JP7567862B2 - Circuit board and circuit module - Google Patents

Description

The present invention relates to a circuit board on which electronic components are mounted.

As an example of a conventional invention related to a circuit module, a three-dimensional package structure described in Patent Document 1 is known. This package structure includes a semiconductor package, an energy storage element, a first electrode, a second electrode, a first conductive element, a second conductive element, a first copper pillar, and a second copper pillar.

The semiconductor package has an upper surface and a lower surface. The first conductive element and the second conductive element are provided on the lower surface of the semiconductor package. The first copper pillar penetrates the semiconductor package in the vertical direction. The lower end of the first copper pillar is connected to the first conductive element. The second copper pillar penetrates the semiconductor package in the vertical direction. The lower end of the second copper pillar is connected to the second conductive element.

The first electrode and the second electrode are provided on the surface of the energy storage element. The first electrode is connected to the upper end of the first copper pillar. The second electrode is connected to the upper end of the second copper pillar. As a result, the first electrode is electrically connected to the first conductive element via the first copper pillar. The second electrode is electrically connected to the second conductive element via the second copper pillar.

US Patent Application Publication No. 2013/0001756 (FIG. 3B)

When the three-dimensional package structure described in Patent Document 1 is used, for example, the energy storage element generates heat. In this case, the heat generated by the energy storage element causes the semiconductor package and the energy storage element to expand. However, the linear expansion coefficient of the semiconductor package is greater than the linear expansion coefficient of the energy storage element. Therefore, the distance between the first copper pillar and the second copper pillar is greater than the distance between the first electrode and the second electrode. As a result, the solder connecting the first copper pillar and the first electrode and the solder connecting the second copper pillar and the second electrode may be damaged.

The object of the present invention is to provide a circuit board and a circuit module that can prevent the connection between the first external electrode of the first electronic component and the first connecting conductor penetrating the resin member from being disconnected, or the connection between the second external electrode of the second electronic component and the second connecting conductor penetrating the resin member from being disconnected.

A circuit board according to one embodiment of the present invention comprises:
a first circuit board including a first circuit board body having a first upper main surface and a first lower main surface aligned in a vertical direction, and a first mounting electrode and a second mounting electrode located on the first upper main surface;
a resin member having a second upper main surface and a second lower main surface aligned in a vertical direction, the second lower main surface being in contact with the first upper main surface;
a cover member having a third upper main surface and a third lower main surface aligned in a vertical direction, a first through hole and a second through hole penetrating the cover member in the vertical direction, and the third lower main surface being in contact with the second upper main surface;
a first connection conductor penetrating the resin member in a vertical direction, a lower end of the first connection conductor being connected to the first mounting electrode, and a portion of the first connection conductor being located within the first through hole;
a second connection conductor penetrating the resin member in a vertical direction, a lower end of the second connection conductor being connected to the second mounting electrode, and a portion of the second connection conductor being located within the second through hole;
Contains
the resin member is present in at least a portion of the periphery of the first connection conductor in the first through hole when viewed in a downward direction,
the resin member is present in at least a portion of the periphery of the second connection conductor in the second through hole when viewed in a downward direction,
The cover member has a smaller linear expansion coefficient than the resin member.

The circuit board according to the present invention can prevent the first external electrode of the first electronic component from being disconnected from the first connecting conductor penetrating the resin member, or the second external electrode of the second electronic component from being disconnected from the second connecting conductor penetrating the resin member.

FIG. 1 is a perspective view of a circuit module 1. FIG. FIG. 2 is a cross-sectional view of the circuit module 1 taken along line AA. FIG. 3 is a top view of the circuit module 1. As shown in FIG. FIG. 4 is a top view of the circuit board 10a. FIG. 5 is a top view of the circuit board 10b.

(Embodiment)
[Circuit module structure]
The structure of a circuit module 1 according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view of the circuit module 1. Fig. 2 is a cross-sectional view of the circuit module 1 taken along line A-A. Fig. 3 is a top view of the circuit module 1.

In this specification, directions are defined as follows. The direction in which the first upper main surface S1 and the first lower main surface S2 of the first circuit board body 122 are aligned is defined as the up-down direction. The directions perpendicular to the up-down direction are defined as the left-right direction and the front-rear direction. The left-right direction and the front-rear direction are perpendicular to each other. Note that the up-down direction, the front-rear direction, and the left-right direction in this embodiment do not have to match the up-down direction, the front-rear direction, and the left-right direction when the circuit module 1 is in use.

