JP6820063B2 - Semiconductor devices, large-scale LSIs or electronic devices - Google Patents

Description

The present invention relates to a semiconductor device, a large-scale LSI or an electronic device using this semiconductor.

As a related technique, Patent Document 1 describes a structure in which a bare chip is connected to a flexible circuit board, the flexible circuit board is bent along the end face of the support, and the bare chip and the support are wrapped with the flexible circuit board. It is described in the description.
In this structure, the support protrudes to the outside of the flexible circuit board and the device 1, and the protruding portion is via the mounting board connected to the semiconductor device, the heat radiating member, and the high thermal conductivity material. By contacting, connecting, or joining, good thermal conductivity is obtained and heat dissipation efficiency is improved.

Further, as another related technique, there are semiconductor devices, semiconductor packages, or electronic devices described in Patent Documents 2, 3, 4, and 5.

Japanese Patent No. 5757573 Japanese Unexamined Patent Publication No. 2004-172322 JP-A-2007-251225 Japanese Unexamined Patent Publication No. 2012-069743 Republished WO2007 / 086481

However, this three-dimensional mounting type semiconductor device has an advantage that the support can be projected to the outside of the device wrapped in the flexible circuit board to secure a large contact area of the support with the atmosphere and improve heat dissipation efficiency. However, in the portion where the support is wrapped in the flexible circuit board, heat is dissipated to the atmosphere through heat conduction from the support to the flexible circuit board, so that the heat dissipation efficiency tends to decrease.
Further, when a semiconductor bare chip having high power consumption is used, the heat dissipation property becomes insufficient and the temperature rises, and this temperature rise may cause a malfunction of the chip.

That is, Patent Document 1 has a problem that the heat dissipation effect is insufficient despite the large size of the support.
Further, even in the related Patent Documents 2 to 5, no special consideration was given to heat dissipation from the support to the atmosphere.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve heat dissipation of a semiconductor device, a large-scale LSI, and an electronic device.

In order to solve the above problems, the present invention has the following configuration.
It has at least a device, a support that is provided in the vicinity of the device and has higher thermal conductivity than the device, and a flexible circuit board, and the flexible circuit board covers at least a part of the device and the support. In the semiconductor device, the surface of the first support in which the support is in contact with the flexible circuit board and the surface of the first support are different from the surface of the flexible circuit board. A semiconductor device having a second support surface that does not come into contact with the surface.

According to the present invention, the heat dissipation of the heat generated in the device can be enhanced.

It is sectional drawing of the semiconductor device which concerns on the minimum configuration example of this invention. FIG. 5 is a cross-sectional view taken along the line II-II of FIG. 4 according to the first embodiment of the semiconductor device of the present invention. It is explanatory drawing of the heat conduction path in the structure of FIG. It is a top view of the first embodiment. It is sectional drawing of 3rd Embodiment. It is sectional drawing of the modification of 3rd Embodiment. It is a side view of the 4th embodiment. FIG. 5 is a cross-sectional view taken along the line VIII-VIII of the fourth embodiment. It is sectional drawing of 5th Embodiment. It is a side view of the device used in 1st Embodiment. It is sectional drawing of the support used in 1st Embodiment. It is an enlarged sectional view of the flexible circuit board used in 1st Embodiment. It is sectional drawing of the flexible circuit board used in 1st Embodiment. It is a top view of the state which the device and the support are arranged on the flexible circuit board of FIG. It is sectional drawing in the state of bending the flexible circuit board in the state of FIG. It is sectional drawing of the completed state which provided the electrode from the state of FIG.

An example of the semiconductor device according to the minimum configuration of the present invention will be described with reference to FIG.
Reference numeral 1 is a device such as a semiconductor bare chip, a packaged electronic component, or a passive component. A support 2 formed of, for example, a material having good thermal conductivity is arranged in the vicinity of the device 1, and the device 1 and the support 2 are surrounded by a flexible circuit board 3. As a specific structure for the flexible circuit board 3 to surround at least a part of the device 1 and the support 2, for example, a structure in which the device 1 and the support 2 are wrapped by one flexible circuit board 3 Will be adopted. The support 2 has a first support surface 4 and a second support surface 5.

