WO2002043135A1 - Semiconductor device and its manufacturing method - Google Patents

Abstract

A semiconductor chip (3) mounted on a substrate (1) is sealed with an insulating first resin coat (6), which is then coated with a second resin coat (7) containing a conductive material. Thus, the semiconductor chip (3) is electromagnetically shielded without providing the periphery of the semiconductor chip (3) with a large metallic case or wall.

Description

 Description Semiconductor device and method for manufacturing the same

 The present invention relates to a semiconductor device and a method for manufacturing the same, and is suitable for use in a device that generates electromagnetic waves, such as a television receiver, a radio receiver, or a mobile portable terminal. Background art

 At present, advances in computer-related equipment, digital home appliances, and mobile terminals are remarkable, and these devices are becoming smaller and thinner. Usually, the electronic components of these devices are composed of a circuit in which passive elements such as resistors, capacitors, and coils, and semiconductor chips are mounted on a substrate. In order to further reduce the size and thickness of the device, research is being actively conducted to integrate the semiconductor chip itself and to mount the semiconductor chip and its peripheral circuits on a substrate at a high density.

 Here, when a circuit using a capacitor, a coil, or the like is configured, an unnecessary electromagnetic field may be emitted from the circuit to the outside. Also

In recent years, the use of ICs in circuits has progressed, and circuits that had been mounted outside of the semiconductor chip using capacitors, coils, and the like are now being incorporated into the semiconductor chip. In this case, an unnecessary electromagnetic field is emitted to the outside from such a semiconductor chip.

When unnecessary electromagnetic fields are emitted from a circuit such as a semiconductor chip to the outside in this way, electronic devices are affected by the electromagnetic field and may cause noise interference or oscillation. In particular, handle high frequency component signals using capacitors, coils, etc. When a circuit is mounted, unnecessary electromagnetic fields tend to leak from the circuit to the outside, and this appears as high frequency component noise.

 For example, when a high frequency circuit used in a television receiver or the like is mounted on a semiconductor chip, if the peripheral circuit receives unnecessary noise of a high frequency component emitted from the semiconductor chip, the image quality of the television screen deteriorates. It can happen. Also, for example, in a radio receiver or the like, a high-frequency signal emitted from a semiconductor chip is affected by a peripheral circuit unit, so that sound quality of reproduced sound may be degraded.

 Therefore, when a circuit that generates an electromagnetic field is mounted on a substrate as a semiconductor chip, the semiconductor chip must be made of a conductive material in order to prevent the semiconductor chip from emitting an electromagnetic field that causes noise to the outside. The creation of walls around the chip necessitates the need to electromagnetically shield the semiconductor chip.

 Conventionally, this electromagnetic shielding has been performed by covering the outer periphery of the target circuit with a metal case. Therefore, when the target circuit is an IC as a semiconductor chip, unnecessary electromagnetic fields are shielded by covering the outer periphery of the semiconductor chip with a metal case. FIGS. 1A and 1B are diagrams showing a configuration example of a semiconductor device having a plurality of semiconductor chips. FIG. 1A is a perspective view of the semiconductor device, and FIG. FIG.

The semiconductor device shown in FIG. 1 has three semiconductor chips 3 mounted on one print substrate 1. These semiconductor chips 3 are electrically connected to the print substrate 1 by, for example, bonding wires 4. In addition, the respective semiconductor chips 3 are connected via wiring, peripheral circuits, and the like (not shown). Conventionally, for such a semiconductor device, each semiconductor chip 3 is electromagnetically shielded by covering the outer periphery of the semiconductor chip 3 with a metal case 2 as shown in FIG. 1 (b). . Further, there is a type in which each semiconductor chip 3 is electromagnetically shielded by partitioning a metal wall for each region where the individual semiconductor chips 3 are present on the print substrate 1.

 FIG. 2 is a cross-sectional view illustrating another configuration example of the semiconductor device. The semiconductor device shown in FIG. 2 has one semiconductor chip 3 mounted on one print substrate 1 and is connected to another circuit outside the substrate by wiring, for example. In such a semiconductor device, the entire printed substrate 1 is covered with a metal case 2 in order to prevent an electromagnetic field generated from the semiconductor chip from being emitted to a circuit portion outside the substrate. The entire printed circuit board 1 including the circuit 3 and its peripheral circuits was electromagnetically shielded.

