JP3134860B2 - Hybrid integrated circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit device mounted on a bare chip using a flexible substrate,
In particular, the present invention relates to a hybrid integrated circuit device in which the back surface of a bare chip is brought into close contact with a housing or a radiator of a main device.

[0002]

2. Description of the Related Art A conventional hybrid integrated circuit device will be described with reference to the drawings.

FIG. 4 is a sectional view showing a first conventional example. In this conventional example, a substrate 16 is connected to a main substrate 12 which is an example of a heat radiation structure used for heat radiation of a ball grid array substrate by using solder bumps 11. Further, the radiation fins 10 are fixed to the substrate 16 using a radiation resin. This example has a heat dissipation structure that can be applied to bare chip mounting.

FIG. 5 is a sectional view showing a second conventional example. This conventional example is an LSI chip and its packaging structure described in Japanese Patent Application Laid-Open No. 7-307421, in which a bare chip 4 of a mixed specification provided with wire connection electrodes and solder bump connection electrodes 11 is mounted on a substrate 12. Later, the wire wiring 14 is performed, and then the heat sink 17 is mounted on the solder bumps 11, and the heat radiation fins 10 are fixed thereon with the heat radiation resin 13. in this case,
The solder bump 11 to which the heat sink 17 is attached has a configuration in which the melting temperature is higher than the fixing position of the radiating fin 10 and the solder does not melt when the radiating fin is fixed to the back surface of the chip.

FIG. 6 is a sectional view showing a third conventional example. This conventional example is a substrate for mounting a semiconductor chip described in JP-A-2-25046,
Is mounted on the radiating fins 10, the connection electrodes 15 are patterned in advance, the substrate 12 provided with the through holes for mounting the bare chips 4 is attached to the radiating fins 10, and the bare chips 4 and the connection electrode patterns 15 are solder bumps 11. It is configured to connect.

[0006]

In the above-described conventional heat dissipation structure, the metal material used for the heat dissipation fins is generally made of aluminum as a basic material, and has a linear expansion coefficient that is lower than that of the bare chip material. There is a 9.28-fold expansion coefficient difference. Therefore, as shown in FIGS. 4 and 5, after the bare chip is mounted on the board, it is necessary to completely fix the radiating fins and the bare chip. In this case, especially when the size of the bare chip is large, the above-mentioned coefficient of thermal expansion is required. Due to the difference, there is a problem that the possibility that cracks occur in the bare chip is large.

Further, as shown in FIG. 6, when the heat radiation fins are fixed in close contact with each other, the structure becomes complicated, and a large number of man-hours are required for assembling the module and fixing the module. In other words, when the heat radiation fin is mounted, the structure becomes complicated, it takes time to assemble, and when mounted on the board,
There is a problem that a man-hour for fixing is further required depending on the size of the radiation fin.

Accordingly, an object of the present invention is to solve the above-mentioned problem by simplifying the structure by bringing the back surface of the bare chip into close contact with the housing of the main unit directly or via a heat radiating sheet.

Another object of the present invention is to prevent occurrence of chip cracks due to a difference in thermal expansion by preventing a bare chip from being completely fixed to a housing when the bare chip is mounted on a flexible substrate.

Still another object of the present invention is to provide a fixing hook, which eliminates the need for screwing, reduces the number of steps for mounting on a main unit, and simplifies removal.

[0011]

In order to achieve the above object, a hybrid integrated circuit device according to the present invention comprises a housing, a flexible board disposed on the housing, and a housing between the housing and the flexible board. In a hybrid integrated circuit device including a bare chip bump-mounted on a flexible substrate, when the mounting surface of the flexible substrate on which the bare chip is mounted is faced up,
A contact elastic part having a contact portion for pressing the flexible substrate toward the bare chip from the back surface side of the flexible substrate, a connecting portion connected to the housing, and an elasticity adjusting portion for connecting the contact portion and the connection is provided. The present invention is characterized in that the bare chip is brought into close contact with the housing while connecting the elastic body for use to the housing.

