JPH11224916A - Semiconductor device, wiring board, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the wiring board for an external lead of electrodes of a semiconductor element when the element is mounted on a motherboard of an electronic device, for providing a semiconductor device having the element mounted on the wiring board, which is able to reduce the number of manufacturing steps and cost and can improve its yield, and also to provide a method for manufacturing the board and the device. SOLUTION: A wiring board includes a substrate 2 formed on its one surface with a wiring pattern to be wired with electrodes of a semiconductor chip C, a bonding sheet 4 of an insulating material bonded on one surface of the substrate 2 and having an opening 4a for semiconductor chip mounting and openings 4b for external electrode formation made therein, and an external electrodes 6 of a conductive material embedded in the openings 4b for external electrode formation to be connected electrically with the wiring pattern of the substrate 2. A semiconductor device 1 includes the wiring board and the chip C which are mounted on the board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, a wiring board used for the semiconductor device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of devices using semiconductor devices and the increase in the amount of semiconductor devices mounted, the development of new semiconductor device mounting techniques has been progressing. Conventionally, a semiconductor chip surrounded by a package made of a ceramic or plastic material and a semiconductor device having leads protruding from the sides of the package have been mounted on a substrate, but recently, a mounting area has been reduced. For this purpose, for example, a method has been adopted in which a semiconductor device having a structure as shown in FIG. 10 is surface-mounted on a motherboard of an electronic device.

A semiconductor device 101 shown in FIG. 10 has a multilayer wiring board 102 on which three layers of substrates 102a to 102c are stacked.
A heat radiating plate 103 is attached to one surface of the substrate. In each of the substrates 102a to 102c of the multilayer wiring board 102, cavities K1 to K3 are formed in a stepwise manner.
To K3, the semiconductor chip C is mounted on the heat sink 103. Each substrate 102a-10 of the multilayer wiring board 102
2c, wiring patterns P1 to P3 are respectively formed, and wiring patterns P1 and P2 are formed of metal wires W
Is electrically connected to each electrode of the semiconductor chip C. The wiring patterns P1 and P2 of the substrates 102a and 102b are electrically drawn to the other surface of the multilayer wiring board 102 by a metal material embedded in a through hole 104 penetrating the substrates 102a to 102c. The through hole 104 is electrically connected to a spherical external electrode 105 formed on the other surface of the multilayer wiring board 102. With such a configuration, each electrode of the semiconductor chip C is connected to the external electrode 1 formed on the other surface of the multilayer wiring board 102.
05 is derived. The semiconductor device 101 and the motherboard are electrically connected to each other through the external electrodes 105 by mounting the semiconductor device 101 on a corresponding portion of the motherboard of the electronic device.

[0004]

The semiconductor device 101 using the above-described multilayer wiring board 102 has a plurality of substrates 10.
After forming wiring patterns on 2a to 102c, these are laminated to form a multilayer wiring board 102, and then a through hole 104 is formed by drilling. Further, the cavities K1 to K3 are formed in a step shape by counterbore processing. Thereafter, the semiconductor chip C is bonded onto the heat sink 103, and the substrate and the semiconductor chip C are electrically connected by wire bonding.

[0005] As described above, the formation of the multilayer wiring board 102 for holding the semiconductor chip C requires a large amount of machining and is disadvantageous in that it is costly. In addition, multilayer wiring board 1
02, and the denser the wiring pattern, the more
The required processing accuracy is high, processing is difficult,
There is also a disadvantage that the proportion of defective products increases.
Further, there is also a disadvantage that wire bonding must be performed over multiple layers, which is likely to cause a defect.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. For example, when a semiconductor element is mounted on a motherboard of an electronic device, a wiring board for extracting each electrode of the semiconductor element to the outside, An object of the present invention is to provide a wiring board, a semiconductor device, and a method for manufacturing the same, which can reduce the number of manufacturing steps, reduce costs, and improve the yield in a semiconductor device in which a semiconductor element is mounted on a wiring board.

