JP2016115696A - Electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component which enables downsizing while achieving good heat radiation effect of an amplifier circuit element and good heat shielding effect.SOLUTION: An electronic component includes: a substrate having a first major surface and a second major surface and including a cavity formed on the first major surface side; and an amplifier circuit element housed in the cavity. The amplifier circuit element is an electronic component fixed in the cavity by a sealing resin. A conductor member covers the cavity while contacting with the sealing resin and the amplifier circuit element. Heat is also radiated from the sealing resin through the conductor member. Further, the conductor member may be connected with thermal via holes connecting the first major surface side with the second major surface side of the substrate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic component used in a mobile communication device such as a mobile phone.

  In a high-frequency circuit unit such as a cellular phone, an amplifying circuit element that amplifies a high-frequency signal from a transmission circuit or a high-frequency signal incident on an antenna and transmits the amplified signal to the next circuit is used. In many cases, the amplifier circuit element is mounted on a substrate made of a ceramic material, a resin material, or the like to form an electronic component. FIG. 6 is a sectional view showing an example of the structure of such an electronic component. A cavity 204 is formed on one main surface side of a substrate 201 made of a ceramic material, a resin material, or the like, and a flip-chip amplifier circuit element 202 is accommodated in the cavity 204 and sealed on its lower surface and outer periphery. A structure in which a resin 211 is deposited and formed is known. The sealing resin 211 supplied in the reduced pressure atmosphere is filled (underfilled) in the gap between the amplifier circuit element 202 and the substrate 201.

  An amplification circuit element generates a large amount of heat during operation, and the heat generation affects the operation of the semiconductor element itself and other circuit elements. Therefore, it is an important issue of the electronic component 210 to efficiently dissipate the heat generation. It has become one. As a heat dissipation structure for the electronic component 210 that is generally used, a heat transfer via hole 208 (hereinafter referred to as a thermal via hole) is provided in the substrate 201 on which the amplifier circuit element 2 is mounted, and the thermal via hole 208 is mounted on the substrate. There is a structure in which heat is released to a mounting board having a large heat capacity by extending to the surface side and soldering to a mounting board (not shown). Normally, a heat dissipation path is formed by a thermal via hole 208 provided at the bottom of the cavity 204. However, in the electronic component disclosed in Patent Document 1 shown in FIG. 6, a metal heat dissipation plate 203 having better thermal conductivity is provided. It is brought into surface contact with the upper surface of the amplifier circuit element 202 and is bridged between the conductor layers 209 provided on the two opposing sides of the cavity 204 that opens in a rectangular shape. The conductor layer 209 is connected to other thermal via holes 208 provided on the two sides, further enhancing the heat dissipation effect.

JP 2003-347485 A

  As in the conventional electronic component described above, using the heat dissipation plate 203 and the thermal via hole 208 to configure the heat dissipation path of the amplifier circuit element 202 brings about a good effect in the heat dissipation effect. However, since the thickness of the heat dissipation plate 203 stacked on the substrate is as thick as 100 μm to 300 μm, and the thickness of the electronic component is increased, there is a problem that the size reduction is hindered. Further, the sealing resin 211 has a lower thermal conductivity than other portions and heat is likely to accumulate, and it is also a problem to dissipate the heat.

  Further, as electronic components are downsized, it is inevitable in terms of structure that the distance between the amplifier circuit element 202 provided on the substrate 201 and other circuit elements is narrowed. For this reason, it may be necessary to provide a structure that blocks the heat path between the amplifier circuit element 202 and the heat-sensitive circuit element.

  An object of the present invention is to provide an electronic component that can be miniaturized while obtaining a good heat dissipation effect of an amplifier circuit element and a heat blocking effect.

  The electronic component of the present invention has a first main surface and a second main surface, a substrate having a cavity formed on the first main surface side, and an amplifier circuit element accommodated in the cavity, The amplification circuit element is an electronic component fixed by a sealing resin in the cavity, and the conductive member covers the cavity in contact with the sealing resin and the amplification circuit element. is there.

  In the present invention, it is preferable that the conductor member is connected to a thermal via hole connecting the first main surface side and the second main surface side of the substrate.

