JP7331636B2 - semiconductor package - Google Patents

Description

The present invention relates to a semiconductor package using a thermoelectric conversion device.

2. Description of the Related Art In a semiconductor package, a thermoelectric conversion device is used to adjust the temperature of a heat-generating semiconductor device. Conventionally, a thermoelectric converter having a square planar shape has been used (see Patent Document 1, for example).

JP-A-9-181360

A circular base plate is used in a circular coaxial semiconductor package. A quadrangular thermoelectric converter cannot be placed in the center of the base plate in order to avoid contact with other parts such as lead terminals, and is miniaturized and placed closer to the edge of the base plate. As the thermoelectric conversion device becomes smaller, the temperature control capability decreases. As a result, the heat cannot be sufficiently radiated, and thermal runaway of the semiconductor device may occur.

Also, the thermoelectric conversion device is soldered to the base plate and the semiconductor device. In this solder joint, the stress due to the difference in thermal expansion coefficients concentrates on the outermost corners of the rectangular thermoelectric converter. Therefore, cracks may occur in the Peltier element of the thermoelectric conversion device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor package which can improve temperature controllability and is less likely to crack.

A first semiconductor package according to the present invention includes a base plate having a circular planar shape, a lower substrate provided on the base plate, an upper substrate arranged to face the lower substrate, and the lower substrate. and a thermoelectric device provided between the thermoelectric device and the upper substrate and having thermoelectric elements in which P-type semiconductors and N-type semiconductors are alternately connected in series, and the planar shape of the thermoelectric conversion device is circular or elliptical. The thermoelectric conversion device has a plurality of electrodes provided respectively on the upper surface of the lower substrate and the lower surface of the upper substrate and connecting the P-type semiconductor and the N-type semiconductor. a first portion bonded to a semiconductor; a second portion bonded to the P-type semiconductor; and a connection portion disposed between the first portion and the second portion to connect the two. and the connecting portion is trapezoidal .
A second semiconductor package according to the present invention includes a base plate having a circular planar shape, a lower substrate provided on the base plate, an upper substrate arranged to face the lower substrate, and the lower substrate. and a thermoelectric device provided between the upper substrate and the thermoelectric element in which P-type semiconductors and N-type semiconductors are alternately connected in series, wherein the planar shape of the thermoelectric conversion device is circular or elliptical. and the N-type semiconductor and the P-type semiconductor are trapezoidal in plan view.
A third semiconductor package according to the present invention includes a base plate having a circular planar shape, a lower substrate provided on the base plate, an upper substrate arranged to face the lower substrate, and the lower substrate. and a thermoelectric device provided between the upper substrate and the thermoelectric element in which P-type semiconductors and N-type semiconductors are alternately connected in series, wherein the planar shape of the thermoelectric conversion device is circular or elliptical. , wherein the N-type semiconductor and the P-type semiconductor have trapezoidal cross-sectional shapes.
A fourth semiconductor package according to the present invention includes a base plate having a circular planar shape, a lower substrate provided on the base plate, an upper substrate arranged to face the lower substrate, and the lower substrate. and a thermoelectric device provided between the upper substrate and the thermoelectric element in which P-type semiconductors and N-type semiconductors are alternately connected in series, wherein the planar shape of the thermoelectric conversion device is circular or elliptical. , the first terminal of the thermoelectric element is arranged on the outer peripheral portion of the lower substrate, the second terminal of the thermoelectric element is arranged on the central portion of the lower substrate, and the central portion of the base plate and the lower substrate are separated from each other. It is characterized by further comprising a lead terminal penetrating through the central portion and connected to the second terminal.
A fifth semiconductor package according to the present invention includes a base plate having a circular planar shape, a lower substrate provided on the base plate, an upper substrate arranged to face the lower substrate, and the lower substrate. and a thermoelectric device provided between the upper substrate and the thermoelectric element in which P-type semiconductors and N-type semiconductors are alternately connected in series, wherein the planar shape of the thermoelectric conversion device is circular or elliptical. , the first terminal of the thermoelectric element penetrates through the central portion of the lower substrate and is led out to the lower surface of the lower substrate, and the second terminal of the thermoelectric element penetrates the central portion of the upper substrate and extends to the upper surface. It is characterized in that it is pulled out to the upper surface of the substrate.

