross-sectional view schematically showing a part of a bonding process. In the bonding step, the electrodes 11 and 12 of the LED element 10 and the electrodes 21 and 21 of the substrate 20 are heat-bonded without load. As a method of heating and bonding without mechanical pressurization without load, atmospheric pressure reflow, vacuum reflow, atmospheric pressure oven, autoclave (pressurized oven), and the like, among them, air bubbles contained in the joint can be eliminated. It is preferable to use a vacuum reflow, autoclave or the like. With no load, since unnecessary resin flow does not occur as compared to an anisotropic conductive connection using a general heating and pressurizing tool, the effect of suppressing curling of air 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, and the solder particles 31 are melted by the main heating above the solder melting temperature, and the solder is transferred to the electrode. It wets while spreading, and the electrode of the LED element 10 and the electrode of the board|substrate 20 are bonded by cooling. In the bonding step, as an example, main heating is preferably performed at a temperature of 200° C. or more and 300° C. or less, more preferably 220° C. or more and 290° C. or less, and still more preferably 240° C. or more and 280° C. or less. Thereby, since the electrode of the LED element 10 and the electrode of the board|substrate 20 are bonded, excellent conductivity, heat dissipation, and adhesiveness can be obtained. In the bonding step, since it is no load, the amount of movement of the solder particles is small, and the efficiency of capturing the solder particles is expected to be high. In addition, the content of the solder particles is such that self-alignment cannot be expected, and in the bonding process, since a plurality of solder particles contained in the anisotropic bonding film are not integrated, a plurality of solder bonding points within one electrode exist. Here, solder bonding refers to connecting each electrode of the opposed electronic component by melting solder.

2 is a cross-sectional view showing a configuration example of an LED mounting body. In this LED mounting body, the LED element 10 and the board|substrate 20 are connected using the anisotropic bonding film in which the solder particle|grains 31 are dispersed in solid resin. That is, the LED mounting body has the LED element 10, the substrate 20, and the solder particles 31, and the electrodes 11 and 12 of the LED element 10 and the electrodes 21 and 22 of the substrate 20 The anisotropic bonding film 32 formed by connecting the LED element 10 is provided, and 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 to be formed. And a solid resin is filled between the LED element 10 and the substrate 20.

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 , When carriers are concentrated in the active layer in the device and recombined, light emission occurs. The distance between the spaces between the first conductive electrode 11 and the second conductive electrode 12 is, depending on the device size, for example, 100 µm or more and 200 µm or less, 100 µm or more and 50 µm or less, 20 µm or more and 50 Some are less than or equal to µm. Although it does not specifically limit as the LED element 10, For example, a blue LED etc. which have a peak wavelength of 400 nm-500 nm can be used suitably.

The substrate 20 has a first electrode 21 and a second electrode 22 at positions corresponding to the first conductivity type electrode 11 and the second conductivity type electrode 12 of the LED element 10 on the substrate, respectively. Has. 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 formed of an anisotropic bonding material in a film form after the bonding step, and the electrodes 11 and 12 of the LED element 10 and the electrodes 21 and 22 of the substrate 20 are bonded to each other by a solder joint 33 In addition to the metal bonding box, the 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 formed of metal by a solder joint 33. It is bonded, and solid resin is filled between the LED element 20 and the board|substrate 30, and it is made. Thereby, intrusion of moisture or the like between the LED element 10 and the substrate 20 can be prevented.

<2. Anisotropic Bonding Film (Anisotropic Bonding Material)>

3 is a cross-sectional view schematically showing a part of an anisotropic bonding film to which the present technology is applied. As shown in FIG. 3, the anisotropic bonding film 30 contains a solid resin, a solder particle 31, and a flux compound. Moreover, on the anisotropic conductive film 30, the 1st film may be affixed to the 1st surface as needed, and the 2nd film may be affixed to the 2nd surface. In addition, the anisotropic bonding film formed an anisotropic bonding material into a film shape.