According to another aspect of the present invention, there is provided a housing, a flexible substrate disposed on the housing, and a bare chip bump-mounted on the flexible substrate between the housing and the flexible substrate. In the hybrid integrated circuit device, when the mounting surface of the flexible substrate on which the bare chip is mounted is the front surface, the contact portion that presses the flexible substrate toward the bare chip from the back side of the flexible substrate, the connection portion that is connected to the housing, An elastic body for contact having an elasticity adjusting portion for connecting the portion and the connection, and a heat dissipating means inserted between the bare chip and the housing, and the bare chip is connected to the housing at the same time as the elastic body for contact is connected to the housing. It is characterized in that it is fixed to the housing, and the heat of the bare chip is easily radiated to the housing by the heat radiating means, and the bare chip is not broken.

Further, the heat radiating means is preferably a flat heat radiating sheet.

Further, it is preferable that the heat radiation means is a heat radiation resin which is not cured by heat.

[0015] The elastic member for close contact has a fixing hook at the connecting portion, the flexible substrate has an insertion hole into which the fixing hook is inserted, and the housing has a fixing hole into which the fixing hook is inserted. After the fixing hook is inserted into the insertion hole and the fixing hole, it is preferable that the hook is fixed to the housing.

Further, it is preferable that two fixing hooks are provided on both sides of the contact portion.

Further, it is preferable that the fixing hook is formed of resin or metal.

Further, it is preferable to adjust the adhesion between the bare chip and the housing by changing the length, thickness and shape of the elasticity adjusting portion.

As described above, the present invention particularly includes a contact elastic body for applying pressure to the flexible substrate to directly adhere the back surface of the bare chip to the housing of the main unit via the heat radiation sheet. Features.

Further, an elastic body for close contact formed of an elastic resin or a metal material is inserted into a mounting hole of a flexible substrate.
The fixed hooks are positioned and attached.

Further, a fixing hook is inserted into a fixing hook mounting hole provided in the housing of the main body device, and a heat radiation sheet is sandwiched between the back surface of the bare chip and the housing by utilizing the elasticity of the elastic body for close contact. By directly fixing the bare chip mounting portion to the housing, the heat generated by the bare chip is directly transmitted to the housing of the main body device to dissipate heat.

[0022]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the hybrid integrated circuit device of the present invention. In this apparatus, the bare chip 4 is positioned so as to be electrically connected to the flexible substrate 2 by the bumps 5, and mounted using the anisotropic conductive film 3. Connection electrodes are provided in advance at connection positions of the bumps 5 so that the flexible substrate 2 and the bare chip 4 are electrically connected by the anisotropic conductive film 3. next,
By inserting the fixing hook 7 of the fixing elastic body 1 formed of resin or metal material through the insertion hole 17 of the flexible substrate 2 and further inserting the fixing hook 7 into the fixing hole 18 of the housing 6, the bare chip 4 is A heat radiation structure that is in pressure contact with 6 is formed. Further, by inserting the fixing hook 7 into the housing 6 of the main body device and directly contacting and fixing the bare chip 4 to the housing 6,
The heat generated by the bare chip 4 is radiated directly by the housing 6.

[0024]

Next, embodiments of the present invention will be described in detail.

First, a first embodiment of the present invention will be described with reference to FIG. In this embodiment, the bare chip 4 is mounted on the flexible substrate 2 using the anisotropic conductive film 3. The alignment of the bumps 5 allows the flexible substrate 2
And the bare chip 4 are electrically connected. Next, by inserting the fixing hook 7 of the fixing elastic body 1 made of resin or metal material into the insertion hole 17 of the flexible substrate 2 from the back side, the heat dissipating structure for pressing the bare chip 4 against the housing 6 is provided. Is configured. The mounting of the bare chip 4 on the flexible substrate 2 may be performed by a method other than the anisotropic conductive film 3, for example, solder bump mounting.

