JP2007012781A - Circuit board, manufacturing method thereof, and display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board which is thin and light in weight, highly accurate and highly reliable, and can be manufactured at a low cost, and its manufacturing method. <P>SOLUTION: The manufacturing method of the circuit board comprises a laminating process of subsequently laminating an exfoliation layer 2 and a diffusion prevention layer 3 on a plate board 1; an element formation process of laminating a heat resistant high polymer film 4 on the diffusion prevention layer 3, and forming a thin film semiconductor element 14 on the heat resistant high polymer film 4 into a laminate plate board 15; a transfer process of superimposing a support resin layer 16 on the laminate plate board 15, and fixing the thin film semiconductor element 14 and the heat resistant high polymer film 4 on the laminate plate board 15 to the support resin layer 16; and a removal process of removing the plate board 1 and the exfoliation layer 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a circuit board manufacturing method, a circuit board, and a display device, and more particularly to a circuit board in which a thin film semiconductor element is embedded in a supporting resin layer and a manufacturing method thereof.

For example, in portable electronic devices such as mobile phones and PDAs, a thin plate-like circuit component module in which a circuit board and various components are integrated is being adopted in order to reduce the size and weight and reduce the cost. Such a circuit component module is, for example, as shown in Patent Document 1, in which various components are embedded in a substrate such as a resin, and a conductive circuit pattern is formed on the surface, and is formed in a flat plate shape with little unevenness. In addition, since it is thin and lightweight and has excellent mass productivity, it is suitable as a component substrate for portable electronic devices that are required to be reduced in size and weight.
Japanese Patent Laid-Open No. 11-220262

  By the way, in the circuit component module described in Patent Document 1, circuit components such as an IC chip are embedded in an insulating substrate whose main component is a thermosetting resin such as an epoxy resin, a phenol resin, or a cyanate resin. Thermosetting resins such as epoxy resins and phenolic resins are resin materials having excellent properties themselves, but instead of these thermosetting resins, polycarbonate and polyethylene are excellent in thermoplasticity and advantageous in cost. There is a demand to use so-called engineering plastics such as terephthalate. In addition, with the demand for further downsizing and thinning of electronic devices, it is also required to realize a circuit component module in which a thin film transistor element (TFT) or the like is embedded in an insulating substrate instead of a circuit component such as an IC chip.

However, it is difficult to realize such a circuit component module simply by applying the conventional technique described in Patent Document 1 as it is. That is, a thin film semiconductor element such as a TFT needs to be heated to a temperature of about 300 ° C. in order to form an insulating film made of SiN _x in the formation process. It has been almost impossible to perform such a thin film semiconductor element forming process that requires a heating process on an engineering plastic that is inferior in heat resistance as compared with a thermosetting resin such as an epoxy resin.

  The present invention has been made in view of the above circumstances, and aims to provide a circuit board that is thin and lightweight, highly accurate, highly reliable, and that can be produced at low cost, and a method for manufacturing the circuit board. To do. It is another object of the present invention to provide a display device including a thin and lightweight circuit board.

In order to achieve the above object, the present invention employs the following configuration.
The method for producing a circuit board of the present invention includes a laminating step of sequentially laminating a release layer and a diffusion preventing layer on a plate substrate, laminating a heat resistant polymer film on the diffusion preventing layer, and the heat resistant polymer film. An element forming step of forming a thin film semiconductor element on the laminated plate substrate; and a supporting resin layer superimposed on the laminated plate substrate to form the thin film semiconductor element and the heat resistant polymer film on the laminated plate substrate; And a removal step of removing the plate substrate and the release layer.

  Note that “fixing” includes embedding a thin film semiconductor element in a support resin layer and laminating a heat-resistant polymer film on the support layer. More specifically, it includes embedding a thin film semiconductor element in a softened support resin layer and laminating a heat resistant polymer film on the support layer.

In the circuit board manufacturing method of the present invention, in the element formation step, a heat resistant polymer film having a thermal expansion coefficient larger than the thermal expansion coefficient of the release layer and smaller than the thermal expansion coefficient of the plate substrate is used. It is preferable. More specifically, the thermal expansion coefficient of the heat resistant polymer film is preferably in the range of 6 ppm / ° C. to 17.5 ppm / ° C., more preferably in the range of 8 ppm / ° C. to 14 ppm / ° C. preferable.
Furthermore, in the method for manufacturing a circuit board according to the present invention, the thin film semiconductor element is preferably a thin film transistor element.
In the method for producing a circuit board of the present invention, it is preferable that a heating step in a range of 150 ° C. or higher and 350 ° C. or lower is involved in forming the thin film semiconductor element in the element forming step.

