JP3890251B2 - Heat dissipation structure for electrical parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat dissipation structure for an electrical component, and specifically, a liquid crystal display element and a driving semiconductor element thereof, more specifically, a liquid crystal display element using a ferroelectric liquid crystal and a driving semiconductor element thereof. This relates to a heat dissipation structure.
[0002]
[Prior art]
Conventionally, an electric element typified by a liquid crystal display element is formed on a substrate, and a drive circuit in which a semiconductor chip is mounted on a film carrier and separated individually by a TAB method as an external circuit for driving the liquid crystal display A device connected to an electrode terminal extending around the glass substrate of the device, or a semiconductor chip directly connected face-down to an electrode terminal extending around the glass substrate of the liquid crystal display device (COG mounting and There are electrical parts.
[0003]
However, in recent years, the liquid crystal display element has become larger and the driving load has increased, the power consumption of the driving semiconductor element has increased, the temperature rise of the semiconductor element has increased, and the life of the semiconductor chip being used has been shortened, Reliability is to be reduced. Furthermore, particularly in the case of a liquid crystal display element in which the driving semiconductor element is COG-mounted, the temperature of the display screen portion of the liquid crystal display element becomes non-uniform across the entire screen due to the heat effect from the semiconductor element, and the optical response characteristic has a temperature characteristic. For this reason, there is a case where the entire screen becomes non-uniform and the display quality is deteriorated.
[0004]
In particular, a liquid crystal display element using a ferroelectric liquid crystal has an advantage that a large screen can be obtained because of its high response speed and memory characteristics compared to liquid crystal display elements using other liquid crystals. Although research and development and commercialization have been promoted, a liquid crystal display element using ferroelectric liquid crystal has a gap between two transparent substrates sandwiching the liquid crystal as compared with a conventional liquid crystal display element using TN type liquid crystal. In general, the driving voltage is large and the dielectric constant of the liquid crystal material is high, so that the load capacity as viewed from the driving circuit is large and the current value output from the driving semiconductor element is large. For this reason, the power consumption is larger and the temperature rise of the semiconductor element is larger. Further, as the load capacity increases, it is necessary to reduce the wiring resistance of the liquid crystal display element in order to suppress the delay of the liquid crystal drive application voltage (in order to accelerate the rise of the applied voltage to the capacitive load). Therefore, the power consumption of the semiconductor element is further increased, and the temperature rise is further increased. When the temperature rise of the semiconductor element is large, the life of the semiconductor chip used is shortened and the reliability is lowered.
[0005]
Furthermore, the temperature of the screen part of the liquid crystal display element becomes non-uniform over the entire screen due to the heat effect from the driving semiconductor element mounted on the COG, and the optical response characteristics of the ferroelectric liquid crystal have temperature dependence. There is a problem in that the optical quality varies due to the temperature variation, and the display quality deteriorates.
[0006]
In order to deal with such problems, for example, as disclosed in Japanese Patent Laid-Open No. 5-313184, a method of directly dissipating heat by attaching a heat radiation member to a driving semiconductor element of a liquid crystal display element has been proposed.
[0007]
[Problems to be solved by the invention]
FIG. 4 shows a conventional example. An anisotropic conductive adhesive film (not shown) is used for the electrode terminal extending around the glass substrate 1b of the liquid crystal display element when the driving semiconductor element 3 is face down. The drive semiconductor element 3 is attached with a heat radiating member 11 (a heat sink in the embodiment). Here, the heat dissipating member 11 is attached so as to be positioned below the upper surface of the display surface (the upper surface of the polarizing plate 2a), and can dissipate heat without increasing the thickness of the liquid crystal display panel. .
[0008]
However, since the heat radiation member 11 is directly attached to the driving semiconductor element 3 in the conventional example, if an aluminum heat sink is attached as a heat radiation member as in the embodiment, for example, a space for it is required in the peripheral portion of the panel. At the same time, the support structure of the heat dissipation member must be taken into consideration.
[0009]
In addition, a liquid crystal display element using ferroelectric liquid crystal has a problem in that when a strong impact or external force is applied, the alignment of the liquid crystal is disturbed and normal display cannot be performed. Japanese Patent Laid-Open No. 9-73072 (this book) It is necessary to support the liquid crystal display panel with a shock absorbing structure as shown in FIG. In such a shock absorbing structure, since the liquid crystal display panel is movable to some extent, if the heat radiating member as shown in the conventional example is directly attached to the driving semiconductor element, the supporting structure is affected. Become.
[0010]
An object of the present invention is to provide an external circuit structure in which a driving semiconductor element is connected to an electric element in view of such problems of the prior art, without taking up extra space for mounting a heat radiating member. It is possible to attach a heat transfer member without affecting the support structure, and by reducing the heat effect on the electrical element due to the heat generated by the driving semiconductor element, high quality performance can be achieved and By suppressing the temperature rise of the element and the driving semiconductor element, the life of the semiconductor chip is extended and the reliability is improved.
