JP2001203305A - Semiconductor device, electronic device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a WPP type semiconductor device at an inexpensive cost. SOLUTION: A semiconductor device, in which a plurality of semiconductor chips made of outer electrodes and circuit elements are formed on a major forming surface of a wafer and which is obtained by separating from the wafer for each semiconductor chip, is provided with bumps formed by an conductive material on each outer electrode. The semiconductor device is provided with a stress buffering material (elastomer) or a sealing material which has not yet been hardened, is provided with a circuit pattern which is electrically connected with the wire bumps or plated bumps on the stress buffering material or the sealing material which has not yet been hardened and is provided with solder balls on the circuit pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, an electronic device, and a method of manufacturing the same, and more particularly, to a WPP (Wa).
The present invention relates to a technology effective when applied to a semiconductor device, an electronic device equipped with the WPP semiconductor device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 6 is a view for explaining the structure of a conventional WPP type semiconductor device. FIG. 6 (a) is a three-dimensional view, and FIG. 6 (b) is an A-type semiconductor device shown in FIG. It is sectional drawing cut | disconnected by the A line.

A conventional WPP type semiconductor device 100 is shown in FIG.
As shown in FIG. 2, a semiconductor chip 10 having peripherally arranged external electrodes 70, a layer of an insulating base material 20 (polyimide) provided on the semiconductor chip 10 except for a portion where the external electrodes 70 are formed, A wiring pattern 30 formed on the layer of the material 20, bonding wires 60 for electrically connecting the wiring pattern 30 to external electrodes 70 of the semiconductor chip 10, and solder for electrically connecting to the wiring pattern 30 It is composed of a ball 40, an external electrode 70, a wiring pattern 30, and a sealing resin 50 for sealing the connection portions thereof.

Next, a method of manufacturing the above-described conventional WPP type semiconductor device 100 will be described.

FIGS. 7 and 8 are views for explaining a method of manufacturing the conventional WPP type semiconductor device 100. FIG.

In manufacturing the conventional WPP type semiconductor device 100, as shown in FIG. 7A, first, a wafer 10a on which circuit elements including external electrodes 70 are formed is prepared.
As shown in (b), the insulating base material 2 is formed on the wafer 10a.
A layer of 0 (polyimide) is laminated, and as shown in FIG. 7 (c), a bonding window 21 for wire bonding is formed by etching with alkali hydrazine water or photolysis of a carbon dioxide laser beam.

Then, as shown in FIG. 8A, a copper foil 30a is provided on the layer of the insulating base material (polyimide) 20.
FIG. 8 is described based on one semiconductor chip 10 cut out from a wafer so that the process can be easily understood.

Next, a photoresist is attached to the copper foil 30a and etching is performed, as shown in FIG.
A wiring pattern 30 is formed, and as shown in FIG.
The external electrodes 70 and the wiring patterns 30 are connected by the bonding wires 60.

Next, as shown in FIG. 8 (d), solder balls 40 are formed on the wiring pattern 30, and as shown in FIG. 8 (e), the external electrodes 70, the wiring pattern 30 and their connection parts are formed. Are sealed with a sealing resin 50.

[0010]

SUMMARY OF THE INVENTION The above-mentioned conventional WPP
In the semiconductor device, as shown in FIG.
A re-wiring structure is provided in which a layer of an insulating base material 20 such as polyimide is formed on the substrate 0 and a wiring is formed thereon.

However, the polyimide used for the insulating base material 20 on which the rewiring is based is very expensive,
There is a problem that the semiconductor device becomes expensive.

Further, in the conventional WPP semiconductor device, it is necessary to form a bonding window 21 for wire bonding, and there is a problem that the number of manufacturing steps is increased and the manufacturing cost is increased.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a technique capable of manufacturing a WPP type semiconductor device at low cost.

[0014]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present invention, typical ones will be briefly described as follows.