The lower limit of the film thickness is 50% or more, preferably 80% or more, and more preferably 90% or more of the average particle diameter of the solder particles. If the film thickness is too thin, it becomes easy to pinch the solder particles between the electrodes, but there is a concern that the degree of difficulty when forming a film is increased. Moreover, the upper limit of the film thickness is 300% or less, preferably 200% or less, and more preferably 150% or less of the average particle diameter of the solder particles. If the film thickness is too thick, there is a concern that it may interfere with bonding. The film thickness can be measured using a known micrometer or digital thickness measuring device capable of measuring 1 μm or less, preferably 0.1 μm or less (for example, Mitsutoyo Co., Ltd.: MDE-25M, minimum display amount 0.0001 mm). I can. The film thickness just needs to measure 10 or more points, and average and obtain|require it. However, when the film thickness is thinner than the particle diameter, since a contact-type thickness meter is not suitable, it is preferable to use a laser displacement meter (eg, Keyence Corporation, a 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 the MFR measured under the conditions of a temperature of 190°C and a load of 2.16 kg is 10 g/10 min or more. The upper limit of the MFR is preferably 5000 g/10 min or less, more preferably 4000 g/10 min or less, and 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 MFR, and may be, for example, an ethyleneacetvinyl copolymer resin, an ethyleneacrylic acid copolymer resin, a polyamide resin, a polyester resin, or the like. When the solid resin is a thermoplastic resin, since the electrode of the first electronic component and the electrode of the second electronic component are metal-bonded by hot melt, sufficient bonding strength can be obtained. Moreover, since the thermoplastic resin does not accompany reaction, there is no need to care about the pot life (the product life becomes longer compared to using a curable resin and a curing agent (reaction initiator)), and handling becomes easy. Further, since the thermoplastic resin is solid at room temperature, the resin does not melt at the time of use, but in the case of melting, a filler may be included to prevent melting.

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

The solid epoxy resin is not particularly limited as long as it is an epoxy resin that is solid at room temperature, satisfies the MFR, and has at least one epoxy group in the molecule, and, for example, a bisphenol A type epoxy resin, a biphenyl type epoxy resin, etc. May be. Thereby, the film shape can be maintained.

Moreover, the anisotropic bonding film may further contain a liquid radical polymerizable resin and a polymerization initiator which are liquid at normal temperature. 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 the like, or may be urethane-modified. By using a liquid radical polymerizable resin, tackiness can be imparted to the anisotropic bonding film, the lamination property to the adherend can be improved, and the fluidity of the entire binder at the time of mounting can be improved.

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 still more preferably 70 parts by mass or less with respect to 100 parts by mass of the solid resin. When the blending amount of the liquid radical polymerizable resin increases, it becomes difficult to maintain the film shape.

The polymerization initiator is preferably an organic peroxide such as diacyl peroxide. Moreover, it is preferable that the reaction initiation temperature of the polymerization initiator is higher than the melting point of the solder particles. Thereby, since curing is started after the flow of the solid resin, good solder bonding can be obtained.

In addition, 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, a bisphenol A epoxy resin, a bisphenol F epoxy resin, or a urethane-modified epoxy resin.

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 still more 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 increases, 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 curing by heat, and examples thereof include anionic curing agents such as amines and imidazoles, and cationic curing agents such as sulfonium salts. Moreover, the curing agent may be micro-encapsulated so that resistance to the solvent used when forming a film is obtained.

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 plan view. When the anisotropic bonding film is viewed in a plan view, the entire arrangement of the solder particles may be a regular arrangement or a random arrangement. As a mode of regular arrangement, a lattice arrangement such as a square lattice, a hexagonal lattice, a rhombic lattice, and a rectangular lattice is mentioned, and there is no particular limitation. In addition, as an aspect of random arrangement, it is preferable that the respective solder particles exist so that they do not contact each other when the film is viewed in plan view, and that the solder particles do not overlap with each other even in the film thickness direction. Moreover, it is preferable that 95% or more of the total number of the solder particles in the anisotropic bonding film is non-contact with other solder particles and is independent. This can be confirmed by using a known metallurgical microscope or an optical microscope, arbitrarily extracting an area of 1 mm 2 or more when viewed in a plan view at 5 points or more, and observing 200 or more, preferably 1000 or more solder particles. have. Moreover, when the solder particles are arranged in plan view in the anisotropic bonding film, the solder particles may be uniformly aligned at the same position in the film thickness direction.

In addition, the solder particles may be disposed as an agglomerate in which a plurality of solder particles are agglomerated. In this case, the arrangement of the aggregates in plan view of the anisotropic bonding film may be a regular arrangement or a random arrangement, similar to the arrangement of the above-described solder particles. In addition, it is preferable that the agglomerates exist so that they do not contact each other when the film is viewed in plan view, and that the agglomerates do not overlap with each other even in the film thickness direction. The average particle diameter of the individual solder particles of the aggregate can be measured in the same manner as the average particle diameter described above.

