JPH11204572A - Mounting structure of semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce stresses applied to an electrode pad for a circuit board through pressure loading by mounting facedown a semiconductor element on the circuit board, in which a bump is formed onto the electrode pad for the circuit board through the use of a connecting material such as gold, solder, etc., by a wire bumping method. SOLUTION: A bump 1 is formed onto an electrode pad 2 for a circuit board 3 through a wire bumping method by employing an electrical connecting material such as gold, solder, etc., and the upper section of the circuit board 3 is filled with an anisotropic conductive encapsulating resin 4. The mean value and dispersion of the contact area of the electrode pad 2 for the circuit board 3 and the bump 1 depend upon the ball shape of wire bumping and the contact area of the electrode pad 2 for the circuit board 3 at that time. An electrode pad 6 for a semiconductor element 5 is loaded at the specified place of the bump 1 on the circuit board 3, while being pressed facedown. The bump 1 is plastically deformed at the time of the contact of the electrode pad 6 for the semiconductor element 5 and the bump 1, and the dispersion in height can be absorbed at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device mounting method and a mounting structure for mounting a semiconductor element face down on a circuit board.

[0002]

2. Description of the Related Art In recent years, notebook computers and mobile phones have been
There is an increasing need for high-density packaging in information devices such as HS, PDA, movie, and camera. In order to cope with this, the so-called bare chip mounting method, in which the semiconductor element is directly mounted on a circuit board, is becoming the mainstream, instead of the conventional method of mounting a packaged product.

The conventional bare chip mounting method is a method of bonding a semiconductor element to a circuit board face-up and connecting the semiconductor element and pads of the circuit board by a wire bonding method.

The conventional bare chip mounting structure requires a pad area for wire bonding and a wiring length by wire bonding in addition to the area of the semiconductor element. On the other hand, a method of adhesively connecting a semiconductor element to a circuit board face down using solder, gold, a conductive adhesive, an anisotropic conductive film, or the like as an electrical connection material (Flip Chip)
Attach: FCA) is the ultimate high-density mounting method because the required mounting area on the circuit board is the chip size and the connection wiring length is several tens of μm.

In the conventional mounting method of the FCA, a protruding electrode (bump) is formed on an electrode pad of a semiconductor element, and the bump is mounted on a circuit board face down and pressurized simultaneously with the bump of the semiconductor element and the electrode pad of the circuit board. In this method, an electric connection between the semiconductor element and the circuit board is filled with a sealing resin such as an anisotropic conductive film or a filling resin and the mixture is heated and cured for the purpose of securing electrical connection and improving connection reliability.

[0006]

The connection portion of the FCA has a variation in the height of the bump of the semiconductor element and the electrode pad of the circuit board, and a variation in the contact area between the bump and the electrode pad of the circuit board. , The pressure variation corresponding to the height variation and the contact area variation of the bump and the electrode pad of the circuit board is applied to the electrode pad of the circuit board,
The electrode pad portion of the circuit board to which the maximum stress has been applied sometimes has a problem that the electrode pad may be cracked by exceeding the tensile strength of the electrode pad of the circuit board, resulting in poor connection reliability.

[0007] An object of the present invention is to solve the above problems.
A semiconductor device that reduces the stress applied to the electrode pads on the circuit board due to the pressure applied when the semiconductor element is mounted face down on the circuit board, and improves the connection reliability without cracking the electrode pads on the circuit board To provide a structure.

Another object of the present invention is to reduce a stress applied to an electrode pad of a circuit board by a pressing force applied when a semiconductor element is mounted face down on a circuit board,
An object of the present invention is to provide a method of manufacturing a mounting structure of a semiconductor device in which connection reliability is improved without cracking of an electrode pad of a circuit board.

[0009]

In order to achieve the above object, the present invention provides a circuit board having a bump formed by using a connection material such as gold or solder on an electrode pad of the circuit board by a wire bumping method. And a semiconductor device mounting structure in which a semiconductor element is mounted face down.

Further, according to the present invention, in the mounting structure of the semiconductor device, the tip of the bump is plastically deformed by contact with an electrode pad of a semiconductor element to absorb a variation in height of the bump and the electrode pad of the circuit board. A mounting structure for a semiconductor device.

Further, the present invention is a mounting structure for a semiconductor device, wherein the variation in the contact area between the bump and the electrode pad of the circuit board is reduced in the mounting structure for the semiconductor device.

The present invention is also directed to a first step of forming a bump by using a connection material such as gold or solder by a wire bumping method on an electrode pad of a circuit board on which a plurality of electrode pads are arranged; A second step of filling the semiconductor element mounting surface of the substrate with a sealing resin, and a third step of face-down mounting the semiconductor element on which a plurality of electrode pads are arranged and mounting the semiconductor element on the circuit board. This is a method for manufacturing a mounting structure of a semiconductor device.

As described above, according to the above configuration,
The average value and the variation of the stress applied to the electrode pads of the circuit board due to the pressure applied when the semiconductor element is mounted face down on the circuit board can be reduced, and the connection reliability can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mounting structure for a semiconductor device according to the present invention will be described.

