JP2000252322A - Semiconductor device, manufacture and mounting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce transmission loss of high frequency signal in a semiconductor device having a mounting structure employing an anisotropic conductive sheet. SOLUTION: In a semiconductor device arranged to connect a semiconductor pellet 10 and a substrate 30 through an anisotropic conductive sheet 20, a low permittivity region 24 is formed by hollowing out a region of the anisotropic conductive sheet 20 corresponding to a transmission line 14 for connecting the circuit block 11 in the semiconductor pellet 10 with the input and output pads 12, 13 so that the passage of the transmission line 14 is surrounded by the low permittivity region 24 comprising the cavity when the assembly is completed. According to the arrangement, transmission loss of high frequency signal on the transmission line 14 caused by high permittivity of the anisotropic conductive sheet 20 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounting technology, a semiconductor device manufacturing technology, and a semiconductor device, and more particularly to a technology effective when applied to a surface mounting technology having a structure in which a sheet member is interposed on a mounting surface. About.

[0002]

2. Description of the Related Art For example, flip chip attach (hereinafter referred to as FCA) is known as one of the mounting techniques for a high frequency integrated circuit. In this FCA, an anisotropic conductive sheet is used between a semiconductor pellet and a mounting substrate or a package in order to simultaneously secure and electrically connect the semiconductor pellet.

[0003]

However, if an anisotropic conductive sheet is interposed between the semiconductor pellet and the mounting board or package, the anisotropic conductive sheet comes into close contact with the entire surface of the semiconductor pellet. There has been a technical problem that the signal loss of the high-frequency signal transmission line inside the semiconductor pellet is increased due to the dielectric property of the anisotropic conductive sheet.

This signal loss is particularly remarkable when the semiconductor pellet is a semiconductor pellet having a high operating frequency, such as a high-frequency IC or a high-frequency LSI, and a countermeasure is required.

[0005] For example, it is conceivable to use a material having a relatively low dielectric constant as the anisotropic conductive sheet. However, the cost of the anisotropic conductive sheet and the manufacturing process using the same is caused by the restriction of the material used. It creates other technical challenges.

An object of the present invention is to provide a semiconductor device mounting technology, a semiconductor device manufacturing technology, and a semiconductor device capable of reducing transmission loss of a high-frequency signal in the semiconductor device.

Another object of the present invention is to provide a semiconductor device mounting technology, a semiconductor device manufacturing technology, and a semiconductor device capable of reducing transmission loss of a high-frequency signal in a semiconductor device at low cost. is there.

Another object of the present invention is to reduce the transmission loss of a high-frequency signal in a semiconductor device employing a mounting structure using an anisotropic conductive sheet without impairing the advantage of using an anisotropic conductive sheet. It is an object of the present invention to provide a semiconductor device mounting technology, a semiconductor device manufacturing technology, and a semiconductor device capable of performing the same.

Another object of the present invention is to provide a semiconductor device mounting technique and a semiconductor device manufacturing technique which enable the application of the FCA assembly technique using an anisotropic conductive sheet to a semiconductor device having a higher operating frequency. It is to provide a technique and a semiconductor device.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0011]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

According to the present invention, in a semiconductor device mounting method for mounting a semiconductor pellet on a substrate by interposing a sheet member between the semiconductor pellet and the substrate, a low dielectric constant region is selectively formed on a part of the sheet member. To form.

Further, the present invention provides a method of manufacturing a semiconductor device, wherein a step of preparing a semiconductor pellet, a step of preparing a substrate, a step of preparing a sheet member on which a low dielectric constant region is selectively formed, Mounting the semiconductor pellet on the substrate via the sheet member.

Further, according to the present invention, in a semiconductor device in which a semiconductor pellet and a substrate are connected via a sheet member, the sheet member is selectively formed with a low dielectric constant region. .

In the present invention as described above, for example, in an FCA using an anisotropic conductive sheet as a sheet member, a region of the anisotropic conductive sheet facing a signal transmission path in a semiconductor pellet is selectively hollowed to form a cavity. By forming a low dielectric constant region by selectively reducing the dielectric constant near the signal transmission path, the signal inside the semiconductor pellet due to the close contact of the anisotropic conductive sheet over the entire surface of the semiconductor pellet An increase in transmission loss in the transmission line can be prevented, and an FCA technique using an anisotropic conductive sheet for a semiconductor pellet having a higher operating frequency can be employed, so that mounting cost of a semiconductor device having a high operating frequency can be reduced.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an exploded view showing an example of a semiconductor device mounting method and a semiconductor device manufacturing method according to an embodiment of the present invention, and FIG. 2 is a sectional view of the semiconductor device in an assembled state. 3, 4 and 5 are enlarged sectional views of a part of the semiconductor device in an assembled state.

