JP2011199090A - Method of manufacturing flexible printed wiring board, method of manufacturing semiconductor device, method of manufacturing display device, flexible printed wiring board, semiconductor device, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a flexible printed wiring board having superior heat dissipation efficiency.SOLUTION: A method of manufacturing a TCP-type flexible printed wiring board 12A includes a step of laminating an adhesive layer 1A on a metal base material film 1; a step of pasting conductor foil 2 to the adhesive layer 1A; a step of laminating a photoresist film 4 on the conductor foil 2; a step of exposing and developing the photoresist film 4; a step of coating the part of the metal base material film 1 not covered with the conductor foil 2 with an etching protection film 15; and a step of forming a conductive pattern 3, by etching the conductor foil 2 via the exposed and developed photoresist film 4 (developed pattern 4A), in a state where the etching protection film 15 is coated.

Description

  The present invention relates to a method for manufacturing a flexible printed wiring board, a method for manufacturing a semiconductor device, a method for manufacturing a display device, a flexible printed wiring board, a semiconductor device, and a display device.

  Various semiconductor devices having improved heat dissipation have been proposed for semiconductor devices in which a semiconductor chip is mounted on a flexible printed wiring board. For example, in the semiconductor device of Patent Document 1, it is proposed to bend the flexible printed wiring board at an appropriate position and arrange the semiconductor chip at a position where heat is easily dissipated in the display device.

JP 2009-10309 A

  In recent years, in order to improve the moving image resolution of a liquid crystal display device, measures for increasing the operation speed of a semiconductor chip have been taken, and the amount of heat generation tends to increase, so that efficient heat dissipation is required. In addition, the plasma display device is conventionally required to dissipate heat efficiently because the driving current is larger and the heat generation amount is larger than that of the liquid crystal display device. Thus, the demand for improving heat dissipation is still high.

  The objective of this invention is providing the manufacturing method of a flexible printed wiring board with sufficient heat dissipation efficiency, the manufacturing method of a semiconductor device, the manufacturing method of a display apparatus, a flexible printed wiring board, a semiconductor device, and a display apparatus.

  The method for producing a flexible printed wiring board of the present invention includes a step of laminating an adhesive layer on a metal base film, a step of attaching a conductor foil to the adhesive layer, and a layer of a photoresist film on the conductor foil. A step of exposing and developing the photoresist film, a step of covering an etching protective film on a portion of the metal base film not covered with the conductor foil, and the etching protection on the metal base film And a step of etching the conductor foil through the photoresist film after exposure and development to form a conductive pattern with the film covered.

  Preferably, the step of covering the etching protective film is performed separately from the step of laminating the photoresist film.

  Preferably, in the method for manufacturing the flexible printed wiring board, after the step of laminating the adhesive layer and before the step of attaching the conductor foil, an opening is formed in the metal base film and the adhesive layer. The conductive pattern further includes a connecting terminal protruding into the opening.

  Preferably, the thermal conductivity of the adhesive layer is 1 W / m · K or more.

  The method for manufacturing a semiconductor device of the present invention includes a step of laminating an adhesive layer on a metal base film, a step of attaching a conductor foil to the adhesive layer, and a step of laminating a photoresist film on the conductor foil. And a step of exposing and developing the photoresist film, a step of covering an etching protective film on a portion of the metal base film not covered with the conductor foil, and the etching protective film on the metal base film. Etching the conductive foil through the photoresist film after exposure and development in a covered state to form a conductive pattern including an external connection terminal and a semiconductor chip connection terminal; and Connecting and mounting the semiconductor chip on the semiconductor chip connection terminal.

  Preferably, in the method for manufacturing the semiconductor device, a first slit that extends in a concave shape with the semiconductor chip side as a concave side in a plan view of the metal base film and surrounds at least a part of the conductor pattern is formed on the metal. It further has the process of forming in a base film.

  Preferably, the shape of the semiconductor chip is a square, and the first slit is formed so as to surround three sides of the square semiconductor chip.

  Preferably, the manufacturing method of the semiconductor device further includes a step of forming a linear second slit in the metal base film and a step of filling the second slit with a soft resin.

  According to the display device manufacturing method of the present invention, a semiconductor device is formed by the semiconductor device manufacturing method described above, the metal base film is folded back with the conductor foil side inside, and the external connection terminals are It is connected to a component different from the semiconductor device.

  Alternatively, the method for manufacturing a display device according to the present invention includes forming the semiconductor device by the method for manufacturing a semiconductor device described above, and in the metal base film, the inner portion of the first slit is not folded back. The outer portion of one slit is folded back with the conductor foil side as the inner side, and the external connection terminal is connected to a component different from the semiconductor device.

  The flexible printed wiring board of the present invention includes a metal base film having an opening formed thereon, an adhesive layer laminated on the metal base film, and a connection terminal laminated on the adhesive layer and protruding into the opening. And a conductive pattern.

  A semiconductor device of the present invention includes the flexible printed wiring board described above, and a semiconductor chip disposed in the opening of the flexible printed wiring board and connected to the connection terminal.

  The display device of the present invention includes the semiconductor device described above, a glass substrate connected to the semiconductor device, and a housing that accommodates the semiconductor device and the glass substrate and contacts the metal base film. Have.

