DE2013684A1 - Semiconductor device - Google Patents

Description

Semiconductor device

Semiconductor arrangements usually contain a semiconductor system, that from a semiconductor wafer - e.g. from silicon or germanium, and usually consists of at least one support plate, e.g. made of molybdenum, for the semiconductor wafer. The semiconductor system is arranged between two connection bodies for the electrical current, of which at least one a heat dissipating body can be made of copper. The heat dissipating The body is in turn in thermally conductive contact with a cooling arrangement. The connection body can be on the semiconductor system be soldered on or only rest against it under pressure. In this pail there is therefore no solder layer between the connection bodies and the semiconductor system.

The heat dissipating body may have the form of a plate which carries on one side of the semiconductor sys tem and the other side in contact with a cooling arrangement is "In this case, the wäraeableitende body on the side remote from the Halbleitersystea side Several pins, the gaps between the Pins «awaken cooling a flowing coolant

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is fed. In this way, a large contact area is obtained between the heat-dissipating body and the respective one Coolant. Bas is of great importance, since the utilization and the performance of the semiconductor arrangement depend on how effectively the power loss in the semiconductor wafer can be dissipated.

The invention relates to a semiconductor device with a heat-dissipating body with protruding pins in which this apart from cooling, they can also be used to exert mechanical pressure in the direction of the semiconductor system, which is held locked between equipment bodies. The pens can can also be used for the supply and discharge of electrical current to and from the semiconductor system. Because of that, dad man If the pins are also used for other punctures than solely for cooling, the semiconductor arrangement can be a very compact one Give ponn. This is of particular importance in systems in which a large number of semiconductor arrangements are stacked on top of one another and are connected in series or in parallel with each other. In addition, one achieves a very simple, safe and effective one Coolant transport without hoses or other connecting elements between the individual semiconductor arrangements System.

The invention starts from a semiconductor device, e.g.

from a crystal diode, a thyristor or an iranistor, in which a semiconductor system with a semiconductor wafer swi-

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see two connection bodies for the electrical current is arranged and is held pressed by this, at least one of the connection bodies is a heat dissipating Body is made of copper, one plate-like and one on one Side on the part adjacent to the semiconductor system and on the other side with several pins protruding from this Has spaces for the supply of a flowing coolant to the pins. Such an arrangement is according to the invention characterized in that. to exert pressure on the semiconductor system, a pressure plate is used, which rests on the end faces of the pins and its pressure is applied via these pins on the plate-like part of the heat-dissipating body and thus on the semiconductor system, and that the plate-like part of the wärmea'cl '* itenden body part a hermetically sealed housing for the semiconductor system forms.

With a load of 30 kilopond, copper should have a Yickers hardness of more than 60 (H_ ₅ q7 60) and preferably more than 70 (BLx ₀ > 70) in order to be able to effectively transfer the pressure from the pressure plate to the semiconductor system. In the claims and the description, copper is not only meant to be pure copper, but also to copper alloys, which are predominantly made of copper and have good electrical and thermal conductivity, e.g. zirconium copper (Zr 0.10-0.30 Ji, Remainder Ott), chromium-copper (Cr 0.2 - T. %, Remainder Cu), chromium-

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Zirconium copper (Zr 0.2 %, Cr 0.5 *, remainder Cu) and silver copper (Ag Ο, Οοθ%, remainder Cu).

In addition to the semiconductor wafer made of e.g. silicon or germanium, the semiconductor system can at least one on the one Side of the semiconductor wafer arranged support plate made of molybdenum, tungsten or another material with approximately have the same coefficient of thermal expansion as the semiconductor wafer. However, the semiconductor system can except the Semiconductor wafer also consist only of thin metal layers arranged on one or both sides of the semiconductor wafer, which are formed by vapor deposition or cathode sputtering or electrolytic assignment are appropriate. The metal layers can also form in connection with the doping of the semiconductors or in a separate process afterwards. Examples of metals in these layers can be gold, silver, copper, aluminum, Hlckel, lead and alloys with one each

these metals are called. The semiconductor system can also consist only of the semiconductor wafer, it being expedient to use a semiconductor wafer with a highly doped outer layer to use. Avoid using a support plate at least on the one facing the heat-dissipating body Side, you get more effective heat dissipation from the semiconductor system.

