JPH1174230A - Manufacture of thin-film semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thin-film semiconductor device, without causing cracks and chips in a production process even if the thickness of the semiconductor device is 100 μm or less. SOLUTION: A first supporting plate 23 is adhered to a circuit formed face 12a of a semiconductor substrate 21 with a first adhesive 22, which allows adhesive force after adhering to reduce. After performing thin-film deposition processing on the rear face of the semiconductor substrate 21, a second supporting plate 25 is adhered to the rear face of the semiconductor substrate with a second adhesive 24 which allows adhesive force after adhering to be reduced. After the first adhesive 21 and the first supporting plate 23 have been peeled, a dicing tape is stuck to the rear face of the second supporting plate 25 to divide the semiconductor substrate 21, and then second supporting plate 25 is peeled off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin film semiconductor device in which a semiconductor element formed in a thin film shape is mounted on a mounting substrate.

[0002]

2. Description of the Related Art Conventionally, a semiconductor element is formed by forming a large number of integrated circuits on a semiconductor substrate (wafer) and dividing the semiconductor substrate for each of these integrated circuits. An integrated circuit is formed by diffusing impurities from the surface to the inside of a semiconductor substrate and then providing an insulating film or a conductive film on the surface of the semiconductor substrate. The thickness of the integrated circuit portion of the semiconductor element is about several μm, and 1 μm depending on the type of the semiconductor element.
In some cases. On the other hand, the thickness of the semiconductor substrate is several hundred μm. The reason why the semiconductor substrate is formed to be much thicker than the integrated circuit portion is to increase the strength of the semiconductor element and prevent the semiconductor element from being damaged during handling.

When the thickness of the semiconductor substrate is large, not only is it difficult to divide the semiconductor element into individual semiconductor elements, but also the formed semiconductor element becomes thick and the package for encapsulating the semiconductor element becomes thick. FIG. 5 shows an example of a package of a conventional semiconductor device.

FIG. 5 is a sectional view of a conventional semiconductor device.
In the figure, reference numeral 1 denotes a package, and 2 denotes a semiconductor element. The package 1 has a structure in which the semiconductor element 2 is adhered to the recess 1 a and the opening of the recess 1 a is closed by the lid 3. Further, an electrode (not shown) of the semiconductor element 2 is connected to a terminal (not shown) in the package by a bonding wire 4 made of gold or aluminum.

In the package 1 configured as described above, the concave portion 1a must be formed deeply in accordance with the thickness of the semiconductor element 2, so that the thicker the semiconductor element 2, the larger the thickness of the package 1. turn into. For this reason, in the related art, the back surface of the semiconductor substrate is ground by grinding before dividing the semiconductor substrate into individual semiconductor elements, thereby reducing the thickness of the semiconductor substrate. A method of manufacturing a semiconductor device in which the back surface of a semiconductor substrate is ground will be described with reference to FIGS.

FIGS. 6A to 6F are cross-sectional views for explaining a conventional method of manufacturing a semiconductor device. In these figures, reference numeral 5 denotes a semiconductor substrate on which an integrated circuit is formed, 6 denotes a surface protection tape, and 7 denotes a dicing tape. Reference numeral 8 denotes a semiconductor element, 9 denotes a package, and 10 denotes a bonding wire.

In order to thin the semiconductor substrate 5 by grinding, first, as shown in FIG. 6A, a surface protection tape 6 is attached to a circuit forming surface of the semiconductor substrate 5 on which a large number of integrated circuits are formed. . The surface protection tape 6 has a function of preventing a circuit forming surface from being damaged during grinding and a function as a cushioning material for reducing a pressing force at the time of grinding. 100-200 thickness
It is formed to be μm.

Next, the semiconductor substrate 5 is loaded into a grinder (not shown). The grinding by the grinder is performed by pressing a drill called a spindle on the surface protection tape 6 on the circuit forming surface side of the semiconductor substrate 5 and pressing a grinding wheel of a back grinder on the back surface of the semiconductor substrate 5. FIG. 6B shows the semiconductor substrate 5 after the grinding.

After grinding, the surface protection tape 6 on the semiconductor substrate 5 is peeled off as shown in FIG. This peeling is performed by attaching a peeling tape (not shown) having a larger adhesive force to the surface of the surface protecting tape 6 and peeling the peeling tape from the semiconductor substrate 5. Next, as shown in FIG. 6D, a dicing tape 7 is adhered to the back surface of the semiconductor substrate 5 after grinding. The dicing tape 7 is used to prevent the semiconductor element from falling off in the next dicing step.

