JP2018186328A - Circulator - Google Patents

Abstract

A circulator capable of reducing cost and size while improving reliability is provided. A circulator 100 includes a plurality of signal terminals 60a, a plurality of ground terminals 60b surrounding the plurality of signal terminals 60a, a die pad 6 and a signal pattern 30a, and a ferrite substrate 3 provided on the die pad 6. The wire 32 that electrically connects the signal terminal 60a and the signal pattern 30a, and the die pad 6, the ferrite substrate 3, and the wire 32 are covered so that the plurality of signal terminals 60a, the plurality of ground terminals 60b, and the die pad 6 are exposed. A mold package 50 made of a mold resin 4 and a permanent magnet 2 provided on the mold package 50 are provided. [Selection] Figure 1

Description

  The present invention relates to a circulator that is a non-reciprocal circuit device.

  In the circulator disclosed in Patent Document 1, the circulator is arranged on a resin substrate by surface mounting, so that an adhesion process is not required and a wire bond is not required, thereby reducing manufacturing costs.

Japanese Patent No. 6000466

  However, the circulator disclosed in Patent Document 1 requires front and back conduction VIA in the substrate, and there is a problem that the manufacturing cost of the substrate increases and the reliability of the substrate decreases. Moreover, in the circulator disclosed in Patent Document 1, it is necessary to increase the distance from the spacer to the VIA in order to avoid the bleeding out of the adhesive into the front and back conductive VIA, and there is a problem that the pattern becomes large.

  The present invention has been made in view of the above, and an object thereof is to obtain a circulator that can be reduced in size while improving reliability.

  In order to solve the above-described problems and achieve the object, the circulator of the present invention has a plurality of signal terminals, a plurality of ground terminals surrounding the plurality of signal terminals, a die pad, and a signal pattern, A ferrite substrate provided; a wire for electrically connecting the signal terminal and the signal pattern; and a mold package made of a resin that covers the die pad, the ferrite substrate, and the wire so that the plurality of signal terminals and the plurality of ground terminals are exposed. And a permanent magnet provided on the mold package.

  According to the present invention, it is possible to reduce the size while improving the reliability.

Sectional drawing of the circulator which concerns on Embodiment 1 of this invention FIG. 1 is a view of a ferrite substrate and a die pad before molding in the mold package shown in FIG. The figure which looked at the mold package shown in FIG. 1 from the other side of the X-axis direction The figure which looked at the ferrite substrate before the mold forming of the mold package with which the circulator which concerns on Embodiment 2 of this invention is equipped, and the die pad from the one side of the X-axis direction The figure which shows the pattern provided in the ferrite substrate shown in FIG. The figure which shows the ground pattern provided in the ferrite substrate shown in FIG. The figure which looked at the mold package shown in FIG. 4 from the other side of the X-axis direction The figure which shows the through hole connected to the electrically conductive film with which the circulator which concerns on Embodiment 2 of this invention is provided

  Below, the circulator which concerns on embodiment of this invention is demonstrated in detail based on drawing. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a circulator according to Embodiment 1 of the present invention. FIG. 2 is a view of the ferrite substrate and the die pad before molding in the mold package shown in FIG. 1 as viewed from one side in the X-axis direction. FIG. 3 is a view of the mold package shown in FIG. 1 as viewed from the other side in the X-axis direction.

  As shown in FIG. 1, the multilayer resin substrate 1 includes a first plate surface 1 a on one end side in the X-axis direction of the multilayer resin substrate 1 and a second plate surface on the other end side in the X-axis direction of the multilayer resin substrate 1. 1b. The first plate surface 1a of the multilayer resin substrate 1 is provided with a first ground surface 11a that is a conductive ground pattern. The second plate surface 1b of the multilayer resin substrate 1 is provided with a second ground surface 11b which is a conductive ground pattern. An inner layer ground surface 11 c is provided in the multilayer resin substrate 1. A plurality of ground VIA holes 12 extending in the X-axis direction and a plurality of signal VIA holes 13 extending in the X-axis direction are formed in the multilayer resin substrate 1. The plurality of ground VIA holes 12 and signal VIA holes 13 are arranged apart from each other in the Y-axis direction. In FIG. 1, in the XYZ coordinates of the left-handed system, the arrangement direction of the circulator 100 and the multilayer resin substrate 1 is the X axis direction, the arrangement direction of the plurality of ground VIA holes 12 is the Y axis direction, and the X axis direction and the Y axis The direction orthogonal to both directions is the Z-axis direction.

