JP2004055598A - Package for high-frequency module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for a high-frequency module which is kept superior in transmission characteristics even when the high-frequency module is advanced to have a higher frequency. <P>SOLUTION: A GND pattern (1) around a connector of a chip connection RF signal wire (2) with an RF signal wire via (3) is eliminated so as to reduce a capacity obtained between the connector of the chip connection RF signal wire (2) with the RF signal wire via (3) and the GND pattern (1) located around it. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a package for a high-frequency module, and more particularly to a package for a high-frequency module with improved transmission characteristics.
[0002]
[Prior art]
2. Description of the Related Art Hitherto, there has been known a dielectric package having a laminated structure that allows passage of a high-frequency signal.
[0003]
FIG. 15 is a sectional view of a dielectric package having a laminated structure. For example, a structure as shown in FIG. 15 is considered as a wiring (RF signal line) structure through which a signal having a frequency of about 5 GHz or less passes.
[0004]
Referring to FIG. 15, this dielectric package includes first to fifth conductive pattern layers and a dielectric layer interposed between the layers.
[0005]
FIGS. 16 to 20 are plan views of the conductor patterns of the fifth to first layers. 16 to 20, the conductor portions are indicated by hatching.
[0006]
The first layer constituting the lowermost part of the conductor pattern layer is called a package backside pattern layer (6), and the wiring structure is electrically connected to the outside by this pattern layer.
[0007]
The fourth layer counted from below the conductor pattern layer is called a chip connection pattern layer (5), and is a layer to which chips are directly connected. The fourth layer and the first layer are provided with an RF signal line for chip connection (2) and an RF signal line (4) on the back surface of the package, respectively. The RF signal line for chip connection (2) and the RF signal line on the back surface of the package (4) are electrically connected by an RF signal line via (3) penetrating the first to fourth layers.
[0008]
The first layer, the fourth layer, and the fifth layer are provided with a GND (ground) pattern (1), and each is electrically connected to a GND via (7).
[0009]
[Problems to be solved by the invention]
However, when the frequency is further increased and a signal of, for example, about 10 GHz or more is allowed to pass, there is a problem that the transmission characteristics are deteriorated in the package configured as described above.
[0010]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a high-frequency module package that can obtain good transmission characteristics even when the frequency is increased.
[0011]
[Means for Solving the Problems]
The following factors are considered as causes of the deterioration of the transmission characteristics when the frequency is increased.
[0012]
-Capacitive coupling between the connection between the RF signal line for chip connection (2) and the RF signal line via (3) and the GND pattern (1) around it-RF signal line (4) on the back of the package and the RF signal line via (3) Capacitive coupling between the GND pattern (1) and the surrounding GND pattern (1), the connection between the RF signal line (2) for chip connection and the RF signal line via (3), and the pattern layer for chip connection The resonance of the GND via (7) connecting the capacitive coupling / chip connecting pattern layer (5) with the GND pattern (1) above (5th layer) and the package backside pattern layer (6), that is, In the examples shown in FIGS. 15 to 20, the RF signal line for chip connection (2) has a coplanar line structure or a grounded coplanar line structure having a characteristic impedance of, for example, 50Ω. The RF signal line via (3) connecting the chip connection pattern layer (5) and the package backside pattern layer (6) is formed by disposing a GND via (7) around the RF signal line via (3). The characteristic impedance is designed to be, for example, 50Ω similarly.
[0013]
However, in the conventional structure shown in FIGS. 15 to 20, the connection between the RF signal line for chip connection (2) and the RF signal line via (3) has a large capacitive coupling with the surrounding GND pattern (1). It has a structure. This unnecessary capacitance causes a mismatch in characteristic impedance, and as a result, transmission characteristics deteriorate.