[0007]

The wiring board according to the present invention comprises:
A substrate on which a wiring pattern to be connected to each electrode of the semiconductor element was formed on one surface, and an opening for mounting a semiconductor element and an opening for forming an external electrode were attached to one surface of the substrate; A bonding sheet made of an insulating material,
An external electrode is formed of a conductive material, is embedded in the opening for forming the external electrode, and is electrically connected to a wiring pattern of the substrate.

In the present invention, a bonding sheet is bonded to a substrate having only one surface on which a wiring pattern is formed, and an opening for mounting a semiconductor element and an opening for forming an external electrode are formed in the bonding sheet. There is no need to form through holes in the substrate or machine a cavity for mounting a semiconductor element in multiple stages.

In the method of manufacturing a wiring board according to the present invention, a bonding sheet made of an insulating material having an opening for mounting a semiconductor element and a wiring pattern connected to each electrode of the semiconductor element are formed on one surface. Bonding the substrate with a substrate, forming an opening for forming an external electrode by opening each region of the bonding sheet corresponding to each terminal for taking out an external electrode formed on the substrate, and forming the external electrode. Forming an external electrode by burying a conductive material in the opening for use.

[0010] The method for manufacturing a wiring board according to the present invention includes:
A step of preparing a substrate on which a wiring pattern electrically connected to each electrode of the semiconductor element is formed on one surface and a bonding sheet on which an opening for mounting a semiconductor element and an opening for forming an external electrode are formed; Bonding the substrate and the bonding sheet, and embedding a conductive material in an opening for forming an external electrode of the bonding sheet, and connecting the conductive material and each terminal for taking out an external electrode formed on the substrate. Forming external electrodes by electrical connection.

[0011] A semiconductor device according to the present invention comprises a substrate having a wiring pattern formed on one surface thereof, which is connected to each electrode of the semiconductor element, an opening for mounting the semiconductor element adhered to one surface of the substrate, and A bonding sheet made of an insulating material having an opening for forming an external electrode, and a conductive material, embedded in the opening for forming an external electrode, and electrically connected to a wiring pattern of the substrate. An external electrode and a semiconductor element in which each electrode is mounted on the substrate through the opening for mounting the semiconductor element and electrically connected to each terminal for extracting an external electrode formed on the substrate by a thin metal wire. Have.

In the semiconductor device according to the present invention, the external electrode embedded in the opening for forming the external electrode of the bonding sheet is electrically connected to the wiring pattern formed on the substrate, and the wiring pattern formed on the substrate is formed. The electrodes of the semiconductor element are electrically connected to the electrodes of the semiconductor element by thin metal wires. As a result, the electrodes of the semiconductor element are led to the external electrodes embedded in the openings for forming the external electrodes of the bonding sheet.

In a semiconductor device according to the present invention, a wiring pattern connected to each electrode of a semiconductor element is formed on one surface,
A substrate in which a cavity for mounting a semiconductor element is formed, a bonding sheet in which an opening for mounting a semiconductor element and an opening for forming an external electrode are formed and adhered to one surface of the substrate; A wiring board having an external electrode made of a conductive material formed in an opening for use in the semiconductor device; a heat sink provided on the other surface of the substrate corresponding to the cavity for mounting the semiconductor element; And a semiconductor element in which each electrode is electrically connected to a wiring pattern formed on the substrate by a thin metal wire.

With such a configuration, heat released from the semiconductor element is directly radiated to the outside through the radiator plate, so that the semiconductor device has a structure corresponding to the semiconductor element generating a large amount of heat.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a sectional view showing one embodiment of a semiconductor device according to the present invention. A semiconductor device 1 shown in FIG. 1 includes a wiring board having a substrate 2 having a wiring pattern formed on one surface and a bonding sheet 4 attached to one surface of the substrate 2, and a semiconductor chip mounting the bonding sheet 4. And a semiconductor chip C mounted on the substrate 2 through the opening 4a.