In the following, X is a part or member of the circuit module 1. In this specification, unless otherwise specified, each part of X is defined as follows. The front part of X means the front half of X. The rear part of X means the rear half of X. The left part of X means the left half of X. The right part of X means the right half of X. The upper part of X means the upper half of X. The lower part of X means the lower half of X. The front end of X means the front end of X. The rear end of X means the rear end of X. The left end of X means the left end of X. The right end of X means the right end of X. The upper end of X means the upper end of X. The lower end of X means the lower end of X. The front end of X means the front end of X and its vicinity. The rear end of X means the rear end of X and its vicinity. The left end of X means the left end of X and its vicinity. The right end of X means the right end of X and its vicinity. The upper end of X means the upper end of X and its vicinity. The lower end of X means the lower end of X and its vicinity.

The circuit module 1 is used in electronic devices such as smartphones. As shown in FIG. 1, the circuit module 1 includes a circuit board 10 and a first electronic component 30. The circuit board 10 includes a first circuit board 12, a resin member 14, a cover member 16, a first connecting conductor 18a, a second connecting conductor 18b, and a second electronic component 20 (see FIG. 2).

2, the first circuit board 12 includes a first circuit board body 122, a first mounting electrode 124a, a second mounting electrode 124b, and mounting electrodes 126a, 126b. The first circuit board body 122 has a first upper main surface S1 and a first lower main surface S2 aligned in the vertical direction. The material of the first circuit board body 122 is, for example, glass epoxy. An electric circuit is provided on the surface and inside of the first circuit board body 122 by a conductor layer (not shown). The first mounting electrode 124a, the second mounting electrode 124b, and the mounting electrodes 126a, 126b are located on the first upper main surface S1. In this embodiment, the first mounting electrode 124a, the mounting electrodes 126a, 126b, and the second mounting electrode 124b are aligned in this order from left to right.

The second electronic component 20 is, for example, an IC (Integrated Circuit). The second electronic component 20 generates heat during operation. The second electronic component 20 is mounted on the first upper main surface S1. More specifically, the second electronic component 20 is fixed to the mounting electrodes 126a and 126b by solder (not shown).

The resin member 14 has a second upper main surface S11 and a second lower main surface S12 aligned in the vertical direction. The resin member 14 is located on the first circuit board 12. The second lower main surface S12 is in contact with the first upper main surface S1. As a result, the resin member 14 covers the first upper main surface S1 of the first circuit board 12. Furthermore, the resin member 14 covers the front, rear, left and right sides of the second electronic component 20. The material of such a resin member 14 is, for example, epoxy resin.

The cover member 16 has a third upper main surface S21 and a third lower main surface S22 aligned in the vertical direction. The cover member 16 is located above the resin member 14 and the second electronic component 20. The third lower main surface S22 is in contact with the second upper main surface S11. In this way, the cover member 16 covers the resin member 14.

The cover member 16 is provided with a first through hole Ha and a second through hole Hb that penetrate the cover member 16 in the up-down direction. The first through hole Ha and the second through hole Hb have a circular shape when viewed from below. The first through hole Ha and the second through hole Hb are lined up in this order from left to right.

The linear expansion coefficient of the cover member 16 is smaller than that of the resin member 14. As a result, the absolute value of the difference between the linear expansion coefficient of the cover member 16 and that of the component body 32 (described below) is smaller than the absolute value of the difference between the linear expansion coefficient of the resin member 14 and that of the component body 32. In this specification, the linear expansion coefficient means the rate at which the length changes in response to an increase in temperature.

The linear expansion coefficient in the solid state (below the glass transition temperature) is different from the linear expansion coefficient in the molten state. The linear expansion coefficient in this specification is the linear expansion coefficient in the solid state. However, the linear expansion coefficient of the cover member 16 may be higher than the linear expansion coefficient of the resin member 14 in the solid state and lower than the linear expansion coefficient of the resin member 14 in the molten state. In addition, the cover member 16 is conductive. The material of the cover member 16 is carbon fiber reinforced plastic. In this case, the thermal conductivity of the cover member 16 is higher than the thermal conductivity of the resin member 14.