  According to the present invention, heat dissipation efficiency can be improved.

(A) thru | or (I) is a manufacturing-process figure of the TCP type flexible printed wiring board which concerns on embodiment of this invention. It is a top view of the TCP type flexible printed wiring board manufactured by the manufacturing process shown in FIG. It is a top view of another TCP type flexible printed wiring board manufactured by the manufacturing process shown in FIG. (A) thru | or (D) is a manufacturing-process figure of the TCP type semiconductor device which concerns on embodiment of this invention. It is a top view of the TCP type semiconductor device manufactured by the manufacturing process shown in FIG. (A) And (B) is a manufacturing-process figure of another TCP type semiconductor device. It is a top view of the TCP type semiconductor device manufactured by the manufacturing process shown in FIG. (A) thru | or (I) is a manufacturing-process figure of the COF type flexible printed wiring board which concerns on embodiment of this invention. It is a top view of the COF type flexible printed wiring board manufactured by the manufacturing process shown in FIG. It is a top view of another COF type flexible printed wiring board manufactured by the manufacturing process shown in FIG. (A) thru | or (D) is a manufacturing-process figure of the COF type semiconductor device which concerns on embodiment of this invention. FIG. 12 is a plan view of a COF type semiconductor device manufactured by the manufacturing process shown in FIG. 11. (A) And (B) is a manufacturing-process figure of another COF type semiconductor device. It is a top view of the COF type semiconductor device manufactured by the manufacturing process shown in FIG. FIG. 6 is a diagram illustrating a usage state of the TCP type semiconductor device illustrated in FIG. 5. It is a use condition figure of the COF type semiconductor device shown in FIG. FIG. 8 is a use state diagram of the TCP type semiconductor device shown in FIG. 7. FIG. 15 is a view illustrating a usage state of the COF type semiconductor device illustrated in FIG. 14. It is a top view of another TCP type semiconductor device concerning an embodiment of this invention. It is a top view of still another TCP type semiconductor device concerning an embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The flexible printed wiring board of the embodiment includes a TCP type flexible printed wiring board in which a device hole is provided and a COF type flexible printed wiring board in which no device hole is provided. Further, the flexible printed wiring board of the embodiment includes a flexible printed wiring board provided with a bending slit and a flexible printed wiring board provided with no slit.

The description will be given in the following order.
<Method for producing flexible printed wiring board>
(TCP type)
No slit formation planned, slit formation planned (COF type)
No slit formation planned, slit formation planned <Semiconductor device manufacturing method>
(TCP type-no slit)
(TCP type-with slit)
(COF type-no slit)
(COF type-with slit)
<Method for Manufacturing Display Device>
(TCP type-no slit)
(COF type-no slit)
(TCP type-with slit)
(COF type-with slit)

<Method for producing flexible printed wiring board>
(TCP type)
The manufacturing method of the TCP type flexible printed wiring board of embodiment is demonstrated using FIG. 1 (A) thru | or (I).

  As shown in FIG. 1A, an adhesive layer 1 </ b> A having a cover film 1 </ b> B for preventing dust is laminated on the surface of the metal base film 1. Hereinafter, the adhesive layer 1A side of the metal base film 1 may be referred to as the front side, and the opposite side may be referred to as the back side.

  The metal base film 1, the cover film 1 </ b> B, and the adhesive layer 1 </ b> A are formed in a long shape in the paper penetration direction. And as the metal base film 1, metal foil with good thermal conductivity and good workability is used. For example, a copper foil having a thickness of 25 μm to 150 μm is used. Alternatively, an aluminum foil having a light specific gravity and good workability may be used.

  The adhesive layer 1A is made of an epoxy adhesive having high electrical insulation and a thickness of 5 to 25 μm. For example, a trade name “TAB adhesive # 8200” manufactured by Toray Industries, Inc. having high electrical insulation, thermal conductivity of about 0.2 W / m · K, and a thickness of about 12 μm is used. Preferably, a product of 1 W / m · K or higher is used. For example, a product name “TSA series” made mainly of epoxy resin and having a thermal conductivity of about 3 W / m · K manufactured by Toray Industries, Inc. Use it. This “TSA series” has a thickness of 20 μm to 100 μm, but it is preferable to use a thin one as much as possible in order to reduce the thermal resistance θ.

  Next, as shown in FIG. 1 (B), sprocket holes 11 are punched and formed at regular intervals in the length direction (paper surface penetrating direction) along both edges of the metal base film 1 using a mold. At the same time, a required number of device holes 11A are punched and formed at predetermined positions for each unit wiring pattern. The device hole 11 </ b> A may be punched later using the sprocket hole 11 as a guide after punching the sprocket hole 11.

  Next, as shown in FIG. 1C, the conductor foil 2 is laminated by applying heat and pressure while peeling the cover film 1B in the length direction of the metal substrate film 1 (through direction in the drawing), and further heat is applied. Is added to cure the adhesive layer 1A. As the conductive foil 2, a metal foil having a low electrical resistance and a high thermal conductivity is used. For example, a copper foil having a thickness of 8 μm to 80 μm is used. In consideration of the formation of a fine conductive pattern, it is preferable to use one having a thickness of about 8 μm to 40 μm.