A wiring pattern (not shown) is formed on one surface of the substrate 2. Further, a lead terminal 2 a electrically connected to each electrode of the semiconductor chip by a metal wire W, and a wiring pattern And external connection lands 2b for drawing out. Therefore, the lead terminal 2a and the external connection land 2b are electrically connected by the wiring pattern formed on the substrate 2. The substrate 2 is made of, for example, an insulating material such as a glass epoxy material or a polyimide material.

The bonding sheet 4 has an opening 4a for mounting a semiconductor chip so as to surround each lead-out terminal 2a of the substrate 2, and has an external electrode forming area corresponding to the formation position of the external connection land 2b. An opening 4b is formed. The bonding sheet 4 is made of, for example, an insulating material such as a glass epoxy material, and the bonding with the substrate 2 is performed by an adhesive applied to one surface of the bonding sheet 4.

An external electrode 6 made of, for example, a conductive material is formed in each external electrode forming opening 4b formed in the bonding sheet 4, and the external electrode 6 is connected to the external connection land 2b. It is electrically connected.
The external electrode 6 is made of, for example, a conductive material such as a copper paste or a solder paste. When the external electrode 6 is mounted on the motherboard of the electronic device when the semiconductor device 1 is mounted,
It will be electrically connected to the electrode terminal of the motherboard.

On the substrate 2, a semiconductor chip C is bonded by a bonding material 8 through a semiconductor chip mounting opening 4 a of the bonding sheet 4. The bonding material 8 includes
For example, materials such as solder, gold, and resin are used.

Each electrode of the semiconductor chip C is connected to each lead terminal 2a of the substrate 2 by a metal wire W. As the metal wire W, for example, a gold wire, an aluminum wire, or the like is used. Thereby, each electrode of the semiconductor chip C is electrically connected to the external electrode 6 through each lead terminal 2a, the wiring pattern, and the external connection land 2b of the substrate 2.

The opening 4a for mounting the semiconductor chip of the bonding sheet 4 is filled with a sealing resin R.
Thereby, the semiconductor chip C and the metal wire W are
It is protected by the sealing resin R.

In the semiconductor device 1 having the above-described structure, the wiring pattern is formed only on one surface (one surface) of the substrate 2, so that the substrate 2 can be made thinner. There is no need to form it and the cost is low. Also,
In the semiconductor device 1, the respective lead-out terminals 2a of the substrate 2 are formed only on the same plane and are not formed in a plurality of stages.
The reliability of the wire W is improved.

Next, a method of manufacturing the semiconductor device 1 having the above configuration will be described. 2 and 3 are cross-sectional views illustrating one embodiment of a method for manufacturing a wiring board according to the present invention. First, a substrate 2 on which a wiring pattern is formed only on one surface and a bonding sheet 4 on which an opening 4a for mounting a semiconductor chip and an opening 4b for forming an external electrode are formed.
Prepare The opening 4a for mounting the semiconductor chip of the bonding sheet 4 and the opening 4b for forming the external electrode are provided.
Is formed in advance by machining, and an adhesive is applied to one surface of the bonding sheet 4 in advance.

Next, as shown in FIG. 2, one surface of the substrate 2 on which the wiring pattern is formed is bonded to the bonding surface of the bonding sheet 4. At this time, the opening 4a for mounting the semiconductor chip of the bonding sheet 4 surrounds each lead-out terminal 2a of the substrate 2, and the opening 4b for forming the external electrode of the bonding sheet 4 is located at the position where the external connection land 2b of the substrate 2 is formed. Correspondingly, the substrate 2 and the bonding sheet 4 are positioned and bonded.

Next, as shown in FIG. 3, a conductive material such as a copper paste is buried in the opening 4b for forming an external electrode of the bonding sheet 4, and is cured to form the external electrode 6. The embedding of the conductive material into the external electrode forming openings 4b can be performed by, for example, a printing method, whereby the external electrodes 6 are collectively formed in the plurality of external electrode forming openings 4b. be able to.