 As described above, in a conventional semiconductor device, a metal case is used to realize electromagnetic shielding. Therefore, in the case of a semiconductor device in which a plurality of semiconductor chips that generate an electromagnetic field are mounted on one substrate, it is necessary to provide a configuration in which a large wall is provided around each semiconductor chip. There is a problem that it is difficult to mount circuits and the like on a substrate at high density.

 In addition, in the case of a semiconductor device configured by connecting a substrate on which a semiconductor chip that generates an electromagnetic field is mounted to another circuit or another substrate, it is necessary to shield the entire substrate with a large metal wall. Therefore, there was a problem that the configuration became considerably large.

In addition, since a step of mounting a metal case or wall on a substrate by soldering or the like is required, there has been a problem that the manufacturing cost of the semiconductor device is increased. The present invention has been made to solve such a problem, and when forming an electromagnetic shield, a semiconductor chip constituting a semiconductor device and its peripheral circuits can be mounted at a high density. It is another object of the present invention to realize a further reduction in the size and thickness of a semiconductor device. Another object of the present invention is to reduce the manufacturing cost of a semiconductor device including a shield. Disclosure of the invention

 The semiconductor device of the present invention is characterized in that a semiconductor chip is sealed with an insulating first resin coat, and the first resin coat is covered with a second resin coat containing a conductive material. I do.

 According to another aspect of the present invention, there is provided a substrate on which at least one semiconductor chip is mounted, an insulating first resin coat sealing the semiconductor chip, and a conductive resin covering the first resin coat. And a second resin coat containing a material.

 In another aspect of the present invention, a concave or convex stopper for suppressing resin outflow is formed around a portion where the semiconductor chip is mounted.

 Here, the stopper is formed over the entire periphery of the semiconductor chip, and the wiring between the semiconductor chip mounted in the inner region of the stopper and the outer region of the stopper is formed in a plurality of layers. It may be performed via an intermediate wiring layer or a back wiring layer of the formed substrate.

 Further, the stopper may be discretely formed around the semiconductor chip.

Further, the method for manufacturing a semiconductor device according to the present invention includes a first step of sealing a semiconductor chip with an insulating first resin coat; And a second step of covering with a second resin coat containing a conductive material.

 In another aspect of the present invention, a first step of forming a concave or convex stopper for suppressing resin outflow around a portion where a semiconductor chip is mounted on a substrate; A second step of mounting the semiconductor chip in an inner region of the topper and electrically connecting the semiconductor chip to the substrate, and a second step of sealing the semiconductor chip mounted on the substrate with an insulating first resin coat. And a fourth step of covering the first resin coat with a second resin coat containing a conductive material.

 Since the present invention includes the above technical means, the semiconductor chip can be electromagnetically shielded without providing a large metal case or wall around the semiconductor chip or the entire substrate. As a result, the semiconductor chip and its peripheral circuits can be mounted at a high density, and the semiconductor device can be further reduced in size, weight, and thickness.

 Further, according to the present invention, the shield can be formed only by performing double coating of the resin, and a troublesome process of mounting a metal case or the like on the substrate by soldering or the like is not required. Thus, the manufacturing cost of the semiconductor device can be significantly reduced.

 According to another feature of the present invention, a concave or convex stopper for suppressing resin outflow is formed around a portion where the semiconductor chip is mounted, so that the viscosity is low and the fluidity is high. Even when the resin is coated, the resin can be uniformly coated to a predetermined shape and a predetermined size.

In this case, the stopper is formed over the entire periphery of the semiconductor chip, and the wiring between the semiconductor chip mounted in the inner region of the stopper and the outer region of the stopper is formed as an intermediate wiring of a substrate formed of a plurality of layers. Layer or backside wiring In the case where the process is performed via a layer, wiring can be performed without providing an opening in the first and second resin coats, and the entire semiconductor chip can be reliably shielded.

 Also, if the stopper is formed discretely around the semiconductor chip, it becomes possible to provide a wiring pattern between the stopper and the wiring between the semiconductor chip and its peripheral circuit portion is formed on the substrate. It is not necessary to use an intermediate wiring layer or the like, and the number of through holes and the number of stacked substrates can be reduced. As a result, the wiring can be simplified, and the device can be further reduced in size, weight, and thickness. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a cross-sectional view illustrating a configuration example of a conventional semiconductor device.

 FIG. 2 is a cross-sectional view showing another configuration example of the conventional semiconductor device.

 FIG. 3 is a cross-sectional view illustrating a configuration example of the semiconductor device according to the first embodiment.

