JP2000133918A - Method of packaging circuit member and adhesive for circuit member packaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of packaging an electronic component, which uses an anisotropic conductive adhesive by the tare weight only of the electronic component without particularly pressuring the adhesive. SOLUTION: Ni grains (10 μm ϕ, 8 vol.%) with the surfaces covered with an Sn-Bi alloy (a melting point of 139 deg.C) are dispersed in a phenolic curing system thermosetting adhesive of a gelation temperature of 160 deg.C and after an anisotropic conductive adhesive obtained by the above dispersion is applied on a glass epoxy circuit board, a BGA package (225 pins) is aligned with the circuit board and thereafter, the package is mounted on the circuit board and after the circuit board is put in a heating furnace for one minute, the circuit board is cured in an oven for three hours to obtain a packaged component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a circuit member for bonding and fixing a semiconductor chip to a substrate by an adhesive, for example, by a flip chip mounting method, and electrically connecting both electrodes, and a method for connecting a circuit member. For adhesives.

[0002]

2. Description of the Related Art In the field of semiconductor mounting, flip chip mounting, in which an IC chip is directly mounted on a printed circuit board or a flexible wiring board, has been attracting attention as a new mounting mode corresponding to cost reduction and high precision. As a flip-chip mounting method, a method of providing a solder bump on a terminal of a chip and performing solder connection or a method of performing electrical connection via a conductive adhesive is known. In these methods, there is a problem in that when exposed to various environments, stress based on the difference in thermal expansion coefficient between the chip to be connected and the substrate is generated at the connection interface and connection reliability is reduced. For this reason, a method of injecting an epoxy resin-based underfill material into a gap between a chip and a substrate is generally studied for the purpose of reducing stress at a connection interface. However, there is a problem that the underfill injection step complicates the process and is disadvantageous in terms of productivity and cost. In order to solve such a problem, flip-chip mounting using an anisotropic conductive adhesive having anisotropic conductivity and a sealing function has recently attracted attention from the viewpoint of process simplicity.

[0003]

Since mounting with an anisotropic conductive adhesive requires heat and pressure, it cannot be mounted on the back side of the substrate and other electronic components must be mounted. There are restrictions such as the fact that it must be performed at the beginning of the component mounting process, and an inefficient mounting process has been adopted in which, after thermocompression bonding, a reflow process is performed together with other electronic components.
The present invention provides a circuit member mounting method and a circuit member connection adhesive, which are simultaneously mounted with other electronic components and are collectively heat-cured by heat treatment and obtain electrical conduction between electrodes of the circuit members. Things.

[0004]

According to the method of mounting a circuit member of the present invention, the circuit member is mounted on a mounting board provided with a terminal (b) corresponding to the terminal (a) of the circuit member.
(B) is mounted oppositely with an adhesive therebetween, and is a method for mounting a circuit member for electrically connecting the terminals (a) and (b) by heating, wherein the adhesive comprises a matrix resin and a fusible metal surface. And the terminals (a) and (b) are electrically connected by the melted and deformed metal particles, and the matrix resin is melted and deformed by the heating. The heating step has a viscosity that does not hinder the electrical connection of the terminals (a) and (b) by the metal particles.

[0005] The mounting method of the present invention realizes mounting of a circuit member via an adhesive by the weight of the circuit member without applying special pressure. In the above method for mounting a circuit member, the matrix resin is a thermosetting resin, and after the terminals (a) and (b) are electrically connected by heating, the matrix resin is heated and cured at a temperature at which the metal particles do not melt. Can be In the above method for mounting a circuit member, the matrix resin is a thermosetting resin, and after the terminals (a) and (b) are electrically connected by heating, the matrix resin is heated and cured at a temperature at which the metal particles melt. You can do so.

In the adhesive for mounting a circuit member of the present invention, the circuit member is provided such that the terminals (a) and (b) face a mounting substrate provided with terminals (b) corresponding to the terminals (a) of the circuit member. An adhesive for mounting a circuit member for electrically connecting the terminals (a) and (b) and including a matrix resin and metal particles having an easily fusible metal surface, wherein the metal particles are heated by heating. The terminals (a) and (b) are electrically connected by melt-deformed and melt-deformed metal particles, and the matrix resin is electrically connected to the terminals (a) and (b) by the melt-deformed metal particles. It is characterized by having a viscosity which does not hinder the connection in the heating step.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the metal particles having a fusible metal surface used in the present invention, Sn, Bi, In, A
g, Sb, Cu, Zn, Ni, Au, Mg, Ga and A
1 is a metal material selected from the group consisting of one metal or two or more metals, and the melting point of the conductive fine particles is preferably 250 ° C. or less, more preferably 100 ° C. or less.
It is higher than or equal to 190 ° C. The metal particle surface layer may be a fusible metal.

