JP2014195032A - High-frequency package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the size of an outermost periphery of a package becomes larger and whereby the package size becomes larger by increasing BGA ball arrays for preventing an unwanted emission signal.SOLUTION: A high-frequency package includes a second dielectric multilayer substrate facing a rear surface of a first dielectric multilayer substrate on which a high-frequency circuit is mounted and bonded to the first dielectric multilayer substrate by a plurality of conductive connection members. The second dielectric multilayer substrate has a first dielectric opening formed on an opposite surface of the first dielectric multilayer substrate and in which a ground conductor is removed; a dielectric waveguide having one end connected to the first dielectric opening; a second dielectric opening connected to the other end of the dielectric waveguide; and an end short-circuit waveguide having one end connected to the second dielectric opening and the other end short-circuited to a plurality of via arrays. The conductive connection members have conductive connection members for unwanted emission prevention arranged in at least one array on the outside along the outer periphery of the first dielectric multilayer substrate.

Description

  The present invention relates to a high-frequency package for processing high-frequency signals such as microwaves and millimeter waves.

  A semiconductor element for processing a high-frequency signal is mounted on a first resin substrate, another resin substrate is disposed so that the mounting surface of the semiconductor element on the first resin substrate faces, and a BGA is provided between the two resin substrates. (Ball Grid Array) There is a high frequency package connected by a ball (for example, see Patent Document 1). An RF (Radio Frequency) circuit, a DC (Direct Current) circuit, or the like formed on the mounting surface of the semiconductor element of the high frequency package generates an unnecessary radiation signal having a frequency band different from that of the desired signal processed by the semiconductor element. Leakage may occur outside the package from the gaps between the solder balls constituting the ball. In order to prevent unnecessary radiation signals generated from inside the high-frequency package from leaking out of the package, the leakage of unnecessary radiation signals was prevented by providing a certain number of BGA ball rows from each circuit to the outermost periphery of the package. Note that the high-frequency signal and the DC signal processed by the RF circuit and the DC circuit are transmitted between the first and second resin substrates via the BGA balls.

JP 2011-155287 A

  However, in addition to the BGA balls used for signal transmission between the first and second receiving boards between each circuit such as an RF circuit and a DC circuit and the outermost package, a BGA for suppressing unnecessary radiation signals Increasing the number of ball rows increases the size of the outermost periphery of the package, resulting in an increase in the size of the package itself.

  This invention is made in order to solve the subject which concerns, and it aims at suppressing the number of the arrangement | sequence of the conductive connection member for unnecessary radiation signal suppression.

  In the radar apparatus according to the present invention, the first dielectric multilayer substrate having a high-frequency circuit mounted on the back surface, and the back surface of the first dielectric multilayer substrate face each other by interposing a plurality of conductive connection members. A second dielectric multilayer substrate that is joined to the first dielectric multilayer substrate and encloses the high-frequency circuit together with the conductive connecting member, and the second dielectric multilayer substrate includes the first dielectric multilayer substrate. A first dielectric opening formed on the opposite surface of the substrate from which the ground conductor is removed, and one end connected to the first dielectric opening formed by being surrounded by the inner ground conductor layer and the via. A dielectric waveguide, a second dielectric opening connected to the other end of the dielectric waveguide, an inner ground conductor layer and a via, and one end portion formed by the via Connected to the second dielectric opening and the other end is short-circuited to a plurality of via rows. The conductive connecting member has an unnecessary radiation suppressing conductive connecting member arranged in at least one row on the outer side along the outer periphery of the first dielectric multilayer substrate. It is.

  According to the present invention, since the number of the conductive connection members arranged for suppressing the unnecessary radiation signal can be suppressed, the size of the outermost periphery of the package can be further reduced.

1 is a diagram illustrating a configuration of a high-frequency package according to a first embodiment. It is a comparison figure which shows the structure of the conventional high frequency package.

Embodiment 1 FIG.
A high-frequency package according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a high-frequency package according to the first embodiment. In FIG. 1, the high frequency package 4 according to the first embodiment includes a dielectric multilayer substrate 1, a dielectric multilayer substrate 2, and a BGA ball 3 that is a conductive connection member. Between the dielectric multilayer substrate 1 and the dielectric multilayer substrate 2, BGA balls 3 made of a plurality of solder balls or gold bumps arranged in a two-dimensional plane are arranged. The dielectric multilayer substrate 1 and the dielectric multilayer substrate 2 are arranged with a predetermined distance between the BGA balls 3 and are joined by the BGA balls 3.