  Next, as shown in FIG. 1D, a photoresist liquid is applied to the surface of the conductor foil 2 by a roll coater method, and then dried by heating to form a photoresist film 4. The photoresist film 4 is formed to have a thickness suitable for forming a fine conductive pattern. Thereafter, as shown in FIG. 1E, exposure and development are performed to form a development pattern 4A.

  Next, an etching protective film is provided on the entire surface excluding the surface of the conductive foil 2 in order to prevent the metal base film 1 from being etched by an etching process for etching the conductive foil 2 to be performed later.

  In order to form this etching protective film, a method is conceivable in which the photoresist solution is applied to the surface of the conductor foil 2 and simultaneously applied to the other entire surface, and then heated and dried to form the photoresist film on the entire surface. .

  In order to form a fine conductive pattern using this method, it is preferable to reduce the thickness of the photoresist film formed on the surface of the conductor foil 2. Therefore, the thicknesses of the other photoresist films are similarly reduced, and the edge portion of the metal substrate film 1 is further thinned by the action of the surface tension of the photoresist solution, and may be damaged by etching. On the other hand, it may be undesirable for the edge portion to be affected by etching. For example, since the device hole 11A has a shape related to the final product, it is preferable that the original shape is maintained.

  Therefore, an electrodeposition resist system in which the film thickness of the edge portion is not easily reduced can be considered. However, in this electrodeposition resist system, since the electrodeposition resist solution changes with time, the management becomes complicated and it is difficult to adjust the film thickness, so that it is difficult to refine the conductive pattern formed later by etching.

  Therefore, in this embodiment, the etching protective film 15 is formed using a different process and material different from the formation of the photoresist film 4.

  After forming the development pattern 4A, a general etching protective film resin solution that can be removed with an alkaline solution is used, for example, using a general method such as a dispenser method, a brush coating method, or a spray method. After coating, the film is heated and dried to form an etching protective film 15 as shown in FIG.

  By the way, the coating thickness of the resin liquid for the etching protective film is thin at the edge portion of the metal base film 1 due to the action of the surface tension, so the thickness of the etching protective film 15 formed on the edge portion is The coating thickness of the resin liquid for the etching protective film is adjusted so that a thickness that is not affected by subsequent etching can be secured.

  In the present embodiment, a method of forming the etching protective film 15 using a different process and material different from the formation of the photoresist film 4 is adopted. However, the etching protective film 15 is formed simultaneously with the formation of the photoresist film 4 described above. A method of forming a film and a method of using an electrodeposition resist method are also included in the present invention.

  Next, as shown in FIG. 1G, etching is performed using the development pattern 4A as an etching resist to form a conductive pattern 3 provided with external connection terminals 3B and semiconductor chip connection terminals 3A.

  Next, as shown in FIG. 1 (H), the development pattern 4A and the etching protective film 15 that are no longer needed are removed using an alkaline solution, and then the surface of the conductive pattern 3 is connected to a semiconductor chip. And tin plating (not shown) for the purpose of corrosion prevention.

  Next, as shown in FIG. 1 (I), a semiconductor chip connection terminal 3A for connecting a semiconductor chip later and an external connection terminal 3B for connecting a glass substrate or a printed wiring board of the display device are left. Then, a solder resist 6 having excellent flexibility is applied to other regions by screen printing or the like, and is heated and cured to form the TCP type flexible printed wiring board 12A. FIG. 2 shows a plan view of the TCP type flexible printed wiring board 12A thus formed. FIG. 1I is a cross-sectional view taken along the line AA in FIG.

  As the solder resist 6 having excellent flexibility, for example, trade name “SN-9000” manufactured by Hitachi Chemical Co., Ltd. is used. This solder resist 6 coating step may be performed before or after the plating step. Here, as shown in FIG. 2, the solder resist 6 leaves a semiconductor chip mounting area 7A for mounting a semiconductor chip having a rectangular outer shape, and the semiconductor chip connection terminal 3A from the semiconductor chip mounting area 7A. Make a peep.

  FIG. 3 shows a plan view of another TCP type flexible printed wiring board 12B formed using the same process as described above. This TCP type flexible printed wiring board 12B is provided with a first slit forming area 5 in a square three-sided shape, leaving a part around the semiconductor chip mounting area 7A, and avoiding the first slit forming area 5. In this way, the conductive pattern 3 is formed by being routed.

(COF type)
Next, a method for manufacturing the COF type flexible printed wiring board of this embodiment will be described with reference to FIGS.

  By the way, in the manufacturing process of the TCP type flexible printed wiring board, as shown in FIG. 1B, the device holes 11A are punched and formed in a predetermined number for each unit wiring pattern. The COF type flexible printed wiring board to be formed is formed using exactly the same processes and materials except that this device hole 11A is not formed. Therefore, in the following description of the manufacturing method, a part of the overlapping contents will be omitted.

  First, as shown to FIG. 8 (A), 1 A of adhesive layers which provided the cover film 1B on the surface of the metal base film 1 are laminated | stacked.

  Next, as shown in FIG. 8B, sprocket holes 11 are punched and formed at regular intervals along both edges of the metal base film 1 using a mold.

  Next, as shown in FIG. 8 (C), heat and pressure are applied while peeling the cover film 1B in the length direction of the metal base film 1 to laminate the conductor foil 2, and further heat is applied to the adhesive. Layer 1A is cured.