The adhesive used in the present invention is a UV curing system, a curing agent system that generates free radicals upon heating, a thermosetting epoxy resin, or a mixture thereof. Benzoin ethers such as benzoin ethyl ether and isopropyl benzoin ether, benzyl, benzyl ketals such as hydroxycyclohexyl phenyl ketone, benzophenone,
There are ketones such as acetophenone and derivatives thereof, thioxanthones, bisimidazoles, and the like.If necessary, sensitizers such as amines, sulfur compounds, and phosphorus compounds may be added to these photoinitiators at any ratio. Is also good.

The curing agent which generates free radicals upon heating is one which decomposes upon heating of a peroxide compound, an azo compound or the like to generate free radicals, and has a desired connection temperature, connection time, pot life and the like. Is selected as appropriate. The compounding amount is about 0.05 to 10% by weight, and more preferably 0.1 to 5% by weight. Specifically, it can be selected from diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, silyl peroxide and the like. Further, in order to suppress the corrosion of the connection terminal of the circuit member, the chlorine ion and the organic acid contained in the curing agent are preferably 5000 ppm or less,
Further, those having less organic acid generated after thermal decomposition are more preferable. Specifically, it is selected from peroxyesters, dialkyl peroxides, hydroperoxides, and silyl peroxides, and is more preferably selected from peroxyesters having high reactivity. These can be used by mixing as appropriate. A microcapsule obtained by coating these curing agents with a polyurethane-based or polyester-based polymer substance or the like is preferable because the pot life is extended.

The radically polymerizable substance used in the present invention is a substance having a functional group capable of being polymerized by a radical, such as acrylate, methacrylate, and maleimide compound. The radical polymerizable substance can be used in any state of a monomer and an oligomer, and the monomer and the oligomer can be used in combination.

The epoxy resin used in the present invention includes a bisphenol type epoxy resin derived from epichlorohydrin and bisphenol A, F, AD, etc., an epoxy novolak resin derived from epichlorohydrin and phenol novolak or cresol novolak, and a naphthalene ring. Naphthalene epoxy resin having a skeleton, glycidylamine, glycidyl ether, biphenyl, various epoxy compounds having two or more glycidyl groups in one molecule, such as alicyclic, are used alone or in combination of two or more. It is possible. It is preferable to use a high-purity epoxy resin in which impurity ions (Na +, Cl −, etc.), hydrolyzable chlorine and the like are reduced to 300 ppm or less for preventing electron migration. The epoxy resin is preferably a trifunctional or higher-functional polyfunctional epoxy resin and / or a naphthalene-based epoxy resin in order to reduce the coefficient of thermal expansion and improve the glass transition temperature. Examples of the trifunctional or higher polyfunctional epoxy resin include a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a trishydroxyphenylmethane type epoxy resin, a tetraphenylolethane type epoxy resin, and a dicyclopentadiene phenol type epoxy resin. Further, the naphthalene epoxy resin has a skeleton containing at least one naphthalene ring in one molecule,
There are naphthol type, naphthalene diol type and the like.

A necessary amount of a rubber component such as an acrylic rubber may be added to the adhesive. As the acrylic rubber, a polymer containing at least one of acrylic acid, acrylic ester, methacrylic ester and acrylonitrile as a monomer component is used. Copolymers or copolymers can be mentioned, and among them, copolymer acrylic rubber containing glycidyl acrylate or glycidyl methacrylate containing a glycidyl ether group is preferably used. In addition, a thermoplastic resin such as a phenoxy resin can be blended with the adhesive in order to make the film formability easier. In particular, the phenoxy resin is preferable because it has a similar structure to the epoxy resin, and has characteristics such as excellent compatibility with the epoxy resin and excellent adhesiveness.

As a curing agent for the epoxy resin, a latent curing agent such as an imidazole-based compound, a hydrazide-based compound, a boron trifluoride-amine complex, an aromatic sulfonium salt, an amine imide, a polyamine salt, or dicyandiamide is used. From the viewpoint, it is effective, and an acid anhydride-based curing agent is also effective because it has less ionic impurities. The reflow treatment according to the present invention is performed by the whole heating method such as infrared ray, air, vapor phase (VPS), nitrogen, etc.
It is a partial heating method such as laser, semiconductor laser, xenon lamp, halogen lamp, pulse heater, hot air and the like.

