JP2001024125A - Flat semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling of semiconductor chips by giving a cooling function to electrode lead elements which are components of a flat semiconductor device and exhibit the performances of the large capacity semiconductor device sufficiently. SOLUTION: A flat semiconductor device comprises a plurality of semiconductor chips 2 arranged on the same plane, hard metal terminals 3, electrode lead elements 4 and a package container 6 made of insulating material. A plurality of partition fins 13 and coolant passages 14 are formed in each electrode lead element 4, and coolant is supplied from the outside through a coolant entrance 15 and a coolant exit 16 to remove heat generated by the semiconductor chips from the electrode lead element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure contact type flat semiconductor device applied to electric power.

[0002]

2. Description of the Related Art First, a conventional structure of a flat semiconductor device described above is shown in FIG. 5, and FIG. 6 shows a conventional structure of a flat semiconductor device stack employing a boiling cooling method. In FIG. 5, a flat semiconductor element 1 includes a plurality of semiconductor chips 2 arranged on the same surface, a hard metal terminal 3 contacting an electrode surface with the main surface of each semiconductor chip 2 sandwiched from both sides, A pair of upper and lower electrode leads 4 that press the metal terminals 3 together from both sides against the main surface of the semiconductor chip 2, a sealing metal plate 5 hermetically bonded to the outer periphery of each electrode lead 4, and an electrode lead 4 And an outer container 6 made of an insulating material, which is interposed between the sealing metal plates 5 to form an airtight chamber.

Here, the hard metal terminal 3 is made of a hard metal such as Mo, for example. When the hard metal terminal 3 comes into pressure contact with the main surface of the semiconductor chip 2, chip cracks caused by uneven pressurization are prevented. I try to prevent it. Further, the electrode lead-out body 4 has a role of conducting electricity to the semiconductor chip 2 and transmitting heat generated in the semiconductor chip 2 to the outside, and is formed by forming a metal plate such as copper having high conductivity and heat conductivity. Have been. Although the hard metal terminals 3 are individually provided for the respective semiconductor chips 2 in the structure of the illustrated example, some hard metal terminals are provided for each of the plurality of semiconductor chips.

[0006] In FIG. 6, reference numeral 7 denotes a cooling body as a heat sink in which the flat semiconductor element 1 is sandwiched from both sides in a sandwich manner, and 8 is provided at both ends of a stack assembly of the flat semiconductor element 1 and the cooling body 7. 9 is a tightening stud, 10 is a disc spring, 11 is a ball,
The cooling body 7 which becomes a hollow block is connected to a refrigerant liquid reservoir 12a of the condensation radiator 12 via a refrigerant pipe 7a.

In this configuration, the heat generated in the semiconductor chip 2 is transferred to the cooling body 7 using the hard metal terminals 3 and the electrode lead-out members 4 pressed against the semiconductor chip 2 as heat transfer paths, and then the hollow cooling body Due to the phase change of the boiling and condensation of the refrigerant sealed in the inside of the, heat is radiated from the condensation radiator 12 to the outside of the system and is removed.

[0006]

However, the above-mentioned flat semiconductor element stack has the following problems due to its cooling property. In other words, the heat loss generated in the flat semiconductor element 1 tends to increase more and more as the function of the device to which the flat semiconductor element is applied becomes higher and the capacity increases. On the other hand, thermal resistance exists in the flat semiconductor element 1 and in the heat transfer path between the semiconductor element 1 and the cooling body 6, and particularly, the contact between the electrode lead 4 and the cooling body 6 of the semiconductor element 1. Since the thermal resistance of the surface is large and varies locally, when the heat generation of the semiconductor element increases, the temperature gradient inside the flat semiconductor element 1 (the surface of the semiconductor chip 2 / the surface of the electrode lead body 4) increases, The temperature of the semiconductor chip 2 reaches an allowable limit. Therefore, in order to operate the semiconductor chip 2 at a temperature equal to or lower than the allowable temperature, it is necessary to lower the refrigerant temperature. However, the cooling body 7 and the condensing radiator 12 increase in size.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to solve the above-mentioned problems and to provide a cooling function to an electrode lead body, which is a component of a flat semiconductor device, to provide a semiconductor chip. It is an object of the present invention to provide a flat semiconductor device improved in cooling efficiency and capable of sufficiently exhibiting the performance of a large-capacity semiconductor device.