[0014]
The same applies to the capacitive coupling between the connection portion of the RF signal line (4) on the back surface of the package and the RF signal line via (3) and the surrounding GND pattern (1). That is, in FIG. 20, the RF signal line (4) on the rear surface of the package forms a coplanar line structure or a grounded coplanar line structure having a characteristic impedance of, for example, 50Ω. Further, as the RF signal line via (3) connecting the chip connecting RF signal line (2) and the package rear surface RF signal line (4), a GND via (7) is arranged around the RF signal line via (3). Thus, the characteristic impedance is designed to be, for example, 50Ω in the same manner.
[0015]
However, the conventional structure shown in FIG. 20 has a structure in which the connection between the RF signal line (4) on the back of the package and the RF signal line via (3) and the surrounding GND pattern (1) have large capacitive coupling. As a result, unnecessary capacitance causes mismatching of characteristic impedance, and transmission characteristics deteriorate.
[0016]
In addition, the connection portion of the chip connection RF signal line (2) and the RF signal line via (3), and the GND pattern (1) in a layer above the chip connection pattern layer (5) (for example, the fifth layer in FIG. 15). Similarly, both have a structure in which the capacitive coupling is large, so that there is a problem that unnecessary capacitance causes mismatching of characteristic impedance and transmission characteristics deteriorate.
[0017]
Further, with respect to the GND via (7) connecting the chip connection pattern layer (5) and the package backside pattern layer (6), in the conventional structure shown in FIGS. 15 to 20, when the frequency becomes higher, When the via length of the GND via (7) connecting the chip connection pattern layer (5) and the package backside pattern layer (6) is approximately equal to λ / 2 (λ: wavelength), there is a problem that resonance occurs. The resonance causes a problem that a signal of a specific frequency does not pass (a singular point occurs in a specific portion of the signal).
[0018]
In order to solve the above problems, the present invention has the following configurations.
That is, according to one aspect of the present invention, a high-frequency module package includes a high-frequency module in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a multilayer structure are connected to an RF signal line and a GND by vias. A module package, wherein a GND pattern around a connection portion between an RF signal line of a chip connection pattern layer and an RF signal line via is removed.
[0019]
According to another aspect of the present invention, a high-frequency module package includes a high-frequency module in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a laminated structure are connected to RF signal lines and GND by vias. A module package, wherein a GND pattern around a connection portion between an RF signal line on a package backside pattern layer and an RF signal line via is deleted.
[0020]
According to still another aspect of the present invention, in the high-frequency module package, the chip connection pattern layer and the package backside pattern layer of the dielectric package having a laminated structure are connected to the RF signal line and the GND by vias. A high-frequency module package characterized by having a structure for increasing a distance between an RF signal line of a chip connection pattern layer and a GND pattern above the RF signal line.
[0021]
According to still another aspect of the present invention, in the high-frequency module package, the chip connection pattern layer and the package backside pattern layer of the dielectric package having a laminated structure are connected to the RF signal line and the GND by vias. A high-frequency module package having a structure in which an RF signal line via connecting an RF signal line of a chip connection pattern layer and an RF signal line of a package back pattern layer is shifted by two or more stages. .
[0022]
According to still another aspect of the present invention, in the high-frequency module package, the chip connection pattern layer and the package backside pattern layer of the dielectric package having a laminated structure are connected to the RF signal line and the GND by vias. A high-frequency module package characterized in that when a wavelength of a signal flowing through an RF signal line is λ, a distance between GND patterns of each layer is λ / 2 or less.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
FIG. 1 is a sectional view of a dielectric package having a laminated structure according to the first embodiment of the present invention, and is a view corresponding to FIG. FIGS. 2 to 6 are plan views of the conductor patterns of the respective layers. 2 to 6, the conductor portions are indicated by hatching.
[0024]
Hereinafter, portions of the dielectric package according to the present embodiment that are different from the conventional technology will be described.
