JPH10275825A - Package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a packaging process by a method, wherein a connection electrode protruding from the one surface of a base is electrically connected to a conductor circuit formed on the other surface of the base, where a semiconductor is connected in a flip-chip connection manner through bonding agent, and the connection electrode is electrically connected to a motherboard through the intermediary of adhesive agent. SOLUTION: A conductor circuit 2, formed on the one surface of a base 3 which is formed of a high-molecular film of polyimide or polyester and mounted with an electronic part 1, such as a semiconductor, is electrically connected to an electrode 7 which is made to protrude from the other surface of the base 3 facing the electrode 7 of a mother board 8 which is formed of the same material with the base 3 through the intermediary of an adhesive agent 5 of thermosetting resin or thermoplastic resin. By this setup, an inner stresses inducing in reliability tests, such as a thermal shock test can be absorbed by the adhesive agent 5, a packaging process is simplified as a result, and a package which is improved in connection reliability is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electrically connecting a connection electrode protruding from the other surface of a base material on a surface of the base material on which an electronic component is mounted to the mother board through an adhesive. The present invention relates to a package that is made conductive.

[0002]

2. Description of the Related Art Conventionally, electronic components such as semiconductors are mounted on an electronic circuit board by a wire bonding method or flip-chip connection using solder bumps. However, in the former method, epoxy resin encapsulation by transfer molding method for the purpose of protecting semiconductor electrodes and wires,
In the latter method, underfill sealing in which epoxy resin with good fluidity is injected into the gap between the semiconductor and the substrate in order to suppress the occurrence of cracks in the solder joint due to thermal stress based on the difference in thermal expansion coefficient between the semiconductor and the substrate. And there is a problem that the packaging process is complicated. Also, when connecting such an electronic circuit board to another electronic circuit board, a solder ball conducting to a conductor circuit on the surface of the substrate on which the electronic component is mounted is provided on the back surface of the package, and the solder ball is melted. A so-called BGA method is used in which the device is electrically connected to a motherboard. Conventionally, when connecting a board on which electronic components such as semiconductors are mounted to a motherboard such as a printed circuit board, solder balls that are electrically connected to conductor circuits on the surface of the board on which the electronic components are mounted are provided on the back of the package, A so-called BGA system in which balls are melted and electrically connected to a motherboard is used.
However, in the conventional BGA method, when a board on which electronic components of a package are mounted is mounted on an electronic component such as a semiconductor, the board is warped due to a stress based on a difference in thermal expansion coefficient from the substrate. However, there is a problem that the solder balls on the back surface of the package and the connection electrodes of the motherboard cannot be sufficiently contacted. In addition, even when contact is made, a package on which electronic components are mounted,
There is a problem that cracks occur in the solder joints due to the stress based on the thermal expansion coefficient difference between the motherboards, resulting in poor connection. Furthermore, the size of the solder ball is 50
There is also a problem that the connection density cannot be increased because of the large size of 0 to 800 microns.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a package having a simple connection process, high connection reliability, and high connection density. It is the purpose.

[0004]

According to the present invention, there is provided a package comprising:
The semiconductor is electrically connected to a conductor circuit on the surface of the substrate flip-chip connected via an adhesive, and the connection electrode protruding from the other surface of the substrate is electrically connected to the motherboard via the adhesive. It is characterized by. The present inventors have found that, unlike a conventional semiconductor package electrically connected by wire bonding or solder balls, a semiconductor is electrically connected to a conductor circuit on the surface of a substrate which is flip-chip connected via an adhesive and the substrate By connecting the connection electrodes protruding from the other surface to the motherboard via an adhesive, the package process that solves the conventional problems is simplified, the connection reliability is high, and a package with a high connection density is found. Was.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The connection electrode 4 that protrudes from the other surface of the substrate 3 that is electrically connected to the conductor circuit 2 on the surface of the substrate 3 on which the electronic component 1 is mounted is a conductor on the surface of the substrate 3 on which the electronic component 1 is mounted. It suffices if it is electrically connected to the circuit 2 and protrudes from the surface as shown in FIG. 1, and a metal having a low electric resistance such as copper, gold, nickel or solder is used as a material of the electrode. This connection electrode 4
Is preferably 100 μm or less in consideration of the thickness of the adhesive and the formability of the protruding electrode.
More preferably, it is 50 microns or less. As the base material 3 and the mother board 8 on which the electronic component 1 of the present invention is mounted, a rigid film made of a polymer film such as polyimide or polyester, or a glass cloth made of polyimide, epoxy or cyanate ester-based resin is used.