In the dicing step, a dicing saw is pressed against the semiconductor substrate 5 from the circuit forming surface side, and the semiconductor substrate 5 is divided for each integrated circuit to form a semiconductor element 8. The semiconductor elements 8 thus formed are respectively removed from the dicing tape 7, mounted on a package 9 as shown in FIG. 6 (f), subjected to wire bonding, and then subjected to resin sealing. A semiconductor device is formed by completing the sealing step.

Electronic devices such as mobile phones and video cameras that make extensive use of this type of semiconductor device have been downsized,
In order to reduce the weight, it is required that the semiconductor device be formed smaller and lighter to improve the mounting density of the semiconductor device.

The packaging density of the semiconductor device is such that the semiconductor device as shown in FIG.
In the case of a semiconductor device that is housed in a package, the size is determined by the size of the package 1. As long as the package 1 is used, there is a limit in improving the mounting density. By employing a structure in which a semiconductor element is connected to a mounting substrate without using a package, that is, a so-called flip-chip structure, the mounting density can be increased as compared with the case where a package is used.
FIG. 7 shows a semiconductor element and a mounting board connected by a flip chip structure.

FIG. 7 is a sectional view showing a flip chip structure. In the figure, reference numeral 11 denotes a semiconductor element, and 1
Reference numeral 2 denotes a mounting board. The semiconductor element 11 has a circuit forming surface 1
1 a is opposed to the mounting substrate 12, and an electrode (not shown) is connected to a terminal (not shown) of the mounting substrate 12 by a bump 13.

By employing the flip chip structure shown in FIG. 7, the area of the mounting surface of the mounting substrate 12 can be reduced by the amount of the package, and the mounting substrate 12 can be reduced in weight. By reducing the weight of the mounting substrate 12, it is possible to reduce the weight of an electronic device using the same.

[0015]

However, there is a demand for a further weight reduction in the above-described electronic equipment, and the weight of the semiconductor element has become a problem in order to meet this demand.
The thickness of the semiconductor element is about 400 μm when the semiconductor element is mounted on a package as shown in FIG.
In the case where the flip chip structure shown in FIG.
It is about μm.

In order to form the semiconductor element into a thin film by reducing the thickness of the semiconductor element, the amount of grinding in the grinding step described with reference to FIGS. 6A and 6B is increased. However, when the grinding amount is increased, the semiconductor substrate is easily broken or chipped due to the pressing force applied from the grinding wheel, and the semiconductor is caused by the fact that the portion hit by the grinding wheel is ground in a slightly curved state. Variations in the thickness of the substrate will increase. Also,
When the surface protection tape is separated from the semiconductor substrate in the surface protection tape separation step described with reference to FIG. 6C, the semiconductor substrate may be broken. Further, a semiconductor element formed by dividing a semiconductor substrate in the form of a thin film must be carefully handled so as not to be broken, and workability in a process of mounting the semiconductor element on a mounting substrate is poor.

For this reason, considering workability and yield,
The limit of the thickness of the semiconductor substrate when thinning is about 200 μm. If the workability and the yield are neglected, the thickness of the semiconductor substrate can be reduced to about 100 μm, but the yield is significantly reduced and the cost is increased. That is, conventionally, when manufacturing a semiconductor device that can be realized as an industrial product, a semiconductor substrate (semiconductor element)
Was difficult to form so that the thickness was 100 μm or less.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is an object of the present invention to provide a method of manufacturing a thin film semiconductor device which does not cause cracking or chipping in the manufacturing process even when the thickness of the semiconductor element is 100 μm or less. With the goal.

[0019]

According to a method of manufacturing a thin film semiconductor device according to the present invention, a first support plate is provided with a first adhesive capable of reducing an adhesive force after bonding to a circuit forming surface of a semiconductor substrate. After the semiconductor substrate is subjected to a thinning process from the back surface side, the second support plate is bonded to the back surface of the semiconductor substrate with a second adhesive capable of reducing the adhesive force after the bonding, After the adhesive and the first support plate are peeled off, a dicing tape is attached to the back surface of the second support plate to divide the semiconductor substrate, and the second support plate is peeled off.