Next, the semiconductor chip C is bonded to a predetermined position on the substrate 2 through the semiconductor chip mounting opening 4a of the bonding sheet 4. In this bonding step, materials such as solder, resin, and gold alloy can be used as the bonding material 8.

Next, each electrode on the semiconductor chip C and each corresponding lead terminal 2a formed on the substrate 2 are wire-bonded and connected by metal wires W.
This wire bonding is a commonly known technique in which the metal wire W and each electrode on the semiconductor chip C and each lead-out terminal 2a of the substrate 2 are pressurized and bonded by applying heat or ultrasonic vibration or both. Note that the above-described semiconductor chip bonding step and wire bonding step can be performed before the step of bonding the substrate 2 and the bonding sheet 4 together.

Next, the sealing resin R is supplied through the semiconductor chip mounting opening 4a of the bonding sheet 4,
The semiconductor chip C and the metal wires W are formed by the sealing resin R
To protect. At this time, the wall formed by the semiconductor chip mounting opening 4a of the bonding sheet 4 serves as a dam for preventing the sealing resin R from flowing outside. The semiconductor device 1 is completed through the above steps.

As described above, according to the present embodiment, since the wiring pattern is formed only on one surface of the substrate 2, there is no need for a step of performing machining such as forming a through hole in the substrate 2, and the manufacturing process is not required. The cost can be reduced, the occurrence of defective products due to processing accuracy can be suppressed, and a decrease in yield can be prevented. Further, since the semiconductor chip mounting opening 4a is formed in the bonding sheet 4, the semiconductor chip mounting opening 4a serves as a dam for blocking the sealing resin R, and thus a step of forming a dam is necessary. Absent.

Second Embodiment FIGS. 4 to 6 are sectional views for explaining another embodiment of the method for manufacturing a wiring board according to the present invention. The structure of the wiring board manufactured in this embodiment is the same as that of the first embodiment described above, but the method of forming the external electrodes 6 is different. That is,
First, a substrate 2 having a wiring pattern formed on only one surface
Then, a bonding sheet 4 having only the opening 4a for mounting a semiconductor chip is prepared. Then, as shown in FIG. 4, the substrate 2 and the bonding sheet 4 are positioned and bonded.

Then, as shown in FIG. 5, a laser beam is applied to a position of the bonding sheet 4 corresponding to the external connection lands 2b of the substrate 2, and a part of the bonding sheet 4 is melted and removed. The part 4b is opened.

Next, as described in the first embodiment, an external electrode 6 is formed by embedding a conductive material in each formed external electrode forming opening 4b. Thereby, the wiring board is completed.

In the present embodiment, the external electrode forming openings 4b are not formed in the bonding sheet 4 in advance, but after the substrate 2 is bonded to the bonding sheet 4, the external electrode forming openings 4b are formed in the bonding sheet 4. Opening 4b
To form With such a configuration, it is not necessary to form the external electrode forming openings 4b in the bonding sheet 4 by machining in advance. That is, it is difficult to machine both the opening 4a for mounting the semiconductor chip and the opening 4b for forming the external electrode on the bonding sheet 4 so that the relative positional accuracy falls within a predetermined range, and the processing cost increases. . After processing both the opening 4a for mounting a semiconductor chip and the opening 4b for forming an external electrode on the bonding sheet 4, the bonding sheet 4 is placed on the substrate 2 so that each opening comes to an accurate position. It is difficult to position.

According to this embodiment, only the opening 4a for mounting the semiconductor chip is formed in the bonding sheet 4 and the opening 4a for mounting the semiconductor chip is positioned on the substrate 2 in order to position the opening 4a with respect to the substrate 2. It is relatively easy to accurately position the lens at a predetermined position. Furthermore, since the external electrode forming opening 4b is opened after the substrate 2 and the bonding sheet 4 are bonded to each other, displacement between the external electrode forming opening 4b and the external connection land 2b of the substrate 2 is less likely to occur. In addition, the occurrence of product defects can be suppressed.