According to the above configuration, the heat-resistant polymer film is formed on the plate substrate, and further, the thin film semiconductor element is previously formed thereon, and the thin film semiconductor element is embedded and fixed in the supporting resin layer. A semiconductor element can be formed on a support resin layer.
In addition, since the thin film semiconductor element is formed in advance on the heat resistant polymer film having excellent heat resistance, the thin film semiconductor element has no problem even when a heating step of about 300 ° C. is required to form the thin film semiconductor element. The thin film semiconductor element thus formed can be easily embedded in the supporting resin layer.
Furthermore, since the diffusion preventing layer is formed, it is possible to prevent the thermal diffusion of the constituent material of the release layer with respect to the heat resistant polymer film.
Further, according to the above configuration, the thermal expansion coefficient of the heat resistant polymer film is larger than the thermal expansion coefficient of the release layer and smaller than the thermal expansion coefficient of the plate substrate. Even when the plate substrate or the like is heated to about 300 ° C., there is no possibility that the heat-resistant polymer film or the release layer is peeled off.

Next, the circuit board of the present invention includes a heat resistant polymer film, a thin film semiconductor element formed on the heat resistant polymer film, and the thin film semiconductor layered on the heat resistant polymer film. And a supporting resin layer in which the element is embedded.
In the circuit board of the present invention, the thin film semiconductor element is preferably a thin film transistor element.

  According to the above configuration, since the thin film semiconductor element is embedded in the support resin layer, the thin film semiconductor element can be protected by the support resin layer, and the support resin layer serves as a main component of the circuit board. Thinner and lighter can be achieved.

  Next, a display device according to the present invention includes any one of the circuit boards described above.

  As described above, according to the present invention, it is possible to provide a circuit board that is thin and lightweight, highly accurate, highly reliable, and that can be produced at low cost, and a method for manufacturing the circuit board. In addition, according to the present invention, a display device including a thin and lightweight circuit board can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The method for manufacturing a circuit board according to the present embodiment includes a lamination step of laminating a release layer and a diffusion prevention layer on a plate substrate, and forming a heat resistant polymer film and a thin film semiconductor element on the diffusion prevention layer, Element forming step, a transfer step for fixing the thin film semiconductor element and the heat-resistant polymer film on the laminated plate substrate to the supporting resin layer, and a removing step for removing the plate substrate and the release layer. . Hereinafter, each process will be described with reference to the drawings. 1 to 17 show process diagrams of a method for manufacturing a circuit board according to the present embodiment. These drawings are for explaining the circuit board of the present embodiment and the manufacturing method thereof, and the size, thickness, dimensions, etc. of the respective parts shown in the drawings are not necessarily the same as the actual dimensional relation of the circuit board. It is not a thing.

"Lamination process"
Hereinafter, the lamination process will be described with reference to FIGS. In this laminating step, first, a plate substrate 1 shown in FIG. 1 is prepared, and then a release layer 2 is formed on at least one surface 1a of the plate substrate 1 as shown in FIG. The plate substrate 1 is preferably a substrate having a heat resistance of about 300 ° C., specifically, a stainless plate having a thickness of about 700 μm is preferable. The release layer 2 is preferably a metal copper layer (hereinafter referred to as a Cu layer) having a thickness of about 3 μm, for example. The release layer 2 may be formed not only on one surface 1a of the plate substrate 1 but also on the entire surface of the plate substrate 1 as shown in FIG. By forming the release layer 2 on the entire surface of the plate substrate 1, the peelability of the release layer 2 can be improved. The release layer 2 (Cu layer) can be formed by an electroless plating method.

  Next, as shown in FIG. 3, the diffusion prevention layer 3 is laminated on the release layer 2. For the diffusion prevention layer 3, for example, any one of a Cr layer, a Ta layer, and a Mo layer having a thickness of about 0.2 μm to 0.7 μm, more specifically about 0.5 μm can be used. Such a diffusion preventing layer 3 can be formed by vapor deposition or sputtering. By laminating the diffusion preventing layer 3 on the release layer 2, Cu constituting the release layer 2 can be prevented from being thermally diffused to other layers.