The first support surface 4 is in contact with the flexible circuit board 3, and the second support surface 5 surrounds, for example, the space inside the support 2 formed in a hollow shape. It is a surface, for example, in contact with the atmosphere inside the housing of an electronic device.

In the semiconductor device configured as described above, in addition to the first support surface 4, a second support surface 5 is provided to increase the heat dissipation area from the support 2 to the air. The heat generated by the device 1 can be dissipated more efficiently, and as a result, the temperature rise of the semiconductor device can be suppressed. In particular, since the second support surface 5 is in direct contact with the atmosphere, a greater heat dissipation effect can be exhibited.

Further, by expanding the heat dissipation area of the support 2, the heat dissipation performance is improved, and it is not necessary to project the support 2 to the outside to secure a large heat dissipation area, or both ends of the flexible circuit board 3 (FIG. 1). It is possible to reduce the protruding area from the left and right ends), reduce the outer size of the semiconductor device, and reduce the weight of the semiconductor device.

(First Embodiment)
Next, the first embodiment of the present invention will be described in detail with reference to the drawings. The components common to the minimum configuration example of FIG. 1 in the drawing are designated by the same reference numerals to simplify the description.
FIG. 2 is a cross-sectional view of an electronic device using a semiconductor device showing the first embodiment of the present invention, and FIG. 4 is a top view. In FIG. 2, when the flexible circuit board 3 is regarded as the paper on which FIG. 2 is printed, the device 1 is arranged in the center of the first surface 7 which is the front surface of the paper, and is supported so as to surround the device 1. The first embodiment formed by arranging the body 2 and wrapping the body 2 on the device 1 and the support 2 while bending the top and bottom of the paper surface toward the front of the paper surface with the first surface 7 inside. The cross section of the semiconductor device of No. 1 is shown by cutting it in the direction orthogonal to the paper surface.
In this semiconductor device, a flexible circuit board 3 having a first external electrode 8 on the first surface 7 and a second external electrode 10 on the second surface 9 and a periphery of the device 1 It is composed of a support 2 arranged so as to surround the two, and a device 1 electrically connected to the first external electrode 8 of the flexible circuit board 3.

Further, the semiconductor device has a structure in which the flexible circuit board 3 is bent at the ends of two opposite sides of the support 2 to wrap the device 1 and the support 2.
Specifically, first, as shown by the broken line in FIG. 4, the device 1 is located on the first surface 7 of the flexible circuit board 3 inside the support 2 which has a rectangular frame shape as a whole. Deploy.
Next, one short side 3A (upper side of FIG. 4) and the other short side 3A (lower side of FIG. 4) of the flexible circuit board 3 developed in a plane as shown by a chain line in FIG. 4 are formed. A semiconductor device having a cross-sectional structure as shown in FIG. 2 can be obtained by bending the device 1 while lifting it upward on the paper surface of FIG. 4 and wrapping it so as to cover the device 1. In FIG. 4, since the length of the flexible circuit board 3 in the long side 3B direction is short, the central portion of the device 1 is exposed, but the long side 3B is made longer than the illustrated example to make the device 1 longer. It may cover the entire upper surface of the. That is, in the cross section of the portion where the device 1 in the center of FIG. 4 is exposed, the side surface (end face) of the flexible circuit board 3 of FIG. 2 can be seen instead of the cross section.

As described above, the support 2 has a frame shape in a plan view, and as shown in the cross section in FIG. 1, the inside is hollow and can be in contact with the outside air. That is, the support 2 has a structure having a first support surface 4 and a second support surface 5 on the hollow portion side. With this structure, heat can be dissipated from the first support surface 4 and the second support surface 5 of the support 2, so that the heat dissipation area is widened and the heat generated from the device 1 is efficiently released to the air. doing.