According to the present invention, the semiconductor substrate and the semiconductor element are connected to the first support plate or the first support plate in all steps from the time when the semiconductor substrate is thinned to the time when the semiconductor element is mounted on the mounting substrate. The second support plate reinforces.
Further, when the first support plate or the second support plate is peeled, no excessive force is applied to the semiconductor substrate or the semiconductor element.

According to another aspect of the invention, there is provided a method of manufacturing a thin film semiconductor device, comprising the steps of:
Before the adhesive force of the second adhesive is reduced, the semiconductor device is mounted on the mounting substrate via the bump.

According to the present invention, the mounting operation can be performed while holding the second support plate in the mounting step.

According to another aspect of the present invention, there is provided a method of manufacturing a thin film semiconductor device in which concave grooves are formed in a lattice shape on a circuit forming surface of a semiconductor substrate so as to surround a semiconductor element, and the bonding force can be reduced after bonding. The first adhesive is applied to the circuit forming surface by the first adhesive.
After performing the thinning process from the back surface side to the semiconductor substrate until the concave groove is exposed, a second adhesive capable of reducing the adhesive force after the bonding is applied to the back surface of the semiconductor substrate. After bonding the second support plate, the first adhesive and the first support plate are peeled off from the semiconductor element, and the semiconductor element is mounted on a mounting substrate via bumps, and then the second support This is performed by peeling the board.

According to the present invention, the semiconductor substrate and the semiconductor element are reinforced by the first support plate or the second support plate in all steps from the step of thinning the semiconductor substrate to the step of mounting. Further, when the first support plate or the second support plate is peeled, no excessive force is applied to the semiconductor substrate or the semiconductor element. Further, all the semiconductor elements can be mounted on the mounting board while being held by one second support plate.

Here, the first adhesive and the second adhesive are:
Those whose adhesive strength is reduced by being heated, those whose adhesive strength is reduced by being irradiated with ultraviolet light,
Use a material whose adhesive strength is reduced by contact with water. In addition, the first adhesive and the second adhesive are made different in the method of reducing the adhesive force so that the second adhesive does not peel when the first adhesive is peeled. be able to.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment Hereinafter, a method for manufacturing a thin film semiconductor device according to the present invention will be described in detail with reference to FIGS. 1 and 2 are cross-sectional views for explaining a method of manufacturing a thin film semiconductor device according to the present invention. FIG. 1 shows the first half of the manufacturing process, and FIG. 2 shows the latter half of the manufacturing process.

In these figures, reference numeral 21 indicates a semiconductor substrate on which an integrated circuit is formed. This semiconductor substrate 21
The upper side of the drawing is the circuit forming surface 21a. Reference numeral 22 denotes a first adhesive, 23 denotes a first support plate, 24 denotes a second adhesive, and 25 denotes a second support plate.

As the first adhesive 22 and the second adhesive 24, those whose adhesive strength is reduced by performing some processing after bonding are employed. For example, those that have the property of reducing the adhesive strength by foaming when heated,
A material having a property of being reduced by being irradiated with ultraviolet rays and having a reduced adhesive strength, or a material having a property of being reduced in adhesive strength when exposed to water is used. In addition, these adhesives 2
2, 24 may be in any form before bonding. For example, it may be liquid, gel, or sheet.

The first support plate 23 and the second support plate 25 are formed of a material having the same hardness as a semiconductor substrate such as a glass plate or a silicon wafer. Further, it is desirable that the thicknesses of these support plates 23 and 25 are approximately equal to the thickness of the semiconductor substrate 21 before being thinned.

In FIG. 2, reference numeral 26 denotes a dicing tape, and 27 denotes a semiconductor element obtained by dividing the semiconductor substrate 21. 2 (c) and 2 (d).
8 indicates a mounting board, and 29 indicates a bump.

Next, a method of manufacturing the thin film semiconductor device according to this embodiment will be described. First, as shown in FIG. 1A, a first adhesive 2 is applied to a circuit forming surface 21a of a semiconductor substrate 21.
Two layers are provided. At this time, if the form of the first adhesive 22 before bonding is in a liquid or gel state, it is changed to the circuit forming surface 21a.
If the form before bonding is a sheet, it is pressed against and bonded to the circuit forming surface 21a. When applying the first adhesive 22, a brush can be used or a spin coating method can be adopted.