[0008]

According to the present invention, there is provided a semiconductor device comprising: a plurality of semiconductor chips arranged on the same surface; Hard metal terminals, two hard metal terminals which are collectively pressed from both sides against the main surface of the semiconductor chip, and a periphery of the electrode lead body, which is hermetically sealed with each electrode lead body. In a flat semiconductor device comprising an insulating outer container which forms an airtight chamber between a sealing metal plate joined and protruding on the periphery thereof, a plurality of partition fins, In addition, a plurality of refrigerant passages are formed along each partition fin, and refrigerant inlets and outlets communicating with the refrigerant passages are provided on the outer peripheral side surface of the electrode lead-out body (claim 1). It can be configured in such a manner.

(1) The partition fin formed inside the electrode lead body is patterned in parallel with the arrangement of the semiconductor chips. (2) The partition fin formed inside the electrode lead body is patterned obliquely to the arrangement of the semiconductor chips.

(3) The surface of the fin is made uneven so that the heat transfer area between the partition fin and the coolant is increased. (4) With respect to a pair of electrode lead-out bodies disposed on both sides of the semiconductor chip, pattern formation is performed so that partition wall fins formed on one of the electrode lead-out bodies and partition wall fins formed on the other lead-out body cross each other (claim). Item 5).

(5) The coolant inlet and outlet are distributed on the diagonal of the electrode lead-out body and provided on the peripheral surface thereof. (6) An insulating layer is formed on the inner surface of the electrode lead body facing the coolant flow passage, so that conductive water can be used as the coolant.

According to the above structure, the electrode lead body itself, which is a component of the flat semiconductor element, has a cooling function, so that the heat transfer resistance inside the electrode lead body is lower than that of the flat semiconductor element having the conventional structure. Become smaller. As a result, the temperature difference (= thermal resistance) between the semiconductor chip and the coolant can be suppressed to a great extent, and the cooling efficiency can be greatly improved. As a result, the stack assembly can be made compact and compact.

Further, in this case, as described in the above item (4), the partition fin formed on one electrode lead and the partition fin formed on the other lead are patterned in a direction crossing each other, thereby forming a stack. Since the partition fins of the electrode leads of the adjacent flat semiconductor element in the assembly work to reinforce each other's electrode leads, the warpage of the electrode leads and the variation in the pressing force caused by this warp are effective. Can be prevented. Furthermore, by arranging the coolant inlet and outlet on the diagonal of the electrode lead-out body as described in the item (5), the coolant passage of each strip formed inside the electrode lead-out body becomes substantially the same length, and Can be made to flow evenly.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given based on each embodiment shown in FIGS. In the drawings of the embodiment, members corresponding to those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Embodiment 1 FIGS. 1A and 1B show an embodiment corresponding to claims 1, 2 and 6 of the present invention. In this embodiment, the flat semiconductor element 1 is basically the same as the conventional structure shown in FIG. 5, but an electrode lead-out body 4 as a pressure block sandwiching a semiconductor chip 2 and hard metal terminals 3 from both sides. A plurality of partition fins 13 and a coolant passage 14 along the partition fins 13 are formed in the inside of the electrode lead body 4 over substantially the entire area thereof in parallel with the arrangement of the semiconductor chips 2 arranged in a grid. In addition, a coolant inlet 15 and an outlet 16 communicating with the coolant passage 14 are opened at diagonally opposite corners on the outer peripheral side surface of the electrode lead-out body 4.

In this configuration, the refrigerant flowing from the refrigerant inlet 15 is divided into the refrigerant passages 14 as shown by arrows in the drawing, flows along the surface of the partition fins 13 and then joins again and flows out from the refrigerant outlet 16. In addition, the refrigerant flowing out from the refrigerant outlet 16 of the electrode lead body 4 moves to a radiator provided separately from the semiconductor element stack, exchanges heat with external air and is cooled, and then the semiconductor element stack is again cooled. It circulates so as to return to the electrode lead-out body 4 and flow into the refrigerant inlet 15.