FIG. 1 is a process diagram showing one embodiment of a mounting process of a main part of a semiconductor device according to the present invention.
FIG. 2 is a process diagram showing an embodiment of a mounting process of a mounting structure diagram of a semiconductor device according to the present invention.

1 and 2, reference numeral 1 denotes a bump;
Is an electrode pad of a circuit board, 3 is a circuit board, 4 is a sealing resin, 5 is a semiconductor element, and 6 is an electrode pad of a semiconductor element.

One embodiment of a semiconductor device mounting structure according to the present invention will be described with reference to FIG. First, as shown in FIGS. 1A and 1B, a bump 1 is formed on an electrode pad 2 of a circuit board 3 by using a wire bumping method using an electrical connection material such as gold or solder. A sealing resin 4 such as an anisotropic conductive film or a filling resin is filled on the substrate 3. At this time, the average value and the area variation of the contact area between the electrode pad 2 and the bump 1 of the circuit board 3 are determined by the ball shape of the wire bumping and the circuit board 3.
Depends on the contact area of the electrode pad 2.

Next, as shown in FIG. 1C, the electrode pads 6 of the semiconductor element 1 are
The bump 1 is positioned at a predetermined position, and is mounted while being pressed. Here, the electrode pad 6 of the semiconductor element 5
The bumps 1 can be plastically deformed at the time of contact between the bumps 1 and the bumps 1 to absorb height variations.

Then, as shown in FIG. 1D, the semiconductor element 5 is heated from the semiconductor element side or the circuit board side while being pressurized to cure the sealing resin 4 such as an anisotropic conductive film or a filling resin. Thus, the semiconductor element 5 and the circuit board 3 are bonded. Here, as shown in FIG.
The contact area between the electrode pad 2 and the bump 1 of the semiconductor device 5
The contact area between the electrode pad 6 and the bump 1 is three times or more, so that the stress applied to the electrode pad 2 of the circuit board 3 can be reduced.

As described above, by forming the bumps 1 on the electrode pads 2 of the circuit board 3, the electrodes of the circuit board 3 are applied by the pressure applied when the semiconductor element 5 is mounted face down on the circuit board 3. The average value and the variation of the stress applied to the pad 2 can be reduced, and as a result,
A mounting structure of a semiconductor device with improved connection reliability can be obtained.

It is needless to say that the same effect as described above can be obtained even if the sealing resin 4 is injected into the gap after the semiconductor element 5 and the circuit board 3 are connected via the bumps 1. .

[0022]

According to the present invention, the average value of the contact area between the electrode pads and the bumps on the circuit board is increased, and the variation in the contact area can be reduced. The average value and the variation of the stress applied to the electrode pads of the circuit board by the applied pressure can be reduced, and as a result, the mounting structure of the semiconductor device can be mounted with high reliability without the occurrence of cracks in the electrode pads of the circuit board. The effect that can be achieved.

Further, according to the present invention, the variation in height between the bumps and the electrode pads on the circuit board can be absorbed by the plastic deformation of the bumps, so that the average value of the stress applied to the electrode pads on the circuit board can be reduced. In addition, the variation can be reduced, and as a result, there is an effect that the mounting structure of the semiconductor device can be mounted with high reliability without causing cracks in the electrode pads of the circuit board.

Further, according to the present invention, since the average value and the variation of the stress applied to the electrode pads of the circuit board can be reduced, the upper limit value of the applied pressure can be increased.
By increasing the upper limit of the pressure range applied to the sealing resin, the amount of voids can be reduced, and the effect of improving connection reliability is achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a mounting process and a structure of a main part of a semiconductor device according to the present invention.

FIG. 2 is a diagram showing a mounting process and a structure of a semiconductor device according to the present invention.

FIG. 3 is a diagram illustrating a mounting structure of a conventional semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bump, 2 ... Electrode pad of a circuit board, 3 ... Circuit board, 4 ... Sealing resin, 5 ... Semiconductor element, 6 ... Electrode pad of a semiconductor element.

Claims (4)

[Claims] 1. A semiconductor device wherein a semiconductor element is mounted face down on a circuit board in which bumps are formed by using a connection material such as gold or solder on electrode pads of the circuit board by a wire bumping method. Mounting structure. 2. The mounting structure of the semiconductor device according to claim 1, wherein a tip of the bump is plastically deformed by contact with an electrode pad of a semiconductor element to absorb a height variation of the bump and the electrode pad of the circuit board. Mounting structure of a semiconductor device. 3. The mounting structure of a semiconductor device according to claim 1, wherein a variation in a contact area between the bump and an electrode pad of a circuit board is reduced. 4. A first step of forming bumps by using a connection material such as gold or solder by a wire bumping method on electrode pads of a circuit board on which a plurality of electrode pads are arranged;
A second step of filling a sealing resin on a semiconductor element mounting surface of the circuit board; and a third step of face-down mounting a semiconductor element on which a plurality of electrode pads are arranged and mounting the semiconductor element on the circuit board. A method for manufacturing a mounting structure of a semiconductor device.