In the present invention, a circular or elliptical thermoelectric conversion device is arranged on a circular base plate. Thereby, the thermoelectric conversion device can be arranged on the base plate without downsizing. Therefore, the temperature control ability can be improved. In addition, since the circular or elliptical thermoelectric conversion device has no corners, stress concentration is alleviated, and cracks are less likely to occur even when the temperature gradient is large.

1 is a perspective view showing a semiconductor package according to Embodiment 1; FIG. 1 is a plan view showing a semiconductor package according to Embodiment 1; FIG. It is a sectional view showing a thermoelectric converter. 2 is a top view showing the lower substrate of the semiconductor package according to the first embodiment; FIG. 4 is a bottom view showing the upper substrate of the semiconductor package according to the first embodiment; FIG. 2 is a plan view showing electrodes of the thermoelectric element according to Embodiment 1. FIG. FIG. 4 is a plan view showing a connecting portion according to Embodiment 1; It is a top view which shows the semiconductor package which concerns on a comparative example. FIG. 4 is a plan view showing Modification 1 of the thermoelectric conversion element according to Embodiment 1; FIG. 8 is a plan view showing Modification 2 of the thermoelectric conversion element according to Embodiment 1; 8 is a top view showing a lower substrate of the thermoelectric conversion device according to Embodiment 2; FIG. FIG. 8 is a bottom view showing the upper substrate of the thermoelectric conversion device according to Embodiment 2; FIG. 6 is a cross-sectional view showing a thermoelectric conversion device according to Embodiment 2; FIG. 11 is a side view showing how the thermoelectric conversion device according to Embodiment 3 is attached to a base plate; FIG. 11 is a plan view showing a state in which the thermoelectric conversion device according to Embodiment 3 is attached to a base plate; FIG. 11 is a plan view showing a lower substrate of a thermoelectric conversion device according to Embodiment 4; FIG. 11 is a plan view showing an upper substrate of a thermoelectric conversion device according to Embodiment 4; FIG. 11 is a cross-sectional view showing a thermoelectric conversion device according to Embodiment 4; FIG. 12 is a cross-sectional view showing a modification of the thermoelectric conversion device according to Embodiment 4;

A semiconductor package according to an embodiment will be described with reference to the drawings. The same reference numerals are given to the same or corresponding components, and repetition of description may be omitted.

Embodiment 1.
FIG. 1 is a perspective view showing a semiconductor package according to Embodiment 1. FIG. This semiconductor package is of the circular coaxial type. A plurality of lead terminals 2 pass through the outer periphery of a base plate 1 having a circular planar shape. A thermoelectric converter 3 is provided on the base plate 1 . A semiconductor device 4 as an object to be cooled or heated is provided on the thermoelectric conversion device 3 . The semiconductor device 4 is an optical semiconductor device having a light emitting element 5, for example.

FIG. 2 is a plan view showing the semiconductor package according to Embodiment 1. FIG. In a package in which a plurality of lead terminals 2 pass through the outer peripheral portion of the base plate 1, there is a circular empty space in the central portion of the base plate 1. FIG. A circular or elliptical thermoelectric conversion device 3 is arranged in an empty space in the center of the base plate 1 avoiding the outer periphery of the base plate 1 where the lead terminals 2 are present.

FIG. 3 is a cross-sectional view showing a thermoelectric conversion device. The thermoelectric conversion device 3 has a lower substrate 6 , an upper substrate 7 arranged to face the lower substrate 6 , and a thermoelectric element 8 provided between the lower substrate 6 and the upper substrate 7 . The lower substrate 6 and the upper substrate 7 are ceramic substrates. The lower substrate 6 is provided on the base plate 1 and both are joined by soldering. A semiconductor device 4 is provided on an upper substrate 7 and both are joined by soldering. A plurality of electrodes 9 made of gold are provided on the upper surface of the lower substrate 6 and the lower surface of the upper substrate 7 respectively.