  In the electronic component of the present invention, the substrate further includes a plurality of thermal via holes, and the first thermal via hole is formed by a thermal via hole provided between the first main surface and the second main surface of the substrate. The second thermal via hole portion is formed by a thermal via hole provided between the bottom surface of the cavity of the substrate and the second main surface, and a part of the connection terminal provided on the surface of the amplifier circuit element facing the cavity. It is preferable that the second thermal via hole portion is electrically connected.

  Further, the first thermal via hole portion is composed of a plurality of thermal via holes provided side by side along the edge of the cavity, and the first thermal via hole portion connects the thermal via hole of the first thermal via hole portion to the first main surface of the substrate. It is preferable that one connection conductor is provided, and it is more preferable that the thermal via holes of the first thermal via hole portion are formed in a plurality of rows along the edge of the cavity.

  In this invention, it is preferable to arrange | position the other conductor member which touches the said conductor member on the side wall of the said cavity, and shall make it excellent in heat conductivity rather than the said conductor member.

  In the present invention, another element mounted on the substrate is provided, and the first thermal via hole portion includes an edge of the amplifier circuit element and the other element as viewed from the first main surface side of the substrate. It is preferable that they are provided side by side so as to cross an imaginary line connecting between the edges and the closest part. It is more preferable that the first thermal via holes provided side by side are formed in a plurality of rows.

  In this invention, it is preferable to provide the 2nd connection conductor which connects the said 1st thermal via-hole part to the 2nd main surface of the said board | substrate. Furthermore, it is preferable that the second connection conductor is connected to the second thermal via hole portion on the second main surface.

  In the present invention, it is preferable that a third connection conductor that connects the second thermal via hole portion is provided on the bottom surface of the cavity of the substrate, and the sealing resin and the third connection conductor are in contact with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic component which can be reduced in size can be provided, acquiring the favorable heat dissipation effect of an amplifier circuit element, and the interruption | blocking effect of heat.

It is sectional drawing of the electronic component which concerns on one Example of this invention. It is a principal part enlarged plan view of the electronic component shown in FIG. It is sectional drawing of the electronic component which concerns on the other Example of this invention. It is sectional drawing of the electronic component which concerns on the other Example of this invention. It is a principal part expanded sectional view of the electronic component shown in FIG. It is sectional drawing of the conventional electronic component.

  Hereinafter, the electronic component of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an electronic component according to an embodiment of the present invention. The electronic component includes a plurality of cavities 14 and 34 that are rectangularly open on the first main surface of the substrate 11, and the amplifier circuit element 12 is accommodated in the cavity 14 and the filter element 32 is accommodated in the cavity 34.

  The substrate 11 can be formed using dielectric ceramics, resin, or a composite material of resin and ceramic. The substrate 11 is a multilayer substrate rather than a single-layer substrate, which is advantageous and preferable for forming L, C, and R elements in the substrate 11 by circuit patterns and incorporating the L, C, and R elements as components. . The multilayer substrate can be manufactured using a known method. For example, when dielectric ceramics are used, an LTC resin (low temperature co-fired ceramic) technology or an HTCC (high temperature co-fired ceramic) technology is used. And build-up technology using polyimide.

In the case of LTCC technology, a ceramic green sheet having a thickness of 10 to 200 μm made of a ceramic dielectric that can be sintered at a low temperature of 1000 ° C. or lower may be used. A conductive paste such as Ag or Cu is printed on the ceramic green sheet to form the circuit pattern or a predetermined conductor pattern to be a connection conductor described later. A substrate can be formed by laminating a plurality of ceramic green sheets and sintering them integrally. Examples of the ceramic dielectric that can be sintered at a low temperature include ceramics that contain Al, Si, and Sr as main components and include Sr anorthite. In the case of HTCC technology, choices extend to ceramic materials such as alumina, cordierite, Si ₃ N ₄ , BaTiO ₃ , and AlN.