The average particle diameter of the solder particles is preferably 1/3 or less of the distance between spaces of the semiconductor element electrode as an adherend, more preferably 1/4 or less, and still more preferably 1/5 or less. If the average particle diameter of the solder particles is larger than 1/3 of the distance between the spaces of the semiconductor element electrodes, the possibility of occurrence of a short circuit 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 less than 1 µm, a good solder joint state with the electrode portion cannot be obtained, and reliability tends to deteriorate. In addition, in order to make 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. Further, when the average particle diameter 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 connection object, the upper limit of the average particle diameter of the solder particles is preferably 15 µm or less. In addition, when a plurality of solder particles are agglomerated aggregates, the size of the aggregate may be made equal to the average particle diameter of the above-described solder particles. In the case of forming an aggregate, the average particle diameter of the solder particles may be smaller than the above-described value. The size of individual solder particles can be determined by observing with an electron microscope.

Solder particles are, for example, Sn-Pb based, Pb-Sn-Sb based, Sn-Sb based, Sn-Pb-Bi based, Bi-Sn based, Sn-Cu based specified in JIS Z 3282-1999. , Sn-Pb-Cu-based, Sn-In-based, Sn-Ag-based, Sn-Pb-Ag-based, Pb-Ag-based, and the like, can be appropriately selected according to electrode materials and connection conditions. The melting point of the solder particles is preferably 110°C or more and 180°C or less, more preferably 120°C or more and 160°C or less, and still more preferably 130°C or more and 150°C or less. In addition, for the purpose of activating the surface of the solder particles, a flux compound may be directly bonded to the surface. By activating the surface, metal bonding with the electrode portion 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 preferably 80 wt% or less, more preferably 70 wt% or less, and still more preferably 60 wt% or less. In addition, the lower limit of the volume ratio range of the amount of the solder particles blended is preferably 5 vol% or more, more preferably 10 vol% or more, further preferably 15 vol% or more, and the upper limit of the volume ratio range of the blending amount of the solder particles is , Preferably it is 30 vol% or less, More preferably, it is 25 vol% or less, More preferably, it is 20 vol% or less. The blending amount of the solder particles satisfies the above-described mass ratio range or volume ratio range, whereby excellent conductivity, heat dissipation, and adhesion can be obtained. When the solder particles are present in the binder, the volume ratio may be used, and when the anisotropic conductive bonding material is produced (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 or mixing ratio of the compound. If the amount of the solder particles is too small, excellent conductivity, heat dissipation, and adhesion cannot be obtained, and if the amount is too large, the anisotropy is impaired, and excellent conduction reliability cannot be obtained.

[Flux compound]

The flux compound removes foreign substances or oxide films on the electrode surface, prevents oxidation of the electrode surface, or reduces the surface tension of the molten solder. As a flux compound, it is preferable to use carboxylic acid, such as levulinic acid, maleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, for example. Thereby, a good solder connection can be obtained, and when an epoxy resin is blended, it can function as a curing agent for the epoxy resin.

Further, it is preferable to use a blocked carboxylic acid in which the carboxyl group is blocked with alkyl vinyl ether as the flux compound. Thereby, the temperature at which the flux effect and the curing agent function are exhibited can be controlled. Moreover, since the solubility in resin is improved, it is possible to improve non-uniformity of mixing and application at the time of film formation. In addition, it is preferable that the dissociation temperature at which blocking is released is equal to or higher than the melting point of the solder particles. Thereby, a good solder connection can be obtained, and when an epoxy resin is blended, since curing starts after the flow of the epoxy resin, good solder joint can be obtained.

[Other additives]

In the anisotropic bonding film, in addition to the above-described solid resin, solder particles, and flux compound, various additives can be blended 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 diameter of the inorganic filler, the organic filler, and the metal filler is smaller than the average particle diameter of the solder particles from the viewpoint of connection stability, and, for example, a nano filler of 10 to 1000 nm, a micro filler of 1 to 10 μm, and the like are used. .

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

Examples of the organic filler include acrylic resin, carbon, and core shell particles, and effects such as blocking prevention and light scattering can be obtained by the addition of the organic filler.

Examples of the metal filler include Ni, Cu, Ag, and Au, and these alloys may be used. For example, since the Cu filler forms a complex with an acid, corrosion of an electrode or the like can be prevented. In addition, even if a metal filler contributes to conduction, it does not need to contribute, and the compounding amount of the metal filler may be adjusted to such an extent that a short circuit does not occur including the solder particles.

In addition, in the anisotropic bonding film described above, for example, a solid resin, a solder particle, and a flux compound are mixed in a solvent, and the mixture is applied to a predetermined thickness on a peeling treatment film with a bar coater, and then dried. It can be obtained by volatilizing a solvent. In addition, in order to increase the dispersibility of the solder particles, it is preferable to apply a high shear in a state containing a solvent. For example, a known batch type planetary stirring device can be used. What can be implemented in a vacuum environment may be sufficient. Moreover, the amount of residual solvent of an anisotropic bonding film becomes like this. Preferably it is 2% or less, More preferably, it is 1% or less.