The first connecting conductor 18a has a cylindrical shape with a central axis extending in the vertical direction. The first connecting conductor 18a penetrates the resin member 14 in the vertical direction. The lower end of the first connecting conductor 18a is connected to the first mounting electrode 124a. The lower end of the first connecting conductor 18a is fixed to the first mounting electrode 124a by solder (not shown), for example. A part of the first connecting conductor 18a is located in the first through hole Ha. In this embodiment, the upper part of the first connecting conductor 18a is located in the first through hole Ha. Then, in the first through hole Ha, the resin member 14 is present in at least a part of the periphery of the first connecting conductor 18a when viewed in the downward direction. In this embodiment, in the first through hole Ha, the resin member 14 is present so as to go around the periphery of the first connecting conductor 18a when viewed in the downward direction. As a result, the first connecting conductor 18a is not in contact with the cover member 16. Therefore, the first connecting conductor 18a is not electrically connected to the cover member 16. In addition, the upper end of the first connecting conductor 18a is exposed from the circuit board 10.

The second connection conductor 18b has a cylindrical shape with a central axis extending in the vertical direction. The second connection conductor 18b penetrates the resin member 14 in the vertical direction. The lower end of the second connection conductor 18b is connected to the second mounting electrode 124b. The lower end of the second connection conductor 18b is fixed to the second mounting electrode 124b by solder (not shown), for example. A part of the second connection conductor 18b is located in the second through hole Hb. In this embodiment, the upper part of the second connection conductor 18b is located in the second through hole Hb. Then, in the second through hole Hb, the resin member 14 is present at least in a part around the second connection conductor 18b when viewed in the downward direction. In this embodiment, in the second through hole Hb, the resin member 14 is present so as to go around the second connection conductor 18b when viewed in the downward direction. As a result, the second connection conductor 18b is not in contact with the cover member 16. Therefore, the second connecting conductor 18b is not electrically connected to the cover member 16. In addition, the upper end of the second connecting conductor 18b is exposed from the circuit board 10. The material of the first connecting conductor 18a and the material of the second connecting conductor 18b as described above are metals. The metal is, for example, copper.

The first electronic component 30 is an element that generates heat during operation. The first electronic component 30 is, for example, an inductor. The first electronic component 30 includes a component body 32, a first external electrode 34a, and a second external electrode 34b. The component body 32 has a rectangular parallelepiped shape. The first external electrode 34a and the second external electrode 34b are provided on the surface of the component body 32. In this embodiment, the first external electrode 34a is provided on the lower surface and left surface of the component body 32. The second external electrode 34b is provided on the lower surface and right surface of the component body 32.

The first electronic component 30 as described above is mounted on the circuit board 10. More specifically, the first external electrode 34a is connected to the upper end of the first connecting conductor 18a. In this embodiment, the first external electrode 34a is fixed to the upper end of the first connecting conductor 18a by solder (not shown). At this time, as shown in FIG. 3, the first external electrode 34a is contained within the outer edge of the first through hole Ha when viewed in the downward direction. As a result, the first external electrode 34a is not electrically connected to the cover member 16. The second external electrode 34b is connected to the upper end of the second connecting conductor 18b. In this embodiment, the second external electrode 34b is fixed to the upper end of the second connecting conductor 18b by solder (not shown). At this time, as shown in FIG. 3, the second external electrode 34b is contained within the outer edge of the second through hole Hb when viewed in the downward direction. As a result, the second external electrode 34b is not electrically connected to the cover member 16.

[effect]
The circuit board 10 can prevent the first external electrode 34a from being disconnected from the first connecting conductor 18a, or the second external electrode 34b from being disconnected from the second connecting conductor 18b. More specifically, when the circuit module 1 is used, the first electronic component 30 generates heat. This causes the first electronic component 30 and the circuit board 10 to thermally expand.

Therefore, the linear expansion coefficient of the cover member 16 is smaller than that of the resin member 14. As a result, the absolute value of the difference between the linear expansion coefficient of the cover member 16 and the linear expansion coefficient of the component body 32 (described later) is smaller than the absolute value of the difference between the linear expansion coefficient of the resin member 14 and the linear expansion coefficient of the component body 32. Therefore, the cover member 16 is less likely to extend in the left-right direction. Therefore, the first connecting conductor 18a and the second connecting conductor 18b are held by the cover member 16. As a result, the distance between the first connecting conductor 18a and the second connecting conductor 18b is prevented from becoming too large compared to the distance between the first external electrode 34a and the second external electrode 34b. As a result, according to the circuit board 10, it is possible to prevent the connection between the first external electrode 34a and the first connecting conductor 18a from being disconnected, or the connection between the second external electrode 34b and the second connecting conductor 18b from being disconnected.