  The dielectric multilayer substrate 1 is mounted with a circuit such as an RF circuit or a DC circuit composed of a high-frequency circuit such as an MMIC (monolithic microwave integrated circuit) 5 and a chip resistor 6 on the mounting surface on the back side, and is joined by solder. . The MMIC 5 and the chip resistor 6 are flip-chip mounted on the back surface of the dielectric multilayer substrate 1 by a plurality of bumps. The MMIC 5 is composed of a semiconductor element that forms an amplifier, a mixer, and the like, and may be composed of a MOSFET (metal-oxide-semiconductor field-effect transistor). A ground conductor is formed on the surface (upper surface) of the dielectric multilayer substrate 1. The dielectric multilayer substrate 1 is bonded to the surface of the dielectric multilayer substrate 2 via the BGA balls 3 with the mounting surface on the back surface (lower surface) facing the surface (upper surface) of the dielectric multilayer substrate 2. The back surface of the MMIC 5 and the chip resistor 6 is arranged with a gap between it and the dielectric multilayer substrate 2. An RF circuit or DC circuit connected to the BGA ball 3 and an IC (integrated circuit) circuit for controlling the operation of the MMIC 5 mounted on the dielectric multilayer substrate 1 are formed on the surface of the dielectric multilayer substrate 2. . A ground conductor is formed on the back surface (lower surface) of the dielectric multilayer substrate 2.

  The BGA ball 3 accommodates RF circuits such as an MMIC 5 and a chip resistor 6 in a gap between some adjacent plural balls. Further, the high frequency signal and the DC signal processed by the RF circuit and the DC circuit perform signal transmission between the first and second resin substrates via a plurality of balls that are part of the BGA ball 3. Further, a plurality of balls in at least one row on one side constituting the outermost package (outer periphery) of the package constitutes a BGA ball row 9 which is a conductive connection member for suppressing unnecessary radiation. The BGA ball rows 9 are arranged at intervals shorter than a quarter of the wavelength λ (propagation wavelength of the high-frequency signal in the dielectric multilayer substrate 2) with the adjacent balls, so that the dielectric multilayer It surrounds the RF circuit together with the substrate 1 and the dielectric multilayer substrate 2 and functions as an electromagnetic shielding wall that prevents leakage of unwanted radiation signals. In the example of FIG. 1, the BGA ball rows 9 for suppressing unnecessary radiation are arranged in two rows. At this time, if the distance between the balls is d, the distance between the two sides of the package is at least 4d.

  The dielectric multilayer substrate 1 is preferably a substrate having a small dielectric loss tangent and a small transmission loss of high-frequency signals such as microwaves and millimeter waves. A resin substrate made of a glass epoxy substrate, a fluororesin substrate, a modified polyimide, or the like, Or it is comprised with the ceramic substrate etc. which consist of LTCC (Low Temperature Co-fired Ceramics). The dielectric multilayer substrate 2 may use the same base material as that of the dielectric multilayer substrate 1 with a small transmission loss of high-frequency signals such as microwaves and millimeter waves, and is preferably composed of a resin substrate. In addition, the dielectric multilayer substrate 2 may use a different base material having a transmission loss of a high frequency signal larger than that of the dielectric multilayer substrate 1, and by providing a waveguide on the dielectric multilayer substrate 2, the dielectric multilayer substrate 2 may be used. A high-frequency signal transmitted from the substrate 1 may be transmitted to the back side of the dielectric multilayer substrate 2.

  In the dielectric multilayer substrate 2, an inner ground conductor layer 22 is formed between a front ground conductor layer 21 formed on the front surface and a rear ground conductor layer 23 formed on the rear surface. The front ground conductor layer 21, the inner ground conductor layer 22, and the rear ground conductor layer 23 are connected by a plurality of vias (VIA) 10 arranged in the inner layer of the dielectric multilayer substrate 2. The surface ground conductor layer 21 has a first dielectric opening 31 that forms a dielectric window from which the conductor layer has been removed. The inner ground conductor layer 22 has a second dielectric opening 32 that forms a dielectric window from which the conductor layer has been removed. The dielectric waveguide 40 is formed by being surrounded by the surface ground conductor layer 21, the inner ground conductor layer 22, and the plurality of VIAs 10. In the dielectric waveguide 40, one end of the conduit is connected to the first dielectric opening 31, and the other end of the conduit is connected to the second dielectric opening 32.