Example

<3.1 First Example>

In Example 1, an LED mounting body was produced using an anisotropic bonding film containing a thermoplastic resin, and the forward voltage, die share strength, and bonding state of the LED mounting body were evaluated.

[Measurement of melt flow rate of solid resin]

According to the method of determining the melt flow rate of plastic plastic according to JIS K7210: 1999, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Jeonggi Co., Ltd.) under conditions of a temperature of 190°C and a load of 2.16 kg. The melt flow rate of the thermoplastic resin AE was measured.

A: Polyester resin, Primaroi A1500 (Mitsubishi Chemical Co., Ltd.), MFR = 11 g/10 min

B: Ethylene acetvinyl copolymer resin, Evaflex EV205WR (Mitsui DuPont Chemical Co., Ltd.), MFR = 800 g/10 min

C: Ethylene acrylic acid copolymer resin, Nucreel N1050H (Dupont Co., Ltd.), MFR = 500 g/10 min

D: Polyamide resin, Griltex D1666A (EMS GRIVORY Co., Ltd.), MFR = 130 g/10 min

E: Phenoxy resin, phenotote YP70 (Shinnittetsu Sumikin Chemical Co., Ltd.), MFR = 1 g/10 min

[Manufacture of LED mounting body]

LED chip (LED chip for Dexerials evaluation, size 45 mil, If = 350 ㎃, Vf = 3.1 V, Au-Sn pad, P electrode and N electrode with pad size 300 µm × 800 µm are formed, respectively, and pad An inter-distance (distance between P electrode and N electrode) 150 µm) and a substrate (a ceramic substrate for Dexerials evaluation, an 18 µm-thick Cu pattern, Ni-Au plating, and an inter-pattern (space) 50 µm) were prepared. The anisotropic bonding film was laminated on the substrate under conditions of 80°C-2 MPa-3 sec, and the LED chip was aligned and mounted, and then the LED chip was mounted by reflow (peak temperature: 260°C).

[Measurement of forward voltage]

The rated current If = 350 mA was made to flow 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 the reading was not made due to the voltage over was called "OPEN".

[Measurement of die share strength]

Using a bonding tester (product number: PTR-1100, manufactured by Lescar), the die share strength of the LED chip was measured at a measurement rate of 20 µm/sec.

[Observation of the junction state]

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

[Measurement of film thickness]

The film thickness was measured at 10 points or more 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 Co., Ltd.), solder particles (42 Sn-58 Bi, Type 6, melting point 139 C, an average particle diameter of 10 µm, Mitsui Metal Co., Ltd.), and titanium oxide (average particle diameter of 0.21 µm, CR-60, Ishihara Industrial Co., Ltd.) were blended in a predetermined mass part to prepare an anisotropic bonding film.

After dispersing the solder particles in a toluene solution in which a thermoplastic resin A, a flux compound, and titanium oxide are mixed and dissolved, peeling PET (PET-02-BU, Shikoku Tosero Co., Ltd.) so that the thickness after drying toluene with a gap coater becomes 20 µm ) Was produced by coating on the top. Toluene drying was carried out under the conditions of 80°C-10 min. The measured value of the film thickness after drying was 20 µm.

In Table 1, the measurement results of the forward voltage and die share strength of the LED mounting body produced using the anisotropic bonding film are shown. The forward voltage was 3.1 V and the die share strength was 40 N/chip.

Fig. 4 is a photomicrograph when the LED chip of Example 1-1 is peeled off and the state of solder bonding on the substrate side is observed. The solder spread and was wet on the LED chip side and the substrate side, and it was a good solder bonding state. In addition, it was confirmed that a plurality of solder bonding points exist 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 mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V and a die share 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 fabricated using the anisotropic bonding film had a forward voltage of 3.0 V and a die share 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 fabricated using the anisotropic bonding film had a forward voltage of 3.0 V and a die share 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 set to 30 µm. The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.1 V and a die share 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 mounting body manufactured using the anisotropic bonding film had an open forward voltage and a die share strength of 19 N/chip.

5 is a photomicrograph when a solder bonding state on the substrate side was observed after the LED chip of Comparative Example 1-1 was peeled off. 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 did not melt.

<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 blended. The LED mounting body manufactured using the anisotropic bonding film had an open forward voltage and a die share strength of 18 N/chip.