In the circuit board 10, when viewed from below, the resin member 14 is present in at least a portion of the periphery of the first connecting conductor 18a within the first through hole Ha. This allows the resin member 14 to adhere closely to the upper part of the first connecting conductor 18a. This allows the first connecting conductor 18a to be held by the resin member 14. This prevents the first connecting conductor 18a from moving within the resin member 14, and prevents the first connecting conductor 18a from coming off the resin member 14.

According to the circuit board 10, the first connecting conductor 18a and the second connecting conductor 18b are prevented from tilting. More specifically, when manufacturing the circuit board 10, the resin member 14 is formed by injecting molten resin into a mold. Since the molten resin is in a high temperature state, the first circuit board 12 is heated. As a result, the first circuit board 12 extends in the left-right direction. At this time, the first connecting conductor 18a and the second connecting conductor 18b may tilt. Therefore, the linear expansion coefficient of the cover member 16 is smaller than the linear expansion coefficient of the resin member 14. Therefore, the cover member 16 is less likely to extend in the left-right direction. As a result, in the circuit board 10, the first connecting conductor 18a and the second connecting conductor 18b are prevented from tilting.

In the circuit board 10, the cover member 16 is conductive. This allows the cover member 16 to function as a shield.

In the circuit board 10, the thermal conductivity of the cover member 16 is higher than that of the resin member 14. This makes it easier for heat generated in the circuit board 10 to be radiated outside the circuit board 10 by the cover member 16.

(Modification)
The circuit boards 10a and 10b according to the modified examples will be described below with reference to the drawings. Fig. 4 is a top view of the circuit board 10a. Fig. 5 is a top view of the circuit board 10b.

As shown in FIG. 4, the circuit board 10a has a plurality of third through holes Hc that penetrate the cover member 16 in the vertical direction. The third through holes Hc have a circular shape when viewed from below. Resin members 14 are present in the third through holes Hc. The third through holes Hc may have a shape other than a circular shape when viewed from below, as shown in FIG. 5. In the circuit board 10b, the third through holes Hc have a square shape and a triangular shape when viewed from below. According to the circuit boards 10a and 10b, the molten resin can flow between the first circuit board 12 and the cover member 16 through the third through holes Hc.

Other Embodiments
The circuit board according to the present invention is not limited to the circuit boards 10, 10a, and 10b, and may be modified within the scope of the present invention. In addition, the structures of the circuit boards 10, 10a, and 10b may be arbitrarily combined.

The material of the cover member 16 is not limited to carbon fiber reinforced plastic, but may be, for example, a metal such as aluminum.

The cover member 16 may be insulating. In this case, the first external electrode 14a may not be within the outer edge of the first through hole Ha when viewed from below. The second external electrode 14b may not be within the outer edge of the second through hole Hb when viewed from below.

The thermal conductivity of the cover member 16 may be equal to or lower than the thermal conductivity of the resin member 14.

The circuit board 10 does not have to include the second electronic component 20.

The present invention has the following structure:

(1)
a first circuit board including a first circuit board body having a first upper main surface and a first lower main surface aligned in a vertical direction, and a first mounting electrode and a second mounting electrode located on the first upper main surface;
a resin member having a second upper main surface and a second lower main surface aligned in a vertical direction, the second lower main surface being in contact with the first upper main surface;
a cover member having a third upper main surface and a third lower main surface aligned in a vertical direction, a first through hole and a second through hole penetrating the cover member in the vertical direction, and the third lower main surface being in contact with the second upper main surface;
a first connection conductor penetrating the resin member in a vertical direction, a lower end of the first connection conductor being connected to the first mounting electrode, and a portion of the first connection conductor being located within the first through hole;
a second connection conductor penetrating the resin member in a vertical direction, a lower end of the second connection conductor being connected to the second mounting electrode, and a portion of the second connection conductor being located within the second through hole;
Contains
the resin member is present in at least a portion of the periphery of the first connection conductor in the first through hole when viewed in a downward direction,
the resin member is present in at least a portion of the periphery of the second connection conductor in the second through hole when viewed in a downward direction,
The linear expansion coefficient of the cover member is smaller than the linear expansion coefficient of the resin member.
Circuit board.

