JP2004039350A - Conductive connection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive connection structure that realizes high connection reliability and high density mounting in the conductive connection structure in which a semiconductor chip or a semiconductor package and a wiring board, and a semiconductor chip and a semiconductor package substrate are connected. <P>SOLUTION: This is the conductive connection structure in which the semiconductor chip or the semiconductor package and the wiring board are electrically connected. In the conductive connection structure, two or more conductive particulates are arranged and connected between the electrode of the above semiconductor chip or semiconductor package and the electrode of the above wiring board connected to this. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a conductive connection structure realizing high connection reliability and high-density mounting.
[0002]
[Prior art]
Conventionally, in an electronic circuit board, the connection between a semiconductor chip or a semiconductor package and a wiring board, and the connection between a semiconductor chip and a semiconductor package have been performed by soldering respective electrodes, but the production efficiency is poor, It was not suitable for high density.
In order to solve this problem, techniques such as a ball grid array (BGA) in which solder is made spherical, and connection is made using conductive fine particles such as so-called solder balls, have been developed. According to this technology, high productivity and high connection reliability are achieved by melting and connecting, at a high temperature, conductive fine particles arranged between a semiconductor chip or a semiconductor package and a wiring board, and between a semiconductor chip and a semiconductor package. A circuit can be configured.
[0003]
In recent years, electronic components have been required to be mounted at a higher density. In BAG, the distance between a semiconductor chip or a semiconductor package and a wiring board and the distance between a semiconductor chip and a semiconductor package are determined by the size of conductive fine particles. A method for reducing the height of a connection part by performing connection has been studied.
[0004]
In a conventional BGA, one conductive fine particle is arranged on one electrode. However, when only one conductive fine particle is arranged on the electrode, the variation in the interval between the connection parts increases, and the connection reliability tends to decrease. In particular, when conductive fine particles having a small particle diameter are used, the area that is conductively connected by the conductive fine particles is reduced, and the variation in the interval is relatively large, so that the connection reliability is reduced. This has been a major problem in reducing the height of the connection.
Further, when solder balls are used as the conductive fine particles, there is a problem that the solder may be cracked by stress due to a difference in linear expansion coefficient between the semiconductor chip, the semiconductor package, and the wiring board due to a temperature change.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has as its object to provide a conductive connection structure that achieves high connection reliability and high-density mounting.
[0006]
[Means for Solving the Problems]
The present invention 1 is a conductive connection structure formed by electrically connecting a semiconductor chip or a semiconductor package and a wiring board, wherein the conductive connection structure includes electrodes of the semiconductor chip or the semiconductor package and electrodes of the wiring board connected thereto. This is a conductive connection structure in which two or more conductive fine particles are arranged and connected therebetween.
The present invention 2 is a conductive connection structure formed by electrically connecting a semiconductor chip and a semiconductor package, wherein two or more electrodes are provided between the electrodes of the semiconductor chip and the electrodes of the semiconductor package connected thereto. This is a conductive connection structure in which conductive fine particles are arranged and connected.
Hereinafter, the present invention will be described in detail.
[0007]
The conductive connection structure according to the first aspect of the present invention electrically connects a semiconductor chip or a semiconductor package to a wiring substrate, and the conductive connection structure according to the second aspect of the present invention electrically connects a semiconductor chip and a semiconductor package. It is connected to.
The above connection is performed by connecting electrodes of a semiconductor chip, a semiconductor package, or a wiring board via two or more conductive fine particles.
FIG. 1 shows a state in which two or more conductive fine particles are arranged on electrodes of a semiconductor chip, a semiconductor package or a wiring board, and FIG. 2 shows a state of a connection portion in one embodiment of the conductive connection structure of the present invention. Was.
[0008]
By arranging and connecting two or more conductive fine particles between a pair of electrodes, connection reliability is improved as compared with a case where only one conductive fine particle is used for connection, and a conductive material having a small particle diameter is used. Even if the height of the connection portion is reduced by using fine particles, sufficient connection reliability can be obtained.
[0009]
Examples of the conductive fine particles include solder balls, copper spheres, and fine particles of resin whose surface is covered with one or more metal layers. Among them, those in which the surface of the base particles made of resin are covered with one or more metal layers are preferable. By using such conductive fine particles, the spacing between the semiconductor chip or the semiconductor package and the wiring board, the distance between the semiconductor chip and the semiconductor package can be kept constant, and the temperature change Accordingly, high connection reliability can be maintained even when stress is applied due to a difference in linear expansion coefficient between the semiconductor chip, the semiconductor package, and the wiring board.
[0010]
As the base fine particles, for example, phenol resin, amino resin, acrylic resin, ethylene-vinyl acetate resin, styrene-butadiene block copolymer, polyester resin, urea resin, melamine resin, alkyd resin, polyimide resin, urethane resin, Thermoplastic resins such as epoxy resins; curable resins; cross-linked resins such as divinylbenzene copolymers; and organic-inorganic hybrid polymers. Among these, a crosslinked resin is preferred from the viewpoint of heat resistance.