  One end of the ground VIA hole 12 in the X-axis direction is connected to the first ground surface 11a. The other end of the ground VIA hole 12 in the X-axis direction is connected to the second ground surface 11b. One end of the signal VIA hole 13 in the X-axis direction is connected to the triplate line 14. The other end of the signal VIA hole 13 in the X-axis direction is connected to the signal pad 15.

  The triplate line 14 provided in the multilayer resin substrate 1 is located between the first ground surface 11a and the inner layer ground surface 11c. That is, the triplate line 14 is provided so as to be surrounded by the ground having the same potential.

  Circulator 100 according to Embodiment 1 is provided on the second plate surface 1b side of multilayer resin substrate 1. The circulator 100 includes a permanent magnet 2 and a mold package 50. The mold package 50 includes a ferrite substrate 3, a mold resin 4, a conductive film 5, a die pad 6, a wire 32 as a conductive connection member, a signal terminal 60a, and a ground terminal 60b.

  The permanent magnet 2 is a magnet that applies a bias magnetic field to the ferrite substrate 3, and the permanent magnet 2 can be exemplified by a ferrite magnet or a rare earth magnet. Examples of the ferrite magnet material include Sr (strontium) ferrite or Ba (barium) ferrite having a hexagonal magnetoplumbite structure. Examples of rare earth magnet materials include samarium cobalt magnets, neodymium magnets, praseodymium magnets, and samarium iron nitrogen magnets.

  The width of the rectangular permanent magnet 2 in the Y-axis direction is equal to the width of the mold resin 4 covered with the conductive film 5 in the Y-axis direction. By making the width of the permanent magnet 2 equal to the width of the mold resin 4, variations in the relative positions of the permanent magnet 2 and the mold package 50 are suppressed, and therefore the electric power of the circulator 100 that varies depending on the position of the permanent magnet 2. The characteristics can be made uniform.

  Examples of the material of the die pad 6 on which the ferrite substrate 3 is mounted include magnetic materials such as Cu (copper), Kovar, and Ni (nickel). By using a magnetic material such as Kovar or Ni instead of copper, the die pad 6 is magnetized by the permanent magnet 2, so that the static magnetic field distribution in the ferrite substrate 3 is further uniformed by these two magnets, A uniform circulator 100 is obtained. A magnetic body similar to the die pad 6 may be provided on the outer periphery of the permanent magnet 2. By providing a magnetic body on the outer periphery and upper part of the permanent magnet 2, leakage from the permanent magnet 2 to the outside will reduce the static magnetic field. Therefore, when a plurality of circulators 100 are arranged adjacent to each other, the repulsion between the adjacent permanent magnets 2 will occur. The force is reduced, and a plurality of circulators 100 and other magnetic materials can be arranged close to each other.

  The signal terminal 60 a of the mold package 50 is connected to the signal pad 15 of the multilayer resin substrate 1 through the solder 7. The signal terminal 60 a of the mold package 50 is connected to the signal pattern 30 a of the ferrite substrate 3 through the wire 32. The triplate line 14, the signal VIA hole 13, the signal pad 15, the solder 7, the signal terminal 60a, the wire 32, and the signal pattern 30a are electrically connected to each other.

  A plurality of ground VIA holes 12 provided near the end surface in the Y-axis direction of the multilayer resin substrate 1 are arranged so as to surround the triplate line 14 and the signal VIA hole 13. Therefore, these ground VIA holes 12 suppress leakage of RF (Radio Frequency) signals transmitted to the triplate line 14 to the periphery of the multilayer resin substrate 1.