  Next, as shown in FIG. 8D, a photoresist liquid is applied to the surface of the conductor foil 2 with a roll coater, and then dried by heating to form a photoresist film 4. Thereafter, as shown in FIG. 8E, exposure and development are performed to form a development pattern 4A.

  Next, as shown in FIG. 8F, an etching protective film resin liquid is applied to the entire surface excluding the surface of the conductive foil 2, and then dried by heating to form the etching protective film 15. In this etching protective film resin solution, the edge portion of the metal base film 1 is thinned by the surface tension of the etching protective film resin solution, so that the thickness of the etching protective film at the edge portion is a predetermined thickness. Adjust the coating thickness so that

  Next, as shown in FIG. 8G, etching is performed using the development pattern 4A as an etching resist to form a conductive pattern 3 provided with external connection terminals 3B and semiconductor chip connection terminals 3A.

  Next, as shown in FIG. 8 (H), the development pattern 4A and the etching protection film 15 that are no longer needed are removed using an alkaline solution, and the surface of the conductive pattern 3 is connected to a semiconductor chip. For the purpose of preventing rust, tin (not shown) is plated.

  Next, as shown in FIG. 8 (I), a semiconductor chip connection terminal 3A for connecting a semiconductor chip later and an external connection terminal 3B for connecting a glass substrate or a printed wiring board of the display device are left. Then, a solder resist 6 having excellent flexibility is applied to other regions by screen printing or the like and is heat-cured to form a COF type flexible printed wiring board 12C. FIG. 9 shows a plan view of the COF type flexible printed wiring board 12C formed as described above. FIG. 8I is a cross-sectional view taken along the line E-E in FIG.

  As the solder resist 6 having excellent flexibility, for example, trade name “SN-9000” manufactured by Hitachi Chemical Co., Ltd. is used. This solder resist 6 coating step may be performed before or after the plating step. Here, as shown in FIG. 9, the solder resist 6 leaves a rectangular semiconductor chip mounting area 7A for mounting a semiconductor chip having a rectangular outer shape, and the semiconductor chip connecting terminal 3A from the semiconductor chip mounting area 7A. Make a peep.

  FIG. 10 shows a plan view of another COF type flexible printed wiring board 12D formed using the same process as described above. The COF type flexible printed wiring board 12D is provided with a first slit forming area 5 in a square three-sided shape while leaving a part around the semiconductor chip mounting area 7A, and the first slit forming area 5 is avoided. In this way, the conductive pattern 3 is formed by being routed.

<Method for Manufacturing Semiconductor Device>
(TCP type-no slit)
Next, a manufacturing method for forming a semiconductor device by mounting a semiconductor chip on the TCP-type flexible printed wiring board 12A (see FIG. 2) will be described with reference to FIGS.

  As shown in FIG. 4A, a heating stage in which a semiconductor chip 7 having a rectangular outer shape is set to 100 ° C. to 150 ° C. while being transported and positioned using the sprocket holes 11 of the TCP type flexible printed wiring board 12A. Set on top of 10 in turn. Then, heat and pressure are applied by using a bonding tool 9 heated to 400 ° C. to 500 ° C. against the gold bumps 8 formed on the semiconductor chip 7 and the semiconductor chip connection terminals 3A. Thus, for example, the gold bump 8 and the tin-plated semiconductor chip connection terminal 3A are Au—Sn eutectic bonded, and the semiconductor chip 7 is mounted on the TCP type flexible printed wiring board 12A.

  Thereafter, while transporting using the sprocket holes 11 of the TCP type flexible printed wiring board 12A and positioning sequentially, the sealing resin 14 discharged from the coating nozzle 13 is applied to the semiconductor chip 7 as shown in FIG. FIG. 4C shows a state where the front side and the semiconductor chip connecting terminal 3A are coated so as to cover and further heated and cured.

  Next, FIG. 4D shows a state in which the TCP type semiconductor device 16A is formed by punching using a die or the like for each unit conductive pattern. FIG. 5 shows a plane of the TCP type semiconductor device 16A formed in this way. 4D is a cross-sectional view taken along the line CC in FIG.

  By the way, when the semiconductor device 16A shown in FIG. 5 is assembled and used, it is curved and used with the front side of the metal base film as the inner side.

(TCP type-with slit)
Next, a manufacturing process for mounting a semiconductor chip on the TCP type flexible printed wiring board 12B (see FIG. 3) to form a TCP type semiconductor device will be described.

  The semiconductor chip 7 is mounted on the TCP-type flexible printed wiring board 12B and sealed using the same manufacturing process and manufacturing method as in FIGS. 4A to 4C showing the manufacturing process of the TCP-type semiconductor device 16A. Resin 14 is applied and post-heat cured.

  Next, as shown in FIG. 6A, the first slit 5A is punched and formed using a mold or the like while being transported and positioned using the sprocket hole 11. The shape of the first slit 5 </ b> A is a shape extending in a concave shape surrounding at least a part of the conductive pattern 3, with the device hole 11 </ b> A side being concave in plan view. Preferably, the shape surrounds three sides of the square semiconductor chip 7.

  Next, as shown in FIG. 6B, a TCP type semiconductor device 16B is formed by punching using a die or the like for each unit conductive pattern. FIG. 7 shows a plane of the TCP type semiconductor device 16B formed as described above. 6B is a cross-sectional view taken along the line DD in FIG.

  By the way, when the semiconductor device 16B shown in FIG. 7 is assembled and used, the first straight line L passing through both ends of the first slit 5A shown in FIG. The slit 5A is used by being bent in a bending range b between the straight line M and the formation range of the slit 5A.

(COF type-no slit)
Next, a manufacturing method for forming a COF type semiconductor device by mounting the semiconductor chip 7 on the COF type flexible printed wiring board 12C (see FIG. 9) will be described with reference to FIGS. .

  First, as shown in FIG. 11A, the semiconductor chip 7 having a rectangular outer shape was set to 100 ° C. to 150 ° C. while being transported and positioned using the sprocket holes 11 of the COF type flexible printed wiring board 12C. Set sequentially on the heating stage 10. Then, heat and pressure are applied using a bonding tool 9 heated to 400 ° C. to 500 ° C. with the gold bumps 8 formed on the semiconductor chip 7 facing the semiconductor chip connection terminals 3A. Thereby, for example, the gold bump 8 and the tin-plated semiconductor chip connection terminal 3A are Au—Sn eutectic bonded, and the semiconductor chip 7 is mounted on the COF type flexible printed wiring board 12C.

  After that, while transporting using the sprocket holes 11 of the COF type flexible printed wiring board 12C and positioning sequentially, the sealing resin 14 discharged from the coating nozzle 13 is applied to the semiconductor chip 7 as shown in FIG. FIG. 11C shows a state in which it is applied along the periphery, penetrated by capillary action, filled between the semiconductor chip 7 and the adhesive layer 1A, and further heated and cured.

  Next, FIG. 11D shows a state in which a COF type semiconductor device 16C is formed by punching using a die or the like for each unit conductive pattern. FIG. 12 shows a plane of the COF type semiconductor device 16C formed in this way. FIG. 11D is a cross-sectional view taken along the line GG in FIG.

  By the way, when the semiconductor device 16C shown in FIG. 12 is assembled and used, it is curved and used with the front side of the metal base film as the inside.

(COF type-with slit)
Next, a manufacturing method for forming a COF type semiconductor device by mounting the semiconductor chip 7 on the COF type flexible printed wiring board 12D (see FIG. 10) will be described.

  The semiconductor chip 7 is mounted on the COF type flexible printed wiring board 12D, and then the sealing resin 14 is applied and post-cured. This manufacturing process is the manufacturing process of the COF type semiconductor device 16C. 11 (A) to (C) are performed using the same manufacturing process and manufacturing method.

  Next, as shown in FIG. 13A, the first slit 5A is punched and formed using a mold or the like while being transported and positioned using the sprocket hole 11.

Next, FIG. 13B shows a state in which a COF type semiconductor device 16D is formed by punching using a die or the like for each unit conductive pattern.
Next, FIG. 14 shows a plane of the COF type semiconductor device 16D formed in this way. FIG. 13B is a cross-sectional view taken along the line H-H in FIG.

  By the way, when the semiconductor device 16D shown in FIG. 14 is assembled and used, a straight line L crossing the metal substrate film 1 through both ends of the first slit 5A shown in FIG. The slit 5A is used by being bent in a bending range b between the straight line M and the formation range of the slit 5A.

<Method for Manufacturing Display Device>
Next, a method for assembling a display device by mounting the TCP type semiconductor device and the COF type semiconductor device will be described.

(TCP type-no slit)
The TCP type semiconductor device 16A (see FIG. 5) is assembled and used as shown in FIG. 15 to form a display device 40A. In the display device 40 </ b> A shown here, a backlight 22, a quadrilateral glass substrate 18, and a quadrilateral display glass 19 are sequentially laminated and used. A printed wiring board 17 for supplying power and signals is arranged.

  Then, as shown in FIG. 15, the TCP type semiconductor device 16A is folded with the front side of the TCP type semiconductor device 16A facing inward, the external connection terminal 3B of the conductive pattern 3 is connected to the glass substrate 18, and the other external The connection terminal 3B is connected to the printed wiring board 17. Then, a part of the back surface side of the metal base film 1 is brought into contact with the first housing member 20. Further, the back surface side of the semiconductor chip 7 is connected to the second casing member 21 with the heat conduction grease 23 interposed therebetween. In this way, a plurality of semiconductor devices 16A are connected to necessary sides of the quadrilateral of the glass substrate 18 and the display glass 19 to assemble the display device 40A.

  Next, heat dissipation of the display device 40A will be described.

Regarding heat conduction, if θ is a thermal resistance, L is a path length, λ is a thermal conductivity, and A is a heat transfer area,
θ = L / λ · A
The following equation holds. Of course, the smaller the thermal resistance θ, the easier the heat is transmitted and the temperature of the heating element can be reduced. In the following description, the symbols in the above formula may be referred to as appropriate.

  The heat generated from the semiconductor chip 7 is transferred from the back surface of the semiconductor chip 7 to the second casing member 21 formed of a metal having high thermal conductivity such as aluminum connected to the tip of the semiconductor chip 7 through the heat conductive grease 23 and diffused. To dissipate heat.

  Further, there is a heat dissipation path different from the above, and the heat generated from the semiconductor chip 7 is transmitted to the gold bumps 8 having a high thermal conductivity, and further to the semiconductor chip connection terminal 3A connected to the conductive bump 3. Spread throughout. Then, the heat diffused throughout the conductive pattern 3 is transmitted to the epoxy adhesive layer 1A to be connected, and is transmitted to the metal base film 1 using copper or the like having a high thermal conductivity to be connected thereto.

  Here, the thermal conductivity of the adhesive layer 1A is as low as about 0.2 W / m · K in the case of a general epoxy system, but the thickness of the adhesive layer 1A is, for example, When the product name “TAB adhesive # 8200” manufactured by Co., Ltd. is used, the thickness is as thin as about 12 μm, and the conductive pattern 3 has a wide drawn area, so the thermal resistance θ is reduced. The heat transferred to the conductive pattern 3 is efficiently transferred to the metal base film 1.

  Further, since the heat is transmitted to the first housing member 20 and the second housing member 21 using aluminum having a high thermal conductivity connected to the tip and diffused, the heat can be efficiently radiated. Further, part of the heat transferred to the metal base film 1 is transferred to the contacting air and further transferred to the first housing member 20 and the second housing member 21, so that the heat of the semiconductor chip 7 is efficiently obtained. It can dissipate heat. Therefore, the operation of the semiconductor can be stabilized and the display quality of the display device can be improved.

  By the way, when the adhesive layer 1A is, for example, a product name “TSA series” manufactured by Toray Industries, Inc. having a thermal conductivity of about 3 W / m · K and having a thickness of 20 μm, the “TAB” Compared to the case where “adhesive for adhesive # 8200” is used, the thermal resistance θ can be reduced to about 1/9 from the above calculation formula, and it is more preferable because heat can be efficiently radiated.

Incidentally, general thermal conductivity is described below.
Copper: about 390 W / m · K, aluminum: about 236 W / m · K, epoxy-based adhesive layer (TSA series) about 3 W / m · K, the thermal conductive grease (JAP004J-2): 6 W / m -About K.

(COF type-no slit)
Next, a method for assembling a display device using the COF type semiconductor device 16C shown in FIG. 12 will be described.

  As shown in FIG. 16, the COF type semiconductor device 16C is turned upside down, the external connection terminal 3B of the conductive pattern 3 is connected to the glass substrate 18, and the other external connection terminal 3B is connected to the printed wiring board 17. Connecting. Then, a part of the back surface side of the metal base film 1 is brought into contact with the first housing member 20 and the second housing member 21. In this way, a plurality of semiconductor devices 16B are connected to the necessary sides of the four sides of the glass substrate 18 and the display glass 19 to assemble the display device 40B.

  Next, heat dissipation of the display device 40B formed in this way will be described. The heat generated from the semiconductor chip 7 is transferred to the gold bumps 8 having high thermal conductivity, and further transferred to the semiconductor chip connection terminals 3A connected to the tip of the semiconductor chip 7 and diffused throughout the conductive pattern 3. The heat diffused throughout the conductive pattern 3 is transferred to the epoxy adhesive layer 1A to be connected, and further transferred to the metal base film 1 using copper or the like having a high thermal conductivity to be connected further.

  Since the adhesive layer 1A used here is the same as the adhesive layer 1A of the TCP type semiconductor device 16A (see FIG. 5), the heat diffused throughout the conductive pattern 3 is efficiently applied to the metal substrate film 1. It is transmitted.

  Further, the heat is transmitted to the first casing member 20 and the second casing member 21 using aluminum having a high thermal conductivity connected to the tip and diffused to dissipate heat. Further, part of the heat transferred to the metal base film 1 is transferred to the contacting air and further transferred to the first housing member 20 and the second housing member 21, so that the heat of the semiconductor chip 7 is efficiently obtained. It can dissipate heat. Therefore, the operation of the semiconductor can be stabilized and the display quality of the display device can be improved.

(TCP type-with slit)
Next, a method for assembling a display device using the TCP type semiconductor device 16B shown in FIG. 7 will be described. As shown in FIG. 7, the TCP type semiconductor device 16B is bent in a bending range b between a straight line L passing through both ends of the first slit 5A and crossing the insulating substrate and a straight line M parallel thereto, and a semiconductor chip The front side of the metal base film 1 is folded back with the front side of the metal base film 1 except the holding portion 30, and the semiconductor chip holding portion 30 is straightened without being bent, and the external connection terminals 3B of the conductive pattern 3 are connected as shown in FIG. Connected to the glass substrate 18, the other external connection terminal 3 </ b> B is connected to the printed wiring board 17.

  The storage formed in the second housing member 21 is caused by bringing the back surface side of the metal base film 1 of the semiconductor chip holding portion 30 extended straight without bending into contact with the second housing member 21. The semiconductor chip 7 is stored in the recess 21 </ b> B, and the back surface of the semiconductor chip 7 is connected to the second housing member 21 through the heat conduction grease 23. Further, the front side of the sealing resin 14 is connected to the first casing member 20 via the heat conductive grease 23. In this manner, a plurality of semiconductor devices 16B are connected to necessary sides of the quadrilateral of the glass substrate 18 and the display glass 19 to assemble the display device 40C.

Next, heat dissipation of the display device 40C formed in this way will be described.
The heat generated from the semiconductor chip 7 is transmitted from the back surface of the semiconductor chip 7 to the heat conduction grease 23, and is transmitted to the second housing member 21 formed of a metal such as aluminum having high heat conductivity connected to the heat conduction grease 23. To dissipate heat.

  Further, there is a heat dissipation path different from the above, and the heat generated from the semiconductor chip 7 is transmitted to the sealing resin 14 and further transmitted to the heat conduction grease 23 connected to the end. Further, the heat is transmitted to the first casing member 20 formed of a metal such as aluminum having high thermal conductivity, which is connected to the tip, and is diffused and radiated.

  Further, there is another heat dissipation path different from the above, and the heat generated from the semiconductor chip 7 is transmitted to the gold bumps 8 having a high thermal conductivity, and further transmitted to the semiconductor chip connection terminals 3A connected to the conductive pattern. 3 spreads throughout. Then, the heat diffused throughout the conductive pattern 3 is transmitted to the epoxy adhesive layer 1A to be connected, and is transmitted to the metal base film 1 using copper or the like having a high thermal conductivity to be connected thereto.

  Since the adhesive layer 1A used here is the same as the adhesive layer 1A of the TCP type semiconductor device 16A (see FIG. 5), the heat diffused throughout the conductive pattern 3 is efficiently applied to the metal substrate film 1. It is transmitted.

  Further, the heat is transmitted to the second casing member 21 and the first casing member 20 using aluminum having a high thermal conductivity connected to the tip and diffused to dissipate heat. Further, part of the heat transferred to the metal base film 1 is transferred to the contacting air and further transferred to the first housing member 20 and the second housing member 21, so that the heat of the semiconductor chip 7 is efficiently obtained. It can dissipate heat. Therefore, the operation of the semiconductor can be stabilized and the display quality of the display device can be improved.

(COF type-with slit)
Next, a method for assembling a display device using the COF type semiconductor device 16D shown in FIG. 14 will be described. As shown in FIG. 14, the COF type semiconductor device 16D is bent in a bending range b between a straight line L passing through both ends of the first slit 5A and crossing the insulating substrate and a straight line M parallel thereto, and a semiconductor chip The front side of the metal base film 1 is folded inside except for the holding portion 30, and the semiconductor chip holding portion 30 is straightened without being bent. As shown in FIG. 18, the external connection terminals 3B of the conductive pattern 3 are connected. Connected to the glass substrate 18, the other external connection terminal 3 </ b> B is connected to the printed wiring board 17.

  Then, the back surface side of the metal base film 1 of the semiconductor chip holding part 30 is brought into contact with the second housing member 21. Further, the back surface side of the semiconductor chip 7 is connected to the first housing member 20 via the heat conductive grease 23. In this way, a plurality of semiconductor devices 16D are connected to the necessary sides of the glass substrate 18 and the display glass 19 among the four sides to assemble the display device 40D.

Next, heat dissipation of the display device 40D formed in this way will be described.
The heat generated from the semiconductor chip 7 is transmitted from the back surface of the semiconductor chip 7 to the thermal conductive grease 23, and is transmitted to and diffused to the first casing member 20 formed of a metal such as aluminum having a high thermal conductivity connected to the tip. To dissipate heat.

  Further, there is a heat dissipation path different from the above, and the heat generated from the semiconductor chip 7 is transmitted to the gold bumps 8 having a high thermal conductivity, and further to the semiconductor chip connection terminal 3A connected to the conductive bump 3. Spread throughout. Then, the heat diffused throughout the conductive pattern 3 is transmitted to the epoxy adhesive layer 1A to be connected, and is transmitted to the metal base film 1 using copper or the like having a high thermal conductivity to be connected thereto.

  Since the adhesive layer 1A used here is the same as the adhesive layer 1A of the TCP type semiconductor device 16A (see FIG. 5), the heat diffused throughout the conductive pattern 3 is efficiently applied to the metal substrate film 1. It is transmitted.

  Further, the heat is transmitted to the second casing member 21 and the first casing member 20 using aluminum having a high thermal conductivity connected to the tip and diffused to dissipate heat. Further, part of the heat transferred to the metal base film 1 is transferred to the contacting air and further transferred to the first housing member 20 and the second housing member 21, so that the heat of the semiconductor chip 7 is efficiently obtained. It can dissipate heat. Therefore, the operation of the semiconductor can be stabilized and the display quality of the display device can be improved.

  By the way, the semiconductor device of this embodiment is assembled by bending as shown in FIGS. 15 to 18. However, when the metal base film 1 is thick, it is difficult to fold the semiconductor device with the front side inward. There is a case. In such a case, in the case where the first slit 5A is not provided, for example, as shown in FIG. 19, between the semiconductor chip 7 sealed with the sealing resin 14 and the external connection terminal 3B, A second slit 5B filled with the soft resin 5C may be provided and folded using the second slit. Further, in the case of the type in which the first slit 5A is provided, as shown in FIG. 20, a second slit 5B filled with a soft resin 5C is provided in the range of the bending range b, and the second slit is provided. Use it to wrap it.