[0011]
The metal layer is not particularly limited, but includes, for example, gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, cadmium, silicon, and the like. And those consisting of These metals may be used alone or in combination of two or more.
[0012]
The metal layer may be composed of one layer, or may be composed of multiple layers. When the metal layer has a multilayer structure, the metal layer may be made of a different metal. For example, there is a configuration in which a nickel layer is provided on fine particles of a base material, and a copper layer or a tin layer is further provided thereon.
[0013]
Although the thickness of the metal layer is not particularly limited, a preferable lower limit is 0.01 μm and an upper limit is 500 μm from the application such as conductive connection and substrate bonding. If the thickness is less than 0.01 μm, sufficient conductivity may not be obtained. If the thickness is more than 500 μm, coalescence of the conductive fine particles may occur, the distance between the substrates may be maintained, and the force applied to the circuit such as the substrate may be reduced. The ability to mitigate may be poor.
[0014]
The particle diameter of the conductive fine particles is smaller than the diameter of an electrode of a semiconductor chip, a semiconductor package, or a wiring board, and is a size that can be arranged on the electrode.
The conductive fine particles preferably have a particle size CV value of 5% or less. If it exceeds 5%, the particle diameters become uneven, so that large conductive fine particles may not pass through the nozzle 4 smoothly, or small conductive fine particles may not reach the electrodes, resulting in poor connection. It is more preferably at most 2%, further preferably at most 1%.
The above CV value is obtained by the following equation.
CV value (%) = (σ / Dn) × 100
In the formula, σ represents the standard deviation of the particle diameter, and Dn represents the number average particle diameter.
Since ordinary fine particles have a large CV value, the conductive fine particles used in the present invention need to have a uniform particle diameter by classification or the like. In particular, since it is difficult to classify fine particles having an average particle diameter of 200 μm or less with high accuracy, it is preferable to combine a sieve, airflow classification, wet classification, and the like.
[0015]
The method of the connection is not particularly limited, for example, an adhesive is applied on one of the electrodes of the semiconductor chip, the semiconductor package or the wiring board, and small conductive fine particles having a particle diameter are sprayed thereon, After removing the conductive fine particles which are not adhered to the electrode with an adhesive, a method of facing a semiconductor chip, a semiconductor package or a wiring substrate on which the conductive fine particles are not arranged, and connecting the semiconductor chip, the semiconductor package or the wiring substrate by using a reflow device is exemplified.
[0016]
The conductive connection structure of the present invention has a higher connection reliability than a case where connection is made using only one conductive fine particle, and is a case where conductive fine particles having a small particle diameter are used. Also, high connection reliability can be realized. Therefore, by using the conductive fine particles having a small particle diameter, the height of the connection portion can be reduced, and high-density mounting can be realized. When the conductive fine particles are made of a resin whose base material fine particles are covered with one or more metal layers, the distance between the semiconductor chip or the semiconductor package and the wiring board, or the distance between the semiconductor chip and the semiconductor package is reduced. Can be kept constant, and high connection reliability can be maintained even when stress is applied due to a difference in linear expansion coefficient between the semiconductor chip, the semiconductor package, and the wiring board due to a temperature change.
[0017]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
[0018]
(Example 1)
A diameter of a semiconductor package having 10 electrodes having a diameter of 400 μm, each having a nickel plating layer, a copper plating layer, and a solder plating layer formed on the outermost layer of fine particles of a base material composed of a copolymer of styrene and divinylbenzene. Ten to thirteen conductive fine particles of 100 μm were arranged.
[0019]
The semiconductor package having the conductive particles mounted on each of the obtained electrodes was soldered on the electrodes using a reflow apparatus, mounted on a wiring board, and reflowed again to electrically connect the semiconductor package and the wiring board. The solder paste was applied to the wiring board by screen printing before mounting the semiconductor package.
As a result of measuring the distance between the semiconductor package and the wiring board for the ten conductive connection structures manufactured as described above, the average was 103 μm and the standard deviation was 0.8 μm.
【The invention's effect】
According to the present invention, it is possible to provide a conductive connection structure that achieves high connection reliability and high-density mounting.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a state in which two or more conductive fine particles are arranged on one electrode.
FIG. 2 is a schematic view showing a state of a connection portion in one embodiment of the conductive connection structure of the present invention.

Claims (3)

A conductive connection structure formed by electrically connecting a semiconductor chip or a semiconductor package and a wiring board,
A conductive connection structure, wherein two or more conductive fine particles are arranged and connected between the electrode of the semiconductor chip or the semiconductor package and the electrode of the wiring board connected thereto. A conductive connection structure formed by electrically connecting a semiconductor chip and a semiconductor package,
A conductive connection structure, wherein two or more conductive fine particles are arranged and connected between an electrode of the semiconductor chip and an electrode of the semiconductor package connected thereto. 3. The conductive connection structure according to claim 1, wherein the conductive fine particles are obtained by covering the surface of base resin fine particles made of a resin with one or more metal layers.

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