6 is a photomicrograph when the state of solder bonding on the substrate side after peeling the LED chip of Comparative Example 1-2 was observed. Since the flux compound was not blended, 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 set to 40 µm. The LED mounting body manufactured using the anisotropic bonding film had an open forward voltage and a die share strength of 25 N/chip.

7 is a photomicrograph when a solder bonding state on the substrate side was observed after peeling the LED chip of Comparative Example 1-3. Since the thickness of the anisotropic bonding film was 40 µm, the pinching between the electrodes of the solder particles was insufficient, the solder bonding was insufficient, and the spot where the solder particles spread and wet only the LED chip side and the spot only on the substrate side were seen.

In Comparative Example 1-1, since 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 electrode of the adherend was not bonded. For this reason, the forward voltage could not be measured. Further, since the resin did not flow sufficiently and no solder bonding was formed, the adhesiveness of the LED chip was weak, and the result was that the die share strength was low.

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

In Comparative Example 1-3, since an anisotropic bonding film having a thickness of 40 µm, which was four times the thickness of the average particle diameter of the solder particles, was used, no solder bonding was formed, and the forward voltage could not be measured. In addition, the die share strength was also low.

On the other hand, in Examples 1-1 to 1-5, a thermoplastic resin AD having a melt flow rate of 1 g/10 min or more was used, and the thickness of 20 to 30 times the average particle diameter of the solder particles was 10 µm. Since an anisotropic bonding film having a thickness of µm was used, the resin melted and flowed, and soldered between the electrodes of the adherend by means of the solder particles, and a value close to the rated voltage of 3.1 V could be obtained. Moreover, the die share strength was also good.

<3.2 Second Example>

In Example 2, an LED mounting body was produced using an anisotropic bonding film containing a radical polymerizable resin, and the forward voltage, insulation, and die share strength of the LED mounting body were evaluated. Fabrication of the LED mounting body, the measurement of the forward voltage of the LED mounting body, and the die share intensity are the same as those of the first embodiment, and thus description thereof is omitted here.

[Measurement of melt flow rate of solid resin]

According to the method of determining the melt flow rate of plastic plastic according to JIS K7210: 1999, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Jeonggi Co., Ltd.) under conditions of a temperature of 190°C and a load of 2.16 kg. The melt flow rate of the thermoplastic resins A to C, E and the solid radical polymerizable resin was measured.

A: Polyester resin, Primaroi A1500 (Mitsubishi Chemical Co., Ltd.), MFR = 11 g/10 min

B: Ethylene acetvinyl copolymer resin, Evaflex EV205WR (Mitsui DuPont Chemical Co., Ltd.), MFR = 800 g/10 min

C: Ethylene acrylic acid copolymer resin, Nucreel N1050H (Dupont Co., Ltd.), MFR = 500 g/10 min

E: Phenoxy resin, phenotote YP70 (Shinnittetsu Sumikin Chemical Co., Ltd.), MFR = 1 g/10 min

Solid radical polymerizable resin: vinyl ester resin, lipoxy VR-90, Showa Denko, MFR = 100 g/10 min

[Evaluation of insulation properties]

A reverse current of 0.1 µA was made to flow through the LED chip through the pattern of the substrate, and the evaluation when no current flows was set as "OK", and the evaluation when the current flowed was set as "NG".

<Example 2-1>

As shown in Table 2, thermoplastic resin A, liquid radical polymerizable resin (hydrogenated bisphenol A diglycidyl ether, Epolite 4000, Kyoeisha Chemical Co., Ltd.), initiator (diacyl peroxide, perhexa 25B, Nichiyu Co., Ltd.), flux compound A (glutaric acid (1,3-propanedicarboxylic acid), Wako Pure Chemical Co., Ltd.), solder particles (42 Sn-58 Bi, Type 6, melting point 139 ℃, average A particle diameter of 10 µm, Mitsui Metal Co., Ltd.), and titanium oxide (average particle diameter of 0.21 µm, CR-60, Ishihara Industrial Co., Ltd.) were blended in a predetermined mass part to prepare an anisotropic bonding film.

A thermoplastic resin A and a liquid radical polymerizable resin are mixed and dissolved with toluene, a flux compound A and titanium oxide are added therein, and dispersed in three rolls (three passes with a gap of 10 μm), and then an initiator and solder A resin solution was obtained by dispersing the particles. This resin solution was applied with a gap coater onto peeling PET (PET-02-BU, Shikoku Tosero Co., Ltd.) so that the thickness after drying of toluene became 20 µm, and produced. Toluene drying was carried out under the conditions of 80°C-10 min.