Thereafter, as shown in FIG. 1B, a first support plate 23 is bonded on the circuit forming surface 21 via the first adhesive 22. Next, the semiconductor substrate 21 is
Is mounted on a grinder (not shown) together with the support plate 23 of FIG. 1, and the back surface of the semiconductor substrate 21 is ground by a back grinder. After the grinding, the back surface is polished or chemically etched to form the semiconductor substrate 21 into a thin film having a thickness of 100 μm or less. Conventionally, it has been difficult to reduce the thickness to 100 μm or less with good yield without cracking or chipping of the semiconductor substrate 21 in the steps up to here. But,
According to this manufacturing method, since the first support plate 23 reinforces the semiconductor substrate 21, the semiconductor substrate 21 has a thickness of 100 μm.
m or less. In the thinning process, polishing or chemical etching may be performed from the beginning without performing grinding with a back grinder.

After the semiconductor substrate 21 is formed into a thin film as described above, the first support plate 23 is gripped in FIG.
As shown in FIG. 3, the second adhesive 24
Is provided. The method of forming this layer is the same as the case where the layer of the first adhesive 22 is provided. However, the second adhesive 24 is different from the first adhesive 22 in a method of reducing the adhesive force. For example, in the case where a material having a property that the adhesive force is reduced by being heated as the first adhesive 22 is used, the second adhesive 24 has a property that the adhesive force is not reduced by heating. An adhesive having a property that the adhesive strength is reduced by ultraviolet irradiation or reaction with water is used.

Next, as shown in FIG. 1E, a second support plate 25 is adhered to the back surface of the semiconductor substrate 21 via the second adhesive 24, and the first adhesive 22 is adhered. The first adhesive 22 and the first support plate 2
3 is peeled off from the semiconductor substrate 21 to expose the circuit forming surface 21 of the semiconductor substrate 21 as shown in FIG. The peeling of the first adhesive 22 and the first support plate 23
This is performed in a state where the support plate 25 is gripped. Since the second adhesive 24 has a property different from that of the first adhesive 22, even if a process for reducing the adhesive strength is performed on the first adhesive 22, the adhesive strength is reduced. Does not decrease.

Thereafter, as shown in FIG. 2A, a dicing tape 26 is adhered to the back surface of the second support plate 25,
As shown in FIG. 2B, the semiconductor substrate 21 is divided into integrated circuits by a conventionally known dicing saw or the like. At this time, the second support plate 25 is also split at the same time as the semiconductor substrate 21 so that the blade (not shown) of the dicing saw reaches the second support plate 25. Thus, the semiconductor substrate 21
Is divided to form the semiconductor element 27.

Then, the divided second support plate 25 is removed from the dicing tape 26. In the mounting process after removing the second support plate 25, the second support plate 25 is gripped and mounted instead of the semiconductor element 27. This mounting is performed so as to realize a conventionally known flip chip structure. That is, as shown in FIG. 2C, the circuit forming surface of the semiconductor element 27 is opposed to the mounting surface of the mounting substrate 28, and the bump 29
The semiconductor element 27 is connected to the mounting substrate 28 via the.

After the mounting is completed, the second adhesive 24 is subjected to a process of reducing the adhesive strength, and as shown in FIG.
The second adhesive 24 and the second support plate 25 are separated from the semiconductor element 27. At this time, only the second support plate 25 is peeled off, and the second adhesive 24 is applied to the semiconductor element 27.
May be left behind. From the viewpoint of weight reduction, it is desirable that the second adhesive 24 is also peeled off.

As described above, the semiconductor element 27 is mounted on the mounting board 28.
After mounting on the semiconductor element 2 by a conventionally well-known sealing structure.
7, the semiconductor element 27 has a thickness of 1
It is possible to manufacture a thin film semiconductor device having a thickness of not more than 00 μm.

Therefore, according to the above-described manufacturing method,
Since the semiconductor substrate 21 and the semiconductor element 27 are reinforced by the first support plate 23 or the second support plate 25 in all the steps from the step of performing the thinning process on the semiconductor substrate 21 to the mounting step, The semiconductor substrate 21 and the semiconductor element 27 in the form of a thin film are not broken or chipped during the process. In addition, the first support plate 23 and the second support plate 2
When peeling 5, no excessive force is applied to the semiconductor substrate 21 or the semiconductor element 27.