  The ground terminal 60 b of the mold package 50 is connected to the second ground surface 11 b of the multilayer resin substrate 1 through the solder 7. First ground surface 11a, a plurality of ground VIA holes 12 provided near the end surface in the Y-axis direction of multilayer resin substrate 1, and a second ground surface 11b provided near the end surface in the Y-axis direction of multilayer resin substrate 1 The ground terminal 60b is electrically connected to each other.

  The die pad 6 is connected to the second ground surface 11 b provided near the center of the multilayer resin substrate 1 through the solder 7. First ground surface 11a, a plurality of ground VIA holes 12 provided near the center of multilayer resin substrate 1, a second ground surface 11b provided near the center of multilayer resin substrate 1, solder 7, and die pad 6 Are electrically connected to each other.

  The upper surface side of the ferrite substrate 3, that is, the surface of the ferrite substrate 3 on the permanent magnet 2 side is covered with the mold resin 4. The upper surface side of the mold package 50, that is, the surface of the mold package 50 on the ferrite substrate 3 side is covered with the mold resin 4. Therefore, the signal pattern 30 a of the ferrite substrate 3, the wire 32, the signal terminal 60 a of the mold package 50, and the ground terminal 60 b of the mold package 50 are covered with the mold resin 4.

  On the other hand, the lower surface side of the mold package 50, that is, the surface of the mold package 50 on the multilayer resin substrate 1 side is exposed without being covered with the mold resin 4. Therefore, the signal terminal 60 a and the ground terminal 60 b of the mold package 50 are exposed without the respective surfaces on the multilayer resin substrate 1 side being covered with the mold resin 4. Note that the conductive pattern 60 c for heat dissipation (equivalent to the die pad 6) of the mold package 50 shown in FIG. 3 is also exposed without being covered with the mold resin 4.

  As shown in FIG. 1, a conductive film 5 is formed on the surface of the mold resin 4. The conductive film 5 is a conductive film such as electroless plating or a conductive adhesive, and examples of the material of the plating film include Ni or Ag (silver). The conductive adhesive includes silver particles. An epoxy material containing can be exemplified. A permanent magnet 2 is provided on the upper side of the mold resin 4 via a conductive film 5. The permanent magnet 2 is fixed to the conductive film 5 by adhesion or the like. The method for fixing the permanent magnet 2 to the conductive film 5 is not limited to adhesion, and any method other than adhesion may be used as long as the permanent magnet 2 can be fixed to the conductive film 5, for example, fixing with a fastening member such as a screw. . In Embodiment 1, the conductive film 5 is provided on the mold resin 4, but the permanent magnet 2 may be directly fixed to the mold resin 4 without the conductive film 5. However, since the conductive film 5 functions as an electromagnetic shield, it is preferable that the conductive film 5 be provided on the mold resin 4. Details of the effect of the conductive film 5 will be described later.

  As shown in FIG. 1, the ferrite substrate 3 and the die pad 6 constituting the mold package 50 are stacked in the X-axis direction, and the ferrite substrate 3 is fixed to the die pad 6 with an adhesive or the like. Thereafter, the upper part is sealed with a mold resin 4 by a transfer mold or the like, and finally a conductive film 5 is coated.

  The ferrite substrate 3 has a first plate surface 31a and a second plate surface 31b. The first plate surface 31 a is a plate surface on one end side of the ferrite substrate 3 in the Y-axis direction. The second plate surface 31 b is a plate surface on the other end side in the Y-axis direction of the ferrite substrate 3. As shown in FIG. 2, a circular signal pattern 30 a is provided on the second plate surface 31 b side of the ferrite substrate 3. Further, as shown in FIGS. 2 and 3, the mold package 50 is provided with a plurality of signal terminals 60a and a plurality of ground terminals 60b.