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In that the heat dissipating body is part of the housing of the semiconductor system, the joints between the semiconductor system, which aggravate the heat transfer, are avoided and the coolant.

The pins on the heat dissipating plate are preferred cylindrical. They can also be e.g. parallel-epipedic or somewhat conical. The longitudinal direction of the pins is also at right angles to the contact surface between the semiconductor system and the heat dissipating body, and the pins themselves are substantially equidistant from each other.

2 Their number is preferably at least 5 per cm of area at right angles to the longitudinal direction of the pins. The cross-sectional area of a pen halfway up the pen and at right angles to its longitudinal direction is expediently at most

2 2

10 mm, preferably 0.5-10 mm.

The heat dissipating body with its pins is preferably a hot-pressed in a single piece (above 800 ⁰ C) or cold-pressed (at room temperature) body. This makes it very easy to produce a body that meets the hardness requirement and has no weak mechanical haste. Cold pressing is particularly preferred because the hardness in the pins is greater than in hot pressing, the surface is better and no oxide skin forms.

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The semiconductor arrangement according to the invention can be cooled on one side. The one connection body from the heat able it ends body and the other consist of a pantograph that is not cooled with a flowing coolant. The pantograph and the pressure plate can thus τοη a pressing arrangement in the direction of the semiconductor system are kept under bridge. Such a semiconductor arrangement has a very compact structure for a semiconductor arrangement cooled on one side.

If both connecting bodies are designed as heat-dissipating bodies of the type mentioned, a double-sided cooled one is obtained Semiconductor arrangement with a very compact structure. Those on the outer end faces of the pins of the heat dissipating body arranged printing plates are pressed with a press arrangement in the direction of the semiconductor system.

A special part of the gate is achieved if the pressure plate or pressure plates are made of copper, αί-ιμΗτη ™ or another Metal can be produced with good electrical conductivity, since then a connecting conductor or several connecting conductors for electrical current to the semiconductor device on the Pressure plate or the pressure plates can be attached. In this case, the pins also serve as conductors.

The invention is illustrated below on the basis of τοη execution examples described. In the drawing show; '

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Fig. 1 and 2 schematically an arrangement for the Manufacture of a heat-dissipating body,

5 shows a schematic cross section of a one-sided cooled semiconductor device according to the invention,

A shows a schematic cross section of a double-sided cooled semiconductor arrangement according to the invention,

Fig. 5 shows a semiconductor arrangement according to - "" ig. 4 in reduced size Hatred and seen from above and

6 shows a system consisting of several stacked one on top of the other Semiconductor arrangements according to the invention.

1 and 2 it is shown how a heat-dissipating body used according to the invention can be produced. For this purpose, a tool is used which consists of a die 10 and a punch 11 and which, when the punch has been inserted into the die to the intended depth, forms a cavity 12 which has the same shape as the outer shape of the heat-dissipating body to be manufactured. In the upper part of the die, as shown in Fig. 1,

13th a solid piece of copper / laid, e.g. from a round

Rod can be cut off * The stamp is inserted into the

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The die is inserted, applying a pressure of approximately 10 ton / ca on the Eupfer piece. The tool 1st In known catfish arranged in a face.

The Eupferetück is at room temperature and the tool is not given a heating arrangement. When pressing in the punch The Eupfer fills the cavity 12 and the small holes 14 to form pins on the heat-dissipating body. The finished heat-dissipating body 15 is with its pins in Pig. 2 shown. The radius of the pmlat-like cylindrical part 17 of the heat-dissipating body can be, for example, 70 mm The diameter of the cylindrical pins 2 mm, the center-to-center distance of the pins 3 mn and the number of pins consequently over 400.