Further, since the mounting operation can be performed while holding the second support plate 25, the semiconductor element 27
The workability of the mounting operation is good even when the thin film is used, and the semiconductor element 27 is not broken during the mounting operation.

In this embodiment, the semiconductor device 2
Although a flip-chip structure is employed to connect the semiconductor chip 7 to the mounting substrate 28, a structure in which the semiconductor element 27 is bonded to a package and connected by bonding wires as shown in FIG. 5 can also be employed.

Second Embodiment One embodiment of a method of manufacturing a thin film semiconductor device according to another invention will be described in detail with reference to FIGS. 3 and 4 are cross-sectional views for explaining a method of manufacturing a thin film semiconductor device according to another invention. FIG. 3 shows the first half of the manufacturing process.
FIG. 4 shows the latter half of the manufacturing process. In these figures, the same or equivalent members as those described in FIG. 1 and FIG. 2 are denoted by the same reference numerals, and detailed description is omitted.

In order to carry out the method of manufacturing a thin film semiconductor device according to this embodiment, first, as shown in FIG. 3A, an integrated circuit (a part to be a semiconductor element) is formed on a circuit forming surface 21a of a semiconductor substrate 21. ) Are formed in a lattice shape so as to surround the groove. The concave groove 31 is formed by moving a blade of a dicing saw (not shown) along a scribe line (not shown) on the circuit forming surface 21a.

The depth of the groove 31 is the same as the thickness of the semiconductor element to be formed. For example, when a semiconductor element having a thickness of 50 μm is formed, the concave groove 31 is formed so as to have a depth of 50 μm. In addition, the concave groove 31 can be formed by other methods such as chemical etching in addition to the dicing saw.

Next, as shown in FIG. 3B, a layer made of the first adhesive 22 is provided on the circuit forming surface 21a. The method of forming this layer is the same as when the first embodiment is employed. Then, as shown in FIG.
1 on the first support plate 23 via the first adhesive 22
Glue.

After bonding the first support plate 23, the semiconductor substrate 21 is loaded together with the first support plate into a grinder (not shown), and the back surface of the semiconductor substrate 21 is ground by a back grinder. This grinding is performed until the groove 31 is exposed, as shown in FIG. When this grinding step is completed, an extra portion is removed from the semiconductor substrate 21 except for the integrated circuit portion, and the semiconductor element 27 is formed.

The semiconductor substrate 21 can be formed into a thin film by polishing or chemical etching, or by a combination of the above-mentioned grinding and these. Since the first support plate 23 reinforces the semiconductor substrate 21 even when this embodiment is adopted, the semiconductor substrate 2
1 can be thinned to a thickness of 100 μm or less.

After thinning the semiconductor substrate 21 to form the semiconductor element 27, the first support plate 23
While holding the semiconductor device, as shown in FIG.
7 is provided with a layer made of the second adhesive 24 on the back surface. The method of forming this layer and the method of selecting the properties of the second adhesive 24 are the same as in the case of the first embodiment. Then, as shown in FIG. 4A, a second support plate 25 is bonded to the back surface of the semiconductor element 27 via the second adhesive 24.

Next, the first adhesive 22 and the first support plate 23 are peeled off from the semiconductor element 27 by performing a process for reducing the adhesive strength of the first adhesive 22, and as shown in FIG. Then, the circuit formation surface of the semiconductor element 27 is exposed. First
The peeling of the adhesive 22 and the first support plate 23 is performed while the second support plate 25 is gripped.

Thereafter, as shown in FIG. 4C, in a state where all the semiconductor elements 27 are fixed on the second support plate 25, each semiconductor element 27 is mounted on the mounting board 28 via the bump 29. I do. Conventionally, semiconductor elements are mounted one by one on a mounting board formed in a tape shape. In this embodiment, a plurality of semiconductor elements 27, 27 # are mounted on the mounting board 28 at one time. For this reason, the mounting substrate 28 used when adopting this embodiment has a structure in which a large number of mounting portions 28a for mounting the semiconductor elements 27 are arranged in a matrix on a sheet 28b. The mounting of the semiconductor element 27 on the mounting board 28 can be performed by mounting the semiconductor element 27 on the second support plate 25 on a plurality of mounting boards 28 in addition to the above-described mounting method. . In this case, for example, the mounting substrate 28 is formed in a tape shape in which the mounting portions 28a are arranged in a line.

