JP6365283B2 - Semiconductor chip and high frequency module - Google Patents

Description

  The present invention relates to a semiconductor chip and a high frequency module.

Conventionally, when a semiconductor chip is connected to the mounting substrate via bumps, the mounting substrate is used to suppress the propagation of high-frequency signals along the surface of the mounting substrate between the semiconductor chip and the mounting substrate. There is a technique in which a layer made of an electromagnetic band gap (EBG) polygon is provided thereon.
In addition, there is a technique in which a metal layer having a lattice shape in a plan view is arranged in the multilayer substrate in order to suppress radiation in a parallel plate mode generated between the grounds in the multilayer substrate on which the semiconductor chip is mounted.

Special table 2007-527629 JP 2010-263413 A

However, it has been found that in a semiconductor chip having a high frequency circuit, signal feedback occurs inside the substrate.
Therefore, it is desired to suppress feedback of signals generated inside the substrate of a semiconductor chip having a high frequency circuit.

The semiconductor chip includes a semiconductor substrate, a high-frequency circuit provided on the front surface side of the semiconductor substrate, and a metal pattern provided on the back surface side of the semiconductor substrate, so that the metal pattern crosses the signal propagation direction of the high-frequency circuit. A plurality of grooves extending in the direction .
The semiconductor chip includes a semiconductor substrate, a high-frequency circuit provided on the front surface side of the semiconductor substrate, and a metal pattern provided on the back surface side of the semiconductor substrate, and the metal pattern has a plurality of shapes that can function as an antenna. The pattern is provided.
The semiconductor chip includes a semiconductor substrate, a high-frequency circuit provided on the front surface side of the semiconductor substrate, and a metal pattern provided on the back surface side of the semiconductor substrate, and the metal pattern includes at least an input part and an output part of the high-frequency circuit. And a groove extending across the signal propagation direction of the high-frequency circuit.
The high-frequency module includes the above-described semiconductor chip and a mounting substrate on which the semiconductor chip is mounted. The semiconductor chip is mounted on the mounting substrate with the high-frequency circuit side down.

The high-frequency module includes a semiconductor chip including a semiconductor substrate, a high-frequency circuit provided on the front surface side of the semiconductor substrate, and a housing having a metal pattern in contact with the back surface side of the semiconductor substrate. A plurality of grooves extending across the signal propagation direction.
The high-frequency module includes a semiconductor chip including a semiconductor substrate, a high-frequency circuit provided on the front surface side of the semiconductor substrate, and a housing having a metal pattern in contact with the back surface side of the semiconductor substrate. A plurality of patterns having a functionable shape are provided.
The high-frequency module includes a semiconductor chip including a semiconductor substrate, a high-frequency circuit provided on the front surface side of the semiconductor substrate, and a housing having a metal pattern in contact with the back surface side of the semiconductor substrate. It has the groove | channel which touches the position corresponding to each of the input part and output part of a circuit, and extends so that the signal propagation direction of a high frequency circuit may be crossed.

  Therefore, according to the present semiconductor chip and the high frequency module, there is an advantage that the feedback of the signal generated inside the substrate of the semiconductor chip including the high frequency circuit can be suppressed.

It is a typical perspective view which shows the structural example of the metal pattern provided in the board | substrate back surface of the semiconductor chip concerning this embodiment. It is a typical perspective view which shows the structural example of the metal pattern provided in the board | substrate back surface of the semiconductor chip concerning this embodiment. (A)-(C) are typical top views which show the structural example of the metal pattern provided in the board | substrate back surface of the semiconductor chip concerning this embodiment. It is a typical perspective view which shows the structural example of the metal pattern provided in the board | substrate back surface of the semiconductor chip concerning this embodiment. It is a typical perspective view showing an example of composition of a high frequency module provided with a semiconductor chip concerning this embodiment. It is a typical perspective view for demonstrating the subject of this invention. (A) is typical sectional drawing which shows the structural example of the high frequency module concerning the modification of this embodiment, (B) is on the surface of the housing | casing with which the high frequency module concerning the modification of this embodiment is equipped. It is a typical perspective view which shows the structural example of the metal pattern provided. It is a figure which shows the simulation result of the propagation characteristic in a 300 GHz band.