Pig. 3 shows a complete semiconductor arrangement cooled on one side in the form of a diode, in which the heat-dissipating

15th Body / at the same time a connection body for the electrical Electricity forms. The semiconductor arrangement has a round silicon wafer 20 made of pnn ⁺ , which is soldered on the underside with an aluminum layer (not shown) to a support plate 21 made of molybdenum or of another material with approximately the same coefficient of thermal expansion as silicon and on its upper side an alloyed gold - Antimony Eontakt in the form of a layer 22 carries. The consisting of the elements 20, 21 and 22 semiconductor system is hermetically enclosed in a housing, which consists of the heat-dissipating body 15 and a

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is composed of the round parts 24, 25 and 26 existing hood. The parts 24 and 26 can for example be made of copper or an iron-nickel-cobalt alloy (Pernico) and the Part 25 e.g. made of ceramic or porcelain. The parts 24, 25 and 26 can be joined together, for example by brazing with silver solder Connected, his and the part 24 to the body 15 by cold pressure welding. On the outside of the hood lies in one cylindrical indentation 27 a current collector 28, which is pressed by peder rings 29 against the hood. The peder rings 29 are over a cylindrical body 30 made of insulating material, e.g. ceramic, from a capsule 31 serving as a counter holder held in the form of a curved press plate, e.g. made of steel. Like from Pig. 3 is the capsule 31 with bolts 32 fixedly mounted on a stiff printing plate 33 made of copper. The pressure of the connection bodies 15 and 29 against the semiconductor system can be regulated with the help of a tensioning screw 34, the one Forms part of the capsule 31.

A connection conductor 35 is connected to the current collector 28. This is from the capsule through which it is passed with a insulating sheath 36, e.g., fiberglass tape, insulated. Another connection conductor 37 is soldered to the pressure plate 33. The contact between the semiconductor system and the connection bodies is only made by pressure. The pressure from the pressure plate 33 in the direction of the semiconductor system is thereby of transferred to the pins 16, the end faces of which bear against the pressure plate 33. The coolant, e.g. water, Ul or air,

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is placed through the opening 38 in the pressure plate in the center of the heat-dissipating body introduced. After the coolant has passed the pins in the radial direction, it leaves the heat dissipating body on the circumference 39. Bas introducing coolant into the center means that cold coolant is in direct Contact with the warmest area of the heat-dissipating body can be brought.

The semiconductor arrangement according to FIGS. 4 and 5, cooled on both sides, forms a thyristor with a semiconductor wafer 20 Silicon (type pnpn). Incidentally, like the arrangement according to, the semiconductor system has. 3 a support plate 21 and an alloyed contact 22. The semiconductor system is hermetically enclosed in a housing consisting of the two heat-dissipating bodies 15a and 15b, resilient rings 40a and 40b, e.g. made of copper or fernico, and an insulation 41 made of e.g. Porcelain or ceramics. The rings 40a and 40b are on the vertical and horizontal contact surfaces by brazing attached to ceramic ring 41 with silver solder. The heat-dissipating body has a flange 42a or 42b, which through intermediate copper rings 57a and 57b with the rings 40a and 40b IaItpreßschweiß is connected. The semiconductor system is in place with the connection bodya, i.e. the heat-dissipating bodies, only through pressure in "connection. The pressure wM from the pressure plates 33a and 33b transferred, which bear against the end faces of the pins 16a and 16b, which in turn are pressed against one another by yokes 43a and 43b. They have recesses 44a and 44b,

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for the feed / or. for the discharge 46 of a coolant (Fig. 4) are intended.