  The tip short-circuited dielectric waveguide 50 is formed so as to be surrounded by the inner ground conductor layer 22, the back ground conductor layer 23, a plurality of VIA 7 rows, and a plurality of VIA 70 rows. The tip short-circuited dielectric waveguide 50 is terminated by a VIA 7 in which one end of the pipe is connected to the second dielectric opening 32 and the other end of the pipe is plurally arranged. A short-circuit surface closed by a plurality of arranged VIAs 70 is formed on one side of the pipe path of the tip short-circuit dielectric waveguide 50, and the second dielectric is formed on the inner ground conductor layer 22 orthogonal to the short-circuit surface. An opening 32 is formed. The dielectric waveguide 40 is connected to the tip short-circuited dielectric waveguide 50 through the second dielectric opening 32. The opening hole of the second dielectric opening 32 has a round shape or a rectangular shape, and the hole is covered with the thin film resistor 8. That is, the thin film resistor 8 is formed at the connection portion between the dielectric waveguide 40 and the tip short-circuited dielectric waveguide 50, and the thin film resistor 8 is connected to the dielectric waveguide 40 and the tip short-circuited dielectric waveguide 50. It arrange | positions so that it may become parallel to an electric field. The thin film resistor 8 and the tip short-circuited dielectric waveguide 50 constitute a termination circuit.

Next, the operation of the high frequency package 4 according to the first embodiment will be described.
In the high frequency package 4 according to the first embodiment, an unnecessary radiation signal having a frequency band different from that of a desired signal processed by a semiconductor element is generated from an RF circuit, a DC circuit, or the like formed on a mounting surface of a circuit such as the MMIC 5 or the chip resistor 6. Occur. This unnecessary radiation signal is made difficult to leak to the outside by the BGA ball row 9 for suppressing unnecessary radiation arranged on the outermost periphery of the BGA ball 3 connecting the dielectric multilayer substrate 1 and the dielectric multilayer substrate 2. ing.

  Here, as a comparative example, a BGA ball row 9 for suppressing unnecessary radiation used in a conventional high-frequency package will be described. FIG. 2 is a comparative view showing a configuration of a conventional high-frequency package 45. In FIG. 2, the high frequency package 45 includes a dielectric multilayer substrate 1 and a dielectric multilayer substrate 2, and a BGA ball 3 that joins between the dielectric multilayer substrate 1 and the dielectric multilayer substrate 2. As in FIG. 1, the dielectric multilayer substrate 1 has the MMIC 5 and the chip resistor 6 mounted on the back surface facing the dielectric multilayer substrate 2. On the outer periphery of the BGA ball 3 that connects the dielectric multilayer substrate 1 and the dielectric multilayer substrate 2, BGA ball rows 9 for suppressing unnecessary radiation are provided. The unnecessary radiation suppressing BGA ball array 9 is arranged with an interval in which the interval between adjacent balls is shorter than a quarter of the wavelength λ (the propagation wavelength of the high-frequency signal in the dielectric multilayer substrate 2). Therefore, it is possible to prevent unnecessary radiation from leaking to the outside. However, as shown in FIG. 2, the BGA ball array 9 for suppressing unnecessary radiation of the high frequency package 100 is used to suppress harmonics such as the second harmonic and the third harmonic of the desired high frequency signal processed by the MMIC 5. It is necessary to provide at least 3 rows (6 rows on both sides) on the outer periphery. At this time, if the distance between the balls is d, the distance between the two sides of the package is at least 6d. For this reason, the outer peripheral size of the high-frequency package 100 has to be increased.