Here, the heat loss generated in the semiconductor chip 2 due to the energization of the flat semiconductor element 1 is transferred from the hard metal terminals 3 in contact with both surfaces of the semiconductor chip 2 to the electrode lead-out body 4, and the partition fins are formed. The heat flowing through the refrigerant flowing from the surface of the refrigerant passage 13 through the refrigerant passage 14 is radiated to the outside of the system.

As described above, the partitioning fins 1 are provided inside the flattened semiconductor element 1 by utilizing the electrode lead-out body 4 as a component.
4, the coolant passages 15 are formed in a dispersed manner, and a coolant flows from the outside to the coolant passages 15 so that the heat resistance of the heat transfer path from the semiconductor chip 2 to the partition fins 14 of the electrode lead-out body 4 is small, and the partition fins 14 Since a large heat transfer area is secured between the semiconductor chip 2 and the refrigerant flowing through the refrigerant passage 15, the semiconductor chip 2 can be efficiently cooled.

Next, several applied embodiments of the present invention based on the above configuration will be described with reference to FIGS. [Embodiment 2] FIG. 2 shows an embodiment corresponding to claim 3 of the present invention. In this embodiment, the partition fins 13 and the coolant passages 14 are patterned so as to extend obliquely with respect to the arrangement of the semiconductor chips 2 (see FIG. 1B). As a result, the refrigerant flows substantially linearly between the refrigerant inlet 15 and the refrigerant outlet 16 arranged at the diagonal corners of the electrode lead-out body 4, so that the flow resistance of the refrigerant can be suppressed lower than in the pattern configuration of FIG. it can.

[Embodiment 3] FIG. 3 shows an embodiment according to claim 4 of the present invention. In this embodiment, the partition wall fin 13 has an uneven surface 13a formed on the surface of the fin facing the refrigerant passage. In addition, this uneven surface 1
Reference numeral 3a also includes a fine uneven surface formed by, for example, sandblasting.

By forming the uneven surface 13a on the surface of the partition fin 13, the heat transfer area between the refrigerant flowing in the refrigerant passage 14 and the partition fin 13 is increased, and the stirring effect is exerted when the refrigerant flows. This promotes heat transfer between the fins / coolant. Further, even when the refrigerant performs boiling heat transfer, the convex portion formed on the surface of the partition wall fins 13 promotes nucleate boiling of the refrigerant and separation of vapor bubbles, maintains stable nucleate boiling, and improves heat transfer performance. .

In the illustrated example, the partition fins 13 are formed in the same pattern as that of the first embodiment shown in FIG. 1. However, it is needless to say that the same can be applied to the oblique pattern of the second embodiment shown in FIG. is there.

Embodiment 4 Next, an embodiment according to claim 5 of the present invention will be described. As described above with reference to FIG. 5, the flat semiconductor element 1 includes the semiconductor chip 2 and the hard metal terminals 3.
Is sandwiched between two electrode lead-out bodies 4 from both sides thereof. Therefore, in this embodiment, the partition wall fin 13 of each of the above-described embodiments formed on one of the two electrode lead-out bodies 4,
The flat semiconductor element 1 is assembled by forming a pattern so that the partition fins 13 formed on the other electrode lead-out body 4 intersect each other.

With such an arrangement, when a stack is assembled with a plurality of flat semiconductor elements 1, the partition fins 13 of the electrode lead bodies 4 of the adjacent semiconductor elements 1 are connected to the other electrode lead bodies. 4 reinforce each other in the easily warped directions. Thereby, it is possible to effectively prevent the electrode lead-out body 4 from warping and the pressure applied to the semiconductor chip 2 due to the warping.