As the adhesive 5 of the present invention, an epoxy-based adhesive,
Polyimide, cyanate ester, phenoxy,
Thermosetting resins such as urethane-based, polystyrene-based, and acrylic-based resins and thermoplastic resins can be used, and among them, epoxy-based resins are particularly preferably used because of their excellent adhesiveness and heat resistance. Epoxy resins include bisphenol-type epoxy resins derived from epichlorohydrin and bisphenol A, F, AD, etc., epoxy novolak resins derived from epichlorohydrin and phenol novolak or cresol novolak, and naphthalene rings having a skeleton containing naphthalene rings. Naphthalene-based epoxy resins having a skeletal skeleton, various epoxy compounds having two or more glycidyl groups in one molecule, such as glycidylamine, glycidyl ester, biphenyl, alicyclic, etc., alone or as a mixture of two or more. Can be used. These epoxy resins are mixed with a latent curing agent such as imidazole, hydrazide, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt, dicyandiamide, etc. for the purpose of obtaining fast curing property and storage stability. Is preferred. Examples of the latent curing agent include imidazole-based, hydrazide-based, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt, dicyandiamide, and the like, and modified products thereof. Can be used. In particular, an amine adduct-type latent curing agent obtained by reacting an epoxy compound with an amine compound or an epoxy compound, or an amine compound and an active hydrogen compound, is suitable in terms of rapid curability and storage stability.

The adhesive of the present invention containing an epoxy resin as a main component can be prepared by mixing 1 to 200 parts by weight of a latent curing agent with respect to 100 parts by weight of an epoxy resin. The adhesive preferably has a low modulus of elasticity in absorbing or relaxing the thermal stress of the connection part generated in an environment such as a thermal shock test, and the elastic modulus at 40 ° C. after bonding in consideration of the melt viscosity. However, an adhesive having a pressure of 100 to 2000 MPa is particularly suitable. The elastic modulus at 40 ° C. after bonding is 100 to 200.
In order to obtain 0 MPa, the adhesive has a molecular weight of 2
More than 100,000 acrylic rubbers can be compounded. If the compounding amount of the rubber component increases, the elastic modulus decreases, which is effective in relieving internal stress. However, the holding force between the connection electrodes becomes insufficient, and if it exceeds 40 wt%, the melt viscosity at the time of connection increases. In order to prevent electrical conduction between the connection electrodes, the rubber component is preferably blended at about 15 to 40 tw%. Also,
A thermoplastic resin such as a phenoxy resin can be added to the adhesive 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.

In the adhesive 5 of the present invention, conductive particles 6 can be dispersed for the purpose of positively imparting anisotropic conductivity in order to absorb variations in height of the connection electrodes. In the present invention, the conductive particles 6 include, for example, Au, Ni, Ag, Cu,
Metal particles such as W and solder or metal particles formed by plating or vapor-depositing a thin film such as gold or palladium on the surface of these metal particles. Ni, Cu, Au Alternatively, conductive particles provided with a conductive layer such as solder can be used. The particle size must be smaller than the minimum distance between the electrodes on the substrate, and if there is a variation in the height of the electrodes, it is preferably larger than the variation in height, and more preferably 1 μm to 10 μm. The amount of the conductive particles dispersed in the adhesive is 0.01 to 30% by volume, and preferably 0.1 to 15% by volume. The film adhesive of the present invention is formed by dissolving or dispersing an adhesive composition comprising an epoxy resin, a phenoxy resin, a latent curing agent, and conductive particles in an organic solvent or by dispersing the adhesive composition on an exfoliable substrate. This is performed by removing the solvent below the activation temperature of the curing agent.

The connection by the adhesive 5 can be performed by heating and pressing. For example, the connection electrodes 4 protruding from the other surface of the base material on which the conductive circuits on the surface of the base material on which the electronic components are mounted are electrically connected to the electrodes 7 of the motherboard are bonded with an adhesive 5.
From the substrate side on which the electronic components are mounted.
Electrical conduction can be achieved by heating and pressing at 80 ° C., 30 kg / cm ² for 20 seconds.

[0010]

As described above, according to the present invention, unlike the conventional package electrically connected by the solder balls, the other of the base which is electrically connected to the conductor circuit on the surface of the base on which the electronic component is mounted. Since the connection electrodes protruding from the surface are electrically connected to the motherboard via an adhesive, the adhesive can absorb internal stress generated in reliability tests such as thermal shock tests, resulting in improved connection reliability. An improved package is obtained. Further, since the projecting electrodes can be made smaller than conventional solder balls, a package having a high connection density can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a package of the present invention.

[Explanation of symbols]

 1. Electronic components 2. 2. Conductor circuit Base material 4. Connection electrode 5. Adhesive 6. Conductive particles 7. Electrode 8. Motherboard

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Noriyuki Taguchi 48 Wadai, Tsukuba, Ibaraki Prefecture, Hitachi Chemical Co., Ltd. Inside Tsukuba Development Laboratory Co., Ltd. Tsukuba Development Laboratory

Claims (4)

[Claims] 1. A connection electrode, which is electrically connected to a conductor circuit on a surface of a substrate to which a semiconductor is flip-chip connected via an adhesive and protrudes from the other surface of the substrate, is electrically connected to a motherboard via the adhesive. A package characterized by being electrically connected to the package. 2. The elastic modulus at 40 ° C. after bonding of the adhesive is
The package according to claim 1, wherein the pressure is 100 to 2000 MPa. 3. The package according to claim 1, wherein the projecting height of the projecting connection electrode from the substrate surface is 100 μm or less. 4. The package according to claim 1, which is an anisotropic conductive adhesive in which 0.01 to 30 vol% of conductive particles are dispersed.