  A cavity 14 is formed in the first main surface of the substrate 11, and the amplifier circuit element 12 is accommodated in a state of being accommodated in the cavity. The cavity 14 is formed to such a depth that the amplifier circuit element 12 does not protrude from the first main surface of the substrate 11. The amplification circuit element 12 has a bare chip internal circuit and an external connection terminal formed as a metal bump 15 such as spherical solder or gold, and is flipped with respect to a plurality of connection pads 16 provided at the bottom of the cavity 14. Chip-mounted, mechanically joined, and electrically connected. The connection terminal 15 of the amplifier circuit element 12 includes a ground terminal in addition to a power supply terminal and a signal terminal. A second thermal via hole portion having a plurality of thermal via holes 8b is formed below the connection pad 16 connected to the ground terminal. A sealing resin 21 made of epoxy resin is filled (underfilled) between the metal bumps 15 to seal the amplifier circuit element 12 from the outside air, and to insulate between the metal bumps 15 and the substrate 11. Increases the bonding strength. The sealing resin 21 is filled in the cavity by a technique such as dispensing or potting. In addition, when the amplifier circuit element 12 is temporarily fixed, a resin in which an ultraviolet curable resin and a thermosetting resin are mixed may be used.

  At least one surface of the amplifier circuit element 12 appears on the opening side of the cavity 14, and the conductor member 13 is filled so as to cover the cavity 14. The conductive member 13 is heated and cured (cured) after filling with a conductive resin or conductive paste obtained by mixing metal flakes or particles of Ag, Cu or the like with a thermosetting resin such as an epoxy resin. It has excellent thermal conductivity. For example, the conductive member 13 is formed by printing a conductive paste in a vacuum atmosphere using a metal mask. When the degree of vacuum is lowered after printing, the conductive paste comes into contact with the sealing resin 21 and the amplifier circuit element 12 appearing from the sealing resin 21 without any gap. The sealing resin 21 has a lower thermal conductivity than other portions and can easily store heat. However, the sealing resin 21 can also dissipate heat from the sealing resin 21 via the conductor member 13. Further, the conductor member 13 is electrically connected to a thermal via hole connecting the first main surface side and the second main surface side of the substrate 11.

  A plurality of thermal via holes are formed in the substrate 11 so that the heat generated by the amplifier circuit element 12 is released through a plurality of paths. The first thermal via hole portion is constituted by a thermal via hole 18a provided from the first main surface to the second main surface of the substrate 11, and a plurality of thermal via holes 18a are formed in the first main conductor 19a. And a second connection conductor 29a formed on the second main surface. The second thermal via hole portion is composed of a thermal via hole 18 b provided from the bottom surface of the cavity 14 of the substrate 11 to the second main surface of the substrate 11, and a plurality of thermal via holes 18 b are formed on the bottom surface of the cavity 14. The connection conductor 19b is electrically connected by a fourth connection conductor 29b formed on the second main surface. When the second connection conductor 19b and the fourth connection conductor 29b are provided close to each other on the second main surface of the substrate 11, the substrate 11 may be configured by a connection conductor having a wide area. In addition to the connection conductors, terminals 26 such as a power supply terminal to the amplifier circuit element 12, a signal input terminal, and a signal output terminal are formed on the second main surface of the substrate 11.

  The second thermal via hole is desirably provided in the vicinity of the signal output side of the amplifier circuit element 12 that generates a large amount of heat. The thermal via hole is filled with a metal conductor such as Cu or Ag. The metal conductor is preferably densely packed, but may have a hollow portion as long as the function is not impaired.

  Since the conductor member 13 covering the cavity 14 is connected to the first thermal via hole portion, the cooling performance of the amplifier circuit element 12 is improved. Furthermore, when a part of the connection terminal 15 of the amplifier circuit element 12 is connected to the second thermal via hole portion, the heat generated by the heat of the amplifier circuit element 12 is mounted on the mounting substrate from the second main surface side of the substrate 11 through two paths. The cooling performance of the amplifier circuit element 12 is further improved.

  Alternatively, the sealing resin 21 filled between the substrate 11 and the amplifier circuit element 12 may be in contact with the connection terminal 15 of the amplifier circuit element 12 connected to the second thermal via heel portion or the third connection conductor 19b. Heat dissipation can be improved.

  In addition, by providing the amplifier circuit element 12 and the sealing resin 21 so as to be substantially flush with the first main surface of the substrate 11, for example, a thin film is formed by a method such as electroless plating, electrolytic plating, or sputtering. It is also possible to form the conductor member 13.