The semiconductor device of the present embodiment has a configuration in which the semiconductor pellet 10 is fixed to a substrate 30 formed of, for example, a mounting substrate or a package substrate via an anisotropic conductive sheet 20.

The semiconductor pellet 10 includes a circuit block 11 formed therein having a desired function, an input pad 12 and an output pad 13 exposed on one main surface of the semiconductor pellet 10, and these input pads. 12 and a transmission line 14 connecting the output pad 13 and the circuit block 11, and the like. Also, a bump electrode 12a and a bump electrode 13a made of a wire bump such as Au are protruded from each of the input pad 12 and the output pad 13.

When the circuit block 11 is, for example, an ultra-high-frequency element having an operation frequency of 10 GHz or more, the transmission line 14 is constituted by a high-frequency transmission line such as a coplanar line or a microstrip line corresponding to the high operation frequency. Is done.

FIG. 3 is a cross-sectional view illustrating a case where a coplanar line structure is employed as the transmission line 14. A semiconductor pellet 10 is formed in the cross section of FIG.
For example, a substrate 10a (for example, having a thickness of 200 to 500 μm) made of a semiconductor such as Si or GaAs,
An interlayer film 10b (for example, having a thickness of 1 to 2 μm) made of an insulating material such as iO, SiO ₂ , Si ₃ N ₄ and a signal line 14a (for example, having a width of 5 μm and a thickness of 1 μm) made of a conductor such as Al
m) and a predetermined distance on both sides thereof (for example, 5 μm)
The transmission line 14 has a coplanar line structure composed of a pair of ground lines 14b (for example, 20 μm in width and 1 μm in thickness) arranged along the line, and is formed so as to cover the entire surface of the semiconductor pellet 10 including the transmission line 14. Si
A protective film 10c (for example, having a thickness of 1 to 2 μm) made of an insulating material such as O, SiO ₂ , or Si ₃ N ₄ is shown.

In the case of the present embodiment, the anisotropic conductive sheet 20 corresponding to the portion of the transmission line 14 of the semiconductor pellet 10 has the lengthwise direction of the transmission line 14 (in the plane of FIG. 3). Vertical direction), for example, transmission line 1
4 (eg, 5 × 3 = 15 μm).
The low-dielectric-constant region 24 composed of the cavity having the above is formed.

As shown in FIG. 4, when the transmission line 14 is constituted by a microstrip line 14c (for example, 5 μm in width and 1 μm in thickness) made of a conductor such as Al, The anisotropic conductive sheet 20 corresponding to the structure of the portion includes, for example, the transmission line 1 in the length direction of the transmission line 14 (the direction perpendicular to the plane of FIG. 4).
4 (eg, 5 × 3 = 15 μm).
The low-dielectric-constant region 24 composed of the cavity having the above is formed.

The materials and dimensional values of each part illustrated in FIGS. 3 and 4 are merely examples, and it goes without saying that various changes can be made.

The substrate 30 has a wiring pattern 31 formed on at least one of the surface and the inside of a base portion made of an insulator, and a part of the wiring pattern 31 is formed on the input pad 12 and the semiconductor pad 10 side. A connection electrode 31a is exposed to the outside at a position corresponding to the position of the output pad 13.

As shown in FIG. 5, for example, the anisotropic conductive sheet 20 is formed by forming fine conductive material particles 21 of several μm to several tens μm into an insulating adhesive film 22 made of polyimide, glass epoxy or the like. When the plurality of conductive material particles 21 in a portion pressed in the thickness direction are in contact with the outer conductor in the pressed portion, the conductive material particles 21 are selectively conductive in the thickness direction in the pressed portion. It is possible to selectively form the conductive region 23 having the property.