[0011]
[Means for Solving the Problems]
The present invention according to claim 1 is connected to a glass substrate on which an electric element is formed and an electrode terminal extending from the electric element to a peripheral edge on the glass substrate , and is disposed on the glass substrate. In addition, a driving semiconductor element for supplying a driving waveform to the electric element, an input signal wiring board for supplying power and a control signal to the driving semiconductor element, and a glass substrate on which the electric element is formed And an electrical component comprising a support frame that supports the input signal wiring substrate , the glass substrate has a thermal conductivity between the glass substrate surface corresponding to the back surface of the glass substrate surface on which the driving semiconductor element is disposed and the support frame. The heat dissipating structure for electrical parts is characterized by providing a high heat transfer member.
[0013]
According to a second aspect of the present invention, there is provided a glass substrate on which an electric element is formed , and an electrode terminal extending from the electric element to a peripheral edge on the glass substrate , and disposed on the glass substrate. In addition, a driving semiconductor element that supplies a driving waveform to the electric element, an input signal wiring board for supplying power and a control signal to the driving semiconductor element, the glass substrate, and an input signal wiring board An electrical component comprising a support frame for supporting an electrical component, wherein a heat transfer member having a higher thermal conductivity than the glass substrate is provided between the driving semiconductor element and the support frame. is there.
[0014]
According to a third aspect of the present invention, in the heat dissipation structure for an electric component according to the first aspect, a heat transfer member is also provided between the driving semiconductor element and the support frame.
[0015]
The present invention according to claim 4, characterized in that the heat transfer member is formed to have or flexibility, is formed by a member having flexibility, any of claims 1 to 3 Or the heat dissipating structure of the electric component according to item 1.
[0016]
The present invention according to claim 5 resides in the heat dissipation structure for an electric component according to any one of claims 1 to 4 , wherein the electric element is a liquid crystal display element .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(Example)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a liquid crystal display element will be described as an example.
[0018]
Example 1
FIG. 1 is a diagram showing an embodiment of the present invention, in which 1a and 1b are glass substrates, 2a and 2b are polarizing plates, 3 is a driving semiconductor element, 4 is a flexible printed circuit board (FPC), and 5 is an input. Signal wiring board (PCB), 6 is a board support rib, 7 is rubber, 8a is a front frame, 8b is a rear frame, 9a is a cover glass, 9b is a rear glass, and 10 is a heat transfer member. In this figure, the liquid crystal display panel is supported in a substantially sealed space by a cover glass 9a, a rear glass 9b, and rubber 7 to form a shock absorbing structure by an air damper effect shown in Japanese Patent Laid-Open No. 9-73072. is doing.
[0019]
In the present embodiment, the driving semiconductor element 3 that is connected to the electrode terminals extending at the peripheral edge on the glass substrate 1b of the liquid crystal display element and supplies a driving waveform to the liquid crystal display element is different in the face-down state. The flexible wiring substrate 4 and the input signal wiring substrate 5 for supplying power and control signals to the driving semiconductor element 3 are connected in the same manner by being connected using a rectangular conductive adhesive film (not shown) and COG mounted. The liquid crystal display panel is formed by mutual connection using an anisotropic conductive adhesive film (not shown). Here, the glass substrates 1a and 1b of the liquid crystal display panel are provided with rubber 7, and the input signal wiring substrate 5 is provided with a cover glass 9a, a rear glass 9b, and front and rear frames 8a and 8b via substrate support ribs 6. It is supported by. Moreover, to substantially close contact with the heat transfer member 10 between the schematic back surface corresponding to the glass substrate surface and the rear frame 8b of the driving semiconductor element 3 is extended in the peripheral edge on the attached glass substrate 1 b electrode terminal Provided.
[0020]
By supplying a driving waveform to display information on the liquid crystal display panel, the driving semiconductor element 3 generates heat according to its power consumption, and since it is directly face-down mounted on the glass substrate 1b, its heat The heat is transferred to the glass substrate 1b, but is further transferred to the rear frame 8b via the heat transfer member 10. Further, the liquid crystal display panel itself generates heat according to its power consumption by driving, but this heat is also transferred from the glass substrate 1 b and further transferred to the rear frame 8 b via the heat transfer member 10. At this time, if the frames 8a and 8b are made of a material having as high a thermal conductivity as possible (metal or the like), the heat is transferred to the entire support frame and dissipated. The semiconductor element can dissipate heat, and in particular, the glass substrate on which the heat generated by the driving semiconductor element has been transferred can be directly radiated, so the heat generated by the driving semiconductor element is transferred to the liquid crystal display element via the glass substrate. Due to the temperature dependence of the optical response characteristics of the liquid crystal, it is possible to effectively reduce the problem of causing variations in optical response due to temperature variations in the screen and degrading display quality.
[0021]
Here, in order to more effectively dissipate heat, it is naturally desirable that the heat transfer member 10 has a higher thermal conductivity than the glass substrates 1a and 1b, and the shock absorption support structure of the liquid crystal display panel works effectively. For this reason, it is desirable that the rubber 7 has almost the same flexibility as the rubber 7 for supporting the glass substrate. Specifically, a silicon rubber for heat dissipation, or a film bag filled with a perfluorocarbon liquid as a refrigerant (trade name 3M liquid heat sink) can be used.