(1) A semiconductor device comprising a plurality of sets of semiconductor chips comprising external electrodes and circuit elements formed on a main forming surface of a wafer, wherein each of the semiconductor chips is separated from the wafer and comprises a conductive material. A wire bump or a plating bump formed on each of the external electrodes, and a thermal buffer material (elastomer) or a buffer material for buffering thermal stress generated between the semiconductor chip and a wiring board of an electronic device to which the semiconductor chip is connected. Providing a hardened encapsulant on the main forming surface of the semiconductor chip, and providing a wiring pattern electrically connected to the wire bump or plated bump on the stress buffer or the uncured encapsulant; It is characterized in that a solder ball is provided thereon.

(2) In the semiconductor device described in (1), the stress buffering material has a glass transition temperature lower than the melting temperature of the solder ball and an elastic modulus at 150 ° C. of 10
It is characterized by being a resin having a pressure of 0 MPa or less.

(3) The semiconductor device according to any one of (1) and (2) is mounted on a wiring board.

(4) In a method of manufacturing a semiconductor device, a first step of forming a plurality of sets of semiconductor chips each including an external electrode and a circuit element on a main formation surface of a wafer; and a step of forming a conductive material on the external electrodes of the wafer. A second step of forming wire bumps or plated bumps, and a stress buffer (elastomer) or an uncured seal for buffering thermal stress generated between the semiconductor chip and a wiring board of an electronic device to which the semiconductor chip is connected. A third step of providing a stopper on the main forming surface of the semiconductor chip; and forming a wiring pattern electrically connected to the wire bump or the plating bump on the stress buffering material or the uncured sealing material. Step 4, a fifth step of forming solder balls on the wiring pattern,
A sixth step is provided for each of the semiconductor chips obtained by separating the semiconductor chip from the wafer.

[0019]

FIG. 1 is a diagram for explaining a configuration of a WPP type semiconductor device according to the present embodiment.
1 is a three-dimensional view, and FIG. 1B is a cross-sectional view taken along line AA shown in FIG.

The WPP type semiconductor device 100 of the present embodiment
As shown in FIG. 1, a semiconductor chip 10 having a circuit element and an external electrode 70 disposed on the periphery thereof formed on a main formation surface, and gold wires formed on the external electrode 70 Bump (hereinafter referred to as gold wire bump) 80
Provided on the main forming surface of the semiconductor chip 10 so that the tip end surface of the gold wire bump 80 is exposed.
A stress buffer (elastomer) 110 for buffering thermal stress generated between the substrate and a substrate of an electronic device connecting the same, a wiring pattern 30 formed on the elastomer 110,
Solder balls 40 provided on the wiring pattern 30
It is composed of

FIG. 2 shows the gold wire bump 80 of this embodiment.
FIG. 2A is a diagram for explaining the configuration of FIG.
FIG. 2A is an overhead view of one gold wire bump 80 shown in FIG. 2A, and FIG. 2B is an enlarged view of the gold wire bump 80 shown in FIG.

As shown in FIG. 2, the gold wire bump 80 is formed by bonding a gold wire bonding wire to a 50 μm square external electrode 70 formed of an aluminum vapor-deposited film by a wire bonder and cutting the wire to a predetermined length. It forms by doing. Alternatively, it may be formed after gold plating or gold plating is performed on a nickel core.

The bumps used in the present invention are not limited to the gold wire bumps 80. For example, bumps plated in a convex shape may be used instead of the gold wire bumps 80. Furthermore, the shape of the bump
It is sufficient if the tip portion is thin enough to break through the stress buffering material or the like, and in that case, it does not have to be convex.

As shown in FIG. 2, a protective film 90 such as a PIQ (polyimide passivation film) or a PIX (photosensitive polyimide coat passivation film) other than the external electrodes 70 of the semiconductor chip 10 is provided. It is provided to protect the element formation surface (not shown in FIG. 1). As shown in FIG. 2, the gold wire bump 80 has a diameter of 40 to 50 μm at a connection portion with the external electrode 70 and a tip portion of about 30 μm.
Is the diameter.

Further, since the gold wire bumps 80 are soft having a Vickers hardness of about Hv 60 to 80, similar to the elastomer 110, the gold wire bumps 80 are connected to the semiconductor chip 10 and a wiring board of another electronic device connecting the semiconductor chip 10 by a cooling / heating temperature cycle. Also acts as a thermal stress buffer for buffering the thermal stress generated during.