After the semiconductor element 27 is mounted on the mounting board 28 as described above, the second adhesive 24 is subjected to a process of reducing the adhesive force, and as shown in FIG. The adhesive 24 and the second support plate 25 are separated from the semiconductor element 27. At this time, only the second support plate 25 may be peeled off and the second adhesive 24 may be left on the back surface of the semiconductor element 27. From the viewpoint of weight reduction, it is desirable that the second adhesive 24 is also peeled off.

Next, as shown in FIG.
8 is divided for each mounting portion 28a, and the semiconductor element 27 is sealed by a conventionally known sealing structure, whereby a thin film semiconductor device having a thickness of the semiconductor element 27 of 100 μm or less can be manufactured.

Therefore, according to the manufacturing method of this embodiment, the semiconductor substrate 21 and the semiconductor element 27 are connected to the first substrate in all the steps from the step of performing the thinning process on the semiconductor substrate 21 to the mounting step. Since the support plate 23 or the second support plate 25 reinforces, the semiconductor substrate 21 or the semiconductor element 27 in the form of a thin film does not break or chip during the manufacturing process. Further, when the first support plate 23 or the second support plate 25 is peeled, no excessive force is applied to the semiconductor substrate 21 or the semiconductor element 27.

Therefore, the thickness of the semiconductor substrate 21 is set to 10
Even if the thickness is 0 μm or less, the yield is good, and the workability is also good because the first support plate 23 and the second support plate 25 can be gripped and handled instead of the thin-film semiconductor substrate 21 and the semiconductor element 27. . Further, since all the semiconductor elements 27 can be mounted on the mounting board 28 while being held by one second support plate 25, compared with the case where the divided semiconductor elements are mounted on the mounting board one by one. The working time of the mounting work can be reduced.

[0055]

The adhesive used to carry out the production method of the present invention, that is, the adhesive capable of lowering the adhesive strength after bonding, reduces the adhesive strength after bonding to a substrate made of synthetic resin. Some substances have been added. The base material is acrylic resin, polyester resin,
Any synthetic resin such as an epoxy resin, a urethane resin, a polythiol resin, and a polyimide resin may be used.

An adhesive whose adhesive strength is reduced by heating is an adhesive obtained by packing a substance having a large coefficient of thermal expansion in a microcapsule and uniformly adding the microcapsule to the base material, that is, a so-called thermal foaming type. An adhesive was used.
As the adhesive whose adhesive strength is reduced by being irradiated with ultraviolet rays, an ultraviolet irradiation-curable adhesive obtained by adding a photopolymerizing agent to the substrate was used.

As an adhesive whose adhesive strength is reduced by contact with water, an adhesive made of a polyimide resin is used.
The adhesive strength of the polyimide resin is reduced by contact with water due to its own hygroscopicity.

[0058]

As described above, according to the present invention, the semiconductor substrate and the semiconductor element are removed in all steps from the time when the semiconductor substrate is thinned to the time when the semiconductor element is mounted on the mounting substrate. The first support plate or the second
Since the support plate is reinforced, the thin-film semiconductor substrate or semiconductor element does not crack or chip during the manufacturing process. In addition, no excessive force is applied to the semiconductor substrate or the semiconductor element when the first support plate or the second support plate is peeled off.

Therefore, the thickness of the semiconductor substrate is set to 100 μm.
Even if it is less than m, the yield is good, and the workability is also good because the first support plate and the second support plate can be gripped and handled instead of the thin film semiconductor substrate or semiconductor element.

According to another invention in which the semiconductor element is mounted on the mounting substrate before the second adhesive is lowered after the semiconductor substrate is divided, the mounting operation is performed while holding the second support plate. Accordingly, the workability of the mounting operation is good even when the semiconductor element is in the form of a thin film, and the semiconductor element is not broken during the mounting operation.

According to another invention, a concave groove is formed on a circuit forming surface of a semiconductor substrate, a first support plate is bonded, and after a thinning process is performed, a second support plate is bonded on the back surface. In all processes from the substrate thinning process to the mounting process, the semiconductor substrate and the semiconductor element are reinforced by the first support plate or the second support plate. The element does not crack or chip. In addition, no excessive force is applied to the semiconductor substrate or the semiconductor element when the first support plate or the second support plate is peeled off.