  As shown in FIG. 2, the plurality of signal terminals 60 a of the mold package 50 are spaced apart from each other so as to surround the entire periphery of the signal pattern 30 a of the ferrite substrate 3. The plurality of ground terminals 60b of the mold package 50 are spaced apart from each other so as to surround the entire periphery of the signal terminal 60a. The signal terminal 60a and the ground terminal 60b of the mold package 50 shown in FIG. 3 are surface-mounted on the multilayer resin substrate 1 shown in FIG. 1 by a reflow process or the like.

  As shown in FIG. 3, a conductor pattern 60 c for heat dissipation and ground connection is provided at the center of the back surface of the mold package 50. The back surface of the mold package 50 is a surface on the side of the multilayer resin substrate 1 shown in FIG. The conductor pattern 60c is provided so as to be surrounded by the plurality of signal terminals 60a. When the circulator 100 generates a large amount of heat, a heat dissipation VIA may be provided between the conductor pattern 60c of the mold package 50 and the first ground surface 11a shown in FIG. May be provided. By providing the heat dissipating VIA and the coin-shaped conductor, heat generated in the ferrite substrate 3 is transmitted to the first ground surface 11a, and heat dissipation is improved.

  According to the circulator 100 according to the first embodiment configured as described above, the width of the permanent magnet 2 in the Y-axis direction can be made wider than the width of the ferrite substrate 3 in the Y-axis direction. The magnetic field distribution is made uniform, and in the conventional configuration, the position of the permanent magnet 2 fluctuates with respect to the ferrite substrate 3, and the magnetic position sensitivity of the electric characteristics that vary due to the change of the magnetic field in the ferrite substrate 3 decreases. In addition, the circulator 100 with uniform electrical characteristics can be manufactured.

  Further, by adopting the permanent magnet 2 that is approximately the same size as the mold resin 4, the magnet installation error is further reduced. In the circulator 100 according to the first embodiment, since the mold resin 4 also serves as a non-conductive spacer between the permanent magnet 2 and the ferrite substrate 3, the spacer disclosed in Patent Document 1, that is, the permanent magnet and the magnetic material are used. There is no need to provide a spacer arranged between the body.

  In the circulator 100 according to the first embodiment, the permanent magnet 2 is fixed to the ferrite substrate 3 through the mold resin 4. Therefore, there is no adhesive bleed-out that occurs when the permanent magnet 2 is directly fixed to the mold resin 4, and a wire bonding pad can be arranged near the signal pattern 30a, and the circulator 100 can be downsized.

  The mold resin 4 can be manufactured in a batch by using a technique such as transfer molding, and the surface mounting is possible, so the cost associated with the assembly of the circulator 100 is reduced. it can.

  The conductive film 5 can be provided by applying a conductive material to the mold resin 4, and is electrically connected to the ground terminal 60 b of the mold package 50 and the second ground surface 11 b of the multilayer resin substrate 1. Electrically connected. Therefore, leakage of the RF signal transmitted to the ferrite substrate 3 and the wire 32 to the periphery is suppressed without adding an electromagnetic shield mechanism that surrounds the entire circulator 100, and the components of the module on which the circulator 100 is mounted can be reduced. This can reduce the size of the module. In addition, according to this configuration, a conductive fine bonding material such as a through hole, a solder ball on the back surface, or a copper pillar is not required for the ferrite substrate 3, and the manufacturing cost of the circulator 100 can be reduced.

Embodiment 2. FIG.
FIG. 4 is a view of a ferrite substrate and a die pad before molding of a mold package provided in a circulator according to Embodiment 2 of the present invention, as viewed from one side in the X-axis direction. FIG. 5 is a diagram showing patterns provided on the ferrite substrate shown in FIG. FIG. 6 is a diagram showing a ground pattern provided on the ferrite substrate shown in FIG. 7 is a view of the mold package shown in FIG. 4 as viewed from the other side in the X-axis direction. FIG. 8 is a diagram showing through holes connected to the conductive film provided in the circulator according to Embodiment 2 of the present invention.