As shown in Table 2, the LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.1 V, an insulation property of OK, and a die share 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 mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share 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 mounting body manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share 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 a solid radical polymerizable resin was used instead of the thermoplastic resin A. The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share strength of 47 N/chip.

<Example 2-5>

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 B (blocked carboxylic acid, Santaside G, Nichiyu Co., Ltd.) was used instead of the flux compound A. . The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share 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 set to 30 µm. The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.1 V, an insulation property of OK, and a die share strength of 49 N/chip.

<Comparative Example 2-1>

As shown in Table 2, after dissolving thermoplastic resin E with a reactive diluent (tetrahydrofurfuryl acrylate, biscoat #150, Osaka Organic Chemical Co., Ltd.), radical polymerizable resin, initiator, flux compound A, oxidation Anisotropic bonding paste was produced by mixing and dispersing titanium and solder particles.

LED chip (LED chip for Dexerials evaluation, size 45 mil, If = 350 ㎃, Vf = 3.1 V, Au-Sn pad, pad size 300 µm × 800 µm, pad distance 200 µm) and substrate (Dexerials A ceramic substrate for Alz evaluation, an 18 µm-thick Cu pattern, Ni-Au plating, and inter-pattern (space) 50 µm) were prepared. The anisotropic bonding paste was applied onto the substrate using a mask having a thickness of 30 µm, and the LED chips were aligned and mounted, and then the LED chips were mounted by reflow (peak temperature: 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 insulation property of NG, and a die share 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 fabricated by using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share 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 blended. The LED mounting body fabricated by using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share 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 set to 40 µm. The LED mounting body fabricated using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share strength of 26 N/chip.

In Comparative Example 2-1, since thermoplastic resin E having a melt flow rate of 1 g/10 min was used and a paste-like anisotropic bonding material was applied, a short circuit due to solder bonding occurred between 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 electrode was not bonded to the adherend. For this reason, the forward voltage could not be measured. Further, since the resin did not flow sufficiently and no solder bonding was formed, the adhesiveness of the LED chip was weak, and the result was that the die share strength was low.

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

In Comparative Example 2-4, since an anisotropic bonding film having a thickness of 40 µm, which was four times the thickness of the average particle diameter of the solder particles, was used, no solder bonding was formed, and the forward voltage could not be measured. In addition, the die share strength was also low.

On the other hand, in Examples 2-1 to 2-5, a thermoplastic resin AD having a melt flow rate of 1 g/10 min or more was used, and the thickness of 20 to 3 times the average particle diameter of the solder particles was 2 to 3 times. Since an anisotropic bonding film having a thickness of 30 µm was used, the resin melted and flowed, and soldered between the electrodes of the adherend by means of the solder particles, and a value close to the rated voltage of 3.1 V could be obtained. Moreover, the die share strength was also good.

<3.3 Third Example>

In Example 3, an LED mounting body was produced using an anisotropic bonding film containing an epoxy resin, and the forward voltage, insulation, and die share strength of the LED mounting body were evaluated. Since the fabrication of the LED mounting body, the measurement of the forward voltage of the LED mounting body, and the die share strength are the same as in the first embodiment, the evaluation of the insulation properties of the LED mounting body is the same as that of the second embodiment, so the description is omitted here. do.

[Measurement of melt flow rate of solid resin]

According to the method of determining the melt flow rate of plastic plastic according to JIS K7210: 1999, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Jeonggi Co., Ltd.) under conditions of a temperature of 190°C and a load of 2.16 kg. The melt flow rate of the thermoplastic resins A to C, E and the solid epoxy resin was measured.

A: Polyester resin, Primaroi A1500 (Mitsubishi Chemical Co., Ltd.), MFR = 11 g/10 min

B: Ethylene acetvinyl copolymer resin, Evaflex EV205WR (Mitsui DuPont Chemical Co., Ltd.), MFR = 800 g/10 min

C: Ethylene acrylic acid copolymer resin, Nucreel N1050H (Dupont Co., Ltd.), MFR = 500 g/10 min

E: Phenoxy resin, phenotote YP70 (Shinnittetsu Sumikin Chemical Co., Ltd.), MFR = 1 g/10 min

Solid epoxy resin: Bisphenol A type epoxy resin, 1001, Mitsubishi Chemical Co., Ltd., MFR = 2600 g/10 min

<Example 3-1>

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

A thermoplastic resin A and a liquid epoxy resin were mixed and dissolved with toluene, a flux compound A and titanium oxide were added thereto, and dispersed in three rolls (three passes with a gap of 10 μm), and then the curing agent A and the solder particles. The resin solution was obtained by dispersing. This resin solution was applied with a gap coater on a peeling PET (PET-02-BU, Shikoku Tosero Co., Ltd.) so that the thickness after drying of toluene became 20 µm, and produced. Toluene drying was carried out under the conditions of 80°C-10 min.

