JP2003100787A - Semiconductor device manufacturing method and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing method which can realize miniaturization and cost reduction of a semiconductor device, and to provide the semiconductor device using the same. SOLUTION: In the method for manufacturing a semiconductor device comprising, correspondingly to each chip on the wafer, pads for mounting each solder ball, bond fingers for connecting with each chip, and circuits for connecting both (re-wiring circuits) on an insulative resin layer formed over the surface of a semiconductor wafer being an aggregate of semiconductor elements, the semiconductor wafer is arranged in a metal mold, and the insulation resin layer is formed by compression molding, transfer molding, or injection molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing method and a semiconductor device. More specifically, the present invention relates to a wafer level package manufacturing method and a semiconductor device obtained by the manufacturing method.

[0002]

2. Description of the Related Art With the recent demand for higher functionality, lightness, thinness, shortness, and miniaturization of electronic equipment, high-density integration and further high-density packaging of electronic parts have been advanced. Semiconductor packages used in these electronic devices have been downsized and have a large number of pins, and mounting substrates for mounting electronic components including semiconductor packages have also been downsized. Furthermore, in order to enhance the storage property in electronic equipment, a rigid flex substrate, which is made by stacking and integrating a rigid substrate and a flexible substrate and is bendable, has come to be used as a mounting substrate.

As semiconductor packages have become smaller,
In a package using a lead frame as in the past, miniaturization has reached its limit, so recently, a BGA (Ball) has been used as a chip mounted on a circuit board.
Grid Array) and CSP (Chip Sc)
A new package method of area mounting type called "ale Package" has been proposed. In these semiconductor packages, the electrical connection between the electrodes of the semiconductor chip and the terminals of the substrate, which is composed of various materials such as plastics and ceramics, called the semiconductor package substrate, which has the function of the lead frame of the conventional semiconductor package. As a dynamic connection method, a wire bonding method or TAB (Tape Automated Bonn)
ing) method, and further FC (Flip Chip)
Although the method is known, recently, BGA and C using the FC connection method, which is advantageous for miniaturization of semiconductor packages.
The structure of SP is actively proposed. However, these packages have to be individually packaged and tested after the semiconductor chips have been separated into individual pieces, which has been a factor of increasing costs.

Therefore, various companies have proposed a method of collectively packaging and testing semiconductor chips before dividing them into individual pieces. Among them, the method of forming a rewiring circuit by a conventional conductive circuit forming method such as a subtractive method or a semi-additive method, in which an insulating layer having a stress relaxation function is formed on a wafer by resin, is high. It is attracting attention as a method that can achieve both reliability and cost in terms of dimensions.

[0005]

In order to connect a pad for mounting a solder ball, a bond finger for connecting with a chip, and a bond finger on a resin film with an adhesive, which has been conventionally proposed. Circuit is repeatedly formed corresponding to each chip on the wafer, an opening for wire bonding for connecting the chip and the circuit is formed, and this is attached to the wafer by the method described above. Although it is possible to manufacture a semiconductor device having the above-mentioned requirements, the increase in the diameter of a wafer, which is useful for cost reduction, requires a high degree of accuracy in the attachment position, and a decrease in yield is one of the problems.

[0006] Further, the processing cost of the router is high,
In the case of press working, when the arrangement of the wire bonding pads is changed by the chip design, it is necessary to newly prepare a punching die for forming the opening, which causes a cost increase.

The present invention has been made in view of the above-mentioned conventional problems, and provides a method of manufacturing a semiconductor device and a semiconductor device obtained by the manufacturing method, which enables miniaturization and cost reduction of the semiconductor device. provide.

[0008]