 FIG. 4 is a diagram illustrating a configuration example of the stove according to the first embodiment, and is a plan view of the semiconductor device according to the present embodiment.

 FIG. 5 is a cross-sectional view illustrating a configuration example of the semiconductor device according to the second embodiment.

 FIG. 6 is a diagram illustrating a configuration example of the stopper according to the second embodiment, and is a plan view of the semiconductor device according to the present embodiment.

 FIG. 7 is a cross-sectional view illustrating a configuration example of the semiconductor device according to the third embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (First Embodiment)

 FIG. 3 is a cross-sectional view illustrating a configuration example of the semiconductor device according to the first embodiment. In FIG. 3, the semiconductor chip 3 mounted on the uppermost layer of the printed board 1 is electrically connected to the electrodes 5 on the printed board 1 by, for example, bonding wires 4. The semiconductor chip 3 and the bonding tracker 4 are entirely made of an insulating first resin coat 6 so as to protect them from dust and moisture and to be insulated from external shocks and vibrations. It is sealed.

 In the present embodiment, the outside of the first resin coat 6 is covered with a conductive material, for example, a second resin coat 7 containing ferrite or other metal powder. As a result, the second resin coat 7 is formed so as to completely cover the semiconductor chip 3. By grounding the second resin coat 7, the semiconductor chip 3 is electromagnetically shielded by the second resin coat 7. can do.

 As a result, the electromagnetic waves emitted from the semiconductor chip 3 are shielded by the second resin coat 7 to prevent them from being emitted as high-frequency noise to the outside, thereby suppressing image disturbance and noise. it can. Of course, by providing such a second resin coat 7, it is possible to prevent an electromagnetic wave emitted outside from penetrating the second resin coat 7 and entering the inside of the semiconductor chip 3.

When forming the first resin coat 6 and the second resin coat 7, it is necessary to prevent the resin from flowing out more than necessary. A method of controlling this by adjusting the viscosity of the resin may be considered, but in the present embodiment, in order to be able to cope with a resin of any viscosity, on the printed circuit board 1, A stopper 10 composed of a concave depression is provided around a portion where the semiconductor chip 3 is mounted. By providing the stopper 10 in this way, the filled resin is prevented from flowing out of the stopper 10, and the first resin coat 6 and the second resin coat 7 are removed by the stopper 10. It can be formed in a prescribed prescribed shape and a prescribed size. At this time, the first resin coat 6 and the second resin coat 7 can be formed to have a desired thickness by adjusting the amount of the resin to be filled.

 FIG. 4 is a diagram showing a configuration example of the stopper 10 and shows a plan view of the semiconductor device according to the present embodiment. FIG. 3 shows a cross section taken along line AA in FIG. Further, FIG. 4 shows a state in which the semiconductor chip 3 and the bonding wire 4 are not yet sealed by the first resin coat 6 and the second resin coat 7 for the sake of explanation. As shown in FIG. 4, in the present embodiment, the entire periphery of the semiconductor chip 3 is formed by a concave portion of the stopper 10. By doing so, even when the semiconductor chip 3 is sealed with a resin having low viscosity, it is possible to prevent the resin from flowing out of the stop 10. Here, a rectangular shape is shown as the shape of the stopper 10. However, the shape is not limited to this, and may be, for example, a circular shape or an elliptical shape.

 Since the stopper 10 is formed all around the semiconductor chip 3, the wiring between the semiconductor chip 3 and a peripheral circuit (not shown) disposed on the same uppermost layer of the substrate is the same as the uppermost wiring. It cannot be connected using layers. Therefore, in the present embodiment, as shown in FIG. 3, the wiring is transferred from the electrode 5 to the intermediate wiring layer 9 inside the printed circuit board 1 through the through hole 8, and the through hole is formed outside the stopper 10. The wiring is returned to the top layer wiring again via 8 'and electrode 5'.

With this configuration, even when the concave stopper 10 is formed around the semiconductor chip 3, the gap between the inside and the outside of the stopper 10 can be reduced. Can be wired. Further, at this time, the first resin coat 6 and the second resin coat 7 do not need to be provided with openings for wiring, so that the entire semiconductor chip 3 can be reliably shielded.

 Here, the wiring between the semiconductor chip 3 and its peripheral circuits is realized by using the intermediate wiring layer 9 of the print substrate 1, but wiring is performed by using the back surface of the print substrate 1. You may do it.

 Next, a method for manufacturing a semiconductor device having the above-described structure will be described below.