"Element formation process"
Next, an element formation process will be described with reference to FIGS. In this element formation step, first, as shown in FIG. 4, a heat resistant polymer film 4 is formed on the diffusion preventing layer 3. The film thickness of the heat-resistant polymer film 4 is preferably about 2 μm to 10 μm, more specifically about 5 μm. Since a thin film semiconductor element is formed on the heat resistant polymer film 4 as will be described later, it is preferable that the heat resistant polymer film 4 has a heat resistance of about 300 ° C. like the plate substrate 1. Specifically, a polyimide film, an aromatic polyamide film, a polybenzimidazole film or the like is preferable. In the case of a polyimide film, it may be formed by a printing method.

Further, in order to prevent the heat-resistant polymer film 4 or the release layer 2 from being peeled off, the thermal expansion coefficient of the heat-resistant polymer film 4 is larger than the thermal expansion coefficient of the release layer 2 and more than the thermal expansion coefficient of the plate substrate 1. It is preferable to make it small. More specifically, the thermal expansion coefficient of the heat resistant polymer film 4 is preferably in the range of 6 ppm / ° C. to 17.5 ppm / ° C., more preferably in the range of 8 ppm / ° C. to 14 ppm / ° C. preferable. If the thermal expansion coefficient is less than 6 ppm / ° C., peeling between the plate substrate 1 and the peeling layer 2 may occur, or the peeling layer 2 may be partially peeled and floated in a dome shape, which is not preferable. Further, when the thermal expansion coefficient exceeds 17.5 ppm / ° C., peeling occurs between the diffusion preventing layer 3 and the heat resistant polymer film 4, or the heat resistant polymer film 4 is partially peeled to form a dome shape. Since it may float, it is not preferable.
When the thermal expansion coefficient is between 8 and 14 ppm / ° C., problems such as peeling and dome-shaped floating hardly occur.
If the thermal expansion coefficient of the heat resistant polymer film 4 is less than 4 ppm / ° C., peeling of the release layer 2 and dome-shaped float frequently occur, which is not preferable. On the other hand, if the thermal expansion coefficient exceeds 19 ppm / ° C., peeling of the heat-resistant polymer film 4 and dome-shaped float frequently occur, which is not preferable.

  For example, when the release layer 2 is a Cu layer (thermal expansion coefficient: 8 ppm / ° C.) and the plate substrate 1 is a stainless steel plate (thermal expansion coefficient: 14-17.5 ppm / ° C.), the heat resistant polymer film 4 It is preferable to use a polyimide film (thermal expansion coefficient: about 8 to 17.5 ppm / ° C.).

Next, a thin film transistor element (hereinafter referred to as TFT) which is a thin film semiconductor element is formed on the heat resistant polymer film 4. The process is shown in FIGS.
First, as shown in FIG. 5, a Cr film 5 to be a gate electrode is formed on the heat resistant polymer film 4. The Cr film 5 is preferably formed to a thickness of 0.1 μm by a sputtering method.
Next, as shown in FIG. 6, the Cr film 5 is etched and patterned by a photolithography technique to form a gate electrode 6.

Next, on the gate electrode 6 and the heat-resistant polymer film 4, a gate insulating film 7 made of SiN _x having a thickness of about 0.3 μm, a semiconductor film 8 made of amorphous silicon having a thickness of about 0.2 μm, and a thickness of 0. A bonding film 9 made of n ⁺ type amorphous silicon of about 05 μm is sequentially laminated. The gate insulating film 7, the semiconductor film 8, and the bonding film 9 are each formed by a CVD method. At this time, the plate substrate 1 and the like are heated to about 150 ° C. to 350 ° C.
In particular, when the gate insulating film 7 is formed, a process of heating in the range of 150 ° C. to 350 ° C. is performed after the SiN _x film is formed by the CVD method. At this time, it is preferable that the heating temperature is lower than 150 ° C., because an electric withstand voltage failure of the gate insulating film 7 occurs, and the characteristics of the gate insulating film 7 change due to heating when the TFT is embedded in the support layer. Absent. On the other hand, if the heating temperature exceeds 350 ° C., peeling between the plate substrate 1 and the peeling layer 2 may occur, or the peeling layer 2 may be partially peeled and floated in a dome shape, which is not preferable.
The heating temperature for forming the gate insulating film 7 is more preferably in the range of 250 ° C. to 300 ° C. Within this range, problems such as poor electrical resistance and peeling of the release layer 2 hardly occur.