As the elastomer 110, for example, an epoxy resin having a glass transition temperature (lower than the eutectic solder melting temperature of 37 mass% Sn-Pb of 180 ° C.) or the like is used. Also, for example, an uncured sealing resin or 15
It is also possible to use a resin having an elastic modulus at 0 ° C. of 100 MPa or less.

Next, a method of manufacturing the above-described WPP type semiconductor device 100 of the present embodiment will be described. FIG. 3 is a diagram for explaining a method of manufacturing the WPP type semiconductor device 100 of the present embodiment.

In the manufacture of the WPP type semiconductor device 10 of the present embodiment, as shown in FIG. 3A, first, a circuit element including the external electrode 70 is formed on the main formation surface of the wafer 10a. As shown in b), a gold wire bonding wire is bonded to the external electrode 70 by a wire bonder to form a gold wire bump 80.

Next, as shown in FIG. 3C, the semiconductor chip 10 is exposed so that the front end face 81 of the gold wire bump 80 is exposed.
The elastomer 110 is formed on the main forming surface of the above. This elastomer 110 has the same height as the gold wire bump 80.
The process of forming the elastomer 110 includes a process of attaching a tape of the elastomer 110 and a process of directly applying the liquefied elastomer 110. In the attaching step, the tape of the elastomer 110 is attached so that the gold wire bumps 80 pierce.

The tip surface 81 of the gold wire bump 80
Is not necessarily required when forming the elastomer.
Sometimes you do not have to leave. This is because even when the gold wire bumps 80 are wrapped in the elastomer 110, the elastomer 110 is heated to a glass transition temperature or higher and melts when connected to another electronic device, so that the gold wire bumps 80 are not melted. Is exposed from the elastomer 110.

Next, as shown in FIG. 3D, a copper foil 30a is attached on the formed elastomer 110 by a vacuum press. At this time, the gold wire bump 80 is stuck so that the front end face 81 thereof is in contact with the copper foil 30a.
Cu-A at 0 ° C., pressure 50-100 HPa, time 30 minutes
u is connected by diffusion to the copper foil 30a and the gold wire bump 80.
Are electrically connected. Further, when the elastomer 110 to which the copper foil 30a is attached in advance is used, as shown in FIGS.
(D) can be performed simultaneously.

Next, as shown in FIG.
Etching is performed on “a” to form a wiring pattern 30, and solder balls 40 are formed on the land portions of the formed wiring pattern 30 as shown in FIG. 4B.

Next, as shown in FIG. 4C, a solder resist 140 is formed at locations other than the locations where the solder balls 40 are formed, and the wafer 10a is shredded for each semiconductor chip 10 to form a WPP type wafer of the present embodiment. The semiconductor device 10 is obtained.

Next, a case where the WPP type semiconductor device 100 of this embodiment is mounted on a memory module which is an example of an electronic device will be described.

FIG. 5 is a diagram for explaining a configuration of a memory module on which the WPP type semiconductor device 100 of the present embodiment is mounted.

As shown in FIG. 5, the WPP type semiconductor device 100 of this embodiment is mounted on a memory module by connecting the solder balls 40 and the wiring patterns 202 of the memory module wiring board 201. Although not shown, a portion other than the connection portion of the wiring pattern 202 is coated with a solder resist 140 (not shown).

As described above, by mounting the WPP type semiconductor device 100 of the present embodiment, which can be manufactured at low cost, on an electronic device such as a memory module, the cost of the electronic device can be reduced.

As described above, in the WPP type semiconductor device of the present embodiment, a gold wire bump is provided on an external electrode, an elastomer is provided on a main forming surface, and a wiring pattern is formed on the elastomer. By forming a solder ball on the top, it is not necessary to use expensive polyimide which is an insulating base material used for performing rewiring for connection with a wiring board of another electronic device, and the polyimide Since a processing step is not required, a WPP type semiconductor device can be manufactured at low cost.

Further, since a gold wire bump can be formed using a conventional wire bonder, there is no need to provide special equipment.