The technique for arranging metal particles of the present invention includes, for example, JP-A-6-163550 and JP-A-6-310.
No. 515, for example, are disclosed in
In the technique described in Japanese Patent No. 163550, a closed space is formed on a glass jig having a large number of through-holes having different diameters on both sides, and a solder ball can be mounted on a surface having a large-diameter hole. Is sent to the closed space by compressed air, and is sucked from the small-diameter hole of the glass jig, so that the solder balls are sucked and arranged in the large-diameter through-hole of the glass jig. Also, Japanese Patent Application Laid-Open No. Hei 6-31051
In the technique described in Japanese Patent Application Laid-Open No. 5 (1999) -1995, solder balls are supplied by a screw feeder or the like on a plate on which solder balls can be mounted in a fixed number, and are vibrated and arranged by a vacuum pump and a vibrator. Also, a method in which suction holes are provided at desired intervals in the mounting head, and the mounting head is moved up and down to vacuum-adsorb the conductive balls and move the mounting head onto a sheet to be arranged, and then release and arrange the suction. And a method using a mesh. These techniques may be used. Further, the adhesive film may have a multilayer structure of a support layer and an adhesive layer, in which case, the steps of adhesive layer coating → drying → support layer coating → curing → adhesive layer coating → drying may be performed. . Regarding the spraying of the conductive fine particles, if the electrostatic force is used, surplus particles can be collected, and efficient spraying can be performed.

In the present invention, when formed into a film, the surface of the conductive fine particles is desirably exposed from the front and back surfaces of the film, and the surface of the film is desirably provided with an adhesive force. In addition, since the conductive fine particles need to have a particle size smaller than the minimum distance between the electrodes of the substrate, the conductive fine particles may be deformed into a predetermined shape as needed. The amount of the conductive particles dispersed in the adhesive is 0.1 to 3 with respect to 100 parts by volume of the adhesive resin composition.
0 parts by volume, preferably 0.2 to 15 parts by volume.

The adhesive for connecting circuit members used in the present invention may be a screen-printed liquid adhesive instead of a film adhesive, which is used on the electrodes of the circuit board. As a circuit member, a semiconductor package (QFP, BGA, C
SP, SOP, TCP, etc.), chip components such as capacitors, resistors, and coils, connectors, and the like are used. The circuit member is provided with a large number of terminals, and the circuit member is mounted on a mounting board provided with a large number of terminals corresponding to the terminals via an adhesive with the terminals facing each other, and the terminals are electrically connected. Implemented. As a substrate on which chip components are mounted, an organic insulating substrate on which electrodes (connection terminals) corresponding to semiconductor chip terminals are formed is used.

As the organic insulating substrate, a synthetic resin film such as a polyimide resin or a polyester resin, or a glass substrate such as a glass cloth or a glass nonwoven fabric is impregnated with a resin such as a polyimide resin, an epoxy resin, or a phenol resin and cured. Laminated boards are used. An electrode connected to a circuit member terminal, a surface insulating layer on which the electrode is formed, a predetermined number of insulating layers, a predetermined number of wiring layers arranged via the respective insulating layers, and a predetermined number of the electrode / wiring layers. A multilayer wiring board having electrically conductive holes for electrical connection can be used. As such a multilayer wiring board, a build-up multilayer in which insulating layers and conductive circuit layers are alternately formed on a substrate composed of insulating layers using glass cloth or a wiring board having one or more conductive circuits. Substrates are preferred.

As the surface insulating layer, a resin film can be used. This resin film is made of an epoxy resin, a polyimide resin, a polyamideimide resin, a modified polyphenylene ether resin, a phenoxy resin, an amide epoxy resin, a phenol resin or a mixture thereof. Films of polymers and the like, and films of heat-resistant thermoplastic engineering plastics such as polysulfone, polyethersulfone, polyetheretherketone, wholly aromatic liquid crystal polyester, and fluororesin can be used. A resin film containing an organic or inorganic filler can be used. As the insulating layer made of a resin reinforced with a glass base material, a prepreg obtained by impregnating a glass base material such as a glass cloth or a nonwoven fabric with a resin such as an epoxy resin or a phenol resin and curing the resin can be used.

On an electrode pad of a semiconductor chip or a substrate,
The tip of the bump or gold wire formed by plating is melted with a torch or the like to form a gold ball, and after this ball is pressed on an electrode pad, a protruding electrode such as a wire bump obtained by cutting the wire is provided. It can be used as a connection terminal.