Third Embodiment FIG. 7 is a sectional view showing another embodiment of the semiconductor device according to the present invention. Semiconductor device 1 in the above embodiment
Has a structure assuming a case where the amount of heat radiation from the semiconductor chip C is relatively small. That is, the semiconductor chip C is directly mounted on the substrate 2, and the heat released from the semiconductor chip C is released to the outside via the substrate 2 and the sealing resin R. However, when the amount of heat radiation from the semiconductor chip C is large, the above structure does not provide sufficient heat radiation.

The semiconductor device 21 according to the present embodiment has a structure that can cope with a large amount of heat radiation from the semiconductor chip C. In FIG. 7, a bonding sheet 4 is bonded to one surface of the substrate 2, and a heat sink 11 is bonded to the other surface by an adhesive. Heat sink 1
1 is made of a material having high thermal conductivity such as aluminum.

A cavity 2c for mounting a semiconductor chip C is formed in the substrate 2, and a bonding sheet 4
Semiconductor chip mounting opening 4a and cavity 2c
Through the bonding material 8 and the heat sink 1
1 is joined to one surface. Further, each electrode of the semiconductor chip C is connected to each of the lead-out terminals 2a of the substrate 2 and the metal wire W, and the semiconductor chip mounting opening 4a is formed.
The cavity 2c is filled with a sealing resin R to protect the semiconductor chip C and the metal wires W. The external electrode forming opening 4b of the bonding sheet 4
Is filled with a conductive material such as a copper paste to form an external electrode 6.

With this configuration, even if the amount of heat radiated from the semiconductor chip C is large, the heat radiating plate 1
1, heat can be released directly to the outside.

Fourth Embodiment FIGS. 8 and 9 are sectional views for explaining an example of a method for forming an external electrode 6 of a semiconductor device according to the present invention. In the semiconductor devices 1 and 21 described above, the external electrode 6 is formed by embedding a conductive material such as a copper paste in the external electrode forming opening 4b of the bonding sheet 4 and curing the material.

However, when the copper paste is buried in the external electrode forming openings 4b and cured, the surface of the external electrodes 6 becomes flat as the surface of the bonding sheet 4. When the surface of the external electrode 6 is flat,
For example, when the semiconductor devices 1 and 21 are surface-mounted on a motherboard of an electronic device, a step of joining the external electrodes 6 and the connection electrodes of the motherboard is required.

In the present embodiment, the external electrodes 6 are formed by so-called reflow soldering. Specifically, first, as shown in FIG. 8, a solder paste is supplied into the external electrode forming openings 4b of the bonding sheet 4. The supply of the solder paste to the external electrode forming opening 4b is as follows.
Supply the required amount of solder by printing.

Next, the semiconductor device 31 in the above state is heated to a predetermined temperature. Thus, the solder supplied to the external electrode forming opening 4b is melted. At this time, since the surface tension acts on the molten solder, the surface becomes spherical and projects in a ball shape from the surface of the bonding sheet 4. When this is cooled, as shown in FIG. 9, external electrodes 6 projecting in a ball shape from the surface of the bonding sheet 4 are formed.

As described above, when the external electrodes 6 projecting in a ball shape from the surface of the bonding sheet 4 are formed,
When the semiconductor device 31 is mounted on the motherboard of the electronic device, the connection between the external electrodes 6 and the connection electrodes of the motherboard becomes very easy.

[0044]

According to the present invention, a bonding sheet is bonded to a substrate having only one surface on which a wiring pattern is formed, and an opening for mounting a semiconductor element and an opening for forming an external electrode are formed in the bonding sheet. This eliminates the need to form a through hole in the substrate or to machine a cavity for mounting a semiconductor element at all or at another stage. As a result, the number of manufacturing steps can be reduced, the incidence of defective products can be reduced, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a semiconductor device according to the present invention.

FIG. 2 is a cross-sectional view for explaining one embodiment of a method for manufacturing a wiring board according to the present invention.