Next, the operation of the first embodiment of the present invention will be described. In the fixing hole 18 provided in the housing 6 of the main unit,
By inserting the fixing hook 7 and bringing the bare chip 4 into direct contact with the housing 6 and pressing the same, the heat generated in the bare chip 4 is directly radiated by the housing 6. At this time, the adhesion strength of the contact portion between the bare chip 4 and the housing 6 is set according to the size, thickness, and shape of the elasticity adjusting section 19 of the elastic body 1 for fixing.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the bare chip 4 is mounted on the flexible substrate 2 using the anisotropic conductive film 3.
By positioning the bumps 5, the flexible substrate 2 and the bare chip 4 are electrically connected. Next, the fixing hook 7 of the fixing elastic body 1 formed of a resin or a metal material is inserted into the insertion hole 17 of the flexible substrate 2 from the back side of the flexible substrate 2. Until the above, the first
In the second embodiment, the heat radiation sheet 8 is further inserted into the fixing hook 7 of the fixing elastic body 1 in the second embodiment. The size of the heat radiating sheet 8 is larger than the contact portion of the bare chip when the bare chip 4 is pressed against the housing 6.

Next, the operation of the second embodiment of the present invention will be described. The fixing hook 7 is inserted into a fixing hole 18 provided in the housing 6 of the main body device, and the bare chip 4 is pressed against the housing 6 via the heat dissipation sheet 8 to radiate heat generated by the bare chip 4 to the housing 6. At this time, the adhesion strength of the contact portion between the bare chip 4 and the housing 6 is set according to the size, thickness, and shape of the elasticity adjusting section 19 of the fixing elastic body 1. In the case of the first embodiment, the housing 6 and the bare chip 4
However, in the second embodiment, there is an effect that the requirement for flatness is eased by interposing the heat dissipation sheet 8.

Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the bare chip 4 is mounted on the flexible substrate 2 using the anisotropic conductive film 3.
By positioning the bumps 5, the flexible substrate 2 and the bare chip 4 are electrically connected. Next, the fixing hook 7 of the fixing elastic body 1 formed of a resin or a metal material is inserted into the insertion hole 17 of the flexible substrate 2 from the back side of the flexible substrate 2. The above is the same as the above-described first embodiment. However, in the third embodiment, the heat dissipation resin 9 is applied or dispensed to the contact surface between the bare chip 4 and the housing 6 and then the housing is Pressing configuration.
At this time, the heat radiation resin 9 is configured to be covered more than the contact portion of the bare chip 4. The heat radiation resin 9 is made of a material that is not hardened by heat. This has the advantage that the bare chip 4 is not broken due to the difference in expansion coefficient.

Next, the operation of the third embodiment of the present invention will be described. The fixing hook 7 is inserted into a fixing hole 18 provided in the housing 6 of the main body device, and the bare chip 4 is pressed against the housing 6 via the heat dissipation resin 9 to radiate heat generated by the bare chip 4 to the housing 6. . At this time, the adhesion strength of the contact portion between the bare chip 4 and the housing 6 is set according to the size, thickness, and shape of the elasticity adjusting section 19 of the fixing elastic body 1. In the case of the above-described first embodiment, the flatness of the housing 6 and the bare chip 4 is required, but in the case of the third embodiment, the requirement of the flatness is eased due to the interposition of the heat dissipation resin 9. There is an effect that.

[0031]

As described above, since the present invention has an elastic body for close contact, the back surface of the bare chip is brought into close contact with the housing of the main unit directly via the heat radiating sheet, thereby eliminating the need for a heat radiating plate. It has the effect of becoming.

Further, since the bare chip is mounted on the flexible substrate and is not completely fixed to the housing, a chip crack due to a difference in thermal expansion with the housing does not occur.