The thermoelectric element 8 is a Peltier element having N-type semiconductors 8a and P-type semiconductors 8b alternately connected in series. An electrode 9 connects the P-type semiconductor 8b and the N-type semiconductor 8a. The thermoelectric element 8 converts electricity into heat to control temperature. Therefore, by supplying DC power to the thermoelectric element 8, one of the lower substrate 6 and the upper substrate 7 can act as a heat radiation surface and the other as a cooling surface. The direction of heat conduction can be changed by changing the direction of the electric current. The amount of heat can be changed by changing the magnitude of the current. A potential proportional to the temperature difference between the upper substrate 7 and the lower substrate 6 is generated in the thermoelectric element 8 due to the Seebeck effect. A power generator can also be constructed by extracting this generated power from both ends of the thermoelectric element 8 .

4 is a top view showing the lower substrate of the semiconductor package according to the first embodiment. FIG. 5 is a bottom view showing the upper substrate of the semiconductor package according to the first embodiment. FIG. A plurality of electrodes 9 are arranged concentrically. Each electrode 9 is connected to an N-type semiconductor 8a and a P-type semiconductor 8b. Both the positive terminal 10 and the negative terminal 11 of the thermoelectric element 8 are arranged on the outer periphery of the upper surface of the lower substrate 6 . The positive terminal 10 and the negative terminal 11 are configured so that the electrodes 9 of the thermoelectric conversion device 3 are led out to the outer peripheral portion of the lower substrate 6 and the gold wires 12 are laid from above. Therefore, it is necessary to secure a space for providing the positive terminal 10 and the negative terminal 11 on the outer peripheral portion of the lower substrate 6 .

6 is a plan view showing electrodes of the thermoelectric element according to Embodiment 1. FIG. The electrode 9 has a first portion 9a joined to the N-type semiconductor 8a, a second portion 9b joined to the P-type semiconductor 8b, and arranged between the first portion 9a and the second portion 9b. and a connecting portion 9c for connecting both. The first portion 9a and the second portion 9b are square, while the connecting portion 9c is trapezoidal.

7 is a plan view showing a connecting portion according to Embodiment 1. FIG. The angle between the lower side and the oblique side of the connecting portion 9c is 75°. The angle between the upper side and the oblique side of the connecting portion 9c is 90°+15°. These angles can be adjusted as needed. The connecting portion 9c is normally rectangular, but is trapezoidal in this embodiment. Thereby, the plurality of electrodes 9 can be densely arranged in a circular or elliptical shape according to the shapes of the lower substrate 6 and the upper substrate 7 . Therefore, the temperature control ability of the thermoelectric converter 3 can be ensured.

Next, the effect of this embodiment will be described in comparison with a comparative example. FIG. 8 is a plan view showing a semiconductor package according to a comparative example. In the comparative example, a thermoelectric conversion device 3 having a square planar shape is used. The quadrangular thermoelectric converter 3 cannot be placed in the center of the circular base plate 1 in order to avoid contact with the lead terminals 2, and is miniaturized and placed closer to the edge of the base plate 1. FIG. As the thermoelectric converter 3 becomes smaller, the temperature control capability is lowered. Moreover, in the solder joints between the thermoelectric converter 3 and the base plate 1 and the semiconductor device 4 , the stress due to the difference in the coefficient of thermal expansion concentrates on the outermost corners of the quadrangular thermoelectric converter 3 . Therefore, cracks may occur in the Peltier element of the thermoelectric conversion device 3 .

On the other hand, in the present embodiment, a circular or elliptical thermoelectric conversion device 3 is arranged on a base plate 1 having a circular planar shape. As a result, the thermoelectric conversion device 3 can be arranged in the empty space in the central portion of the base plate 1 without downsizing. Therefore, the temperature control ability can be improved. In addition, since the circular or elliptical thermoelectric conversion device 3 does not have corners where stress is concentrated, cracks are less likely to occur even when the temperature gradient is large.