FIG. 3 is a cross-sectional view for explaining a manufacturing step following FIG. 2;

FIG. 4 is a cross-sectional view for explaining another embodiment of the method for manufacturing a wiring board according to the present invention.

FIG. 5 is a cross-sectional view for explaining a manufacturing step following FIG. 4;

FIG. 6 is a cross-sectional view for explaining a manufacturing step following FIG. 5;

FIG. 7 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 8 is a cross-sectional view for explaining an example of a method for forming an external electrode of a semiconductor device according to the present invention.

FIG. 9 is a cross-sectional view for explaining a forming step following FIG. 8;

FIG. 10 is a cross-sectional view illustrating an example of the structure of a conventional semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 2 ... Substrate, 2a ... Lead-out terminal, 2
b: external connection land, 4: bonding sheet, 4a ...
Opening for mounting semiconductor chip, 4b: Opening for forming external electrode, 6: External electrode, 8: Bonding material, C: Semiconductor chip,
W: bonding wire, R: sealing resin.

Claims (9)

[Claims] 1. A substrate having a wiring pattern formed on one surface thereof and connected to each electrode of a semiconductor element, an opening for mounting a semiconductor element and an opening for forming an external electrode adhered to one surface of the substrate. A bonding sheet made of an insulating material having a portion formed thereon, and an external electrode made of a conductive material, embedded in the opening for forming the external electrode, and electrically connected to a wiring pattern of the substrate. Board. 2. A step of bonding a bonding sheet made of an insulating material having an opening for mounting a semiconductor element thereon and a substrate on one side of which a wiring pattern connected to each electrode of the semiconductor element is formed; Forming an opening for forming an external electrode by opening each region of the bonding sheet corresponding to each terminal for taking out an external electrode formed in the step of: forming a conductive material in the opening for forming an external electrode; Embedding to form external electrodes. 3. The method of manufacturing a wiring board according to claim 2, wherein the step of opening the opening for forming an external electrode of the bonding sheet is performed by irradiating a laser beam. 4. A substrate having a wiring pattern electrically connected to each electrode of a semiconductor element on one surface and a bonding sheet having an opening for mounting a semiconductor element and an opening for forming an external electrode. A step of preparing; a step of bonding the substrate and a bonding sheet; and a step of embedding a conductive material in an opening for forming an external electrode of the bonding sheet, and taking out the external electrode formed on the conductive material and the substrate. Electrically connecting the respective terminals to each other to form external electrodes. 5. The method according to claim 4, wherein the external electrodes are formed by reflow soldering. 6. A substrate having a wiring pattern formed on one surface thereof, which is connected to each electrode of the semiconductor element, an opening for mounting a semiconductor element and an opening for forming an external electrode, which are adhered to one surface of the substrate. A bonding sheet made of an insulating material having a portion formed thereon; an external electrode made of a conductive material, embedded in the opening for forming the external electrode, and electrically connected to a wiring pattern of the substrate; Is mounted on the substrate through the opening for mounting a semiconductor element, and has a semiconductor element electrically connected to each terminal for taking out an external electrode formed on the substrate by a thin metal wire. 7. The semiconductor device according to claim 6, wherein the opening for mounting the semiconductor element is filled with a sealing resin. 8. A substrate having a wiring pattern connected to each electrode of a semiconductor element formed on one surface thereof, a cavity for mounting a semiconductor element formed therein, an opening for mounting a semiconductor element and an opening for forming an external electrode. A wiring board having a portion, a bonding sheet attached to one surface of the substrate, and an external electrode made of a conductive material formed in the opening for forming the external electrode; and A heat sink provided on the other surface of the substrate corresponding to the cavity of the semiconductor; and a semiconductor provided on the heat sink and each electrode electrically connected to a wiring pattern formed on the substrate by a thin metal wire. A semiconductor device having an element. 9. The semiconductor device according to claim 8, wherein a sealing resin is filled in the cavity and the opening for mounting the semiconductor element.