That is, the anisotropic conductive sheet 20 is sandwiched between the semiconductor pellet 10 and the substrate 30 so that the insulating adhesive film 22 adheres to the input pad 12 and the output pad of the semiconductor pellet 10. Pad 1
3 is bonded to the substrate 30 at the same time as the bump electrodes 12a and 13a protruding from the input pads 12 and the output pads 13 and the corresponding connection electrodes 31a on the substrate 30 side. The region sandwiched between them forms a conductive region 23 having conductivity in the thickness direction, and through this conductive region 23, the input pad 12 and the output pad 13 of the semiconductor pellet 10 and the corresponding substrate 30
Is selectively electrically connected to the connection electrode 31a.

In the case of the present embodiment, as described above, in the anisotropic conductive sheet 20, a low dielectric having a cavity formed by selectively hollowing out a region facing the transmission line 14 on the side of the semiconductor pellet 10. The rate region 24 is formed. That is, the low dielectric constant region 24 has a dielectric constant (for example, ε ≒ 1) similar to that of air filling the cavity, and is a solid region other than the anisotropic conductive sheet 20 (for example, ε ≒ 3).
Dielectric constant is lower than that of

That is, as illustrated in FIGS. 2, 3 and 4, the substrate 30 in the transmission line 14 of the semiconductor pellet 10 is formed by the low dielectric constant region 24 made of a cavity formed in the anisotropic conductive sheet 20. The side surface on the side is surrounded by a low dielectric constant region 24 having a lower dielectric constant than the insulating adhesive film 22, and an effect of reducing transmission loss of a high-frequency signal flowing through the transmission line 14 is obtained.

As shown in FIG. 6, if necessary, a low dielectric constant material 25a is filled in the hollow portion of the anisotropic conductive sheet 20 by a method described below. The region 25 may be formed.

Hereinafter, an example of a method of mounting a semiconductor device and a method of manufacturing a semiconductor device according to the present embodiment will be described with reference to the flowchart of FIG.

First, in the step of preparing the semiconductor pellet 10, a semiconductor wafer manufacturing step (step 101) of slicing an ingot obtained by pulling a semiconductor single crystal and obtaining a bulk wafer through external shape shaping, surface polishing, etc. A wafer process step (step 10) in which a plurality of semiconductor elements having desired functions are collectively and regularly arranged on a semiconductor wafer in a grid pattern by repeating known thin film formation, photolithography, ion implantation, and other steps.
2) a step of forming bump electrodes 12a (13a) for external connection to individual semiconductor elements by a wire bump forming method using, for example, a wire bonding apparatus (step 103), and individual semiconductor elements by a method such as a wafer probe. (Step 104), a dicing step (step 10) in which the semiconductor wafer is cut along the boundaries of the individual semiconductor elements to individually separate the individual semiconductor elements as semiconductor pellets 10.
5), etc.

The step of preparing the anisotropic conductive sheet 20 includes:
The anisotropic conductive sheet 20 in which the conductive material particles 21 are dispersed and present inside the insulating adhesive film 22 is manufactured by mixing the conductive particles with the plastic insulating adhesive and forming the film into a film shape. Step (Step 106): A part of the anisotropic conductive sheet 20 is made to correspond (overlap) with the routing path of the transmission line 14 of the semiconductor pellet 10 so as to overlap (overlap).
A step (step 107) of selectively hollowing out the low dielectric constant region 24 consisting of a cavity by punching using a die or the like. In the process of forming the low dielectric constant region 24 composed of the cavity, the assembly is completed in advance so that the cavity is not crushed and disappeared in the subsequent softening / adhesion process by heating the anisotropic conductive sheet 20. The width dimension of the cavity can be formed larger than the expected dimension at the time.

In the step of preparing the substrate 30 such as a mounting substrate or a package substrate, for example, in the case of using ceramics or the like, a plastic green sheet is appropriately molded, and then the wiring pattern 31 (connection electrode 31a) and the like are formed. After printing and laminating the required number of layers, it is obtained by pressure molding and further heating and firing (step 108).

The steps of preparing each of the semiconductor pellet 10, the anisotropic conductive sheet 20, and the substrate 30 can be performed independently of each other.

After preparing the semiconductor pellet 10, the anisotropic conductive sheet 20, and the substrate 30 in this manner, the FCA in which the anisotropic conductive sheet 20 is positioned and sandwiched between the substrate 30 and the semiconductor pellet 10 to pinch it. Bonding is performed (step 109).