FIG. 3 shows a heat flow path in the semiconductor device of this embodiment. The heat generated in the device 1 is transferred to the flexible circuit board 3 in contact with the surface of the device 1, then transferred to the support 2 in contact with the flexible circuit board 3, and finally supported. It can efficiently escape to air from the first support surface 4 and the second support surface 5 of the body 2.
Further, the second external electrode 10 on the second surface 9 of the flexible circuit board 3 is formed with an external terminal for connection with the mounting substrate 6, and includes, for example, Sn as the external terminal. A so-called solder ball B or the like made of a metal material is preferable.
In FIGS. 2 and 3, the flexible circuit board 3 is formed by filling the gap existing between the device 1 and the support 2 with a thermally conductive filler such as grease having good thermal conductivity. In addition to the path passing through, a heat conduction path passing through the device 1-filler-support member 2 may be provided.

In the above, a solder ball is used as the shape of the semiconductor device, but it goes without saying that the structure of the present embodiment can be applied as long as it is the shape of the surface mount type component.
As the device 1, for example, a semiconductor bare chip, a packaged electronic component, a passive component (capacitor, resistor, inductor) or the like can be used.
Examples of the material of the support 2 include metals (iron, aluminum, alloys containing aluminum, alloys containing Ni and Fe, alloys containing Ni and Cr, alloys containing Cr, copper), silicon, and resin materials. (Nickel, polypropylene, epoxy resin, carbon, aramid resin), mica, and the like can be used.

Next, an example of the method for manufacturing the semiconductor device of the first embodiment will be described.
In order to manufacture the semiconductor device of the first embodiment, one device 1 (for example, external size: about 13 mm × 13 mm × height 0.7 mm) as shown in FIG. 10 and a hole in the center as shown in FIG. 11 are provided. One support 2 (for example, external size: about 23 mm × 17 mm × thickness 0.7 mm) forming a frame shape having an open space inside and, for example, the first insulation as shown in FIG. A flexible circuit board 3 composed of a layer 11, a second insulating layer 12, and a third insulating layer 13 (that is, a flexible circuit board having two wiring layers, for example, an external size: about 17 mm × One 36 mm × 0.14 mm thick) and about 100 SnAgCu solder balls having a diameter of about 0.8 mm were used as the solder balls used as the external terminals of the semiconductor device of the present embodiment.
In the present embodiment, the case where the flexible circuit board 3 has a two-layer structure is described, but it goes without saying that the flexible circuit board 3 having a single layer or three or more layers can also be configured. No.

Further, as shown in FIG. 12, the first surface 7 of the flexible circuit board 3 has a thickness of about 25 μm as an adhesive layer on the surface of the support 2 and the portion corresponding to the portion to be bonded to the surface of the device 1 in advance. The thermoplastic adhesive sheet 14 of the above was attached. For this thermoplastic resin, a material that can be adhered at about 150 ° C. was used. The means for adhering the support 2 and the flexible circuit board 3 is not necessarily limited to the adhesive sheet 14, and may be an adhesive layer 14 interposed between them.

First, a flux or cream solder is applied onto the first external electrode 8 on the first surface 7 of the flexible circuit board 3, and the device 1 and the support are used by using the flip chip mounting mounter and the chip mounter. 2 was temporarily mounted on the flexible circuit board 3. FIG. 13 is a cross-sectional view up to the above steps, and FIG. 14 is a top view up to the above steps.

Next, the semiconductor device is adsorbed and fixed on a heater stage heated to 180 ° C., and the flexible circuit board 3 is bent along the two sides 15 of the support 2 using a pressurizing tool to support the device 1. A package as shown in FIG. 15 was produced by adhering to the surface of the body 2 and adhering the flexible circuit board 3 around the device 1 and the support 2.