Hereinafter, a semiconductor chip and a high frequency module according to an embodiment of the present invention will be described with reference to FIGS.
The semiconductor chip of this embodiment is a semiconductor chip including a high frequency circuit, for example, an MMIC chip (amplifier MMIC chip) including an amplifier (semiconductor amplifier; amplifier circuit) used in a high frequency band. Note that the semiconductor chip is also referred to as a monolithic integrated circuit chip or a semiconductor device.

  In the present embodiment, for example, as shown in FIG. 1, the semiconductor chip 1 includes a semiconductor substrate 2, a high-frequency circuit 3 provided on the front surface side of the semiconductor substrate 2, and a metal pattern provided on the back surface side of the semiconductor substrate 2. (Substrate back metal) 4. The metal pattern 4 is separated so as to cross the signal propagation direction of the high-frequency circuit 3. Here, the metal pattern 4 is a metal film (metal thin film) patterned on the back surface of the semiconductor substrate 2. For example, the metal pattern 4 may have a groove 4 </ b> A (or slit) extending in a direction orthogonal to the signal propagation direction of the high-frequency circuit 3. Thereby, the feedback of the signal which arises inside the board | substrate of the semiconductor chip 1 provided with the high frequency circuit 3 can be suppressed. Moreover, the feedback of the signal which arises with the board | substrate back surface metal 4 can also be suppressed. That is, in the semiconductor chip 1 including the high-frequency circuit 3, substrate mode propagation and substrate back surface metal propagation can be suppressed. In particular, when the high-frequency circuit 3 is an amplifier circuit, such unnecessary oscillation due to signal feedback can be suppressed. The metal pattern 4 is also referred to as a ground pattern, a GND pattern, a ground metal pattern, a ground plane, a GND plane, a ground metal, a GND metal, and a back metal.

  In particular, the metal pattern 4 is preferably separated into a plurality of patterns 4X having a shape that can function as an antenna, for example, as shown in FIG. Thereby, each pattern 4X which comprises the metal pattern 4 functions as an antenna which radiates | emits the electromagnetic wave of board | substrate mode actively outward, and it becomes possible to suppress the signal feedback by board | substrate mode reliably.

  As such a metal pattern, a plurality of square-shaped patterns 4X whose length of one side is ½ of a wavelength λ of a signal (1 / 2λ) whose feedback is desired to be suppressed, that is, a patch antenna or the like A plurality of patterns 4X having a shape may be arranged in a tile shape and spread on the back surface of the semiconductor chip 1 substrate. Such a metal pattern 4 is referred to as a tile-shaped metal pattern. In FIG. 2, Port 1 is an input port, and Port 2 is an output port.

  The metal pattern 4 is not limited to this, and any metal pattern 4 may be used as long as it is separated into a plurality of patterns 4X having a shape that can function as an antenna (planar antenna). For example, a plurality of patterns 4X having a shape such as a dipole antenna (see, for example, FIG. 3A), a slot antenna (see, for example, FIG. 3B), and a staggered lattice (see, for example, FIG. 3C) are tiled. It is good also as what was put in order and spread on the back surface of the board | substrate of the semiconductor chip 1. FIG.

  Here, the plurality of patterns 4X constituting the metal pattern 4 are arranged on the entire back surface of the substrate of the semiconductor chip 1, but the present invention is not limited to this. For example, as shown in FIG. 4, the plurality of patterns 4 </ b> X constituting the metal pattern 4 may be provided at positions corresponding to at least the input unit 3 </ b> A and the output unit 3 </ b> B of the high-frequency circuit 3. That is, the metal pattern 4 should just be provided in the position corresponding to each of the input part 3A and the output part 3B of the high frequency circuit 3 at least. Note that the positions corresponding to the input unit 3A and the output unit 3B of the high-frequency circuit 3 include positions in the vicinity of the positions corresponding to the input unit 3A and the output unit 3B of the high-frequency circuit 3, respectively. As described above, it is the position corresponding to each of the input unit 3A and the output unit 3B of the high-frequency circuit 3 provided on the surface side of the semiconductor chip 1 and its vicinity (periphery) that easily affects the signal feedback. Therefore, it is also effective to provide a pattern only in a place where resonance easily occurs in accordance with the circuit layout of the high frequency circuit 3 provided on the surface side of the semiconductor chip 1.