Further, when the respective films 7 to 9 are formed by the CVD method, as shown in FIG. 7, a metal mask 10 having a plurality of rectangular openings 10a is disposed above the heat-resistant polymer film 4. The films 7 to 9 are preferably formed on the heat-resistant polymer film 4 through the openings 10a. The opening 10 a is preferably arranged so as to overlap with a region where the gate electrode 6 is formed and over a region wider than the region where the gate electrode 6 is formed. As a result, the films 7 to 9 are divided into rectangular islands corresponding to the openings 10a, and the gate electrode 6 is completely covered with the films 7 to 9. In addition, as the respective films 7 to 9 are formed in an island shape, the non-formation regions of the respective films 7 to 9 are formed in the heat resistant polymer film 4.
By thus dividing each film 7-9 into islands, the thermal stress in each film 7-9 is reduced, and film peeling between the plate substrate 1 and the heat resistant polymer film 4 is eliminated. This prevents the warpage of the plate substrate 1 itself.

Next, as shown in FIG. 8, the semiconductor film 8 and the bonding film 9 are etched and patterned by a photolithography technique to expose the peripheral portion 7 a of the gate insulating film 7.
Next, as shown in FIG. 9, an electrode film 11 made of Cr or the like having a thickness of about 0.3 μm is formed. The electrode film 11 is formed by patterning using a photolithography technique so as to cover a part of the gate insulating film 7, a part of the semiconductor film 8, and a part of the bonding film 9.
Next, as shown in FIG. 10, the electrode film 11 is divided into two. The division is performed by etching a part of the electrode film 11 on the bonding film 9 by a photolithography technique. Thereby, one of the divided electrode films becomes the source electrode 12 and the other electrode film becomes the drain electrode 13. In this manner, a TFT 14 (thin film transistor element) composed of the gate electrode 6, the source electrode 12, the drain electrode 13, the gate insulating film 7, the semiconductor film 8, and the bonding film 9 is formed on the heat resistant polymer film 4. Hereinafter, the entire laminated body including the plate substrate 1 to the TFT 14 is referred to as a laminated plate substrate 15.

"Relocation process"
Next, the transfer process will be described with reference to FIGS. In this transfer step, first, as shown in FIG. 11, the support resin layer 16 is disposed on the laminated plate substrate 15. The supporting resin layer 16 is desirably heated to a temperature near the melting point or softening point of the resin, specifically about 120 to 130 ° C., and is softened to some extent. Further, the support resin layer 16 may be softened by adding a solvent to the support resin layer 16 to swell the support resin layer 16 itself. The support resin layer 16 is made of a resin film having a thickness of about 3 to 9 μm, specifically about 5 μm. Specifically, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyacetal, nylon or other polyamide, modified polyphenylene What consists of what is called engineering plastics, such as an oxide / polyphenylene ether, is preferable.

  Next, as shown in FIG. 12, the supporting resin layer 16 in a softened state is pressed against the laminated plate substrate 15 to be laminated. By pressing the support resin layer 16 in a soft state against the laminated plate substrate 15, the TFT 14 is embedded in the support resin layer 16 and the support resin layer 16 is overlaid on the heat resistant polymer film 4 as shown in FIG. The

Next, as shown in FIG. 13, the support resin layer 16 is provided with holes 17 for through holes. The hole 17 is formed by etching the supporting resin layer 16 until it hits the source electrode 12 and the drain electrode 13.
Next, as shown in FIG. 14, an electrode layer 18 made of Cr or the like is formed in the through hole 17. One end 18 a of the electrode layer 18 is connected to the source electrode 12 and the drain electrode 13, and the other end 18 b is exposed on the support resin layer 16. Thereby, the source electrode 12 and the drain electrode 13 are drawn on the support resin layer 16. In this way, the through hole 19 is formed.