The contact pressure is generated by bolts 47 and 48, which go through both yokes and are isolated from at least one pressure plate with a sleeve made of insulating material. Each bolt has a spring washer or the like in order to achieve a resilient tightening. The two pressure plates 33a and 33b together with an annular part 49 », e.g. made of glass fiber reinforced polyester plastic, form a space 50 for the coolant flowing through. The coolant, e.g. water, oil or air, is passed via the feed 45 into the center of the heat-dissipating body 15a, passes the pins 16a in the radial direction, passes the sleeve of the semiconductor system on the outside, goes in at the outer pins 16b of the heat dissipating body 15b, passes the pins in the radial direction and goes out through the outlet 46 in the middle of the heat dissipating body 15b A connection conductor 37a or 37b is soldered to each pressure plate.

The firing electrode 51 of the thyristor, which is attached centrally to the top of the semiconductor system, is in one Copper pipe 52 is arranged and passed through the heat dissipating body 15b. The copper pipe has an insulating sleeve 53, e.g. made of porcelain, which has a ring 54 and a hood 55, both e.g. on copper or Pernico, sealing with the heat » dissipative body 15b or the copper pipe 52 is connected. the

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The ignition electrode is connected to the insulated lead 56. '

Pig. 6 shows a stack of several semiconductor arrangements according to the invention. Each is of essentially the same type as that shown in Figure 4 with the following modifications.

The printing plates used in Pig. 6 denoted by 33 ac and 33 bc are thicker to provide effective seating and sealing between adjacent panels. The seal consists of rubber O-rings 58 which are located in grooves 59a and 59b in the plates. The inlet openings 45c and outlet openings 46c for the coolant in adjacent semiconductor arrangements are at the same level as the Printing plates. The connected to the ignition electrodes 51 insulated leads 56c pass through holes 60 in pins 16b of upper heat sink 15b as well as holes 61 in the annular housings 49. A rubber ring 62 is arranged as a seal between the conductor 56c and the housing 49.

The stack is made by yokes 43a and 43b as in Pig. 5 shown held together.

The coolant is in the same way as for the semiconductor according to Pig.4 via the inlet 45 in the center of the heat dissipating Body 15a of the lowermost semiconductor arrangement passed, this is possible by passing through this semiconductor arrangement Coolant such as that for the semiconductor device according to Pig.

is described, through the outlet 46c out and into the Inlet 45c of the next (second) semiconductor arrangement. This semiconductor arrangement is traversed in the same way like the previous one (first) and the coolant goes in the same way and passes the next one (third) Semiconductor device. The coolant then goes into the next (fourth) semiconductor arrangement and leaves the stack at the outlet of the last-mentioned semiconductor arrangement. In the example case the semiconductor devices are connected in "series, and there are only two connecting conductors 37 ac and 37 bc.

As can be seen from Fig. 6, the cooling of the semiconductor devices Without the use of hoses or other connecting pipes between the individual semiconductor arrangements, which makes cooling very simple, safe and effective.

In the case of the semiconductor devices shown in Figs. 3, 4 and 6, the semiconductor system can be sealed on one side with a solder, e.g. a gold-tin-Iiot, to be fixed to the connecting body located there. Thus, a solder can be used between the support plate 21 and the heat dissipating body 15 in the arrangement shown in FIG Fig. 3 be arranged and a solder between the support plate 21 and the heat dissipating body 15a in the arrangement according to FIG lig. 4 and 6.

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Claims (13)