[0025]
First, referring to FIG. 1, in the present embodiment, the GND pattern (1) on the right side of the fourth layer (chip connection pattern layer (5)) is deleted. That is, the structure of the conventional example of FIG. 17 is compared with the structure of the present embodiment of FIG. 3, and in the present embodiment, the connection of the chip connecting RF signal line (2) and the RF signal line via (3) is performed. In order to reduce the capacitance between the portion and the GND pattern (1) surrounding the portion, the GND pattern around the connection portion of the RF signal line for chip connection (2) and the RF signal line via (3) is deleted. More specifically, as shown in FIG. 3, the RF signal line for chip connection (2) has a shape in which the pattern becomes thinner toward the RF signal line via (3), and the portion where the conductor portion is not formed ( The portion shown in white in the figure) becomes thicker in the direction in which the RF signal line via (3) is present from the direction in which the chip-connecting RF signal line (2) is present.
[0026]
Also, the GND pattern (1) on the right part of the RF signal line via (3) has been deleted.
[0027]
As shown in FIGS. 4 and 5, in the third and second layers, GND patterns (1) for connecting four GND vias (7) are formed in a plane.
[0028]
Further, as shown in FIG. 6, in order to reduce the capacitance between the connection portion between the RF signal line (4) and the RF signal line via (3) on the package back surface and the GND pattern (1) around the connection portion, the package back surface is reduced. The GND pattern (1) around the connection between the RF signal line (4) and the RF signal line via (3) is deleted. Thus, also in the first layer, the distance from the RF signal line via (3) to the surrounding GND pattern (1) is increased.
[0029]
Thus, in the present embodiment, unnecessary capacity in the package can be reduced. As a result, it is possible to prevent the transmission characteristics from deteriorating due to the mismatch of the characteristic impedance.
[0030]
[Second embodiment]
FIG. 7 is a sectional view of a dielectric package having a laminated structure according to the second embodiment of the present invention.
[0031]
The dielectric package according to the present embodiment is different from the dielectric package according to the first embodiment in that the connection portions of the chip connection RF signal line (2) and the RF signal line via (3) and the chip connection pattern are provided. In order to reduce the capacitance of the GND pattern (1) above the layer (5), the chip connection pattern layer (5) is connected to the GND pattern (1) above the chip connection pattern layer (5). The point is that the distance is increased, and unnecessary capacitance in this part is reduced to such a degree that characteristic impedance mismatch does not occur.
[0032]
As a result, in the present embodiment, unnecessary capacitance in the package can be further reduced as compared with the first embodiment. Then, it is possible to prevent the transmission characteristics from deteriorating due to the mismatch of the characteristic impedance.
[0033]
[Third Embodiment]
FIG. 8 is a sectional view of a dielectric package having a laminated structure according to the third embodiment of the present invention, and corresponds to FIG. 9 to 13 are plan views of the conductor pattern of each layer as viewed in plan. 9 to 13, the conductor portions are indicated by hatching.
[0034]
The difference between the dielectric package according to the present embodiment and the dielectric package according to the first embodiment is that the RF signal line via (3) allows the chip connection pattern layer (5) and the intermediate layer (chip connection pattern layer). An RF signal line (10) (see FIG. 11) which is a lower layer of the (5) layer in the example of FIG. 8) is connected from a position facing the air of the chip connection pattern layer (5). It is a point. Further, the RF signal line (10) of the mediation layer and the package backside pattern layer (6) are connected by a via. Thus, the package according to the present embodiment has a structure in which the vias are shifted by two or more stages as shown in FIG. As a result, the distance between the chip-connecting RF signal line (2) and the GND pattern (1) above the chip-connecting pattern layer (5) is increased, and unnecessary capacitance in this portion is reduced by characteristic impedance mismatch. It can be so small that it does not occur. As a result, deterioration of the transmission characteristics can be prevented.
[0035]
In the above embodiment, the vias are shifted in two stages, but the vias may be shifted in two or more stages.
[0036]
Further, in the above-described embodiment, as a measure against resonance of the GND via (7) connecting the chip connection pattern layer (5) and the package backside pattern layer (6), the distance between the GND patterns of each layer is λ / 2 or less. It is desirable to provide a GND pattern such that the wavelength of a signal flowing through the RF signal line is λ.
[0037]
FIG. 14 is a diagram for explaining an effect in the third embodiment.