That is, the present invention provides the following semiconductor device manufacturing method and semiconductor device. (1) A pad for mounting a solder ball, a bond finger for connecting with a chip, and a bond finger for connecting both, on an insulating resin layer formed on the entire surface of a semiconductor wafer which is an assembly of semiconductor elements Circuit (rewiring circuit)
In the method of manufacturing a semiconductor device formed corresponding to each chip on a wafer, the semiconductor wafer is placed in a molding die, and an insulating resin layer is molded by compression molding, transfer molding or injection molding. Characterized by forming
Manufacturing method of semiconductor device. (2) When placing the semiconductor wafer in the molding die,
The copper foil for forming a rewiring circuit is arranged on the semiconductor wafer with a gap for forming an insulating resin layer, and the (1)
A method of manufacturing a semiconductor device according to the item. (3) The method for manufacturing a semiconductor device according to the item (2), wherein the copper foil for forming a rewiring circuit is provided with a reinforcing material on the side opposite to the surface on which the insulating resin layer is formed. (4) The semiconductor according to (1), (2) or (3) above, wherein the rewiring circuit is formed by a subtractive or semi-additive method using a rewiring circuit forming copper foil. Device manufacturing method. (5) Exposing the input / output terminals by removing the insulating resin layer on the input / output terminals of the semiconductor element with a laser,
The input / output terminal and the rewiring circuit are connected by copper plating through the opening, and the above (1), (2),
A method of manufacturing a semiconductor device according to item (3) or (4). (6) A semiconductor device manufactured by the manufacturing method described in any one of (1) to (5) above.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An example of a method for manufacturing a semiconductor device of the present invention will be described below, but the present invention is not limited to these. First, a semiconductor wafer, which is an assembly of semiconductor elements, is placed in a molding die with the input / output terminals of the semiconductor elements facing upward. Next, a copper foil for forming a rewiring circuit is provided with a gap for forming an insulating resin layer on the semiconductor wafer,
The semiconductor wafer is arranged in a mold opposite to the mold in which the semiconductor wafer is arranged, and preparation for molding is performed.

As the copper foil for forming the rewiring circuit, an electrolytic copper foil is used. To secure the fineness of the rewiring circuit, for example, a foil having a thickness of 1 μm or more and 15 μm or less can be used, but 2 μm or more. It is more desirable to use the one having a thickness of 7 μm or less. Further, it is more preferable to provide a reinforcing material on the surface opposite to the surface on which the insulating resin layer is formed, in order to prevent the copper foil from breaking and wrinkling during molding. Any reinforcing material can be used as long as it can withstand heat during molding, and a plastic sheet such as polyester, polyether sulfone, or polyimide can be used. Further, it is more preferable to attach a backing copper foil of about 20 to 50 μm between the copper foil and the reinforcing material sheet.

Next, by injecting an insulating resin into the insulating resin layer forming portion in the mold to form a semiconductor wafer,
A molded product including an insulating resin layer, a copper foil for forming a rewiring circuit, and a reinforcing material is obtained. After this, the reinforcing material is removed.

As the molding method, compression molding, transfer molding,
Injection molding can be used. In order to prevent voids generated in the insulating resin layer due to gas generated during molding,
Vacuum suction molding is recommended. In the case of compression molding, it is preferable to weigh the insulating resin and mold it into a tablet shape. Further, the injection of the insulating resin for compression molding into the mold can be carried out by placing it on the semiconductor wafer arranged in the mold and applying heat and pressure in the preparation for the molding.

The insulating resin may be a thermosetting resin or a thermoplastic resin as long as it is suitable for the manufacturing method of the present invention. For example, an epoxy resin or a polyimide resin used as an insulating resin of a semiconductor device is preferable.

In the manufacturing method of the present invention, the copper foil for the rewiring circuit may be formed without disposing it. In this case, after forming the insulating resin layer by molding, the molded product can be taken out from the mold, and the copper foil layer for the rewiring circuit can be formed on the surface of the insulating resin layer by electrolysis. From the viewpoint of simplifying the manufacturing process, it is preferable to arrange the copper foil for rewiring circuit at the time of molding.

In the thus obtained wafer with insulating resin whose surface is covered with copper foil, the insulating resin layer on the input / output terminals of the semiconductor element is removed by a laser processing machine to form an opening. The surface of the copper foil is roughened with a chemical solution so that the laser energy is concentrated, and then the insulating resin layer is removed together with the copper foil by a laser processing machine.

The opening is electroless plated to electrically connect the copper foil covering the surface of the insulating resin layer to the semiconductor element input / output terminal. Further, electrolytic copper plating is performed on the copper foil using the copper foil for rewiring circuit formation made of electrolytic copper foil and the electroless plating layer as the power feeding layer. The plating thickness at this time is the rewiring circuit formation used as the power feeding layer. 25 together with the thickness of copper foil
The control is performed so that it is less than or equal to μm.

Further, an etching resist layer is formed on the electroplating layer only at a portion where a rewiring circuit is to be formed,
By removing unnecessary portions of the electrolytic plating layer, the electroless plating layer and the rewiring circuit forming copper foil with an etching solution, a rewiring circuit electrically connected to the semiconductor element input / output terminals is obtained.

When the thickness of the rewiring circuit forming copper foil made of the electrolytic copper foil is 3 μm or less, after the electroless plating step, the plating resist layer is coated on portions other than the portion where the rewiring circuit is to be formed. Thus, the electrolytic copper foil is used as a power feeding layer, and the electrolytic copper foil layer is formed on the copper foil. Next, after removing the plating resist, the electrolytic copper foil and the electroless plating layer are removed with perhydrosulfuric acid to obtain a rewiring circuit electrically connected to the semiconductor element input / output terminals at predetermined positions. Is also possible.