"Removal process"
Next, the removal process will be described with reference to FIGS. In this removing step, first, the plate substrate 1 is peeled off together with the peeling layer 2 as shown in FIG. 15, and then the diffusion preventing layer 3 is removed by etching as shown in FIG. When removing the diffusion preventing layer 3, it is desirable to protect the support resin layer 16 by applying a resist in advance.
As described above, as shown in FIG. 16, the TFT 14 formed on the heat resistant polymer film 4 and the supporting resin layer 16 superimposed on the heat resistant polymer film 4 and embedded with the TFT 14 are formed. The provided circuit board 20 is obtained.
As shown in FIG. 17, the support resin layer 16 may be cut for each TFT 14 as necessary.

As described above, according to the circuit board manufacturing method of the present embodiment, the heat-resistant polymer film 4 is formed on the plate substrate 1 and the TFT 14 is further formed thereon, and then the TFT 14 is supported on the supporting resin. Since it is embedded and fixed in the layer 16, the TFT 14 can be finally formed inside the support resin layer 16. As a result, even when the TFT 14 is manufactured at a temperature exceeding the heat resistance temperature of the support resin layer 16, the TFT 14 is embedded in the support resin layer 16 after the TFT 14 is manufactured. The support resin layer 16 can be prevented from being deteriorated without being heated.
Since the heat resistance temperature of the engineering plastic constituting the support resin layer 16 is generally about 150 ° C., it is impossible to manufacture the TFT 14 with a heating process of about 300 ° C. on the support resin layer 16. Therefore, the circuit board manufacturing method of this embodiment is an excellent method in that the TFT 14 can be embedded in engineering plastic.

In addition, since the TFT 14 is formed in advance on the heat-resistant polymer film 4, even if a heating step of about 300 ° C. is required for forming the TFT 14, the TFT 14 can be formed without any problems. The support resin layer 16 can be easily embedded.
Further, according to the above configuration, the thermal expansion coefficient of the heat resistant polymer film 4 is larger than the thermal expansion coefficient of the release layer 2 and smaller than the thermal expansion coefficient of the plate substrate 1. Even if the plate substrate 1 or the like is heated to about 300 ° C., the heat resistant polymer film 4 or the release layer 2 is not likely to be peeled off.
Furthermore, by forming the gate insulating film 7, the semiconductor film 8, and the bonding film 9 constituting the TFT 14 in an island shape, compared to the case where these films 7 to 9 are formed on the entire surface of the heat resistant polymer film 4, The thermal stress applied to these films 7 to 9 can be relaxed, and damage to the TFT 14 can be prevented.
Furthermore, since the diffusion prevention layer 3 made of Cr or the like is provided between the release layer 2 and the heat resistant polymer film 4, even if the release layer 2 is heated during the formation of the TFT 14, The diffusion of the constituent Cu is blocked by the diffusion preventing layer, whereby there is no possibility that the heat resistant polymer film is deteriorated by Cu.

In addition, according to the circuit board of the present embodiment, the supporting resin layer 16 made of engineering plastic is used as the main constituent member of the circuit board 20, so that the circuit board 20 itself can be made strong and lightweight. Furthermore, since no glass epoxy resin is used, the cost of the circuit board itself can be reduced.
Moreover, according to the circuit board of this embodiment, since TFT14 is embedded in the support resin layer 16, TFT14 can be protected.

  Next, FIG. 18 shows a schematic cross-sectional view of a liquid crystal display device 21 (display device) provided with the circuit board of the present embodiment. The liquid crystal display device 21 is a so-called active matrix type liquid crystal display device, and includes a circuit board 22 according to the present embodiment, a counter board 23 disposed opposite to the circuit board 22, and the circuit board 22 and the counter board 23. And a liquid crystal layer 24 disposed between the two.

The circuit board 22 is laminated on the heat-resistant polymer film 4, the TFT 14 formed on the heat-resistant polymer film 4, and the TFT 14 embedded therein. It is schematically composed of a support resin layer 16 made of polyester or the like. The TFT 14 includes a gate electrode 6 made of Cr or the like, a gate insulating film 7 made of SiN _x or the like covering the gate electrode 6, a semiconductor film 8 and a bonding film 9 stacked on the gate insulating film 7, and a bonding The source electrode 12 and the drain electrode 13 cover the film 9 and the gate insulating film 7. A through hole 19 is connected to the source electrode 12 and the drain electrode 13, and the source electrode 12 and the drain electrode 13 are drawn out on the support resin layer 16 by the through hole 19. Further, a reflective pixel electrode 25 made of Al is laminated on the support resin layer 16. The reflective pixel electrode 25 is connected to the drain electrode 13 through the through hole 19. An alignment film 26 made of polyimide is laminated on the support resin layer 16 and the reflective pixel electrode 25.