A solder ball B, which is an external terminal of the semiconductor device, is temporarily mounted on the external electrode of the package thus produced by flux, and then put into a reflow furnace to perform solder connection to complete the semiconductor device shown in FIG. It was.
Next, the completed semiconductor device was mounted on the mounting board 5 using a mounter, and these support semiconductor devices were solder-connected to the mounting board 5 using the reflow device to obtain a semiconductor device as shown in FIG. It was completed.

According to the semiconductor device of the first embodiment, the following effects can be obtained.
The first effect is that the structure has the first support surface 4 and the second support surface 5 of the support, so that the heat generated by the device is dissipated to the air through the support. By expanding the area, heat dissipation can be improved.
The second effect is that the support 2 is formed in a hollow shape to secure a large surface area and enhance heat dissipation, so that the flexible circuit board 1 does not necessarily have a flexible circuit board 1 as described in the related Patent Document 1. It is not necessary to project the support 2 to the outside, and the outer size of the semiconductor device can be reduced.
The third effect is that the weight of the semiconductor device can be reduced because the support 2 is formed in a hollow shape and the inside becomes a space.
The fourth effect is that it is possible to provide a semiconductor device that can be mounted on a device that is difficult to use in a high temperature environment by enhancing heat dissipation.
The fifth effect is that by increasing heat dissipation and reducing the size, it is possible to provide a semiconductor device that can be mounted on a device that is difficult to use due to heat problems and restrictions on the mounting space.

Hereinafter, the second to sixth embodiments of the present invention will be described. In the second to sixth embodiments, the same reference numerals are given to the configurations common to those of the first embodiment to simplify the description. Further, in the second to sixth embodiments, the flexible circuit board 3 is shown by the arrow line of FIG. 4, regardless of whether or not the flexible circuit board 3 covers the entire device 1 and the support 2. It is assumed that the cross section of the place where is present is shown.
(Second Embodiment)
In the first embodiment, the support 2 protrudes to the outside of the flexible circuit board 3, but as shown in the minimum configuration example of FIG. 1, the support 2 is the same as the flexible circuit board 3. It may be configured in width.
FIG. 1 is a cross-sectional view of a semiconductor device showing a second embodiment of the present invention. The shape of the support is different from that of FIG. 2, indicating that the configuration of the present invention can be realized even if the support does not protrude to the outside of the flexible circuit board 3. The structure having the outer support surface 4 and the inner support surface of the support 2 of the present invention improves heat dissipation efficiency, so that the support 2 does not need to protrude to the outside of the flexible circuit board 3. , The size of the semiconductor device can be reduced.

(Third Embodiment)
FIG. 5 is a cross-sectional view of a semiconductor device showing a third embodiment of the present invention.
This third embodiment has a different shape of the support from that of FIG. 2, and shows that the configuration of the present invention can be realized even if the inner support surface is not necessarily flat.
The support 2A of this embodiment is formed in a hollow shape, and is provided with ridges 20 having a rectangular cross section on the inner surface. As described above, since the ridge 20 is provided and is not flat, the heat radiation area to the air is increased, and the heat radiation efficiency can be further improved.
Further, the heat dissipation effect can be similarly enhanced by providing the ridge 21 having a triangular cross section as in the support 2B of the modified example of FIG.
Needless to say, in the present embodiment, the supports 2A and 2B may be a semiconductor device having a structure that does not protrude from the flexible circuit board 3.

(Fourth Embodiment)
FIG. 7 is a side view of the semiconductor device showing the fourth embodiment of the present invention, and FIG. 8 is a view taken along the line VIII-VIII of FIG.
In the fourth embodiment, the upper surface side of the inner support 2C of the support 2C and the lower surface side of the inner support 2C are connected to the structure of the third embodiment by the columnar structure 22 to connect the support. It is possible to improve the rigidity of 2C. That is, the columnar structure 22 compensates for the decrease in strength due to the hollow support 2C in order to increase the surface area, and is used as a heat conduction path in the thickness direction of the support 2.
Needless to say, in the present embodiment, the support 2C may be a semiconductor device having a structure that does not protrude from the flexible circuit board 3.