[0022]
(Example 2)
FIG. 2 shows a structure in which a heat transfer member 10 is provided between the driving semiconductor element 3 and the front frame 8a as compared with the first embodiment. In this heat dissipation structure, the heat generated by the driving semiconductor element 3 is directly generated by the front frame 8a. Therefore, the drive semiconductor element 3 can be radiated more effectively.
[0023]
However, in this heat dissipation structure, the heat of the liquid crystal display panel cannot be directly radiated, but the heat generation of the driving semiconductor element can be directly radiated and the heat generation of the driving semiconductor element can be reduced as compared with the first embodiment. As a result, it is possible to reduce the heat generated by the driving semiconductor element from being transferred to the liquid crystal display element through the glass substrate.
[0024]
However, since the embodiment 1 is more effective in reducing the heat generated by the driving semiconductor element from being transferred to the electric element and exerting a thermal influence, the embodiment in which heat dissipation is prioritized. The heat dissipation structure of 1 or Example 2 can be used properly.
[0025]
(Example 3)
FIG. 3 shows a structure in which the heat transfer member 10 is provided at both the positions of the first and second embodiments. The frames 8a and 8b are directly connected to both the liquid crystal display panel and the driving semiconductor element 3 through the heat transfer member 10. Therefore, heat can be radiated more efficiently, and both the effects described in the first and second embodiments can be effectively exhibited.
[0026]
In the above-described embodiment, the description has been given with the shape having the front frame and the rear frame as the support frame. However, even if only one of the shapes is present, it is the same by using either the embodiment 1 or the embodiment 2. The effect of can be demonstrated.
[0027]
In the above embodiment, the driving semiconductor element 3 is connected in a face-down state to the electrode terminal on the upper surface extending to the peripheral edge of the substrate 1b. However, the driving semiconductor element 3 extends to the peripheral edge of the substrate 1a. Even when the driving semiconductor element 3 is connected to the electrode terminal on the lower surface in a face-down state, the same effect can be exhibited if the embodiment is used upside down.
[0028]
Although all the above embodiments have described liquid crystal display elements, for example, an area sensor using amorphous silicon (a-Si) and a heat dissipation structure such as a driving semiconductor thereof can be used similarly. Applicable to all electrical parts with structure.
[0029]
【The invention's effect】
As described above, by using the heat dissipation structure of the electrical component in the present invention, the heat transfer member can be attached without taking up an extra space for mounting the heat dissipation member and without affecting the support structure of the electric element. It is possible to dissipate heat through the support frame, and by reducing the thermal effect on the electrical element due to the heat generated by the semiconductor element, high quality performance is achieved and the temperature of the semiconductor element for driving the electrical element rises By suppressing this, the life of the semiconductor chip can be extended and the reliability can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment according to the present invention.
FIG. 2 is a diagram showing a second embodiment according to the present invention.
FIG. 3 is a diagram showing a third embodiment according to the present invention.
FIG. 4 is a diagram showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a, 1b Glass substrate 2a, 2b Polarizing plate 3 Drive semiconductor element 4 Flexible wiring board (FPC)
5 Input signal wiring board (PCB)
6 Substrate support rib 7 Rubber 8a Front frame 8b Rear frame 9a Cover glass 9b Rear glass 10 Heat transfer member 11 Heat dissipation member

Claims (5)

A glass substrate having electrical elements are formed, which is connected from the electrical device to the electrode terminals extending in the peripheral edge portion on the glass substrate, and arranged on the glass substrate, the drive to the electric element A driving semiconductor element for supplying a waveform, an input signal wiring board for supplying power and a control signal to the driving semiconductor element, a glass substrate on which the electric element is formed, and an input signal wiring board are supported. In electrical parts consisting of support frames,
Dissipating heat from an electrical component, wherein a heat transfer member having a higher thermal conductivity than the glass substrate is provided between the glass substrate surface corresponding to the back surface of the glass substrate surface on which the driving semiconductor element is disposed and the support frame. Construction. A glass substrate having electrical elements are formed, which is connected from the electrical device to the electrode terminals extending in the peripheral edge portion on said glass substrate, and arranged on the glass substrate, the drive to the electric element An electrical component comprising a driving semiconductor element for supplying a waveform, an input signal wiring board for supplying power and control signals to the driving semiconductor element, and a support frame for supporting the glass substrate and the input signal wiring board In
A heat dissipation structure for an electrical component, wherein a heat transfer member having higher thermal conductivity than the glass substrate is provided between the driving semiconductor element and the support frame. Characterized in that a heat transfer member in between said driving semiconductor element and the support frame, the heat radiation structure of an electric component according to claim 1, wherein. Or the heat transfer member is formed of a member having flexibility, or characterized in that it is formed to have a flexibility, the electrical component according to any one of claims 1 to 3 Heat dissipation structure. The heat dissipation structure for an electrical component according to any one of claims 1 to 4 , wherein the electrical element is a liquid crystal display element.

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