  Next, the counter substrate 23 includes a resin layer 27 made of polyester or the like, a counter electrode film 28 made of a transparent conductive material such as ITO laminated on the surface of the resin layer 27 on the liquid crystal layer 24 side, and a counter electrode film 28. The alignment film 29 is made of a laminated polyimide film.

In the liquid crystal display device 21 shown in FIG. 18, when the TFT 14 operates and a voltage is applied to the reflective pixel electrode 25, the liquid crystal molecules in the liquid crystal layer 24 between the reflective pixel electrode 25 and the counter electrode film 28 are aligned. Further, by controlling the voltage of the reflective pixel electrode 25, the degree of orientation of the liquid crystal molecules is changed, whereby hierarchical display can be performed.
Further, since the circuit board 22 is roughly composed of the heat-resistant polymer film 4, the TFT 14, and the support resin layer 16 made of polyester or the like, the circuit board 22 itself is rich in flexibility. Further, since the counter substrate 23 is composed of the resin layer 27 made of polyester or the like, the counter electrode film 28, and the alignment film 29, the counter substrate 23 itself is highly flexible like the circuit board. Accordingly, the liquid crystal display device 21 shown in FIG. 18 can be a flexible and deformable display device by adopting the circuit board 22 according to this embodiment.

FIG. 1 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining a lamination process. FIG. 2 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining a stacking process. FIG. 3 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining a stacking process. FIG. 4 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 5 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 6 is a process diagram showing a method for manufacturing a circuit board according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 7 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 8 is a process diagram showing a method of manufacturing a circuit board according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 9 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 10 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining an element formation process. FIG. 11 is a process diagram illustrating a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram illustrating a transfer process. FIG. 12 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining a transfer process. FIG. 13 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining a transfer process. FIG. 14 is a process diagram illustrating a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram illustrating a transfer process. FIG. 15 is a process diagram showing a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram for explaining a removal process. FIG. 16 is a process diagram illustrating a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram illustrating a removal process. FIG. 17 is a process diagram illustrating a circuit board manufacturing method according to an embodiment of the present invention, and is a diagram illustrating a removal process. FIG. 18 is a schematic cross-sectional view showing a main part of a liquid crystal display device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plate substrate, 2 ... Release layer, 3 ... Diffusion prevention layer, 4 ... Heat-resistant polymer film, 14 ... Thin-film transistor element (thin film semiconductor element), 15 ... Laminated plate board, 16 ... Support resin layer, 20, 22 ... Circuit board, 21 ... Liquid crystal display device (display device)

Claims (8)

A laminating step of sequentially laminating a release layer and a diffusion prevention layer on the plate substrate;
An element forming step of laminating a heat resistant polymer film on the diffusion preventing layer, and forming a thin film semiconductor element on the heat resistant polymer film to form a laminated plate substrate;
A transfer step of superimposing a supporting resin layer on the laminated plate substrate, and fixing the thin film semiconductor element and the heat-resistant polymer film on the laminated plate substrate to the supporting resin layer;
A circuit board manufacturing method comprising: a plate substrate and a removing step of removing the release layer.   2. The circuit according to claim 1, wherein in the element formation step, a heat resistant polymer film having a thermal expansion coefficient larger than a thermal expansion coefficient of the release layer and smaller than a thermal expansion coefficient of the plate substrate is used. A method for manufacturing a substrate.   The method for manufacturing a circuit board according to claim 2, wherein the heat-resistant polymer film has a coefficient of thermal expansion of 17.5 ppm / ° C or less.   4. The method for manufacturing a circuit board according to claim 1, wherein the thin film semiconductor element is a thin film transistor element.   5. The circuit board manufacturing method according to claim 1, wherein a heating step in a range of 150 ° C. or more and 350 ° C. or less is involved in forming the thin film semiconductor element in the element forming step. Method.   A heat-resistant polymer film; a thin-film semiconductor element formed on the heat-resistant polymer film; and a support resin layer that is superimposed on the heat-resistant polymer film and has the thin-film semiconductor element embedded therein. A circuit board comprising the circuit board.   The circuit board according to claim 6, wherein the thin film semiconductor element is a thin film transistor element. A display device comprising the circuit board according to claim 6.

Images