  By the way, in this embodiment, as shown in FIG. 5, the high frequency module 5 includes the semiconductor chip 1 configured as described above and the mounting substrate 6 on which the semiconductor chip 1 is mounted. The semiconductor chip 1 is mounted on the mounting substrate 6 with the high-frequency circuit 3 side down. That is, in the present embodiment, the semiconductor chip 1 is flip-chip mounted (face-down mounted) on the mounting substrate 6. In this case, the semiconductor chip 1 and the mounting substrate 6 are bonded via bumps (or pillars) 7. Further, the back side of the substrate of the semiconductor chip 1 is on the upper side, and the upper side is covered with air or a dielectric. For this reason, when the metal pattern 4 provided on the back side of the substrate is separated into a plurality of patterns 4X having a shape that can function as an antenna, these patterns 4X positively remove unnecessary electromagnetic waves from the semiconductor chip. It is possible to radiate out of 1 and reliably suppress the feedback of the signal.

The semiconductor chip 1 and the high-frequency module 5 configured as described above are particularly useful in an ultrahigh frequency band exceeding 100 GHz, for example, and are a semiconductor used in a radio communication device, a radar device, an imaging device, or the like used in the ultrahigh frequency band. It is preferable to apply to a chip or a high frequency module.
By the way, the reason why the above configuration is adopted is as follows.

In recent years, the use of ultra-high frequency bands has been expanded by increasing the speed of electronic devices, but new problems specific to high frequencies have emerged.
That is, as shown in FIG. 6, in the semiconductor chip 1 including the high-frequency circuit 3, it was found that signal feedback occurs inside the substrate 2 (see the dotted arrow in FIG. 6).

  For example, when it is desired to achieve a high gain in a high-frequency amplifier, suppression of oscillation becomes a problem. For example, in a semiconductor chip having a high-frequency circuit operating in a submillimeter wave band with a wavelength of 1 mm or less, the wavelength is about the same as the chip size, and the potential of the GND plane becomes unstable. For this reason, unnecessary oscillation may occur in the amplifier due to signal feedback that cannot be predicted by conventional circuit design techniques. In particular, a signal leaked to the substrate side of the semiconductor chip may propagate depending on the substrate mode or propagate through the GND metal, resulting in feedback and unnecessary oscillation.

In this case, it is conceivable to reduce the thickness of the substrate of the semiconductor chip to suppress the substrate mode, or to strengthen the connection with the GND on the back surface of the substrate by providing through vias densely in the substrate of the semiconductor chip.
In these methods, as the wavelength becomes shorter, it is necessary to further reduce the thickness of the substrate of the semiconductor chip, and it is necessary to further reduce the interval between the through vias. For example, if the design frequency is 300 GHz and the relative permittivity of the semiconductor chip substrate is 10, the quarter wavelength is 80 μm in the substrate, so that the thickness of the substrate is sufficiently thinner than this, or more than this It is necessary to make the interval between the through vias very small.

However, in such a thin substrate or a substrate provided with many through vias, the mechanical strength is lowered, so that it is difficult to process the substrate itself or handle it at the time of mounting.
Therefore, the above-described configuration is employed in order to suppress the feedback of the signal generated inside the substrate of the semiconductor chip having the high frequency circuit.
Therefore, according to the semiconductor chip and the high frequency module according to the present embodiment, there is an advantage that the feedback of the signal generated inside the substrate of the semiconductor chip 1 including the high frequency circuit 3 can be suppressed.