Therefore, the thickness of the semiconductor substrate is set to 100 μm.
Even if it is less than m, the yield is good, and the workability is also good because the first support plate and the second support plate can be gripped and handled instead of the thin film semiconductor substrate or semiconductor element. Also, since all the semiconductor elements can be mounted on the mounting board while being held by one second support plate,
The operation time of the mounting operation can be reduced as compared with the case where the divided semiconductor elements are mounted on the mounting substrate one by one, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a method for manufacturing a thin-film semiconductor device according to the present invention.

FIG. 2 is a cross-sectional view illustrating a method for manufacturing a thin-film semiconductor device according to the present invention.

FIG. 3 is a cross-sectional view for explaining a method for manufacturing a thin-film semiconductor device according to another invention.

FIG. 4 is a cross-sectional view for explaining a method of manufacturing a thin-film semiconductor device according to another invention.

FIG. 5 is a cross-sectional view of a conventional semiconductor device.

FIG. 6 is a cross-sectional view for explaining a conventional method for manufacturing a semiconductor device.

FIG. 7 is a sectional view showing a flip chip structure.

[Explanation of symbols]

Reference Signs List 21 semiconductor substrate, 22 first adhesive, 23 first support plate, 24 second adhesive, 25 second support plate, 2
6: dicing tape, 27: semiconductor element, 28: mounting board, 29: bump, 31: concave groove.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Ohto 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Within Japan Telegraph and Telephone Corporation (72) Inventor Shigeo Ogawa 3-192-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (7)

[Claims] In a method of manufacturing a thin film semiconductor device in which a semiconductor element formed in a thin film shape is mounted on a mounting substrate, before the semiconductor substrate is divided for each semiconductor element and after a circuit is formed, an adhesive force after bonding is reduced. A first support plate is adhered to a circuit forming surface of the semiconductor substrate via a first adhesive that can be reduced, the semiconductor substrate is subjected to a thinning treatment from the back surface side, and the adhesive force after the adhesion is applied. A second support plate is adhered to the back surface via a second adhesive capable of reducing the adhesive strength, and then the adhesive strength of the first adhesive is reduced to reduce the first adhesive and The first support plate is peeled from the semiconductor substrate, and then a dicing tape is attached to the back surface of the second support plate to divide the semiconductor substrate together with the second support plate to form a semiconductor element. After a while
A method for manufacturing a thin-film semiconductor device, comprising: separating a second support plate from the semiconductor element by lowering an adhesive force of a second adhesive. 2. The method of manufacturing a thin film semiconductor device according to claim 1, wherein the semiconductor substrate is divided together with the second support plate to form a semiconductor element, and before the adhesive strength of the second adhesive is reduced. A method of manufacturing a thin film semiconductor device, comprising: mounting a semiconductor element on a mounting substrate via a bump. 3. A method of manufacturing a thin-film semiconductor device in which a semiconductor element formed in a thin-film form is mounted on a mounting substrate, wherein a circuit is formed before the semiconductor substrate is divided into semiconductor elements and after a circuit is formed. On the formation surface, concave grooves are formed in a lattice shape so as to surround the semiconductor element, and on the circuit formation surface,
The first support plate is bonded via a first adhesive capable of reducing the bonding force after bonding, and the thinning process is performed on the semiconductor substrate from the back surface side until the groove is exposed. To form a divided semiconductor device, and then
A second support plate is bonded to the back surface of the semiconductor element via a second adhesive capable of reducing the adhesive force after the bonding, and thereafter, the adhesive force of the first adhesive is reduced. The first adhesive and the first support plate are peeled off from the semiconductor element to expose a circuit forming surface of the semiconductor element, and the semiconductor element is mounted on a mounting substrate via bumps, and the second adhesive is A method for manufacturing a thin-film semiconductor device, comprising: separating a second support plate from the semiconductor element by reducing an adhesive force. 4. The method for manufacturing a thin film semiconductor device according to claim 1, wherein an adhesive whose adhesive strength is reduced by performing a heat treatment is used. 5. The method for manufacturing a thin film semiconductor device according to claim 1, wherein an adhesive whose adhesive strength is reduced by being irradiated with ultraviolet rays is used. . 6. The method for manufacturing a thin film semiconductor device according to claim 1, wherein an adhesive whose adhesive strength is reduced by contact with water is used. 7. The method for manufacturing a thin film semiconductor device according to claim 1, wherein the first adhesive and the second adhesive are different from each other in a method of reducing an adhesive force. A method for manufacturing a thin film semiconductor device.