9 is a plan view showing Modification 1 of the thermoelectric conversion element according to Embodiment 1. FIG. The planar shapes of the N-type semiconductor 8a and the P-type semiconductor 8b are trapezoidal. As a result, the plurality of N-type semiconductors 8a and P-type semiconductors 8b can be efficiently arranged according to the shapes of the lower substrate 6 and the upper substrate 7, so that the thermoelectric conversion device 3 can ensure the temperature control capability. The shape of the electrode 9 must be designed so that it can be joined to the trapezoidal N-type semiconductor 8a and the P-type semiconductor 8b.

10 is a plan view showing Modification 2 of the thermoelectric conversion element according to Embodiment 1. FIG. The cross-sectional shapes of the N-type semiconductor 8a and the P-type semiconductor 8b are trapezoidal. As a result, the vertical stress applied to the thermoelectric element 8 can be dispersed, so cracking, peeling, or deformation of the thermoelectric element 8 can be suppressed. Even if the N-type semiconductor 8a and the P-type semiconductor 8b have trapezoidal planar shapes as in Modification 1, the stress can be dispersed. Further, although a plurality of N-type semiconductors 8a, P-type semiconductors 8b, and electrodes 9 are provided, it is necessary to standardize the size and shape of each member in order to prevent stress concentration. In addition, evenly arranging the N-type semiconductors 8a and the P-type semiconductors 8b can prevent concentration of stress.

Embodiment 2.
11 is a top view showing the lower substrate of the thermoelectric conversion device according to Embodiment 2. FIG. 12 is a bottom view showing the upper substrate of the thermoelectric converter according to Embodiment 2. FIG. 13 is a cross-sectional view showing a thermoelectric conversion device according to Embodiment 2. FIG.

A positive terminal 10 of the thermoelectric element 8 is arranged on the outer peripheral portion of the lower substrate 6 , and a negative terminal 11 of the thermoelectric element 8 is arranged on the central portion of the lower substrate 6 . The negative terminal 11 is drawn out to the lower surface of the lower substrate 6 through the central portion of the lower substrate 6 and connected to the base plate 1 at GND potential. Therefore, it is not necessary to secure a wire-bondable space for providing the minus terminal 11 on the upper surface of the lower substrate 6 . Moreover, since a wire connected to the negative terminal 11 is not required, the risk of wire breakage can be reduced. Although the resistance of the wire is eliminated, the resistance at the time of thermal runaway can be ensured by adjusting the width and thickness of the electrodes 9 of the thermoelectric element 8 .

Embodiment 3.
14 is a side view showing how the thermoelectric conversion device according to Embodiment 3 is attached to a base plate. FIG. 15 is a plan view showing a state in which the thermoelectric conversion device according to Embodiment 3 is attached to a base plate. FIG. A negative terminal 11 of the thermoelectric element 8 is arranged in the central portion of the lower substrate 6 . A through hole 13 is provided in the central portion of the lower substrate 6 . A lead terminal 14 passes through the central portion of the base plate 1 and the central portion of the lower substrate 6 and is connected to the negative terminal 11 . Even if the solder that joins the base plate 1 and the thermoelectric converter 3 is remelted due to thermal runaway, the anchor effect of the lead terminals 14 passing through the lower substrate 6 can prevent the thermoelectric converter 3 from being dislocated.

Embodiment 4.
16 is a plan view showing the lower substrate of the thermoelectric converter according to Embodiment 4. FIG. 17 is a plan view showing the upper substrate of the thermoelectric converter according to Embodiment 4. FIG. 18 is a cross-sectional view showing a thermoelectric conversion device according to Embodiment 4. FIG. A negative terminal 11 of the thermoelectric element 8 penetrates through the central portion of the lower substrate 6 and is drawn out to the lower surface of the lower substrate 6 . A positive terminal 10 of the thermoelectric element 8 penetrates through the central portion of the upper substrate 7 and is drawn out to the upper surface of the upper substrate 7 . In this case, wire bonding may be performed on the outer peripheral portion of the upper surface of the upper substrate 7 .

19 is a cross-sectional view showing a modification of the thermoelectric converter according to Embodiment 4. FIG. A plurality of thermoelectric converters 3 are stacked and connected in series to form a multilayer wiring structure. Since this improves the temperature control ability, the controllable temperature range can be widened, and the object can be efficiently heated or cooled.