In the above-described embodiment, the metal pattern 4 separated so as to cross the signal propagation direction of the high-frequency circuit 3 is provided on the back surface of the substrate of the semiconductor chip 1, and the semiconductor chip 1 is placed with the high-frequency circuit 3 side down. The high-frequency module 5 is configured by mounting on the mounting substrate 6 (see FIG. 5), but is not limited thereto.
For example, as shown in FIGS. 7A and 7B, the high-frequency module 5X includes a semiconductor substrate 2 and a high-frequency circuit 3 provided on the surface side of the semiconductor substrate 2 (not shown in FIG. 7A). ) And a housing 8 having a metal pattern 4 in contact with the back side of the semiconductor substrate 2. The metal pattern 4 is separated so as to cross the signal propagation direction of the high-frequency circuit 3. It is good as well. That is, the casing 8 has a metal pattern 4 separated on the surface so as to cross the signal propagation direction of the high-frequency circuit 3, and the substrate back surface side of the semiconductor chip 1 is in contact with the metal pattern 4. The semiconductor chip 1 may be mounted on the housing 8. Here, the housing 8 is a metal housing. The metal housing 8 is also referred to as a metal module. Further, when such a configuration is adopted, a metal pattern is not provided on the back surface of the semiconductor chip 1.

  In this case, the metal pattern 4 in contact with the back side of the substrate of the semiconductor chip 1 is provided on the surface of the housing 8 on which the semiconductor chip 1 is mounted. This metal pattern 4 is the metal pattern 4 of the above-described embodiment. It may be configured in the same manner as. In particular, as in the case of the above-described embodiment, the metal pattern 4 is preferably separated into a plurality of patterns 4X having a shape that can function as an antenna. Further, it is preferable that the metal pattern 4 is in contact with positions corresponding to at least the input part 3A and the output part 3B of the high-frequency circuit 3 (see, for example, FIG. 4).

  For example, as shown in FIGS. 7A and 7B, a groove 8X extending in a direction orthogonal to the signal propagation direction of the high-frequency circuit 3 and a high-frequency wave are formed on the surface of the metal housing 8 on which the semiconductor chip 1 is mounted. The metal pattern 4 having a plurality of patterns 4X may be provided on the surface of the metal housing 8 by providing the grooves 8Y extending in the signal propagation direction of the circuit 3 so that these grooves 8X and 8Y intersect each other. In this case, the plurality of square-shaped patterns 4X in a plan view formed by the grooves 8X and 8Y intersecting each other has a length (1/2) of the wavelength λ of the signal whose one side length is desired to suppress feedback. / 2λ), and a plurality of patterns 4X shaped like patch antennas may be arranged in a tile and arranged on the surface of the metal housing 8. And what is necessary is just to mount the semiconductor chip 1 on the metal housing 8 by making the board | substrate back surface of the semiconductor chip 1 contact and affix on the surface of the metal housing | casing 8 which has such a metal pattern 4. FIG. In this case, the semiconductor chip 1 is mounted face up on the metal housing 8. Further, by directly adhering the semiconductor chip 1 to the metal housing 8, it is possible to ensure heat dissipation.

By the way, in order to confirm the effects in the structure of the above-described embodiment (see FIG. 2) and the structure of the above-described modification (see FIG. 7), simulation of propagation characteristics in each structure was performed, as shown in FIG. Results were obtained.
Here, the distance between the input port and the output port of the semiconductor chip 1 is about 500 μm, the thickness of the substrate 2 of the semiconductor chip 1 is about 200 μm, and the dielectric constant of the substrate 2 is about 11.9. The propagation characteristics were simulated in the 300 GHz band. Also, in FIG. 8, the reference numeral A indicates the propagation characteristic simulation result in the structure of the above-described embodiment (see FIG. 2), and the reference numeral B indicates the structure of the above-described modification (FIG. 7) shows the simulation result of the propagation characteristics. In FIG. 8, as a comparative example, the simulation result of the propagation characteristics of the structure (solid metal structure) in which metal is provided on the entire back surface of the substrate of the semiconductor chip 1 is also denoted by reference symbol C.

As shown in FIG. 8, compared with the solid metal structure of the comparative example, the structure of the above-described embodiment (see FIG. 2) and the modified example (see FIG. 7) is used as the feedback amount at 300 GHz. It has been confirmed that the structure of the form (see FIG. 2) can be suppressed by about 3 dB, and the structure of the above-described modified example (see FIG. 7) can be suppressed by about 9 dB.
Note that the present invention is not limited to the configurations described in the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the present invention.