  FIG. 2 is an enlarged plan view of a main part when the electronic component is viewed from the first main surface side. Here, in order to clarify the configuration of the first thermal via hole portion, the conductor member 13 is represented by a broken line, and the cavity portion covered with the conductor member 13 is shown in a transparent manner. A first main surface of the substrate 11 is provided with a cavity 14 and a cavity 34 that are open in a rectangular shape and are arranged adjacent to each other. The amplifier circuit element 12 is disposed in the cavity 14, and the filter element 32 is disposed in the cavity 34. The filter element 32 is, for example, a SAW (surface acoustic wave) filter or a BAW (bulk wave) filter. The amplifier circuit element 12 and the filter element 32 are sealed with a sealing resin 21.

  A plurality of thermal via holes 18a are formed side by side around the cavity 14 in which the amplifier circuit element 12 is disposed. The thermal via hole 18a is arranged in consideration of heat dissipation, and it is not always necessary to provide it all around the cavity 14. In the first thermal via hole portion, the plurality of thermal via holes 18a are electrically connected by the first connection conductor 19a. Since the heat generation of the amplifier circuit element 12 is relatively larger on the signal output side than on other parts, the thermal via hole 18a is preferably disposed in the vicinity thereof. Further, the thermal via holes 18a are formed in multiple rows on one side of the edge of the cavity 14, thereby increasing the heat path and enhancing the heat dissipation effect. Note that the number or density of thermal via holes may be reduced as the distance from the cavity increases in the surface direction of the substrate, or the density may be sparse. If comprised in this way, the strength reduction of the board | substrate 11 by forming many thermal via holes can be suppressed. The formation density may be reduced by increasing the formation interval of the thermal via holes and decreasing the number of formations to reduce the formation density of the thermal via holes, or by changing the diameter of the thermal via holes from a relatively large diameter to a small diameter.

  The diameter of the thermal via hole is preferably 300 μm or less. Further, the thermal via hole may not have a circular shape in plan view but may have a shape such as an ellipse or an ellipse. In the illustrated example, the first connection conductor 19a has a single annular pattern. However, the connection conductor may be divided into a plurality of parts. The same applies to the second connection conductor 29a.

  Further, the first thermal via hole portion is provided in the substrate 11 so as to block the heat path between the amplifier circuit element 12 and the filter element 32. Assuming a virtual line (indicated by a one-dot chain line in the figure) connecting the edge of the amplifier circuit element 12 and the edge of the filter element 32 closest to each other when viewed from the first main surface side of the substrate 11, A first thermal via hole portion is provided so as to cross the line. If a large signal is input to the filter element at a high temperature, the filter element may be destroyed. The first thermal via hole portion and the second thermal via hole portion improve heat dissipation, and the first thermal via hole portion blocks the heat path from the amplification circuit element 12 to the filter element 32 in the substrate 11, thereby amplifying circuit. Even if the element 12 and the filter element 32 are brought close to each other, the thermal destruction of the filter element 32 can be prevented, and the electronic component can be downsized.

  FIG. 3 is a cross-sectional view of another embodiment of an electronic component. As long as the strength of the substrate 11 is not impaired, a via hole 50 that is not filled with a metal conductor may be provided between the amplifier circuit element 12 and the filter element 32 as an air gap that cuts off the heat path. A groove may be provided.

  FIG. 4 is a cross-sectional view of an electronic component according to another embodiment of the present invention, and FIG. 5 is an enlarged plan view of a main part of the electronic component. In this electronic component, another conductor member 40 in contact with the conductor member 13 is disposed on the side wall of the cavity 14 in which the amplifier circuit element 12 is accommodated. The other conductor member 40 is more excellent in thermal conductivity than the conductor member 13. In the illustrated example, the other conductor member 40 is formed of a semicircular via hole filled with a metal conductor such as Cu or Ag. In order to obtain such a structure, via holes filled with metal conductors are formed in a plurality of ceramic green sheets, and after laminating them, a portion that becomes a cavity of the substrate 11 is formed with a part of the via hole being a side wall of the cavity. Can be formed by punching the laminated ceramic green sheets. The other conductor member 40 may be formed on the entire side wall of the cavity by plating or the like. According to such a configuration, a large contact area between the conductor member 13 and the other conductor member 40 having excellent thermal conductivity can be obtained, so that heat dissipation can be improved. It is also preferable to connect the other conductor member 40 to the first connection conductor 19a and the third connection conductor 19b or to the thermal via hole 18a via a conductor layer (not shown) provided in the inner layer of the substrate 11. Further, the conductor member 40 may be formed from the first main surface to the second main surface of the substrate 11.