[Embodiment 4] Next, FIG. 4 shows an embodiment corresponding to claim 7 of the present invention. In this embodiment, an electrical insulating layer 17 made of resin or ceramics is formed on the inner wall surface of the electrode lead-out body 4 so as to cover the entire inner surface of the coolant passage 14 formed inside the electrode lead-out body 4. Have been. As a result, since the electrode lead-out body / refrigerant is electrically insulated, a conductive refrigerant such as water can be used. In each of the embodiments described above, the outer shape of the flat semiconductor device is square, but the same can be applied to a flat semiconductor device having a round outer shape.

[0026]

As described above, according to the structure of the present invention, a coolant passage and a partition fin are provided inside an electrode lead-out body, which is a current-carrying part of a flat semiconductor device, so that the coolant flows directly through the passage. With this configuration, the heat transfer resistance inside the electrode lead-out body can be reduced and the temperature difference between the semiconductor chip and the coolant (= thermal resistance) can be reduced as compared with the conventional flat semiconductor element. Since the cooling efficiency of the semiconductor element is greatly improved, and the temperature rise inside the semiconductor element is also suppressed to a low level, a margin is allowed for the allowable temperature of the semiconductor chip, and the reliability of the flat semiconductor element can be improved.

Even when a stack is formed by a plurality of flat semiconductor elements, the stack can be made small and compact by omitting the cooling body interposed between the semiconductor elements in the conventional stack structure. .

[Brief description of the drawings]

FIGS. 1A and 1B are structural views of a flat semiconductor device according to a first embodiment of the present invention, wherein FIG. 1A is a longitudinal sectional view, and FIG.
X sectional view

FIG. 2 is a cross-sectional plan view illustrating a pattern of partition fins of an electrode lead-out body according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional plan view illustrating a pattern of partition fins of an electrode lead-out body according to Embodiment 3 of the present invention.

FIG. 4 is a sectional view of a refrigerant passage of an electrode lead-out body according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a conventional assembly structure of a flat semiconductor element.

6 is an assembling configuration diagram of a semiconductor element stack by a boiling cooling method assembled by the flat semiconductor elements of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat semiconductor element 2 Semiconductor chip 3 Hard metal terminal 4 Electrode lead body 5 Sealing metal plate 6 Enclosure container 13 Partition fin 13a Irregular surface 14 Refrigerant passage 15 Refrigerant inlet 16 Refrigerant outlet 17 Insulating layer

Claims (7)

[Claims] 1. A semiconductor device comprising: a plurality of semiconductor chips arranged on the same surface; a hard metal terminal which is superimposed on both main surfaces of each semiconductor chip and comes into contact with its electrode; Two electrode lead bodies pressed against the main surface of the chip,
A flat semiconductor element comprising an outer container made of an insulator surrounding the electrode lead-out body and hermetically bonded to each electrode lead-out body and forming an airtight chamber between the metal lead-out and a sealing metal plate protruding on the periphery thereof. A plurality of partition fins and a plurality of coolant passages along each partition fin are formed inside the electrode lead body, and a coolant inlet and an outlet communicating with the coolant passage are provided on an outer peripheral side surface of the electrode lead body. A flat semiconductor device characterized by the above-mentioned. 2. The flat semiconductor device according to claim 1, wherein
A flat semiconductor device, wherein partition fins formed inside an electrode lead body are formed in a pattern in parallel with the arrangement of semiconductor chips. 3. The flat semiconductor device according to claim 1, wherein
A flat semiconductor device, wherein a partition fin formed inside an electrode lead body is pattern-formed obliquely to an arrangement of semiconductor chips. 4. A flat semiconductor device according to claim 2, wherein the surface of the partition wall fin is made uneven. 5. A flat semiconductor device according to claim 1, wherein a pair of electrode lead-out members arranged on both sides of the semiconductor chip is provided with a partition fin formed on one of the electrode lead-out members and the other. And a partition fin formed on the lead-out body of (1) is patterned in a direction crossing each other. 6. The flat semiconductor device according to claim 1, wherein a coolant inlet and a coolant outlet are distributed on a diagonal of the electrode lead-out body. 7. The flat semiconductor device according to claim 1, wherein an inner surface of the electrode lead body facing the coolant flow passage is coated with an insulating layer.