That is, in this FCA bonding,
First, the semiconductor pellet 10 and the substrate 30 are positioned so as to face each other, and the anisotropic conductive sheet 20 is further placed between the semiconductor pellet 10 and the substrate 30. After being positioned so as to overlap with the routing path of the line 14, the three members are superimposed and pressurized while being heated to a softening temperature of, for example, 150 ° C.
Then cool.

Thus, as illustrated in FIGS. 2 and 5, etc., the anisotropic conductive sheet 20
The portion sandwiched between the 0 bump electrode 12a and the bump electrode 13a and the connection electrode 31a of the substrate 30 becomes a conductive region 23 having conductivity, and is connected to each of the bump electrode 12a and the bump electrode 13a of the semiconductor pellet 10. Substrate 30
Are electrically connected to the connection electrodes 31a individually, and the semiconductor pellet 10 is separated from the substrate 30 via the anisotropic conductive sheet 20 by the adhesive force of the anisotropic conductive sheet 20.
It is in a state of being adhered to.

Thereafter, the back side of the semiconductor pellet 10 fixed to the substrate 30 is covered with, for example, potting resin or the like, or a cap-shaped package member (not shown) is joined to the substrate 30 so that the semiconductor pellet 10 is placed inside. A semiconductor device is obtained by sealing the semiconductor pellet 10 by forming a sealed space to be accommodated therein (Step 11).
0). Then, after performing necessary inspection such as aging and sorting (step 111), the product is shipped (step 11).
2).

As described above, in the case of the present embodiment, the transmission of the semiconductor pellet 10 is performed in the process of manufacturing a semiconductor device having a structure in which the semiconductor pellet 10 is bonded to the substrate 30 via the anisotropic conductive sheet 20. Since the low dielectric constant region 24 formed of a cavity having a lower dielectric constant than the anisotropic conductive sheet 20 is formed in the region of the anisotropic conductive sheet 20 corresponding to the line 14, the attenuation of the high frequency signal propagating through the transmission line 14 is attenuated. Can be reduced. Further, in order to reduce the dielectric constant of the anisotropic conductive sheet 20, it is not necessary to take measures such as using a material having a specially low dielectric constant for the insulating adhesive film 22. Since it can be used, there is an advantage that the attenuation of the high-frequency signal propagating through the transmission line 14 can be reduced at low cost without increasing the cost.

As shown in FIG. 8, the thickness of the protective film 10c covering the upper portion of the transmission line 14 in the semiconductor pellet 10 is changed by the mask used in the photolithography for forming the transmission line 14. The protrusion 10c 'is formed by selectively forming the region 10c thicker than other regions by a method such as an etch-back utilizing the above. In this case, the protective film 10
As the substance c, a substance having a dielectric constant smaller than that of the anisotropic conductive sheet 20 is used (FIG. 8A).

At the time of FCA bonding, the softened anisotropic conductive sheet 20 is replaced with the protrusions 10 of the protective film 10c.
When c ′ is displaced, the anisotropic conductive sheet 20 having a large dielectric constant is removed from the vicinity of the transmission line 14 in the completed state of the FCA bonding (FIG. 8B), and the protrusion 10 c ′ becomes anisotropic. It functions as the low dielectric constant region 25 in the layer of the conductive sheet 20.

In the case of FIG. 8 as well, the effect of reducing the attenuation of the high-frequency signal flowing through the transmission line 14 can be obtained, and no special processing is required on the side of the anisotropic conductive sheet 20, thereby reducing the manufacturing cost. Can be reduced. Also, the protrusion 1
By arbitrarily selecting a material constituting 0c '(protective film 10c), there is an advantage that the dielectric constant of the low dielectric constant region 25 can be controlled to an arbitrary value.

As shown in FIG. 9, the anisotropic conductive sheet 20 is provided directly above the route of the transmission line 14 in the semiconductor pellet 10 instead of the protrusion 10c '.
A protrusion pattern 10d made of a substance having a lower dielectric constant than that of the material is formed (FIG. 9A). At the time of FCA bonding, the protrusion pattern 10d pushes away the softened anisotropic conductive sheet 20 to complete the FCA bonding. FIG.
In (b)), the anisotropic conductive sheet 2 having a large dielectric constant
0 may be excluded from the vicinity of the transmission line 14, and the projection pattern 10d may function as the low dielectric constant region 25 in the layer of the anisotropic conductive sheet 20.

In this case, the formation of the projection pattern 10d is as follows.
It can be performed by photolithography using a mask used for forming the transmission line 14. Also in the case of FIG. 8, the effect of reducing the attenuation of the high-frequency signal flowing through the transmission line 14 can be obtained, and no special processing is required on the side of the anisotropic conductive sheet 20, so that the manufacturing cost can be reduced. In addition, there is an advantage that the dielectric constant of the low dielectric constant region 25 can be controlled to an arbitrary value by arbitrarily selecting a substance constituting the projection pattern 10d.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say, there is.

[0047]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

According to the semiconductor device mounting method of the present invention,
An effect is obtained that transmission loss of a high-frequency signal in a semiconductor device can be reduced.

Further, according to the semiconductor device mounting method of the present invention, it is possible to reduce the transmission loss of a high-frequency signal in a semiconductor device at low cost.

Further, according to the method of mounting a semiconductor device of the present invention, a high-frequency signal in a semiconductor device employing a mounting structure using an anisotropic conductive sheet can be obtained without impairing the advantage of using an anisotropic conductive sheet. The transmission loss can be reduced.

Further, according to the semiconductor device mounting method of the present invention, it is possible to apply the FCA assembly technique using an anisotropic conductive sheet to a semiconductor device having a higher operating frequency. Can be

According to the method of manufacturing a semiconductor device of the present invention,
An effect is obtained that transmission loss of a high-frequency signal in a semiconductor device can be reduced.

Further, according to the method of manufacturing a semiconductor device of the present invention, it is possible to reduce the transmission loss of a high-frequency signal in a semiconductor device at low cost.

Further, according to the method of manufacturing a semiconductor device of the present invention, a high-frequency signal in a semiconductor device employing a mounting structure using an anisotropic conductive sheet is maintained without deteriorating the advantage of using an anisotropic conductive sheet. The transmission loss can be reduced.

Further, according to the method of manufacturing a semiconductor device of the present invention, there is obtained an effect that the assembling technique using FCA using an anisotropic conductive sheet can be applied to a semiconductor device having a higher operating frequency. Can be

According to the semiconductor device of the present invention, the effect that the transmission loss of the high-frequency signal in the semiconductor device can be reduced can be obtained.

Further, according to the semiconductor device of the present invention, it is possible to reduce the transmission loss of a high-frequency signal in the semiconductor device at low cost.

Further, according to the semiconductor device of the present invention, the transmission loss of a high-frequency signal in a semiconductor device employing a mounting structure using an anisotropic conductive sheet can be reduced without impairing the advantage of using the anisotropic conductive sheet. The effect of being able to reduce is obtained.

Further, according to the semiconductor device of the present invention, it is possible to apply the FCA assembling technique using the anisotropic conductive sheet to a semiconductor device having a higher operating frequency.
The effect is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded view showing an example of a semiconductor device mounting method and a semiconductor device manufacturing method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the semiconductor device in an assembled state in the semiconductor device mounting method and the semiconductor device manufacturing method according to one embodiment of the present invention;

FIG. 3 is an enlarged cross-sectional view of a part of the semiconductor device in an assembled state in the semiconductor device mounting method and the semiconductor device manufacturing method according to one embodiment of the present invention;

FIG. 4 is an enlarged sectional view of a part of the semiconductor device in an assembled state in the semiconductor device mounting method and the semiconductor device manufacturing method according to one embodiment of the present invention;

FIG. 5 is an enlarged sectional view of a part of the semiconductor device in an assembled state in the semiconductor device mounting method and the semiconductor device manufacturing method according to one embodiment of the present invention;

FIG. 6 is a cross-sectional view showing a modified example of the semiconductor device in an assembled state in the semiconductor device mounting method and the semiconductor device manufacturing method according to one embodiment of the present invention;

FIG. 7 is a flowchart showing an example of the operation of the semiconductor device mounting method and the semiconductor device manufacturing method according to an embodiment of the present invention;

FIGS. 8A and 8B are cross-sectional views showing a modification of the semiconductor device mounting method and the semiconductor device manufacturing method according to an embodiment of the present invention in the order of steps.

FIGS. 9A and 9B are cross-sectional views illustrating a modification of the semiconductor device mounting method and the semiconductor device manufacturing method according to the embodiment of the present invention in the order of steps.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Semiconductor pellet 10a Substrate 10b Interlayer film 10c Protective film 10c 'Projection part 10d Projection pattern 11 Circuit block 12 Input pad 12a Bump electrode 13 Output pad 13a Bump electrode 14 Transmission line 14a Signal line 14b Ground line 14c Microstrip line 20 Anisotropic Conductive sheet 21 Conductive material particles 22 Insulating adhesive film 23 Conductive region 24 Low dielectric constant region 25 Low dielectric constant region 25a Low dielectric constant material 30 Substrate 31 Wiring pattern 31a Connecting electrode

Claims (10)

[Claims] 1. A method for mounting a semiconductor device, comprising: mounting a semiconductor pellet on a substrate by interposing a sheet member between the semiconductor pellet and a substrate; A method for mounting a semiconductor device, wherein a low dielectric constant region having a smaller dielectric constant than other regions is selectively formed. 2. The method of mounting a semiconductor device according to claim 1, wherein the low dielectric constant region is selectively formed in a region of the sheet member along a signal transmission path in the semiconductor pellet. A method for mounting a semiconductor device. 3. The method for mounting a semiconductor device according to claim 1, wherein the sheet member includes an external connection terminal provided on a side of the semiconductor pellet and a wiring pattern provided on a side of the substrate. A first method of selectively forming an electrically conductive anisotropic conductive sheet, wherein a part of the sheet member before assembling is selectively hollowed out to selectively form the low dielectric constant region comprising a cavity. A region of the insulating protective film in the semiconductor pellet, which covers the signal transmission path, is selectively projected, and the signal of the sheet member interposed between the semiconductor pellet and the substrate is projected by the projected insulating protective film. A second method for selectively excluding a region corresponding to a transmission path to selectively present the low dielectric constant region made of the insulating protective film in a layer of the sheet member; Forming a projection pattern made of a material having a low dielectric constant so as to cover an area along the signal transmission path on the side of the side, and selectively removing the sheet member with the projection pattern, thereby forming the projection having a low dielectric constant. A method for mounting a semiconductor device, wherein the low dielectric constant region is selectively formed by any one of the third method and the third method in which the low dielectric constant region made of a substance is selectively present. 4. The semiconductor device mounting method according to claim 1, wherein the substrate is a part of a mounting substrate or a package for sealing the semiconductor pellet. Method. 5. A step of preparing a semiconductor pellet, a step of preparing a substrate, a step of preparing a sheet member on which a low dielectric constant region is selectively formed, and the step of preparing the semiconductor pellet via the sheet member. Mounting a semiconductor device on a substrate. 6. The method of manufacturing a semiconductor device according to claim 5, wherein the low dielectric constant region of the sheet member is selectively formed in a shape along a signal transmission path in the semiconductor pellet. Manufacturing method of a semiconductor device. 7. The method for manufacturing a semiconductor device according to claim 5, wherein the sheet member is an anisotropic conductive sheet, and a part of the sheet member before assembly is selectively hollowed out from a cavity. A first method for selectively forming the low dielectric constant region, wherein a region of the insulating protective film of the semiconductor pellet covering the signal transmission path is selectively protruded, and the semiconductor is formed on the protruding insulating protective film. By selectively excluding a region corresponding to the signal transmission path of the sheet member interposed between the pellet and the substrate, the low dielectric constant region made of the insulating protective film is formed in a layer of the sheet member. A second method of selectively presenting the semiconductor device; forming a projection pattern made of a material having a low dielectric constant so as to cover a region along the signal transmission path on the side of the semiconductor pellet; A third method in which the low-dielectric-constant region made of the low-dielectric-constant material is selectively present by selectively excluding the low-constant member. A method for manufacturing a semiconductor device, which is selectively formed. 8. The method for manufacturing a semiconductor device according to claim 5, wherein the substrate is a part of a mounting substrate or a package for sealing the semiconductor pellet. Method. 9. A semiconductor device in which a semiconductor pellet and a substrate are connected via a sheet member, wherein the sheet member has a selectively formed low-permittivity region. . 10. The semiconductor device according to claim 9, wherein:
The semiconductor device, wherein the sheet member is an anisotropic conductive sheet, and the low dielectric constant region is formed in a shape along a signal transmission path in the semiconductor pellet.