Next, a solder resist layer is formed so as to cover the insulating resin layer and the rewiring circuit other than the portion where the solder bumps are formed, and the solder balls are arranged at predetermined positions where the solder bumps are to be formed, and then reflow is performed. Solder bumps are formed by charging in a furnace or stencil printing a solder paste and then charging in a reflow furnace.

Finally, the semiconductor wafer is divided into individual semiconductor elements to obtain a semiconductor device having the same area as the semiconductor element.

[0021]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 A wafer was placed in a mold heated to 175 ° C., and an epoxy encapsulating material formed into a tablet shape (manufactured by Sumitomo Bakelite: product number EME-7) was formed on the wafer.
880) is placed on the backing foil side of the electrolytic copper foil with a thickness of 3 μm, which is lined with an electrolytic copper foil with a thickness of 35 μm.
The one to which the T film is attached is placed near the die that directly faces the die on which the wafer is placed. At this time, the PE
The copper foil with the T film is suctioned and fixed by the intake port provided on the outer periphery of the mold. After that, the upper mold and the lower mold are closed with a mold clamping force of 120 t, pressure is applied by the mold on which the wafer is mounted, and pressure and heat are applied for 120 seconds at an effective pressure of 9.8 MPa, and then the mold is taken out from the mold. By removing the backing copper foil together with the PET film, a thickness of 10
A structure was obtained in which a copper foil having a thickness of 3 μm was attached via an insulating resin having a thickness of 5 μm. After roughening the copper foil of the above structure with a roughening liquid (CPE900 manufactured by Mitsubishi Gas Chemical Co., Ltd.), using a UV laser processing machine (Mitsubishi Heavy Industries: Model 605LDX),
The diameter of resin and copper foil right above the semiconductor device input / output terminals is 75
Remove in a circle of μm. Next, a copper layer having a thickness of 0.5 μm is formed on the resin opening and the surface of the copper foil by electroless plating, and then a copper layer having a thickness of 15 μm is further formed by electrolytic plating. Next, an etching resist layer (manufactured by Asahi Kasei: product number AQ2558) is formed on the copper layer, and the copper foil other than the rewiring circuit for connecting the opening portion and the predetermined solder ball arrangement portion is treated with an alkali etching solution. Removed. After that, a photosensitive solder resist (CFP-1123 made by Sumitomo Bakelite) layer is formed so as to cover the entire surface of the wafer, and a solder ball arrangement portion is opened. Thereafter, together with the flux, solder balls were placed in the solder resist openings, put into a reflow step, and each semiconductor element was diced into individual pieces by a dicing machine to obtain a semiconductor device that independently functions. It was confirmed that the semiconductor device thus obtained has no problem in its operation as a semiconductor device.

[0023]

According to the present invention, a method of manufacturing a semiconductor device, which enables downsizing and cost reduction of the semiconductor device, can be applied, and the semiconductor device obtained by the manufacturing method has high quality reliability. Excel.

Claims (6)

[Claims] 1. A pad for mounting a solder ball, a bond finger for connecting to a chip, and a bond between the two are formed on an insulating resin layer formed on the entire surface of a semiconductor wafer which is an assembly of semiconductor elements. In the method of manufacturing a semiconductor device in which a circuit for rewiring (circuit for rewiring) is formed corresponding to each chip on the wafer, the semiconductor wafer is placed in a molding die, and compression molding, transfer molding or injection molding is performed. A method for manufacturing a semiconductor device, comprising forming an insulating resin layer by molding. 2. The copper foil for forming a rewiring circuit is arranged with a gap for forming an insulating resin layer on the semiconductor wafer when the semiconductor wafer is arranged in a molding die. Of manufacturing a semiconductor device of. 3. The method for manufacturing a semiconductor device according to claim 2, wherein the rewiring circuit forming copper foil has a reinforcing material on the side opposite to the surface on which the insulating resin layer is formed. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the redistribution circuit is formed by a subtractive or semi-additive method using a redistribution circuit forming copper foil. 5. The input / output terminal is exposed by removing the insulating resin layer on the input / output terminal of the semiconductor element with a laser, and the input / output terminal and the rewiring circuit are connected by copper plating through the opening. The method for manufacturing a semiconductor device according to claim 1, 2, 3, or 4. 6. A semiconductor device manufactured by the manufacturing method according to any one of claims 1 to 5.