  According to the electronic component of the present invention, since the conductor member that covers the cavity in which the amplifier circuit element is housed is brought into contact with the amplifier circuit element and the sealing resin, the heat dissipation effect can be further enhanced as compared with the related art.

  In addition, instead of a metal heat sink, the conductor member is made of a conductive resin or conductive paste in which metal flakes or grains are mixed with a thermosetting resin such as an epoxy resin, or a plating film, etc. The thickness of parts can be reduced. Further, it is not necessary to consider the influence on the surface contact due to the deformation of the heat radiating plate itself, the inclination of the upper surface due to the mounting state of the amplifier circuit element, or the deformation of the substrate. Furthermore, the conductive member is configured to be in contact with the sealing resin and the amplifier circuit element, so that a high thermal conductivity such as a grease shape or a rubber sheet shape is formed so as to fill a gap between the amplifier circuit element and the heat sink. A heat path can be secured without using a conductive resin.

  According to the electronic component of the present invention, it is possible to operate the electronic component while maintaining stable performance by increasing the cooling effect of the amplifier circuit element and reducing the influence of heat applied to the filter element. .

  Moreover, the influence of the noise radiated from the amplifier circuit element to the space or the noise incident from the space can be reduced by the conductor member covering the cavity containing the amplifier circuit element.

DESCRIPTION OF SYMBOLS 10 Electronic component 11 Board | substrate 12 Amplifying circuit element 13 Conductive member 14, 34 Cavity 15 Connection terminal 16 Connection pad 18a, 18b Thermal via hole 19a 1st connection conductor 19b 3rd connection conductor
21 Sealing resin 26 Terminal 29a Second connection conductor 29b Fourth connection conductor 32 Filter element

Claims (11)

A substrate having a first main surface and a second main surface and having a cavity formed on the first main surface side; and an amplifying circuit element accommodated in the cavity, wherein the amplifying circuit element comprises: An electronic component fixed with a sealing resin in a cavity,
An electronic component, wherein a conductor member covers the cavity in contact with the sealing resin and the amplification circuit element. The electronic component according to claim 1,
The electronic component, wherein the conductor member is connected to a thermal via hole connecting the first main surface side and the second main surface side of the substrate. The electronic component according to claim 2,
The substrate includes a plurality of thermal via hole portions, the first thermal via hole portion is formed by a thermal via hole provided between the first main surface and the second main surface of the substrate, and the second thermal via hole portion is a cavity of the substrate. Formed with a thermal via hole provided between the bottom surface and the second main surface,
An electronic component, wherein a part of a connection terminal provided on a surface of the amplification circuit element facing the cavity is electrically connected to the second thermal via hole portion. The electronic component according to claim 3,
The first thermal via hole portion includes a plurality of thermal via holes provided side by side along the edge of the cavity, and a first connection that connects the thermal via hole of the first thermal via hole portion to the first main surface of the substrate. An electronic component comprising a conductor. The electronic component according to claim 4,
An electronic component, wherein the thermal via holes of the first thermal via hole portion are formed in a plurality of rows along an edge of the cavity. An electronic component according to any one of claims 1 to 5,
An electronic component, wherein another conductor member in contact with the conductor member is disposed on a side wall of the cavity, and the other conductor member is superior in thermal conductivity to the conductor member. The electronic component according to any one of claims 1 to 6,
Another element mounted on the substrate, and the first thermal via hole portion has the edge of the amplifier circuit element and the edge of the other element most viewed from the first main surface side of the substrate. An electronic component characterized by being provided side by side so as to cross a virtual line that connects the approaching. The electronic component according to claim 7,
The first thermal via-hole portions provided side by side so as to cross each other are formed side by side in a plurality of rows. The electronic component according to any one of claims 1 to 8,
An electronic component comprising: a second connection conductor connecting the first thermal via hole portion to a second main surface of the substrate. The electronic component according to claim 9,
The electronic component according to claim 1, wherein the second connection conductor is connected to the second thermal via hole portion at the second main surface. The electronic component according to any one of claims 1 to 10,
An electronic component comprising: a third connection conductor connecting the second thermal via hole portion to a bottom surface of a cavity of the substrate, wherein the sealing resin and the third connection conductor are in contact with each other.

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