As shown in Table 3, the LED mounting body produced using the anisotropic bonding film had a forward voltage of 3.1 V, an insulation property of OK, and a die share 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 mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share 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 mounting body manufactured using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share 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 fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share strength of 47 N/chip.

<Example 3-5>

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

<Example 3-6>

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 B (blocked carboxylic acid, Santaside G, Nichiyu Co., Ltd.) was used instead of the flux compound A. . The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share 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 set to 30 µm. The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.1 V, an insulation property of OK, and a die share strength of 49 N/chip.

<Comparative Example 3-1>

As shown in Table 3, an anisotropic bonding paste was produced by mixing and dispersing liquid epoxy resin, curing agent A, flux compound A, titanium oxide, and solder particles.

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

As shown in Table 3, the LED mounting body produced using the anisotropic bonding paste had a forward voltage of 3.0 V, an insulation property of NG, and a die share 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 fabricated by using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share 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 blended. The LED mounting body fabricated by using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share 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 set to 40 µm. The LED mounting body fabricated using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share strength of 26 N/chip.

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

In Comparative Example 3-2, since 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 electrode was not bonded to the adherend. For this reason, the forward voltage could not be measured. Further, since the resin did not flow sufficiently and no solder bonding was formed, the adhesiveness of the LED chip was weak, and the result was that the die share strength was low.

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

In Comparative Example 3-4, since an anisotropic bonding film having a thickness of 40 µm, which was four times the thickness of the average particle diameter of the solder particles, was used, no solder bonding was formed, and the forward voltage could not be measured. In addition, the die share strength was also low.

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

<3.4 Fourth Example>

In Example 4, an LED mounting body was produced using an anisotropic bonding film containing carboxylic acid as a flux compound, and the forward voltage, insulation, and die share strength of the LED mounting body were evaluated. Since the fabrication of the LED mounting body, the measurement of the forward voltage of the LED mounting body, and the die share strength are the same as in the first embodiment, the evaluation of the insulation properties of the LED mounting body is the same as that of the second embodiment, so the description is omitted here. do.

[Measurement of melt flow rate of solid resin]

According to the method of determining the melt flow rate of plastic plastic according to JIS K7210: 1999, using a melt flow rate measuring device (product name: Melt Indexer G-02, manufactured by Toyo Jeonggi Co., Ltd.) under conditions of a temperature of 190°C and a load of 2.16 kg. The melt flow rates of thermoplastic resins A, E and solid epoxy resins were measured.

A: Polyester resin, Primaroi A1500 (Mitsubishi Chemical Co., Ltd.), MFR = 11 g/10 min

E: Phenoxy resin, phenotote YP70 (Shinnittetsu Sumikin Chemical Co., Ltd.), MFR = 1 g/10 min

Solid epoxy resin: Bisphenol A type epoxy resin, 1001, Mitsubishi Chemical Co., Ltd., MFR = 2600 g/10 min

<Example 4-1>

As shown in Table 4, thermoplastic resin A, liquid epoxy resin (bisphenol A type epoxy resin, YL980, Mitsubishi Chemical Co., Ltd.), flux compound A (glutaric acid (1,3-propanedicarboxylic acid), Waco Pure Chemical Co., Ltd.), solder particles (42 Sn-58 Bi, Type 6, melting point 139 ℃, average particle diameter 10 ㎛, Mitsui Metal Co., Ltd.), titanium oxide (average particle diameter 0.21 ㎛, CR-60, Ishihara Industrial Co., Ltd.) )) was blended in a predetermined mass part to prepare an anisotropic bonding film.

By mixing and dissolving the thermoplastic resin A and the liquid epoxy resin with toluene, adding the flux compound A and titanium oxide therein, and dispersing it in three rolls (three passes with a gap of 10 μm), and then dispersing the solder particles. A resin solution was obtained. This resin solution was applied with a gap coater on a peeling PET (PET-02-BU, Shikoku Tosero Co., Ltd.) so that the thickness after drying of toluene became 20 µm, and produced. Toluene drying was carried out under the conditions of 80°C-10 min.

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

<Example 4-2>

As shown in Table 4, the anisotropic bonding film was produced like Example 4-1 except having used the solid epoxy resin instead of the thermoplastic resin A. The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.1 V, an insulation property of OK, and a die share strength of 45 N/chip.