Patent claims: Semiconductor arrangement, e.g. a crystal diode, a thyristor or a transistor, in which a semiconductor system with a Semiconductor wafer is arranged between two connection bodies for the electrical current and pressed by this is held, wherein at least one of the connection body is a heat-dissipating body made of copper, a plate-like and on one side adjacent to the semiconductor system and on the other side several protruding from this Has pins with spaces for the supply of a flowing coolant to the pins, characterized in that to exert pressure on the semiconductor system (20, 21, 22) a pressure plate (33) is used, which is attached to the end faces of the pins (16) is applied and its pressure via these pins on the plate-like Part of the heat-dissipating body (15) and thus transfers to the semiconductor system, and that the plate-like Part of the heat-dissipating body forms part of a hermetically sealed gel film for the semiconductor system. 2. Semiconductor arrangement according to claim 1, characterized in that the copper for the heat-dissipating body (15) »at least that of the pins (16) at 30 kilopond load has a Vickers hardness of more than 60 (H ₇ ^ q" ^ 60). 3. Semiconductor arrangement according to claim 1 or 2, characterized in that that the wänsabeltende body (15) ait its pins 009886/1346 - 15 - (16) is a body pressed in a single piece. 4. Semiconductor arrangement according to one of claims 1 to 3, characterized in that the heat-dissipating body (15) with its pins (16) is a body cold-pressed in a single piece. 5. Semiconductor arrangement according to one of claims 1 to 4, characterized in that the one connection body from the heat-dissipating body (15) and the second connection body consists of a pantograph (28) that is not connected to a flowing coolant is cooled, and that the current collector (28) and the pressure plate (33) with a pressing arrangement in Direction of the semiconductor system (20) are kept pressed. 6. Semiconductor arrangement according to one of claims 1 to 4, characterized in that the one connection body from the heat dissipating body (15a) and the second connection body also from a heat-dissipating body (15b) in the Claims 1 to 4 specified type consists that the end faces of the pins both heat able! tender body on one each Pressure plate (33a, 33b) and one in the direction of the Semiconductor system (20) are subjected to effective pressure, and that the pressure plates with a pressing arrangement in the direction of the semiconductor system are kept pressed. - 16 0 09 8 8 6/1 "3'4 6 7. Semiconductor arrangement according to one of claims 1 to 5, characterized in that the cross-sectional area at half the height of each pin and at right angles to its longitudinal direction ^{is 0.5-10 mm 2} and that on each cm ² area of the plate-like part is at right angles to the longitudinal direction of the Pins at least five pins are arranged. 8. A semiconductor device according to claim 6, characterized in that in at least one of the heat-dissipating body (15) the Cross-sectional area halfway up each pin (16) and 2 is at right angles to its longitudinal direction 0.5-10 mm and that on every cm ² area of the plate-like part of this body, at least five pins are arranged at right angles to the longitudinal direction of the pins. 9. Semiconductor arrangement according to one of claims 1 to 5 and 7, characterized in that it is provided with an arrangement for the Supply of coolant in the central part of the heat dissipating Body (15) is provided at right angles to its plate-like • part. 10. Semiconductor arrangement according to one of claims 6 and 8, characterized in that it is provided with an arrangement for the Supply of coolant at least into the central part of the one heat-dissipating body (15) at right angles to its plate-like body Part is provided. 009886/1346 - 17 - 11. Semiconductor arrangement according to one of claims 6, 8 and 10, characterized in that the semiconductor system (20) with its hermetically sealed housing (15, 25, 26) and the heat-dissipating body (15) with their pins (16) in one Housing (49) are arranged for the flowing coolant, the at the central part of a heat dissipating body (15) with an inlet opening (45th) and at the central part of the another heat dissipating body with a ^ / outlet opening (46) is provided for the flowing coolant, and that also arranged around the housing of the semiconductor system Passage (50) is provided for the coolant from one of the two heat-dissipating bodies to the other. 12. Stack of semiconductor devices, consisting of several Semiconductor arrangements according to one of Claims 6, 8, 10 and 11, characterized by a pressure plate (33) in each semiconductor arrangement, which rests against a pressure plate of the adjacent semiconductor device. 13. Stack of semiconductor devices according to claim 12, characterized characterized in that the inlet and outlet openings (45, 46) / the flowing coolant in the pressure plates (33) and the discharge openings of the one semiconductor arrangement as follows are arranged that they did directly into the inlet opening of the adjoining Skip semiconductor arrangements. \. - 003886/134 6 Blank page