In this graph, the horizontal axis indicates the frequency of a signal flowing through the package, and the vertical axis indicates reflection. In the graph, the solid line shows the characteristics when the via has a two-stage structure as in the third embodiment, and the dotted line shows the characteristics when the via has a one-stage structure as in the first embodiment. ing.
[0038]
As shown in the figure, it can be seen that two stages of vias have an effect of suppressing reflection in a high frequency region.
[0039]
The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a sectional view of a semiconductor package according to a first embodiment of the present invention.
FIG. 2 is a plan view of a fifth-layer conductor pattern of the semiconductor package of FIG. 1;
FIG. 3 is a plan view of a conductor pattern of a fourth layer of the semiconductor package of FIG. 1;
FIG. 4 is a plan view of a third-layer conductor pattern of the semiconductor package of FIG. 1;
FIG. 5 is a plan view of a conductive pattern of a second layer of the semiconductor package of FIG. 1;
FIG. 6 is a plan view of a first-layer conductor pattern of the semiconductor package of FIG. 1;
FIG. 7 is a sectional view of a semiconductor package according to a second embodiment of the present invention.
FIG. 8 is a sectional view of a semiconductor package according to a third embodiment of the present invention.
FIG. 9 is a plan view of a fifth-layer conductor pattern of the semiconductor package of FIG. 8;
FIG. 10 is a plan view of a conductor pattern of a fourth layer of the semiconductor package of FIG. 8;
FIG. 11 is a plan view of a third-layer conductor pattern of the semiconductor package of FIG. 8;
FIG. 12 is a plan view of a conductive pattern of a second layer of the semiconductor package of FIG. 8;
FIG. 13 is a plan view of a conductive pattern of a first layer of the semiconductor package of FIG. 8;
FIG. 14 is a diagram showing an effect in the third embodiment.
FIG. 15 is a cross-sectional view of a semiconductor package in the related art.
16 is a plan view of a fifth-layer conductor pattern of the semiconductor package of FIG. 15;
17 is a plan view of a conductor pattern of a fourth layer of the semiconductor package of FIG. 15;
18 is a plan view of a third-layer conductor pattern of the semiconductor package of FIG. 15;
FIG. 19 is a plan view of a conductive pattern of a second layer of the semiconductor package of FIG. 15;
20 is a plan view of a first-layer conductor pattern of the semiconductor package of FIG. 15;
[Explanation of symbols]
1 GND pattern, 2 chip connection RF signal line, 3 RF signal line via, 4 package back RF signal line, 5 chip connection pattern layer, 6 package back pattern layer, 7 GND via, 10 intermediary layer RF signal line.

Claims (5)

A high-frequency module package in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a laminated structure are connected to vias for RF signal lines and GND, respectively,
A high frequency module package, wherein a GND pattern around a connection portion between an RF signal line of a chip connection pattern layer and an RF signal line via is removed. A high-frequency module package in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a laminated structure are connected to vias for RF signal lines and GND, respectively,
A package for a high-frequency module, wherein a GND pattern around a connection portion between an RF signal line on a package backside pattern layer and an RF signal line via is removed. A high-frequency module package in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a laminated structure are connected to vias for RF signal lines and GND, respectively,
A high-frequency module package comprising a structure for increasing a distance between an RF signal line of a chip connection pattern layer and a GND pattern above the RF signal line. A high-frequency module package in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a laminated structure are connected to vias for RF signal lines and GND, respectively,
A high-frequency module package comprising a structure in which RF signal line vias for connecting an RF signal line of a chip connection pattern layer and an RF signal line of a package backside pattern layer are shifted by two or more stages. A high-frequency module package in which a chip connection pattern layer and a package backside pattern layer of a dielectric package having a laminated structure are connected to vias for RF signal lines and GND, respectively,
A high-frequency module package, wherein a distance between GND patterns of each layer is designed to be λ / 2 or less when a wavelength of a signal flowing through the RF signal line is λ.

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