  On the other hand, in the high frequency package 4 according to the first embodiment, the tip short-circuited dielectric waveguide 50 is second in the position of λ / 4 from the short-circuit surface (short-point) formed by the arrangement of the VIA 7. A dielectric opening 32 is provided, and the thin film resistor 8 is formed in the second dielectric opening 32. This unwanted radiation signal generated from the RF circuit such as the MMIC 5 and the chip resistor 6, the DC circuit, etc. enters the dielectric waveguide 40 from the first opening hole 31 and from the first opening hole 32 to the tip short-circuited dielectric conductor. Enter the wave tube 50. Here, since the thin film resistor 8 is formed at the position of λ / 4 of the wavelength of the unnecessary radiation signal to be suppressed from the short point of the VIA 7, the thin film resistor 8 terminates the unnecessary radiation signal and causes unnecessary radiation to the outside of the package. Can be suppressed. Due to the effect of suppressing unwanted radiation by the thin film resistor 8, the high frequency package 4 according to the first embodiment can reduce the number of rows of BGA ball rows 9 for suppressing unwanted radiation installed on the outer periphery of the package. In the example of FIG. 1, the BGA ball rows 9 for suppressing unwanted radiation are two rows (four rows on both sides), compared with the three rows (six rows on both sides) of the conventional high-frequency package 45 shown in the comparative example of FIG. 2. Thus, it can be seen that the outermost periphery becomes smaller (when the distance between the balls is d, the distance is reduced by at least 2d on both sides of the package).

  As described above, the high-frequency package 4 according to the first embodiment includes the first dielectric multilayer substrate 1 having a high-frequency circuit mounted on the back surface, and a plurality of the high-frequency packages 4 facing the back surface of the first dielectric multilayer substrate 1. A second dielectric multilayer substrate 2 that is joined to the first dielectric multilayer substrate 1 through the conductive connection member 3 and surrounds the high-frequency circuit (MMIC 5) together with the conductive connection member 3, The second dielectric multilayer substrate 2 includes a first dielectric opening 31 from which the ground conductor formed on the opposing surface of the first dielectric multilayer substrate 1 is removed, an inner ground conductor layer 22 and vias. 10, a dielectric waveguide 40 having one end connected to the first dielectric opening 31 and a second connected to the other end of the dielectric waveguide 40. In the dielectric opening 32, the inner ground conductor layer 22 and the vias 7 and 17 A tip short-circuited dielectric waveguide 50 having one end connected to the second dielectric opening 32 and the other end short-circuited to the plurality of via rows 7 formed rarely, The connection member (BGA ball 3) has a conductive connection member (BGA ball 9) for suppressing unnecessary radiation arranged in at least one row on the outer side along the outer periphery of the first dielectric multilayer substrate 1. And

  Thereby, since the number of arrangement | sequences of the conductive connection member for unnecessary radiation signal suppression can be suppressed, the size of the package outermost periphery can be made smaller. This also makes it possible to configure the first dielectric multilayer substrate 1 and the second dielectric multilayer substrate 2 at a lower cost.

  DESCRIPTION OF SYMBOLS 1 Dielectric multilayer substrate, 2 Dielectric multilayer substrate, 3 BGA ball | bowl, 4 High frequency package, 5 MMIC, 6 Chip resistance, 7 VIA, 8 Thin film resistance, 9 BGA ball row | line for unnecessary radiation suppression, 10 VIA, 21 Surface ground conductor Layer, 22 inner ground conductor layer, 23 back ground conductor layer, 31 first dielectric opening, 32 second dielectric opening, 40 dielectric waveguide, 50 tip short-circuited dielectric waveguide, 70 VIA .

Claims (2)

A first dielectric multilayer substrate having a high-frequency circuit mounted on the back surface;
Opposing to the back surface of the first dielectric multilayer substrate, a second conductive material is joined to the first dielectric multilayer substrate by interposition of a plurality of conductive connection members, and surrounds the high-frequency circuit together with the conductive connection members. A dielectric multilayer substrate;
With
The second dielectric multilayer substrate is surrounded by a first dielectric opening formed by removing a ground conductor formed on an opposing surface of the first dielectric multilayer substrate, an inner ground conductor layer and a via. A dielectric waveguide formed at one end connected to the first dielectric opening, a second dielectric opening connected to the other end of the dielectric waveguide, and an inner layer A tip short-circuited dielectric waveguide having one end connected to the second dielectric opening and the other end short-circuited to a plurality of via rows formed by being surrounded by the ground conductor layer and the via; ,
The high-frequency package having the conductive connection member for suppressing unnecessary radiation arranged in at least one row on the outer side along the outer periphery of the first dielectric multilayer substrate.   2. The high frequency package according to claim 1, wherein the first dielectric multilayer substrate and the second dielectric multilayer substrate are resin substrates.

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