1 base plate 2, 14 lead terminal 3 thermoelectric converter 6 lower substrate 7 upper substrate 8 thermoelectric element 8a N-type semiconductor 8b P-type semiconductor 9 electrode 9a first portion 9b second Part 9c Connection part 10 Plus terminal (first terminal) 11 Minus terminal (second terminal)

Claims (9)

a base plate having a circular planar shape;
a lower substrate provided on the base plate; an upper substrate facing the lower substrate; and alternately p-type semiconductors and n-type semiconductors provided between the lower substrate and the upper substrate. A thermoelectric conversion device having a thermoelectric element connected in series,
The planar shape of the thermoelectric conversion device is circular or elliptical,
The thermoelectric conversion device has a plurality of electrodes provided respectively on the upper surface of the lower substrate and the lower surface of the upper substrate and connecting the P-type semiconductor and the N-type semiconductor,
The electrode has a first portion that is bonded to the N-type semiconductor, a second portion that is bonded to the P-type semiconductor, and is disposed between the first portion and the second portion to connect the two. and a connecting portion to be connected,
The semiconductor package , wherein the connecting portion is trapezoidal . a base plate having a circular planar shape;
a lower substrate provided on the base plate; an upper substrate facing the lower substrate; and alternately p-type semiconductors and n-type semiconductors provided between the lower substrate and the upper substrate. A thermoelectric conversion device having a thermoelectric element connected in series,
The planar shape of the thermoelectric conversion device is circular or elliptical,
A semiconductor package, wherein the planar shapes of the N-type semiconductor and the P-type semiconductor are trapezoidal. a base plate having a circular planar shape;
a lower substrate provided on the base plate; an upper substrate facing the lower substrate; and alternately p-type semiconductors and n-type semiconductors provided between the lower substrate and the upper substrate. A thermoelectric conversion device having a thermoelectric element connected in series,
The planar shape of the thermoelectric conversion device is circular or elliptical,
A semiconductor package, wherein cross-sectional shapes of the N-type semiconductor and the P-type semiconductor are trapezoidal. 4. The semiconductor package according to claim 1, wherein both the first terminal and the second terminal of said thermoelectric element are arranged on the periphery of said lower substrate. The thermoelectric element according to any one of claims 1 to 3 , wherein the first terminal of the thermoelectric element is arranged in the outer peripheral portion of the lower substrate, and the second terminal of the thermoelectric element is arranged in the central portion of the lower substrate. The semiconductor package according to any one of items 1 and 2. a base plate having a circular planar shape;
a lower substrate provided on the base plate; an upper substrate facing the lower substrate; and alternately p-type semiconductors and n-type semiconductors provided between the lower substrate and the upper substrate. A thermoelectric conversion device having a thermoelectric element connected in series,
The planar shape of the thermoelectric conversion device is circular or elliptical,
a first terminal of the thermoelectric element is arranged on the outer peripheral portion of the lower substrate, and a second terminal of the thermoelectric element is arranged on the central portion of the lower substrate;
A semiconductor package, further comprising a lead terminal penetrating through the central portion of the base plate and the central portion of the lower substrate and connected to the second terminal. a base plate having a circular planar shape;
a lower substrate provided on the base plate; an upper substrate facing the lower substrate; and alternately p-type semiconductors and n-type semiconductors provided between the lower substrate and the upper substrate. A thermoelectric conversion device having a thermoelectric element connected in series,
The planar shape of the thermoelectric conversion device is circular or elliptical,
a first terminal of the thermoelectric element penetrates the central portion of the lower substrate and is drawn out to the lower surface of the lower substrate;
A semiconductor package, wherein a second terminal of said thermoelectric element penetrates through a central portion of said upper substrate and is led out to the upper surface of said upper substrate. 8. The semiconductor package according to claim 7 , wherein a plurality of said thermoelectric conversion devices are stacked and connected in series to form a multilayer wiring structure. further comprising a plurality of lead terminals penetrating the outer periphery of the base plate,
9. The semiconductor package according to any one of claims 1 to 8, wherein said thermoelectric conversion device is arranged in a central portion of said base plate.

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