 First, a printed board 1 including a through hole 8 and an intermediate wiring layer 9 is formed by stacking a plurality of boards. Next, a stopper 10 is formed by performing, for example, etching using a mask pattern on a predetermined portion of the printed substrate 1 formed as described above.

 In this case, the stop 10 is provided after the print substrate 1 having a plurality of layers is formed.However, a substrate on which the stop 10 is formed is prepared in advance, and this and other substrates are prepared. The print substrate 1 having the stopper 10 may be formed by laminating layers.

 Next, the semiconductor chip 3 is mounted in a region surrounded by the stopper 10, and the semiconductor chip 3 is electrically connected to the print substrate 1 by bonding wires 4. Then, after the semiconductor chip 3 and the bonding wires 4 are sealed with the first resin coat 6, the semiconductor chip 3 and the bonding wires 4 are covered with the second resin coat 7 to form the semiconductor device of the present embodiment.

As described above in detail, according to the present embodiment, the insulating first resin coat 6 that seals the semiconductor chip 3 for moisture proof and the like is replaced with the second resin coat having conductivity. Since the semiconductor chip 3 is further covered, the semiconductor chip 3 can be electromagnetically shielded without providing a large metal case or wall around the semiconductor chip 3. As a result, for example, when a semiconductor device having a plurality of semiconductor chips 3 mounted on one print substrate 1 is configured, it is not necessary to provide a large metal case or the like around each semiconductor chip 3. The semiconductor chip and its peripheral circuits can be mounted on the printed circuit board 1 at high density.

 Also, for example, when a semiconductor device is composed of a printed board 1 on which a semiconductor chip 3 having a high-frequency circuit is mounted and another circuit or board, it is necessary to cover the entire printed board 1 with a large metal case. This can contribute to a reduction in the size, weight, and thickness of the semiconductor device. In particular, recently, with the progress of IC technology, various components can be contained in one chip. In this case, the chip itself may be shielded by the second resin coat 7. Therefore, according to the present embodiment, a troublesome process of mounting a metal case on the printed circuit board 1 by soldering or the like is not required. It also has the advantage that the manufacturing cost can be reduced.

 Further, it is possible to coat the outside of the first resin coat 6 having an insulating property with a material composed of a metal itself, but in the present embodiment, the coating is performed using a resin containing metal powder. Like that. Thereby, not only can the semiconductor chip 3 be electromagnetically shielded, but also the moisture resistance and dust resistance can be further improved.

(Second embodiment)

Next, a second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view (a BB cross-sectional view in FIG. 6) illustrating a configuration example of a semiconductor device according to the second embodiment. FIG. 6 shows a configuration example of the stopper 20 according to the second embodiment. FIG. 3 is a plan view of the semiconductor device according to the present embodiment. FIG. 6 shows a state in which the semiconductor chip 3 and the bonding wire 4 are not yet sealed by the first resin coat 6 and the second resin coat 7 for convenience of explanation.

 As shown in FIG. 6, in the second embodiment, unlike the first embodiment in which the stopper 10 is formed over the entire periphery of the semiconductor chip 3, the shape surrounding the semiconductor chip 3 is different from that of the first embodiment. The stopper 20 is formed only in a part of. If the first resin coat 6 and the second resin coat 7 have a certain degree of viscosity, the resin may flow out of the gap between the stoppers 20 even if the stoppers 20 are provided discretely. However, the resin can be formed in a predetermined shape and a predetermined size.

 When the stoppers 20 are discretely provided, a wiring pattern can be provided between the stoppers 20 and 20. This eliminates the need for wiring between the semiconductor chip 3 and its peripheral circuits using the intermediate wiring layer 9 of the printed circuit board 1 and the like, and reduces the number of through holes and the number of stacked printed circuit boards 1. can do.

 That is, according to the present embodiment, wiring from the electrode 5 electrically connected to the semiconductor chip 3 by the bonding wire 4 to the peripheral circuit portion can be performed using the same wiring layer. Therefore, as shown in FIG. 5, it is not necessary to provide the through-hole 8 and the intermediate wiring layer 9 used in FIG. 3, so that the wiring can be simplified, and the size and weight of the device can be further reduced. The thickness can be reduced.

(Third embodiment)

Next, a third embodiment of the present invention will be described. FIG. 7 is a cross-sectional view illustrating a configuration example of a semiconductor device according to the third embodiment. As shown in FIG. 7, in the present embodiment, the stopper provided around the semiconductor chip 3 has a structure opposite to that of the concave stoppers 10 and 20 described in the first and second embodiments. The stoppers 30 and 31 having a convex structure are used. Here, the first stopper 30 is a stopper for the first resin coat 6, and the taller second stopper 31 is a stopper for the second resin coat 7. It is.

 In the third embodiment, the stoppers 30 and 31 are discretely formed around the semiconductor chip 3 as shown in FIG. Therefore, it is unnecessary to provide a through-hole or an intermediate wiring layer for connecting the semiconductor chip 3 and its peripheral circuit portion. Although the stoppers 30 and 31 are discretely formed here, they may be formed over the entire circumference of the semiconductor chip 3 as shown in FIG.

 Even when the stoppers 30 and 31 having the convex structure are configured as described above, the semiconductor chip 3 can be electromagnetically shielded without providing a metal case or a wall around the semiconductor chip 3. It is possible to realize high-density mounting of semiconductor chips, and furthermore, downsizing and weight reduction and thinning of semiconductor devices. It should be noted that the shapes and structures of the respective parts shown in the above-described embodiment are merely examples of specific examples in practicing the present invention, and these limit the technical scope of the present invention. It must not be interpreted. That is, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

For example, in the above embodiment, the print substrate 1 is shown as a substrate on which the semiconductor chip 3 is mounted, but various substrates can be used for this. For example, a ceramic substrate such as alumina or aluminum nitride, a glass substrate, or a tape-like carrier film may be used. Further, as a method of electrically connecting the semiconductor chip 3 to the substrate, a method other than the bonding wire method may be used.

 In the above embodiment, ferrite / metal powder is used as the material to be included in the second resin coat 7 having conductivity, but the material is not limited to this. For example, if the circuit to be shielded is a circuit that handles signals in the high frequency band, the use of ferrite and other metallic materials with high electrical conductivity, such as copper and aluminum, will reduce the generation of high frequency component noise. Can be deterred. In addition, in the low frequency band, the use of a material having a high magnetic susceptibility such as permalloy can effectively suppress the generation of noise of low frequency components.

 Further, in the above-described embodiment, an example has been described in which a circuit that generates an electromagnetic field, for example, a semiconductor chip having a high-frequency circuit is shielded. However, a semiconductor chip that does not generate an electromagnetic field by itself is covered by a second resin coat 7. It may be allowed to be ignored. In this way, the externally generated electromagnetic field is cut off by the second resin coat 7 so that the semiconductor chip shielded by the second resin coat 7 is not affected by external noise. Can be Industrial applicability

 INDUSTRIAL APPLICABILITY The present invention is useful for realizing further miniaturization and thinning of a semiconductor device by configuring a semiconductor chip and its peripheral circuits at a high density when forming an electromagnetic shield. is there. Further, the present invention is useful for reducing the manufacturing cost of a semiconductor device including a shield.

Claims

The scope of the claims 1. A semiconductor device wherein a semiconductor chip is sealed with an insulating first resin coat, and the first resin coat is covered with a second resin coat containing a conductive material.  2. a substrate on which at least one semiconductor chip is mounted;  A semiconductor device comprising: an insulating first resin coat that seals the semiconductor chip; and a second resin coat containing a conductive material that covers the first resin coat.  3. The semiconductor device according to claim 1, wherein a concave or convex stopper for suppressing resin outflow is formed around a portion where the semiconductor chip is mounted.  The above-mentioned stopper is formed over the entire periphery of the above-mentioned semiconductor chip, and the wiring between the above-mentioned semiconductor chip mounted in the inner region of the above-mentioned stopper and the outer region of the above-mentioned stopper is formed by a substrate formed of a plurality of layers. 4. The semiconductor device according to claim 3, wherein the step is performed via an intermediate wiring layer or a back wiring layer.  5. The semiconductor device according to claim 3, wherein said stopper is formed discretely around said semiconductor chip.  6. A first step of sealing the semiconductor chip with an insulating first resin coat and a second step of covering the first resin coat with a second resin coat containing a conductive material. A method for manufacturing a semiconductor device, comprising: 7. A first step of forming a concave or ώ-shaped stopper around the portion where the semiconductor chip is mounted on the substrate to prevent resin from flowing out; After mounting the chip, A second step of pneumatically connecting,  A third step of sealing the semiconductor chip mounted on the substrate with an insulating first resin coat;  A fourth step of covering the first resin coat with a second resin coat containing a conductive material.