Hereinafter, additional notes will be disclosed regarding the above-described embodiment and modifications.
(Appendix 1)
A semiconductor substrate;
A high-frequency circuit provided on the surface side of the semiconductor substrate;
A metal pattern provided on the back side of the semiconductor substrate,
A semiconductor chip, wherein the metal pattern is separated so as to cross a signal propagation direction of the high-frequency circuit.

(Appendix 2)
2. The semiconductor chip according to appendix 1, wherein the metal pattern is separated into a plurality of patterns having a shape that can function as an antenna.
(Appendix 3)
The semiconductor chip according to appendix 1 or 2, wherein the metal pattern is provided at a position corresponding to at least an input part and an output part of the high-frequency circuit.

(Appendix 4)
The semiconductor chip according to any one of appendices 1 to 3,
A mounting substrate for mounting the semiconductor chip,
The high-frequency module, wherein the semiconductor chip is mounted on the mounting substrate with the high-frequency circuit side down.

(Appendix 5)
A semiconductor chip comprising a semiconductor substrate and a high-frequency circuit provided on the surface side of the semiconductor substrate;
A housing having a metal pattern in contact with the back side of the semiconductor substrate;
The high frequency module, wherein the metal pattern is separated so as to cross a signal propagation direction of the high frequency circuit.

(Appendix 6)
The high frequency module according to appendix 5, wherein the metal pattern is separated into a plurality of patterns having a shape that can function as an antenna.
(Appendix 7)
The high frequency module according to appendix 5 or 6, wherein the metal pattern is in contact with at least a position corresponding to each of an input part and an output part of the high frequency circuit.

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 2 Semiconductor substrate 3 High frequency circuit 3A Input part 3B Output part 4 Metal pattern (substrate back surface metal)
4A Groove 4X Pattern 5, 5X High-frequency module 6 Mounting board 7 Bump (or pillar)
8 Housing 8X, 8Y Groove

Claims (7)

A semiconductor substrate;
A high-frequency circuit provided on the surface side of the semiconductor substrate;
A metal pattern provided on the back side of the semiconductor substrate,
The semiconductor chip, wherein the metal pattern has a plurality of grooves extending across the signal propagation direction of the high-frequency circuit. A semiconductor substrate;
A high-frequency circuit provided on the surface side of the semiconductor substrate;
A metal pattern provided on the back side of the semiconductor substrate,
The metal pattern, the semi-conductor chip you comprising a plurality of patterns having a shape capable of functioning as an antenna. A semiconductor substrate;
A high-frequency circuit provided on the surface side of the semiconductor substrate;
A metal pattern provided on the back side of the semiconductor substrate,
The metal pattern, at least the provided at positions corresponding to the inputs and outputs of the high frequency circuit, characterized by having a groove extending across the direction of signal propagation of the high frequency circuit semiconductors Chip. The semiconductor chip according to any one of claims 1 to 3,
A mounting substrate for mounting the semiconductor chip,
The high-frequency module, wherein the semiconductor chip is mounted on the mounting substrate with the high-frequency circuit side down. A semiconductor chip comprising a semiconductor substrate and a high-frequency circuit provided on the surface side of the semiconductor substrate;
A housing having a metal pattern in contact with the back side of the semiconductor substrate;
The high-frequency module, wherein the metal pattern has a plurality of grooves extending so as to cross a signal propagation direction of the high-frequency circuit. A semiconductor chip comprising a semiconductor substrate and a high-frequency circuit provided on the surface side of the semiconductor substrate;
A housing having a metal pattern in contact with the back side of the semiconductor substrate;
The metal pattern, high-frequency modules that comprising a plurality of patterns having a shape capable of functioning as an antenna. A semiconductor chip comprising a semiconductor substrate and a high-frequency circuit provided on the surface side of the semiconductor substrate;
A housing having a metal pattern in contact with the back side of the semiconductor substrate;
The metal pattern is then contact the corresponding to the position of at least the input portion of the high-frequency circuit, and an output section, the high frequency you characterized by having a groove extending across the direction of signal propagation of the high frequency circuit module.