FIG. 1 shows a QFP using the mounting method of the present invention.
FIG. 2 is a cross-sectional view in which the package is mounted on a mounting board, and FIG. 2 is a cross-sectional view in which the CSP package is mounted on the mounting board using the mounting method of the present invention. 1 is a mounting board, 2 is an electrode on the board, 3 is a QFP package, 4 is a lead terminal, 5 is N
i particles, 6 an Sn—Bi alloy, 7 an adhesive, 8 a semiconductor element, 9 a sealant, 10 an interposer, and 11 solder balls.

[0021]

EXAMPLE An Sn-Bi alloy (melting point 13) was formed on the surface of Ni particles.
9 ° C.) is dispersed in a phenol-curing thermosetting adhesive having a gelling temperature of 160 ° C., applied on a glass-epoxy circuit board, and then dispersed in a BGA package (225 pins). ) Is mounted after alignment, passed through a heating furnace (max. 150 ° C.) for 1 minute, then checked for continuity, the NG sample is repaired and reconnected, and the OK sample is placed in a 200 ° C. oven for 3 hours. Cured to obtain a mounted component. Heat cycle test (-55 ° C to 125 ° C), high temperature and high humidity test (85 ° C / 85
% RH). The viscosity of the phenol-cured thermosetting adhesive was 1,000 CP in a heating furnace (max. 150 ° C.).

[0022]

According to the mounting method of the present invention, mounting of an electronic component using an anisotropic conductive adhesive can be realized only by the weight of the electronic component without applying special pressure, and other electronic components can be realized. In addition, heat curing can be performed at the same time as the mounting, and electrical conduction between the electrodes of the circuit members can be obtained, so that the mounting process can be simplified and the cost can be significantly reduced. In addition, it is possible to provide an inspection step and a repair step between the electrical connection step and the mechanical connection step as needed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in which a QFP package is mounted on a mounting board using the mounting method of the present invention.

FIG. 2 is a cross-sectional view in which a CSP package is mounted on a mounting board using the mounting method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2 Electrode on board 3 QFP package 4 Lead terminal 5 Ni particle 6 Sn-Bi alloy 7 Adhesive 8 Semiconductor element 9 Sealant 10 Interposer 11 Solder ball

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenzo Takemura 48 Wadai, Tsukuba-shi, Ibaraki F-term in Tsukuba Development Laboratory, Hitachi Chemical Co., Ltd. (Reference) 5E319 AA03 AB01 AB05 AC01 BB04 BB11 BB16 CC12 CD29 5F044 LL07 LL13

Claims (4)

[Claims] A circuit member is mounted on a mounting board provided with a terminal (b) corresponding to the terminal (a) of the circuit member, with the terminals (a) and (b) facing each other via an adhesive, and heated. A method of mounting a circuit member for electrically connecting the terminals (a) and (b), wherein the adhesive includes a matrix resin and metal particles having an easily fusible metal surface; The terminals (a) and (b) are electrically connected by metal particles that are melt-deformed and melt-deformed, and the matrix resin is electrically connected to the terminals (a) and (b) by the melt-deformed metal particles. A method for mounting a circuit member, wherein the heating step has a viscosity that does not hinder connection. 2. The method for mounting a circuit member according to claim 1, wherein the matrix resin is a thermosetting resin, and after the terminals (a) and (b) are electrically connected by heating, the metal particles are melted. A method for mounting a circuit member, wherein the matrix resin is heated and cured at a temperature not to be applied. 3. The method for mounting a circuit member according to claim 1, wherein the matrix resin is a thermosetting resin, and after the terminals (a) and (b) are electrically connected by heating, the melting of the metal particles is performed. A method for mounting a circuit member, which heats and cures the matrix resin at a desired temperature. 4. The circuit member is mounted on a mounting board provided with a terminal (b) corresponding to the terminal (a) of the circuit member so that the terminals (a) and (b) face each other. b) an adhesive for mounting a circuit member for electrical connection, comprising: a matrix resin and metal particles having an easily fusible metal surface, wherein the metal particles are melt-deformed by heating and are formed by melt-deformed metal particles. The terminals (a) and (b) are electrically connected, and the matrix resin has a viscosity that does not hinder the electrical connection of the terminals (a) and (b) by the melt-deformed metal particles. An adhesive for mounting a circuit member, characterized in that the adhesive has: