JP2012191002A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which has a structure efficiently radiating heat generated from a circuit part of a semiconductor chip to the side of a substrate, reduces the damage to the circuit part caused when the semiconductor chip is mounted on the substrate, and achieves higher reliability.SOLUTION: A semiconductor device 100 includes a flexible substrate 45 and a semiconductor chip 43 having a circuit part 15 where a circuit is formed on one main surface. The semiconductor chip 43 is disposed so that the circuit part 15 faces a surface of the flexible substrate 45, and grease for heat radiation 41 fills a space between the circuit part 15 and the flexible substrate 45.

Description

  The present invention relates to a semiconductor device, and more particularly to heat dissipation of a semiconductor device.

  In recent years, an increase in the capacity of an analog signal system accompanying an increase in the display size of a liquid crystal panel has caused an increase in current in a liquid crystal driver (semiconductor device). Furthermore, as a result of increasing the gate cycle and increasing the driver speed in order to improve the image quality, the current further increases, thereby increasing the amount of heat generation. In addition, some circuits formed in semiconductor chips are vulnerable to heat, but such circuits are also a necessary technology, and current increases due to the increase in the size of liquid crystal displays and the high-speed driving of liquid crystal drivers. In response to an increase in the amount of heat generated by the semiconductor device, there is an increasing need for improving the heat dissipation of a semiconductor chip used in a liquid crystal driver and developing a semiconductor package structure capable of protecting fragile circuits. As a semiconductor package (semiconductor device) for this liquid crystal driver, a chip-on-film package is indispensable, and the development of technology that can maintain high reliability against fragile circuits while maintaining good heat dissipation. There is a growing need.

FIG. 11 is a cross-sectional view schematically showing a schematic configuration of a conventional semiconductor device 700 described in Patent Document 1. In FIG.
A semiconductor device 700 shown in the figure includes a plurality of main bumps (electrode bumps) 3 that are electrically bonded to electrode pads (bonding pads) 1c formed on the main surface 1a of the semiconductor chip 1 that is a read / write chip, The semiconductor chip 1 includes a plurality of heat radiation bumps 4 bonded to the dummy electrodes 1d formed on the main surface 1a, the semiconductor chip 1 is supported by flip chip mounting, and includes a plurality of wiring leads 2c and a heat radiation solid layer 2e. The tape-shaped film substrate 2, the suspension 5 that is a support member that supports the tape-shaped film substrate 2 and is formed of a material having high thermal conductivity, and the bump joint portions of the main bump 3 and the heat-radiating bump 4. And a sealing portion 9 formed by resin sealing.

  The tape-shaped film substrate 2 is formed by forming wiring leads 2c on a solder resist film 2b and laminating a polyimide film 2a thereon. In the portion of the tape-like film substrate 2 where the semiconductor chip 1 is mounted, a through hole is provided in a portion facing the dummy electrode 1d. The suspension 5 is provided with a protrusion 5a, and the heat radiation solid layer 2e is formed on the protrusion 5a. The suspension 5 supports the tape-like film substrate 2 in a state where the protrusion 5a and the heat radiation solid layer 2e are located in the through hole.

  The main bump 3 is joined to the wiring lead 2c by reflow using solder or the like. Similarly, the heat dissipation bumps 4 are joined to the dummy electrode 1d and the heat dissipation solid layer 2e by reflow or the like using solder or the like.

  With such a configuration, the heat generated from the circuit of the semiconductor chip 1 is guided to the suspension 5 through the plurality of heat dissipation bumps 4 and the heat dissipation solid layer 2e, and released to the outside, thereby improving heat dissipation. It is increasing.

JP 2001-110951 A JP 2006-135247 A

  However, as shown in FIG. 11, in the prior art, when the semiconductor chip 1 is flip-chip connected to the tape-like film substrate 2, the main surface 1a on the side where the circuit of the semiconductor chip 1 is formed and the heat radiation solid Since the layer 2e is connected to the heat dissipation bump 4, the circuit of the semiconductor chip 1 is subjected to stress from the heat dissipation bump 4 having high hardness, and the circuit may be damaged. Further, the circuit may be damaged by thermal stress when the heat-radiating bumps 4 are joined by reflow. These damages may cause circuit breakdown and characteristic fluctuations during circuit operation, leading to a decrease in reliability of the semiconductor device.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a semiconductor device in which damage to a circuit of a semiconductor chip due to flip chip connection is reduced while ensuring good heat dissipation. To do.

  In order to achieve the above object, a semiconductor device according to the present invention includes a substrate and a semiconductor chip having a circuit portion in which a circuit is formed on one main surface, and the semiconductor chip includes the circuit portion described above. It is arranged so as to face the surface of the substrate, and a space between the circuit portion and the substrate is filled with thermally conductive grease.

  With the above configuration, the heat generated in the circuit portion of the semiconductor chip can be led to the substrate side through the thermally conductive grease to be dissipated, and the thermally conductive grease is a fluid and can be easily deformed. When the semiconductor chip is mounted on the substrate, the stress applied to the circuit portion can be reduced to reduce damage to the circuit portion.

  Furthermore, since the heat conductive grease does not need to be heated as in the case of using a heat dissipation bump such as solder, the thermal stress applied to the circuit portion can be reduced, and damage to the circuit portion can be reduced. .

  The substrate includes a through hole provided in a portion facing the circuit portion, and a thermally conductive thin film that covers the through hole on a surface side of the substrate, and the inside of the through hole includes the A heat conductive member having higher heat conductivity than the substrate may be disposed so as to be in contact with the heat conductive thin film.

  As a result, the heat from the circuit unit can be transferred to the heat conductive member having a higher thermal conductivity than the substrate through the heat conductive grease and the heat conductive thin film, and more efficiently from the circuit unit. Heat can be dissipated.

The heat conducting member may be a heat conducting grease.
Thereby, since it is not necessary to use another member as the heat conductive member, an increase in the types of materials can be suppressed, and the assembly can be performed by an easy method of application, which can contribute to cost reduction.

  Further, a surface electrode formed outside the circuit portion on the semiconductor chip main surface, and formed on the surface of the substrate at a position outside the thermally conductive thin film and facing the surface electrode. And a protruding terminal that is disposed between the surface electrode and the wiring lead and electrically connects the surface electrode and the wiring lead.

As a result, since the wiring lead and the surface electrode are electrically connected by the protruding terminal, it is possible to supply power necessary for operating the circuit and to input / output signals.
Further, the connection of the protruding terminal to the wiring lead and the surface electrode is usually performed by thermocompression bonding. At this time, the surface electrode is formed outside the circuit portion, and the protruding terminal is formed at the time of thermocompression bonding. Since the circuit portion is not directly subjected to the stress from the thermal stress, the stress due to thermal strain is reduced and damage to the circuit portion can be reduced.

  The substrate-side convex portion further includes a substrate-side convex portion standing on the surface of the substrate in a form that passes between the thermal conductive thin film and the wiring lead and surrounds the thermal conductive thin film. It is made of a conductive member and may be provided apart from the wiring lead and the protruding terminal.

  As a result, the board-side convex part is insulated from the wiring leads and the protruding terminals, and when the thermal conductive grease wets and spreads, the board-side convex part is exposed to thermal conductive grease like a dam. When heat conductive grease with higher heat conductivity mixed with metal filler to increase heat conductivity is used to prevent clogging and contact with protruding terminals and wiring leads Even so, it is possible to more efficiently dissipate heat from the circuit section while suppressing the risk of occurrence of problems such as electrical shorts during circuit operation.

  Further, the thermally conductive thin film, the wiring lead, and the substrate-side convex portion are made of the same member and have the same height from the substrate, and the substrate-side convex portion has the thermal conductivity. It may be provided apart from the thin film.

  Thereby, when forming a heat conductive thin film and a wiring lead by etching etc., since a board | substrate side convex part can also be formed simultaneously, an additional material and process are not required and it can contribute to cost control. .

  Furthermore, since the substrate-side convex portion is provided away from the thermal conductive thin film, it is possible to accommodate a part of the thermal conductive grease that has spread in the gap between the two, and the substrate-side convex portion is dammed up. The effect can be further enhanced.

  Further, the heat conductive thin film is formed so as to surround a portion of the thermally conductive thin film that passes between the portion facing the circuit portion and the wiring lead and the protruding terminal, and surrounds the portion of the thermally conductive thin film that faces the circuit portion. You may further provide the board | substrate side convex part erected on the conductive thin film.

Thereby, the heat conductive grease dampening effect can be further enhanced.
Further, since the size of the heat conductive thin film can be increased to increase the area of the portion in contact with the substrate of the heat conductive thin film, the possibility of peeling of the heat conductive thin film from the substrate can be reduced. .

Furthermore, since the size of the heat conductive thin film can be increased, the size of the through hole and the heat conductive member can be increased to further improve the heat dissipation.
The substrate-side convex portion may be made of a conductive member, and may be provided apart from the wiring lead and the protruding terminal.

Thereby, the metal which is relatively easy to process can be used for the substrate-side convex portion, and can be easily created.
Moreover, the said board | substrate side convex part may consist of an insulating member.

Thereby, the board-side convex portion can be provided widely up to a position where it comes into contact with the protruding terminal and the wiring lead, and the amount of the heat conductive grease can be increased to further improve the heat dissipation.
In addition, the semiconductor chip side convex portion that is erected on the main surface of the semiconductor chip on which the circuit portion is formed in a form that passes between the circuit portion and the surface electrode and surrounds the circuit portion. May be further provided.

  Even with the above configuration, the convex part on the semiconductor chip side prevents the thermal grease that has high thermal conductivity from spreading and prevents it from coming into contact with the protruding terminals, and suppresses the risk of problems such as electrical shorts. However, there is an effect that the heat from the circuit unit can be radiated more efficiently.

The semiconductor chip side convex portion may be made of an insulating member.
Thereby, the semiconductor chip side convex portion can be widely provided up to a position in contact with the protruding terminal, and even when the protruding terminal is provided close to the circuit portion, the thermally conductive grease and the semiconductor chip It is possible to ensure a good heat dissipation by widening the contact area as much as possible.

Further, the semiconductor chip side convex portion may be made of a conductive member, and may be provided apart from the surface electrode, the protruding terminal, and the wiring lead.
Thereby, the semiconductor chip side convex part can be easily formed by etching or the like using a metal thin film or the like, which can contribute to cost reduction.

Further, a heat radiating member having higher thermal conductivity than that of the substrate and in contact with the heat conductive member may be disposed on the back side of the substrate.
Thereby, the heat generated in the circuit portion can be conducted to the heat radiating member via the heat conductive grease, the heat conductive thin film, and the heat conductive member, and can be radiated more efficiently.

1 is a cross-sectional view showing a schematic configuration of a semiconductor device according to a first embodiment. FIG. 6 is a cross-sectional view showing a schematic configuration of a semiconductor device according to a second embodiment. 3A and 3B are diagrams illustrating a schematic configuration of a semiconductor chip in a semiconductor device according to a second embodiment, where FIG. 3A is an external perspective view, and FIG. FIG. 6 is a cross-sectional view showing a schematic configuration of a semiconductor device according to a third embodiment. It is a figure which shows typically the procedure of the manufacturing process of the flexible substrate tape which concerns on manufacture of the semiconductor device which concerns on Embodiment 3, Comprising: (a) is an opening part and through-hole which are required for a polyimide tape opened with a punch press. (B) is a cross-sectional view taken along the line AA 'in (a), and (c) is a solid copper foil attached to the polyimide tape in (a). (D) is a cross-sectional view taken along the line BB ′ in (c), and (e) shows that a resist is applied on the copper foil, and the copper foil is required by etching. It is a top view which shows the state shape | molded in the shape, (f) is CC 'arrow sectional drawing in (e), (g) is a resist coat coated on copper foil and a flexible substrate. , Flexi in a finished state with further tinning Is a plan view showing a substrate tape, (h) is a D-D 'arrow sectional view in (g). FIG. 6 is a cross-sectional view showing a schematic configuration of a semiconductor device according to a fourth embodiment. FIG. 6 is a diagram schematically showing a part of the procedure of the manufacturing process of the semiconductor device according to the fourth embodiment using the flexible substrate tape of FIG. 5, wherein (a) is a semiconductor chip side convex frame on the semiconductor chip; Is a perspective view showing a state in which a heat dissipation grease is applied to the inside and further electrode bumps are mounted on a bonding pad, and (b) is a flexible substrate after the heat dissipation grease is applied to the semiconductor chip side. It is a perspective view which shows the mounting positional relationship of the semiconductor chip at the time of mounting a tape, and a flexible substrate tape (partially notched), (c) mounts a semiconductor chip after apply | coating the thermal radiation grease to the flexible substrate side It is a perspective view which shows the mounting positional relationship of a semiconductor chip and a flexible substrate tape (partially notched) at the time of carrying out, (d) is half a flexible substrate tape. Is a perspective partial cut-away view of a flexible substrate tape was completed by sealing with a sealing resin after mounting the body tip. FIG. 8 is a diagram schematically showing a continuation of the procedure of the manufacturing process of the semiconductor device according to the fourth embodiment shown in FIG. 7, wherein (a) removes the feed guide hole of the flexible substrate tape by press cutting, and individually It is the external appearance perspective view of the chip-on film of the state cut out, (b) applied the heat-release grease on the heat conductive thin film from the back surface side of the application opening hole (through hole) of the flexible substrate of the chip-on film It is an external appearance perspective view which shows a back state, (c) is the embodiment which completed after apply | coating the thermal radiation grease to the heat conductive thin film, closely_contact | adhering an external heat sink to a flexible substrate, and fixing with a fixing screw 4 is an external perspective view of a semiconductor device according to FIG. 10 is a cross-sectional view illustrating a schematic configuration of a semiconductor device according to Modification 7. FIG. 10 is a cross-sectional view illustrating a schematic configuration of a semiconductor device according to Modification 8. FIG. 10 is a cross-sectional view illustrating a configuration of a semiconductor device according to Patent Document 1. FIG.

Embodiments according to the present invention will be described below with reference to the drawings.
<Embodiment 1>
FIG. 1 is a cross-sectional view showing a schematic configuration of a semiconductor device 100 according to the present embodiment.

  The flexible substrate 45 is provided with a coating opening hole 22 that is a through-hole, and a heat conductive thin film 28 is formed on the front surface of the flexible substrate 45 so as to cover and close the coating opening hole 22. A formed copper foil inner lead (wiring lead) 27 is formed outside the thermally conductive thin film 28 on the surface of the flexible substrate 45. The heat conductive thin film 28 is made of a copper foil film, and the heat conductive thin film 28 and the formed copper foil inner lead 27 are formed by etching from the same copper foil film formed on the surface of the flexible substrate 45. Details will be described later.

  A circuit portion 15 including a fragile semiconductor circuit is formed on the surface of the silicon substrate 10, an aluminum pad 12 is disposed on the outer side, and a glass-based protective film 11 is formed thereon. The glass-based protective film 11 is opened on the aluminum pad 12 by an etching process, whereby the aluminum pad 12 is exposed and a bonding pad (surface electrode) 13 is formed. A semiconductor chip 43 is constituted by the silicon substrate 10, the circuit portion 15, the glass-based protective film 11, the bonding pad 13, and the like.

  The semiconductor chip 43 is flip-chip mounted on the flexible substrate 45 so that the circuit unit 15 faces the heat conductive thin film 28. At this time, the bonding pad 13 of the semiconductor chip 43 and the formed copper foil inner lead 27 are formed in advance at positions facing each other, and the electrode bumps (protruding terminals) 42 interposed therebetween are thermocompression bonded. Both are electrically connected.

  In the space between the portion of the semiconductor chip 43 where the circuit portion 15 is formed (more precisely, the portion covering the circuit portion 15 of the glass-based protective film 11) and the thermally conductive thin film 28, Conductive heat-dissipating grease (thermal conductive grease) 41 is applied (filled) so that the portion of the semiconductor chip 43 where the circuit portion 15 is formed and the thermally conductive thin film 28 are spread and connected.

As the heat dissipation grease 41, for example, silicone grease or the like is used.
In addition, the part in which the circuit part 15 of the semiconductor chip 43 including the glass-based protective film 11 is formed may be simply referred to as “circuit part 15” hereinafter.

  A liquid sealing resin is applied and then thermally cured after the flip chip connection between the semiconductor chip 43 and the flexible substrate 45 and around the semiconductor substrate 43 to form a mold part 44. A resist coat 30 is formed on the outside of the mold part 44.

  Further, an external heat radiating plate 49 is attached to the back surface of the flexible substrate 45, and heat radiating grease is applied (filled) as a heat conductive member 46 in the coating opening hole 22 of the flexible substrate 45. The heat conductive thin film 28 and the external heat dissipation plate 49 are wet and spread by a heat conductive member 46.

  Here, grease having higher thermal conductivity than that of the flexible substrate 45 is used for the heat conductive member 46, thereby comparing with the case where the application opening 22 is not formed, that is, the flexible substrate 45. Compared with the case where heat is transmitted from the heat conductive thin film 28 to the external heat radiation plate 49 through the heat conduction, heat conduction (heat radiation) is performed more efficiently.

  The bonding pad 13 is formed away from the circuit portion 15, and the formed copper foil inner lead 27 is also formed away from the thermally conductive thin film 28. The amount of heat radiation grease 41 applied is sufficient to wet and connect the circuit portion 15 and the heat conductive thin film 28, and the bonding pad 13, the electrode bump 42, and the formed copper foil inner lead. The amount up to 27 is such that it does not spread (not contact).

  Therefore, even when a grease made of silicone or the like mixed with a metal filler having a high thermal conductivity such as copper is used as the heat radiation grease 41 in order to improve the heat dissipation (thermal conductivity), there is a problem such as an electrical short circuit. Low risk of causing.

(Summary of Embodiment 1)
As described above, since the heat radiation grease 41 is filled between the circuit portion 15 and the heat conductive thin film 28, the heat generated in the circuit portion 15 is transferred to the substrate side via the heat radiation grease 41. It can lead to the heat conductive thin film 28 and can be radiated.

  Here, the heat dissipating grease 41 is a viscous fluid and can be easily deformed. Therefore, when the semiconductor chip is mounted on the substrate, the stress applied to the circuit unit is small, and the circuit unit is damaged. Can be small.

  This reduces the risk of circuit damage due to damage and fluctuations in characteristics during circuit operation, and the heat generated in the circuit section is efficiently dissipated, making it difficult for the circuit section to reach a high temperature. Therefore, it is possible to realize a semiconductor device having a simple structure and high heat dissipation efficiency and high reliability without using a heat dissipation bump.

  In addition, since the heat conducted from the circuit unit 15 to the heat conductive thin film 28 is further conducted to the external heat radiation plate 49 through the heat conduction member 46 and then radiated, the heat can be radiated more efficiently. Thus, the reliability of the semiconductor device can be further ensured.

<Embodiment 2>
FIG. 2 is a cross-sectional view showing a schematic configuration of the semiconductor device 200 according to the present embodiment. In addition, in order to avoid duplication of description, about the same component as Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Similar to the semiconductor device 100 of the first embodiment, the semiconductor device 200 includes the semiconductor chip 43, the flexible substrate 45, the external heat dissipation plate 49, the electrode bumps 42, the formed copper foil inner leads 27, the heat conductive thin film 28, and the heat dissipation grease. 41 and 46, a mold part 44, a resist coat 30 and the like.

  A characteristic of the semiconductor device 200 is that a semiconductor chip side convex frame 14 for preventing leakage of heat radiating grease is formed on the glass-based protective film 11 outside the portion where the circuit portion 15 is formed. . The semiconductor chip-side convex frame 14 is formed so as to surround a portion where the circuit portion 15 is formed, and a heat-dissipating grease 41 is applied to the inside thereof so as to wet and spread on the heat conductive thin film 28. Connected. The semiconductor chip side convex frame 14 is made of, for example, a resin such as silicone resin or polyimide.

  Here, the heat dissipating grease 41 is blocked by the semiconductor chip-side convex frame 14 and does not spread out on the outside thereof, so that the heat dissipating grease 41 flows out and comes into contact with the electrode bumps 42 to cause an electrical short during circuit operation. The risk is reduced, and a more reliable semiconductor device can be realized.

3A is an external perspective view of the semiconductor chip 43 on which the semiconductor chip-side convex frame 14 is formed, and FIG. 3B is a cross-sectional view taken along the virtual plane P in FIG.
In general, a glass-based protective film is formed on a silicon substrate on which a fragile circuit portion is formed to protect the circuit portion from an external impact or the like. When transporting a single semiconductor chip such as COG (Chip On Glass), a resin-based protective film such as a polyimide-based film is applied on the upper layer of the glass-based protective film to protect the circuit surface of the semiconductor chip from external impact. That is also generally done. Therefore, by providing the resin-based protective film in a convex frame shape surrounding the circuit unit 15 between the circuit unit 15 and the electrode bumps 42, it is possible to prevent leakage of the heat-dissipating grease 41 to the resin-based protective film. Can have a function.

(Summary of Embodiment 2)
As described above, according to the configuration of the present embodiment, on the surface of the semiconductor chip 43, the semiconductor chip side which is a convex frame surrounding the circuit unit 15 between the circuit unit 15 and the electrode bump 42. By providing the convex frame 14, it is possible to prevent the heat radiation grease 41 from spreading more than necessary outside the circuit portion 15, and the heat radiation grease 41 comes into contact with the electrode bumps 42, thereby causing an electrical short during circuit operation. This reduces the risk of damage and can provide a more reliable semiconductor device.

<Embodiment 3>
FIG. 4 is a cross-sectional view showing a schematic configuration of the semiconductor device 300 according to the present embodiment. In addition, in order to avoid duplication of description, the same components as those in Embodiments 1 and 2 are denoted by the same reference numerals and description thereof is omitted.

  Similar to the semiconductor device 100 and the semiconductor device 200, the semiconductor device 300 includes the semiconductor chip 43, the flexible substrate 45, the external heat dissipation plate 49, the electrode bump 42, the formed copper foil inner lead 27, the heat conductive thin film 28, and the heat dissipation grease 41. And 46, a mold part 44, a resist coat 30, and the like.

  A characteristic of the semiconductor device 300 is that a flexible substrate-side convex frame 29 is formed on the flexible substrate 45 around the thermally conductive thin film 28 to stop the heat spreading grease 41 from spreading. The flexible substrate-side convex frame 29 is made of a copper foil film, and is formed between the heat conductive thin film 28 and the formed copper foil inner lead 27 so as to surround the heat conductive thin film 28.

  Here, the flexible substrate side convex frame 29 is formed with the same height from the heat conductive thin film 28 and the formed copper foil inner lead 27 and the flexible substrate 45. This is because the heat conductive thin film 28, the formed copper foil inner lead 27, and the flexible substrate side convex frame 29 are formed by etching from the same copper foil film formed on the surface of the flexible substrate 45. is there. Thereby, when forming the heat conductive thin film 28 and the formed copper foil inner lead 27, the flexible substrate-side convex frame 29 can be simultaneously formed without using a separate member or providing a separate process. There are advantages of cost reduction and productivity reduction suppression. The process of forming the heat conductive thin film 28, the formed copper foil inner lead 27, and the flexible substrate side convex frame 29 will be described in detail later.

  The flexible substrate side convex frame 29 is provided apart from the heat conductive thin film 28, and the heat radiation grease 41 that has spread out and protrudes from the heat conductive thin film 28 is formed by the heat conductive thin film 28 and the flexible substrate side convex frame. By being accommodated in the gap between the flexible substrate-side convex frame 29, the heat-release grease leakage preventing effect of the flexible substrate-side convex frame 29 is further enhanced.

  Further, since the flexible substrate side convex frame 29 is also provided apart from the formed copper foil inner lead 27, the flexible substrate side convex frame 29 and the formed copper foil inner lead 27 are electrically insulated. Yes. As a result, even when conductive grease is used as the heat radiation grease 41, the occurrence of problems such as electrical shorts during circuit operation is suppressed.

(Process for manufacturing flexible substrate tape)
FIG. 5A to FIG. 5H are diagrams schematically showing a manufacturing process of the flexible substrate tape 31. Hereafter, the manufacturing process of the flexible substrate tape 31 is demonstrated based on Fig.5 (a)-FIG.5 (h).

  FIG. 5A is a plan view showing a state where openings and through holes necessary for the polyimide tape 21 are opened by a punch press, and FIG. 5B is a cross-sectional view taken along line AA ′ in FIG. It is arrow sectional drawing.

  First, as shown in FIG. 5A, a feed guide hole 23 is formed on a polyimide tape 21 which is a base of a flexible substrate 45 processed and formed by a press, using a punching press. The feed guide hole 23 is used when the polyimide tape 21 is fed forward in the manufacturing process of the flexible substrate tape 31 described below. Each flexible substrate 45 is cut out from the polyimide tape 21 and separated. Details will be described later.

  Then, while sequentially feeding the polyimide tape 21 using the feed guide hole 23, a coating opening hole 22, an external heat sink fixing screw hole 24, and a slit 25 are further formed by a punch for punching. Here, the external heat sink fixing screw hole 24 is a hole for fixing the flexible substrate 45 to the external heat sink 49. Further, the slit 25 is formed in order to facilitate the separation when the individual flexible substrates 45 are separated from the flexible substrate tape 31 and to prevent the polyimide tape 21 from being deformed during the forward feeding.

Next, as shown in FIG.5 (c), the copper foil plane 26 is affixed on the polyimide tape 21 with an adhesive sheet. FIG. 5D is a cross-sectional view taken along the line BB ′ in FIG.
Subsequently, as shown in FIG. 5E, the copper foil plane 26 is etched and plated to form a formed copper foil inner lead 27 as an electrode, and at the same time, a thermally conductive thin film 28 is formed. Is done. The heat conductive thin film 28 is formed so as to cover and close the coating opening hole 22.

  Here, the heat conductive thin film 28 is a member that guides and dissipates the heat conducted from the circuit portion 15 via the heat radiation grease 41 to the heat conduction member 46, and has an electromagnetic wave shielding effect as well as a heat radiation effect. The effect of making it less likely to be affected by noise or the like can be expected.

At the same time, a flexible substrate side convex frame 29 for preventing leakage of the heat dissipating grease 41 is formed around the thermally conductive thin film 28 so as to surround the thermally conductive thin film 28.
FIG.5 (f) is CC 'arrow sectional drawing in FIG.5 (e).

  Subsequently, as shown in FIG. 5G, a resist coat 30 is formed on the polyimide tape 21, and the flexible substrate tape 31 is completed. Here, the resist coat 30 is for protecting the formed copper foil inner lead 27 and other important portions.

FIG.5 (h) is DD 'arrow sectional drawing in FIG.5 (g).
The flexible substrate tape 31 is formed by the process described above. Then, after the semiconductor chip 43 is mounted on the flexible substrate tape 31, the individual flexible substrates 45 are separated to form the semiconductor device 300.

The flexible substrate 45 in the semiconductor devices 100 and 200 is also manufactured by the same process as described above, although there is a difference in the presence or absence of the flexible substrate-side convex frame 29.
(Summary of Embodiment 3)
As described above, according to the configuration of the present embodiment, on the flexible substrate 45, between the heat conductive thin film 28 and the formed copper foil inner lead 27, a convex shape surrounding the heat conductive thin film 28 is formed. By providing the flexible substrate-side convex frame 29 as a frame, the heat-dissipating grease 41 is prevented from spreading more than necessary outside the heat-conductive thin film 28 (the portion facing the circuit portion 15 thereof). 41 makes contact with the electrode bumps 42 and the formed copper foil inner leads 27 to reduce the risk of electrical shorts during circuit operation, and a more reliable semiconductor device can be obtained.

<Embodiment 4>
FIG. 6 is a cross-sectional view showing a schematic configuration of the semiconductor device 400 according to the present embodiment. In addition, in order to avoid duplication of description, the same code | symbol is attached | subjected about the same component as Embodiment 1-3, and the description is abbreviate | omitted.

  Similar to the semiconductor device 100, the semiconductor device 200, and the semiconductor device 300, the semiconductor device 400 includes the semiconductor chip 43, the flexible substrate 45, the external heat dissipation plate 49, the electrode bump 42, the formed copper foil inner lead 27, and the heat conductive thin film 28. , Heat radiation greases 41 and 46, a mold part 44, a resist coat 30, and the like.

  A characteristic of the semiconductor device 400 is that the semiconductor chip side convex frame 14 is formed outside the portion where the circuit portion 15 is formed on the glass-based protective film 11, and the thermal conductivity is formed on the flexible substrate 45. That is, a flexible substrate side convex frame 29 is formed around the thin film 28.

  A heat dissipating grease 41 is applied to the inside of the semiconductor chip-side convex frame 14, and is spread and connected on the heat conductive thin film 28 formed on the flexible substrate 45. At this time, the heat-dissipating grease 41 spreads more than necessary outside the circuit portion 15 by the semiconductor chip-side convex frame 14 and does not come into contact with the electrode bumps 42. The heat radiation grease 41 further spreads more than necessary outside the heat conductive thin film 28 (the portion facing the circuit portion 15) by the flexible substrate side convex frame 29, and spreads over the electrode bumps 42 and the formed copper foil inner leads. 27 is not in contact with.

Thereby, the possibility of causing an electrical short during circuit operation is reduced, and a more reliable semiconductor device can be realized.
(Assembly process of semiconductor device 400)
FIGS. 7A to 7D are diagrams schematically showing a part of the assembly process of the semiconductor device 400 of the present embodiment, and FIGS. 8A to 8C are subsequent processes. It is a figure shown typically.

  FIG. 7A is an external perspective view showing the semiconductor chip 43 of the semiconductor device 400. First, as shown in the figure, a plurality of bonding pads 13 are provided in a line shape on the surface side edge of the silicon substrate 10, and electrode bumps 42 are mounted on the bonding pads 13.

  Further, on the surface of the silicon substrate 10, the semiconductor chip side convex frame 14 is formed so as to surround the periphery of the portion where the circuit portion 15 is formed, and the heat radiating grease 41 is applied to the inside thereof.

  In the figure, the bonding pad 13 is hidden by the electrode bump 42 and is not shown. A glass-based protective film 11 is also formed on the surface of the silicon substrate 10, but is not shown in the figure. The same applies to FIGS. 7B to 7D.

  Next, as shown in FIGS. 7B and 7C, the semiconductor chip 43 and the flexible substrate tape 31 are mounted by thermocompression bonding. FIG. 7B is a partially cutaway perspective view showing the semiconductor chip 43 and the flexible substrate tape 31 before mounting. FIG. 7C shows the flexible substrate tape 31 and the semiconductor shown in FIG. It is a partially cutaway perspective view showing a state where the chip 43 is turned upside down.

  At this time, the main surface (front surface) on the side where the semiconductor chip side convex frame 14 of the semiconductor chip 43 is formed, and the surface (front surface) on the side where the flexible substrate side convex frame 29 of the flexible substrate tape 31 is formed. Implement to face each other.

In addition, the flexible substrate tape 31 is formed by the steps shown in FIGS.
In the above description, as shown in FIG. 7A, the heat radiation grease 41 is applied to the inside of the semiconductor chip side convex frame 14. The heat conductive thin film 28 may be applied. Here, when the heat radiation grease 41 is applied to the lower member of the semiconductor chip 43 and the flexible substrate tape 31 when assembled, unintentional flow (wetting and spreading) of the heat radiation grease 41 occurs during the assembly. Can be prevented.

Next, as shown in FIG. 7D, a liquid sealing resin is applied around the semiconductor chip 43 mounted on the flexible substrate tape 31, and then thermosetting is performed to form the mold portion 44.
Then, as shown in FIG. 8A, after the excess feed guide hole 23 is separated from the flexible substrate tape 31 by press cutting, the individual flexible substrates 45 are separated by product processing press cutting and processed.

Next, as shown in FIG. 8B, heat radiation grease is applied as a heat conduction member 46 inside the application opening hole 22 of the flexible substrate 45 with the flexible substrate 45 on the back side.
Finally, as shown in FIG. 8C, the external heat sink 49 is fixedly attached to the flexible substrate 45 through the fixing screw 48 in the external heat sink fixing screw hole 24. At this time, the external heat radiating plate 49 is mounted on the surface (back surface) of the flexible substrate 45 on which the heat conductive member 46 is applied to obtain the semiconductor device 400. In FIG. 8C, the external heat sink fixing screw hole 24 is hidden behind the screw head of the fixing screw 48 and cannot be seen.

  Here, the heat radiation grease used as the heat conductive member 46 is applied in an amount sufficient to spread and connect the heat conductive thin film 28 and the external heat radiation plate 49. Thereby, the heat conductive thin film 28 and the external heat dissipation plate 49 are thermally connected by the heat conductive member 46, and heat from the circuit unit 15 conducted through the heat radiation grease 41 and the heat conductive thin film 28 is converted into heat. Heat can be radiated by conduction from the heat conductive thin film 28 to the external heat radiating plate 49 through the conductive member 46.

The external heat sink fixing hole 50 is for fixing the semiconductor device 400 to another substrate or the like with another fixing screw.
The semiconductor device 400 according to the present embodiment is manufactured by the assembly process described above.

  The semiconductor devices 100, 200, and 300 also have the semiconductor chip side convex frame 14 and the flexible substrate side convex frame 29, and the heat radiation grease 41 is applied to the semiconductor chip 43 side or the flexible substrate 45 side. Although there is a difference, it is manufactured by the same process as described above.

(Summary of Embodiment 4)
As described above, according to the configuration of the present embodiment, the flexible substrate side convex frame 29 is provided in addition to the semiconductor chip side convex frame 14, so that the heat radiation grease 41 is transferred to the circuit portion 15 and the heat conductive thin film 28. When the circuit is in operation, the heat radiation grease 41 is in contact with the electrode bumps 42 and the formed copper foil inner leads 27 more effectively than necessary. This can further reduce the risk of electrical shorts and provide a more reliable semiconductor device.

<Modification>
As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described embodiment, and other forms realized by combining arbitrary components in the above-described embodiment. In addition, the present invention includes modifications obtained by making various modifications to the above-described embodiment without departing from the spirit of the present invention, and various devices incorporating the semiconductor device according to the present invention. Variations can be implemented. In addition, in order to avoid duplication of description, the description is abbreviate | omitted about the same content as Embodiment 1-4, and shall attach | subject the same code | symbol about the same component.

  (1) In each of the above embodiments, the heat conductive thin film 28 is a copper foil film, but is not limited thereto. For example, another metal foil film such as aluminum or a thin film made of another material such as a heat conductive resin may be used.

  (2) In each of the above embodiments, the example in which the heat dissipating grease is used for the heat conducting member 46 has been described. However, the present invention is not limited to this. For example, a member such as a resin having thermal conductivity may be used. In this case, it is preferable that the resin has a shape and a size that are in contact with the heat conductive thin film 28 and the external heat dissipation plate 49. Accordingly, the resin can conduct heat from the heat conductive thin film 28 to the external heat radiating plate 49 and dissipate it without pushing up the heat conductive thin film 28 to cause peeling from the flexible substrate 45.

  (3) In the second to fourth embodiments, the shape of the semiconductor chip-side convex frame 14 (the shape when viewed in plan) is described as an example, as shown in FIG. Not limited to this. For example, it may be a triangle, a pentagon or more polygon, a rounded polygon, or a circle such as an ellipse. Further, it passes between the circuit portion 15 and the electrode bump 42 and passes through the circuit portion 15. If it is a surrounding shape, it may be an irregular frame.

  (4) In Embodiments 2 and 4 described above, the semiconductor chip side convex frame 14 is made of a resin such as silicone resin or polyimide, but is not limited to this. You may form with another member. When the semiconductor chip side convex frame 14 is formed using a conductive material such as a metal, the semiconductor chip side convex frame 14 is provided apart from the electrode bump 42 and the bonding pad 13, or It is necessary to ensure electrical insulation between them by interposing an insulating member between them.

  (5) In Embodiments 3 and 4, the flexible substrate-side convex frame 29 is formed of a copper foil, but is not limited to this, and other metal foils such as aluminum or other members such as resins. It may be formed from. Further, when the flexible substrate-side convex frame 29 is made of an insulating member such as a resin, it is not necessarily required to be separated from the formed copper foil inner lead 27.

  (6) Moreover, the height of the flexible substrate side convex frame 29 may be higher than the heat conductive thin film 28 and the formed copper foil inner lead 27. In this case, the flexible substrate side convex frame 29 and the heat conductive thin film 28 do not necessarily need to be separated from each other. When the height of the flexible substrate-side convex frame 29 is sufficiently higher than that of the heat conductive thin film 28, the heat-release grease 41 can sufficiently prevent the heat-release grease from leaking out.

  (7) In Embodiments 3 and 4, the flexible substrate-side convex frame 29 is formed on the flexible substrate 45, but the present invention is not limited to this. For example, when a heat conductive thin film 280 made of an insulating member such as a resin thin film is used instead of the heat conductive thin film 28 made of copper foil as in the semiconductor device 500 shown in FIG. Since the conductive thin film 280 and the formed copper foil inner lead 27 do not have to be provided apart from each other, they may be formed adjacent to each other as shown in FIG. A convex frame 290 may be provided on the heat conductive thin film 280.

  In such a case, when the flexible substrate side convex frame 290 is formed using an insulating member such as a resin thin film instead of the flexible substrate side convex frame 29 made of copper foil, the flexible substrate side convex frame 290 is formed. The electrode bumps 42 and the formed copper foil inner leads 27 can be widely provided, and the heat radiation performance can be further increased by increasing the amount of the heat radiation grease 41. This is more effective when the electrode bumps 42 are provided close to the circuit portion 15 as shown in FIG.

  (8) As in the semiconductor device 600 shown in FIG. 10, a flexible substrate-side convex frame 291 also made of copper foil may be provided on the heat conductive thin film 28 made of copper foil. In this case, since the heat conductive thin film 28 can be formed large up to the space where the flexible substrate side convex frame 29 is provided in the third and fourth embodiments, the sizes of the coating opening hole 22 and the heat conductive member 46 can be reduced. The heat dissipation can be further increased by increasing the size.

In the present modification, the thermally conductive thin film 28 is made of copper foil and has conductivity, and therefore needs to be provided apart from the formed copper foil inner lead 27.
Further, the flexible substrate-side convex frame 291 may be formed from a conductive member such as copper foil or other metal foil, or may be formed from an insulating member such as a resin. When a flexible member is used, the flexible substrate-side convex frame 291 is formed away from the formed copper foil inner lead 27 and the electrode bump 42, and electrical insulation between them is required. In addition, when the flexible substrate side convex frame 291 is formed from a metal or the like, it may be formed by etching or the like from a metal thin film formed on the heat conductive thin film 28.

  The present invention has a simple configuration, can reduce damage to the circuit portion when a semiconductor chip is mounted on a flexible substrate, and can have good heat dissipation, improving the quality and reliability of a semiconductor device. It is useful as a technique to plan.

1, 43 Semiconductor chip 1c Electrode pad 1d Dummy electrode 2 Tape-like film substrate 2a Polyimide film 2c Wiring lead 2e Heat radiation solid layer 3, 42 Electrode bump 4 Heat radiation bump 5 Suspension 10 Silicon substrate 11 Glass-based protective film 13 Bonding pad 14 Semiconductor chip side convex frame 15 Circuit part 21 Polyimide tape 22 Application opening hole 23 Feed guide hole 24 External heat sink fixing screw hole 25 Slit 26 Copper foil solid 27 Formed copper foil inner leads 28, 281 Thermal conductive thin films 29, 290, 291 Flexible substrate side convex frame 30 Resist coat 31 Flexible substrate tape 41 Heat radiation grease 42 Electrode bump 44 Mold part 45 Flexible substrate 46 Thermal conduction member 48 Fixing screw 49 External heat dissipation plate 100, 200, 300, 400, 500, 600, 70 Semiconductor device

Claims (13)

A substrate,
A semiconductor chip having a circuit portion in which a circuit is formed on one main surface,
The semiconductor chip is arranged so that the circuit portion faces the surface of the substrate,
A space between the circuit portion and the substrate is filled with thermally conductive grease. The substrate has a through-hole provided in a portion facing the circuit unit, and a thermally conductive thin film that covers the through-hole on the surface side of the substrate,
2. The semiconductor device according to claim 1, wherein a thermal conductive member having higher thermal conductivity than the substrate is disposed inside the through hole so as to be in contact with the thermal conductive thin film. The semiconductor device according to claim 2, wherein the heat conductive member is a heat conductive grease. A surface electrode formed outside the circuit part on the semiconductor chip main surface;
On the surface of the substrate, a wiring lead formed outside the thermally conductive thin film and at a position facing the surface electrode;
4. The semiconductor device according to claim 2, further comprising: a protruding terminal that is disposed between the surface electrode and the wiring lead and electrically connects the surface electrode and the wiring lead. 5. . Further comprising a substrate-side convex portion erected on the surface of the substrate in a manner that surrounds the thermally conductive thin film, passing between the thermally conductive thin film and the wiring lead,
The semiconductor device according to claim 4, wherein the substrate-side convex portion is made of a conductive member and is provided apart from the wiring lead and the protruding terminal. The thermally conductive thin film, the wiring lead, and the substrate-side convex portion are made of the same member, and the height from the substrate is the same,
The semiconductor device according to claim 5, wherein the substrate-side convex portion is provided apart from the thermal conductive thin film. The thermal conductivity in a form that surrounds a portion of the thermally conductive thin film that passes between the portion facing the circuit portion and the wiring lead and the protruding terminal, and that surrounds the portion of the thermally conductive thin film that faces the circuit portion. The semiconductor device according to claim 4, further comprising a substrate-side convex portion erected on the thin film. The semiconductor device according to claim 7, wherein the substrate-side convex portion is made of a conductive member and is provided apart from the wiring lead and the protruding terminal. The semiconductor device according to claim 7, wherein the substrate-side convex portion is made of an insulating member. A semiconductor chip-side convex portion that is erected on the main surface of the semiconductor chip on which the circuit portion is formed in a form that passes between the circuit portion and the surface electrode and surrounds the circuit portion; The semiconductor device according to claim 4, wherein the semiconductor device is provided. The semiconductor device according to claim 10, wherein the semiconductor chip side convex portion is made of an insulating member. The semiconductor device according to claim 10, wherein the semiconductor chip side convex portion is made of a conductive member and is provided apart from the surface electrode, the protruding terminal, and the wiring lead. The heat radiation member which has higher heat conductivity than the said board | substrate and contacted the said heat conduction member is arrange | positioned on the back surface side of the said board | substrate. The one of Claim 2 to 12 characterized by the above-mentioned. Semiconductor device.

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