(Fifth Embodiment)
FIG. 9 is a cross-sectional view of a semiconductor device showing a fifth embodiment of the present invention. In the semiconductor device of the fifth embodiment of the present invention shown in FIG. 9, the semiconductor device described in the first embodiment or the second embodiment of the present invention is used, and the same semiconductor device or different types of semiconductor devices are combined. It has a three-dimensional mounting structure in which multiple layers are stacked. In this structure, the second external electrode 10 on the second surface 9 of the semiconductor device located below is wired to the upper surface on the first surface 7 or the second surface 9, and the second external electrode 10 is also on the upper surface. Is arranged, and the structure is such that the second external electrode 10 and the external terminal of the semiconductor device located above are electrically connected.
With this structure, the mounting area can be reduced as compared with the case where the semiconductor devices are two-dimensionally mounted in parallel, and the semiconductor device having excellent heat dissipation efficiency can be obtained.

(Sixth Embodiment)
Further, although not shown, if an electronic device is assembled using the semiconductor devices of the respective embodiments of the present invention described so far, the heat dissipation effect is higher than before, so that the cost is low and the operating temperature becomes a problem. It can be easily incorporated into small electronic devices. Similarly, it can be applied to an LSI (Large Scale Integrated circuit) provided with a large-scale circuit.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims. It goes without saying that they are also included in the scope of the present invention.

The present invention may be used in semiconductor devices, LSIs, or many electronic devices using these. For example, home-use game machines, medical devices, and workstations that require particularly small size and high integration Stations, servers, personal computers, car navigation systems, mobile phones, robots and the like are suitable.

1 Device 2, 2A, 2B, 2C Support 3 Flexible circuit board 4 First support surface 5 Second support surface 6 Mounting board 7 First surface 8 First external electrode 9 Second surface 10 Second external electrode 11 First insulating layer 12 Second insulating layer 13 Third insulating layer 14 Adhesive sheet (adhesive layer)
15 Sides 20, 21 Convex 22 Columnar structure B External terminal (solder ball)

Claims (9)

It has at least a device, a support provided in the vicinity of the device, a support having higher thermal conductivity than the device, and a flexible circuit board, and the flexible circuit board covers at least a part of the device and the support. It ’s a semiconductor device
The surface of the first support in which the support is in contact with the flexible circuit board and the surface of the second support which is different from the surface of the first support and is not in contact with the flexible circuit board. And have
A semiconductor device in which the support has a hollow shape, the surface of the first support is the outer surface of the support, and the surface of the second support is the inner surface surrounding the hollow portion . The semiconductor device according to claim 1 , wherein the first surface side and the second surface side of the support are connected by a heat conductor connecting to each other in the thickness direction of the flexible circuit board. .. The semiconductor device according to any one of claims 1 or 2, wherein the support projects outside the flexible circuit board and the device. The semiconductor device according to any one of claims 1 or 2, wherein the support does not project to the outside of the flexible substrate and the device. A semiconductor device according to any one of claims 1 to 4 , wherein a plurality of the same or different types of the semiconductor device are combined and laminated. The semiconductor device according to any one of claims 1 to 5 , wherein a heat conductive material is mounted in a gap portion between the device and the support, which is wrapped in the flexible circuit board. The support is one of Fe, an alloy containing Ni and Fe, aluminum, an alloy containing aluminum, copper, an alloy containing Ni and Cr, an alloy containing Cr, silicon, a resin material, mica, and mica. The semiconductor device according to any one of claims 1 to 6 , wherein the material is composed of the same material or a plurality of materials. The semiconductor device according to any one of claims 1 to 7 , wherein the device is composed of any of a semiconductor bare chip, a packaged electronic component, and a passive component. A large-scale LSI or electronic device equipped with the semiconductor device according to any one of claims 1 to 8 .

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