<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 B (blocked carboxylic acid, Santaside G, Nichiyu Co., Ltd.) was used instead of the flux compound A. . The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.0 V, an insulation property of OK, and a die share strength of 44 N/chip.

<Example 4-4>

As shown in Table 4, the anisotropic bonding film was produced like Example 4-1 except having set the thickness of the anisotropic bonding film to 30 micrometers. The LED mounting body fabricated using the anisotropic bonding film had a forward voltage of 3.1 V, an insulation property of OK, and a die share strength of 48 N/chip.

<Comparative Example 4-1>

As shown in Table 4, an anisotropic bonding paste was produced by mixing and dispersing liquid epoxy resin, curing agent A, flux compound B, titanium oxide, and solder particles.

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

As shown in Table 4, the LED mounting body produced using the anisotropic bonding paste had a forward voltage of 3.0 V, an insulation property of NG, and a die share 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 fabricated by using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share 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 blended. The LED mounting body fabricated using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share 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 set to 40 µm. The LED mounting body fabricated by using the anisotropic bonding film had an OPEN net voltage, an OK insulation property, and a die share strength of 25 N/chip.

In Comparative Example 4-1, since a paste-like anisotropic bonding material was applied without mixing a solid resin, a short circuit due to solder bonding occurred between adjacent terminals of the substrate.

In Comparative Example 4-2, since 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 electrode was not bonded to the adherend. For this reason, the forward voltage could not be measured. Further, since the resin did not flow sufficiently and no solder bonding was formed, the adhesiveness of the LED chip was weak, and the result was that the die share strength was low.

In Comparative Example 4-3, since the flux compound was not blended, 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 was four times the thickness of the average particle diameter of the solder particles, was used, no solder bonding was formed, and the forward voltage could not be measured. In addition, the die share strength was also low.

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

In addition, in the above-described examples, a film-like anisotropic bonding material was used, but it is considered that the same result will be obtained when the paste-like anisotropic bonding material is adjusted to a predetermined thickness.

10: LED element
11: first conductivity type electrode
12: second conductivity type electrode
20: substrate
21: first electrode
22: second electrode
30: anisotropic bonding film
31: solder particles
32: anisotropic conductive film
33: solder joint

Claims (13)

At least one solid resin selected from thermoplastic resins, solid radical polymerizable resins, and solid epoxy resins having a melt flow rate of 10 g/10 min or more, which is solid at room temperature and has a melt flow rate of 10 g/10 min or more measured at a temperature of 190° C. and a load of 2.16 kg, and , A solder particle and an anisotropic bonding material containing a flux compound is interposed between the electrode of the first electronic component and the electrode of the second electronic component at a thickness of 50% or more and 300% or less of the average particle diameter of the solder particles,
A method for manufacturing a connection body, wherein the electrode of the first electronic component and the electrode of the second electronic component are heat-bonded with no load. The method of claim 1,
The method for manufacturing a connected body, wherein the anisotropic bonding material is an anisotropic bonding film having a thickness of 50% or more and 300% or less of the average particle diameter of the solder particles. The method of claim 2,
The second electronic component is a substrate,
A method for manufacturing a connected body, wherein the anisotropic bonding film is laminated on the substrate, and a plurality of the first electronic components are mounted on the anisotropic bonding film to be heat-bonded. The method according to any one of claims 1 to 3,
The method for producing a connected body, wherein the flux compound is a carboxylic acid. The method according to any one of claims 1 to 3,
The method for producing a connected body, wherein the flux compound is a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether. At least one solid resin selected from thermoplastic resins, solid radical polymerizable resins, and solid epoxy resins having a melt flow rate of 10 g/10 min or more, which is solid at room temperature and has a melt flow rate of 10 g/10 min or more measured at a temperature of 190° C. and a load of 2.16 kg, and , A solder particle 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 method of claim 6,
The anisotropic bonding material, wherein the flux compound is a carboxylic acid. The method of claim 6,
The anisotropic bonding material, wherein the flux compound is a blocked carboxylic acid in which a carboxyl group is blocked with an alkyl vinyl ether. The method according to any one of claims 6 to 8,
An anisotropic bonding material further containing a liquid radical polymerizable resin in a liquid state at room temperature and a polymerization initiator. The method according to any one of claims 6 to 8,
An anisotropic bonding material further containing a liquid epoxy resin and a curing agent at room temperature. The method of claim 10,
The anisotropic bonding material, 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. The 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. A connection body formed by bonding an electrode of a first electronic component and an electrode of a second electronic component using the anisotropic bonding material according to any one of claims 6 to 11 or the anisotropic bonding film according to claim 12.

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