(2)
The thermal conductivity of the cover member is higher than the thermal conductivity of the resin member.
The circuit board according to (1).

(3)
The material of the cover member is carbon fiber reinforced plastic.
The circuit board according to (1) or (2).

(4)
The circuit board includes:
A second electronic component mounted on the first upper main surface,
It further includes:
A circuit board according to any one of (1) to (3).

(5)
A third through hole is provided penetrating the cover member in the vertical direction,
The resin member is present in the third through hole.
A circuit board according to any one of (1) to (4).

(6)
A circuit board according to any one of (1) to (5),
a first electronic component including a component body and a first external electrode and a second external electrode provided on a surface of the component body;
Equipped with
the first external electrode is connected to an upper end of the first connecting conductor,
the second external electrode is connected to an upper end of the second connecting conductor;
Circuit module.

(7)
The cover member is conductive,
When viewed from below, the resin member is present in the first through hole so as to surround the first connection conductor.
A circuit module according to (6).

(8)
When viewed in a downward direction, the first external electrode is contained within an outer edge of the first through hole,
When viewed in a downward direction, the second external electrode is located within an outer edge of the second through hole.
A circuit module according to (7).

1: Circuit module 10, 10a, 10b: Circuit board 12: First circuit board 14: Resin member 14a: First external electrode 14b: Second external electrode 16: Cover member 18a: First connecting conductor 18b: Second connecting conductor 20: Second electronic component 30: First electronic component 32: Component body 34a: First external electrode 34b: Second external electrode 122: First circuit board body 124a: First mounting electrode 124b: Second mounting electrodes 126a, 126b: Mounting electrode Ha: First through hole Hb: Second through hole Hc: Third through hole S1: First upper main surface S11: Second upper main surface S12: Second lower main surface S2: First lower main surface S21: Third upper main surface S22: Third lower main surface

Claims (8)

a first circuit board including a first circuit board body having a first upper main surface and a first lower main surface aligned in a vertical direction, and a first mounting electrode and a second mounting electrode located on the first upper main surface;
a resin member having a second upper main surface and a second lower main surface aligned in a vertical direction, the second lower main surface being in contact with the first upper main surface;
a cover member having a third upper main surface and a third lower main surface aligned in a vertical direction, a first through hole and a second through hole penetrating the cover member in the vertical direction, and the third lower main surface being in contact with the second upper main surface;
a first connection conductor penetrating the resin member in a vertical direction, a lower end of the first connection conductor being connected to the first mounting electrode, and a portion of the first connection conductor being located within the first through hole;
a second connection conductor penetrating the resin member in a vertical direction, a lower end of the second connection conductor being connected to the second mounting electrode, and a portion of the second connection conductor being located within the second through hole;
Contains
the resin member is present in at least a portion of the periphery of the first connection conductor in the first through hole when viewed in a downward direction,
the resin member is present in at least a portion of the periphery of the second connection conductor in the second through hole when viewed in a downward direction,
The linear expansion coefficient of the cover member is smaller than the linear expansion coefficient of the resin member.
Circuit board. The thermal conductivity of the cover member is higher than the thermal conductivity of the resin member.
The circuit board according to claim 1 . The material of the cover member is carbon fiber reinforced plastic.
The circuit board according to claim 1 or 2. The circuit board includes:
A second electronic component mounted on the first upper main surface,
It further includes:
The circuit board according to claim 1 or 2. A third through hole is provided penetrating the cover member in the vertical direction,
The resin member is present in the third through hole.
The circuit board according to claim 1 or 2. The circuit board according to claim 1 or 2;
a first electronic component including a component body and a first external electrode and a second external electrode provided on a surface of the component body;
Equipped with
the first external electrode is connected to an upper end of the first connecting conductor,
the second external electrode is connected to an upper end of the second connecting conductor;
Circuit module. The cover member is conductive,
When viewed from below, the resin member is present in the first through hole so as to surround the first connection conductor.
The circuit module according to claim 6 . When viewed in a downward direction, the first external electrode is contained within an outer edge of the first through hole,
When viewed in a downward direction, the second external electrode is located within an outer edge of the second through hole.
The circuit module according to claim 7.

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