  As shown in FIG. 4, a first ground pattern 30 b is provided on the second plate surface 31 b of the ferrite substrate 3. The first ground pattern 30b is provided so as to surround the periphery of the signal pattern 30a. As shown in FIG. 6, a second ground pattern 30 c is provided on the first plate surface 31 a side of the ferrite substrate 3. The second ground pattern 30c shown in FIG. 6 is mounted on the die pad 6 shown in FIG. The first ground pattern 30b and the second ground pattern 30c are electrically connected by a first through hole 36 extending in the X-axis direction. Further, the first ground pattern 30 b shown in FIG. 4 and the conductive film 5 shown in FIG. 8 are electrically connected by the second through hole 37. The second through hole 37 is provided inside the mold resin 4 shown in FIG. In FIG. 4, the connection position of the second through hole 37 is also shown.

  Since the outer periphery of the mold resin 4 is electrically closed by the conductive film 5, when the mold resin 4 is enlarged with an increase in the size of the ferrite substrate 3 in order to achieve electrical requirements, the ground surface is entirely surrounded. There is a possibility that the cavity resonance due to the closure is close to the operating frequency. According to the second embodiment, since the die pad 6 and the conductive film 5 are electrically connected by the first through hole 36 and the second through hole 37, the resonance frequency is increased and a desired circulator operation is ensured. Is done. The numbers and positions of the first through holes 36 and the second through holes 37 are determined by the operating frequency, and are determined by the dielectric constants of the mold resin 4 and the ferrite substrate 3. The first ground pattern 30b may be disposed in a band shape only in the region where the first through hole 36 and the second through hole 37 are disposed. A part of the signal terminal 60a is a ground terminal 61 connected to the ground VIA hole 12 in the multilayer resin substrate 1, and the first ground pattern 30b and the ground terminal 61 are connected by a wire to surround the RF terminal. Thus, the ground terminal can be arranged, and the RF signal on the signal pattern 30a can be electrically connected to the triplate line 14 of the multilayer resin substrate 1 with low reflection.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  DESCRIPTION OF SYMBOLS 1 Multilayer resin substrate, 1a, 31a 1st board surface, 1b, 31b 2nd board surface, 2 Permanent magnet, 3 Ferrite board, 4 Mold resin, 5 Conductive film, 6 Die pad, 7 Solder, 11a 1st ground Plane, 11b second ground plane, 11c inner layer ground plane, 12 ground VIA hole, 13 signal VIA hole, 14 triplate line, 15 signal pad, 30a signal pattern, 30b first ground pattern, 30c second ground pattern , 32 wires, 36 first through hole, 37 second through hole, 50 mold package, 60a signal terminal, 60b, 61 ground terminal, 60c conductor pattern, 100 circulator.

Claims (5)

Multiple signal terminals;
A plurality of ground terminals surrounding the plurality of signal terminals;
Die pad,
A ferrite substrate having a signal pattern and provided on the die pad;
A wire for electrically connecting the signal terminal and the signal pattern;
A mold package made of a resin covering the die pad, the ferrite substrate and the wire so that the plurality of signal terminals and the plurality of ground terminals are exposed;
A circulator comprising: a permanent magnet provided on the mold package. Comprising a conductive film covering the outer periphery of the resin;
The circulator according to claim 1, wherein the plurality of ground terminals are electrically connected to the conductive film. The ferrite substrate is
A first ground pattern provided on one end side of the ferrite substrate so as to surround the periphery of the signal pattern;
A second ground pattern provided on the other end side of the ferrite substrate so as to face the die pad;
A first through hole that electrically connects the first ground pattern and the second ground pattern; and the resin electrically connects the conductive film and the first ground pattern. The circulator according to claim 2, wherein a second through hole is provided. The permanent magnet has a rectangular shape,
The circulator according to any one of claims 1 to 3, wherein a width of the permanent magnet is equal to a width of the resin.   The circulator according to any one of claims 1 to 4, wherein the die pad is made of a magnetic material.

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