Also, by providing the gold wire bumps, it is not necessary to perform wire bonding, so that a step of providing a bonding window in an elastomer or the like is not required, and low-cost and easy manufacturing becomes possible.

Furthermore, the Vickers hardness is Hv 60-80.
Provide gold wire bumps using gold which is a soft material of about
In addition, by providing the elastomer, the gold wire bumps and the elastomer buffer thermal stress caused by a difference in thermal expansion coefficient between the semiconductor chip and a wiring board of another electronic device to which the semiconductor chip is connected, so that the connection is performed in a cooling / heating temperature cycle. The reliability of the part is further improved.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiment, the present invention
It is needless to say that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the scope of the invention.

[0043]

The effects obtained by the representative inventions among the inventions disclosed in the present invention will be briefly described.
It is as follows.

A gold wire bump is provided on an external electrode, an elastomer is provided on a main formation surface, a wiring pattern is formed on the elastomer, and a solder ball is formed thereon, thereby forming a wiring board for another electronic device. It is not necessary to use expensive polyimide, which is an insulating base material used to perform rewiring for connection, and a process for processing the polyimide is not required, so that a WPP-type semiconductor device can be manufactured at low cost. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a WPP type semiconductor device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a configuration of a gold wire bump 80 of the present embodiment.

FIG. 3 is a diagram illustrating a method of manufacturing the WPP type semiconductor device 100 according to the embodiment.

FIG. 4 is a diagram illustrating a method for manufacturing the WPP type semiconductor device 100 according to the embodiment.

FIG. 5 is a diagram illustrating a configuration of a memory module 200 including the WPP type semiconductor device 100 according to the embodiment.

FIG. 6 is a diagram illustrating a configuration of a conventional WPP type semiconductor device.

FIG. 7 is a view illustrating a method of manufacturing a conventional WPP semiconductor device.

FIG. 8 is a view for explaining a method of manufacturing a conventional WPP type semiconductor device.

DESCRIPTION OF SYMBOLS 10 Semiconductor chip 20 Insulating base material 30 Wiring pattern 40 Solder ball 50 Sealing resin 60 Bonding wire 70 External electrode 80 Gold wire bump 90 Solder resist 100 WPP type semiconductor device 110 Elastomer 140 Solder resist 200 Memory module 201 Memory module Wiring board 202 Wiring pattern of memory module

Claims (4)

[Claims] 1. A semiconductor device comprising a plurality of sets of semiconductor chips each comprising an external electrode and a circuit element formed on a main forming surface of a wafer, wherein each of the semiconductor chips is obtained by separating the semiconductor chips from the wafer. A formed wire bump or plated bump is provided on each of the external electrodes, and a stress buffer material (elastomer) or uncured for buffering a thermal stress generated between the semiconductor chip and a wiring board of an electronic device to which the semiconductor chip is connected. Providing a sealing material on the main forming surface of the semiconductor chip; providing a wiring pattern electrically connected to the wire bump or plating bump on the stress buffering material or the uncured sealing material; A semiconductor ball provided with a solder ball. 2. The semiconductor device according to claim 1, wherein the stress buffer has a glass transition temperature lower than a melting temperature of the solder ball and an elastic modulus at 150 ° C. of 10%.
A semiconductor device comprising a resin having a pressure of 0 MPa or less. 3. An electronic device, wherein the semiconductor device according to claim 1 is mounted on a wiring board. 4. A first step of forming a plurality of sets of semiconductor chips comprising external electrodes and circuit elements on a main formation surface of a wafer, and forming a wire bump or a plating bump of a conductive material on the external electrodes of the wafer. 2) a stress buffer (elastomer) or an uncured sealing material for buffering thermal stress generated between the semiconductor chip and a wiring board of an electronic device to which the semiconductor chip is connected; A third step of providing a wiring pattern electrically connected to the wire bump or the plating bump on the stress buffering material or the uncured sealing material;
And a fifth step of forming solder balls on the wiring pattern, and a sixth step of obtaining each semiconductor chip by separating the semiconductor chip from the wafer.