Further, in the present invention, a fixed hook which is configured to generate a constant pressure is provided in the housing of the main body device in advance by using an elastic resin or a metal material as a material of the elastic body for contact. Insert the hybrid integrated circuit device of the present invention in close contact with the housing by inserting a heat dissipation sheet between the back surface of the bare chip and the housing using the elasticity of the elastic body for adhesion, or insert it directly into the housing using the elasticity of the elastic body for adhesion. By fixing, the heat generated by the bare chip can be directly transmitted to the housing of the main body device to radiate heat. Therefore, since there is a fixing hook for applying pressure to the bare chip with the elasticity of the elastic body for close contact to fix the bare chip tightly, screwing is not required, and the number of steps for mounting on the main body device is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a first embodiment of the present invention is mounted on a main unit housing.

FIG. 2 is a cross-sectional view showing a state in which a second embodiment of the present invention is mounted on a main unit housing.

FIG. 3 is a cross-sectional view showing a state where a third embodiment of the present invention is mounted on a main unit housing.

FIG. 4 is a sectional view showing a first conventional example.

FIG. 5 is a sectional view showing a second conventional example.

FIG. 6 is a sectional view showing a third conventional example.

[Explanation of symbols]

 Reference Signs List 1 elastic body for fixing 2 flexible substrate 3 anisotropic conductive film 4 bare chip 5 bump 6 housing (of main body device) 7 fixing hook 8 heat dissipation sheet 9 heat dissipation resin 10 heat dissipation fin 11 solder bump 12 main board 13 heat dissipation resin 14 Wire wiring 15 connection electrode pattern 16 substrate 17 insertion hole 18 fixing hole 19 elasticity adjustment part

Claims (8)

(57) [Claims] 1. A hybrid integrated circuit device comprising: a housing; a flexible substrate disposed on the housing; and a bare chip bump-mounted on the flexible substrate between the housing and the flexible substrate. In the above, when the mounting surface of the flexible substrate on which the bare chip is mounted is a front surface, a contact portion for pressing the flexible substrate toward the bare chip from the back surface side of the flexible substrate, and a connection portion connected to the housing. A contact elastic part having an elasticity adjusting part connecting the contact part and the connection, wherein the bare chip is brought into close contact with the housing while the elastic body for contact is connected to the housing. A hybrid integrated circuit device. 2. A hybrid integrated circuit device comprising: a housing; a flexible substrate disposed on the housing; and a bare chip bump-mounted on the flexible substrate between the housing and the flexible substrate. In the above, when the mounting surface of the flexible substrate on which the bare chip is mounted is a front surface, a contact portion for pressing the flexible substrate toward the bare chip from the back surface side of the flexible substrate, and a connection portion connected to the housing. , An elastic body for contact having an elasticity adjusting portion for connecting the contact portion and the connection, and a heat dissipating means inserted between the bare chip and the housing; and At the same time that the bare chip is connected to the housing, the bare chip is fixed to the housing, and the heat radiating means makes it easy to radiate the heat of the bare chip to the housing. Hybrid integrated circuit device which is characterized in that so as not to cause destruction of the chip. 3. The hybrid integrated circuit device according to claim 2, wherein said heat radiating means is a flat heat radiating sheet. 4. The hybrid integrated circuit device according to claim 2, wherein said heat radiating means is a heat radiating resin which is not cured by heat. 5. The contact elastic member has a fixing hook at the connection portion, the flexible substrate has an insertion hole into which the fixing hook is inserted, and the housing has the fixing hook inserted therein. 5. The device according to claim 1, further comprising a fixing hole, wherein the fixing hook is fixed to the housing after being inserted into the insertion hole and the fixing hole. 6. Hybrid integrated circuit device. 6. The hybrid integrated circuit device according to claim 5, wherein said fixing hooks are provided at two places on both sides of said contact portion. 7. The hybrid integrated circuit device according to claim 5, wherein said fixing hook is formed of resin or metal. 8. The method according to claim 1, wherein the adhesion between the bare chip and the housing is adjusted by changing the length, thickness, and shape of the elasticity adjusting portion. A hybrid integrated circuit device as described.