  The second slit 5B filled with the soft resin 5C is formed by punching using a mold or the like simultaneously with the sprocket hole 11 or the device hole 11A shown in FIG. 1 (B), and then into the second slit 5B. It is formed by filling the soft resin 5C and then heat-curing. As this soft resin 5C, for example, a trade name “Iupicoat FS-100L” manufactured by Ube Industries, Ltd. is used.

  The second slit 5B extends linearly in a direction orthogonal to the bending direction. When the first slit 5A is formed, the second slit 5B is on a straight line that intersects the first slit 5A at two locations in plan view, and on the concave side of the first slit 5A. It extends on the outer side. In the case where the first slit 5A has a three-sided square shape, the first slit 5A preferably extends on a straight line orthogonal to two sides of the first slit 5A and parallel to one side.

DESCRIPTION OF SYMBOLS 1 Metal base film 1A Adhesive layer 1B Cover film 2 Conductor foil 3 Conductive pattern 3A Semiconductor chip connection terminal 3B External connection terminal 4 Photoresist film 4A Development pattern 5 1st slit formation area 5A 1st slit 5B Second slit 5C Soft resin 6 Solder resist 7 Semiconductor chip 7A Semiconductor chip mounting area 8 Gold bump 9 Bonding tool 10 Heating stage 11 Sprocket hole 11A Device hole 12A TCP flexible printed wiring board 12B TCP flexible printed wiring board 12C COF type Flexible printed wiring board 12D COF type flexible printed wiring board 13 Coating nozzle 14 Sealing resin 15 Etching protective film 16A TCP type semiconductor device 16B TCP type semiconductor device 16C COF Semiconductor device 16D COF type semiconductor device 17 Printed wiring board 18 Glass substrate 19 Display glass 20 First housing member 21 Second housing member 21B Storage recess 22 Backlight 23 Thermal conduction grease 30 Semiconductor chip holding portion 40A Display device 40B Display device 40C Display device 40D Display device b Bending range L A straight line that crosses the metal substrate film through both ends of the slit M A straight line parallel to the straight line L

Claims (13)

Laminating an adhesive layer on a metal substrate film;
A step of attaching a conductive foil to the adhesive layer;
Laminating a photoresist film on the conductor foil;
Exposing and developing the photoresist film; and
A step of covering an etching protective film on a portion of the metal base film not covered with the conductor foil;
Etching the conductor foil through the photoresist film after exposure and development in a state where the etching protective film is covered on the metal base film, and forming a conductive pattern;
The manufacturing method of the flexible printed wiring board which has this. The method for manufacturing a flexible printed wiring board according to claim 1, wherein the step of covering the etching protective film is performed separately from the step of laminating the photoresist film. After the step of laminating the adhesive layer, before the step of attaching the conductor foil, further comprising the step of forming an opening in the metal base film and the adhesive layer,
The method for manufacturing a flexible printed wiring board according to claim 1, wherein the conductive pattern has a connection terminal protruding into the opening. The manufacturing method of the flexible printed wiring board of any one of Claims 1-3 whose heat conductivity of the said adhesive bond layer is 1 W / m * K or more. Laminating an adhesive layer on a metal substrate film;
A step of attaching a conductive foil to the adhesive layer;
Laminating a photoresist film on the conductor foil;
Exposing and developing the photoresist film; and
A step of covering an etching protective film on a portion of the metal base film not covered with the conductor foil;
Etching the conductor foil through the photoresist film after exposure and development in a state where the metal protective film is covered with the etching protective film, and an external connection terminal and a semiconductor chip connection terminal Forming a conductive pattern including:
Connecting and mounting a semiconductor chip on the semiconductor chip connection terminals;
A method for manufacturing a semiconductor device, comprising: The method further includes forming a first slit in the metal base film that extends in a concave shape with the semiconductor chip side as a concave side in a plan view of the metal base film and surrounds at least a part of the conductor pattern. 6. A method for manufacturing a semiconductor device according to 5. The method for manufacturing a semiconductor device according to claim 6, wherein the shape of the semiconductor chip is a square, and the first slit is formed so as to surround three sides of the square semiconductor chip. Forming a linear second slit in the metal substrate film;
Filling the second slit with a soft resin;
The method for manufacturing a semiconductor device according to claim 5, further comprising: A semiconductor device is formed by the method for manufacturing a semiconductor device according to claim 5,
A method of manufacturing a display device, wherein the metal base film is folded back with the conductor foil side inside, and the external connection terminal is connected to a component different from the semiconductor device. A semiconductor device is formed by the method for manufacturing a semiconductor device according to claim 6,
In the metal substrate film, without folding back the inner part of the first slit, the outer part of the first slit is folded back with the conductor foil side as the inner side, and the external connection terminal is connected to the semiconductor device. Is a method of manufacturing a display device that is connected to another component. A metal substrate film in which an opening is formed;
An adhesive layer laminated on the metal substrate film;
A conductive pattern including connection terminals stacked on the adhesive layer and projecting into the opening;
A flexible printed wiring board. The flexible printed wiring board according to claim 11,
A semiconductor chip disposed in the opening of the flexible printed wiring board and connected to the connection terminal;
A semiconductor device. A semiconductor device according to claim 12,
A glass substrate connected to the semiconductor device;
A housing that houses the semiconductor device and the glass substrate and contacts the metal base film;
A display device.

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