WO1999041960A1

WO1999041960A1 - Electronic module with semiconductors, with liquid-cooling system and transmitter comprising at least one such module

Info

Publication number: WO1999041960A1
Application number: PCT/FR1999/000215
Authority: WO
Inventors: François Ursenbach; Arnaud De Grammont
Original assignee: Thomson-Csf
Priority date: 1998-02-10
Filing date: 1999-02-02
Publication date: 1999-08-19
Also published as: FR2774850B1; FR2774850A1

Abstract

The invention concerns electronic modules with semiconductors, with liquid-cooling system, said module comprising a fixed part consisting of a cooling device (M1) and a plug-in unit (M2) on the fixed part. Said cooling device comprises a truncated base (C) wherein circulates a heat transferring liquid (F). The plug-in unit (M2) comprises a metal block (D) whereon are pressed electronic circuits to be cooled. Said block has a recess (E) with the same truncated profile as the base. When the unit is plugged in the recess walls and the base are in contact. The invention is applicable, in particular, to power transmitters.

Description

SEMICONDUCTOR ELECTRONIC MODULE WITH LIQUID COOLING AND AT LEAST COMPONENT TRANSMITTER

SUCH A MODULE

The present invention relates to the cooling of semiconductor electronic modules and, in particular, amplifier modules for transmitters working at microwave frequencies. These modules are, most often, plug-in and include one or more electronic circuits including, generally, at least one amplifier circuit; when the module can be changed even though the assembly of which it is a part continues to operate, it is called a hot-pluggable module. The present invention also relates to transmitters fitted with at least one of these modules.

In transmitters working in microwave several modules are necessary to provide the desired transmission power. To function optimally the semiconductor junctions must be kept below a certain temperature otherwise their behavior deteriorates; efficient cooling is therefore necessary.

When air cooling, either by natural convection or by forced convection, is insufficient, there remains liquid cooling with, most often, water as liquid. In fact, liquid cooling makes it possible to locally evacuate a very large number of calories if the circulation of the liquid takes place in the immediate vicinity of the circuits to be cooled. It is known to produce modules where the electronic circuits are fixed to a cooling plate inside which the liquid circulates. The implementation of such a plate is inconvenient because it requires numerous clamping points between the plate and the circuits in order to ensure a suitable planar thermal contact; it follows that the circuits are difficult or very difficult to separate from the cooling plate and that it is therefore preferable that the plate-circuit assembly is removable. To be able to change the modules without stopping the operation of the assembly of which they are a part, it is then necessary to provide for a self-sealing of the liquid supply and return conduits to the modules. In addition, the fact that the electrical connectors are associated, in the modules, with hydraulic connectors, entails risks of leaks and increases the precision with which the module must be manufactured so that it can be inserted.

The present invention aims to avoid or, at least, reduce the aforementioned drawbacks.

This is obtained by separating the module into a first plug-in component with the circuits to be cooled and into a second fixed component with a liquid circulation cooling device, the shapes of the two components being designed to ensure good thermal conduction between the circuits and the liquid when the first component is plugged in above the second.

According to the invention, an electronic module is proposed for this, comprising electronic semiconductor circuits and a device for cooling by circulation of a liquid, as described in claim 1 of this document.

The present invention will be better understood and other characteristics will appear from the following description and the figures relating thereto which represent:

FIGS. 1 and 2, schematic views of an electronic module according to the invention,

- Figures 3 and 4, more detailed but partial views of two modules according to the invention, - Figures 5, 6a and 6b, diagrams relating to the module according to Figure 4. In the different figures the corresponding elements are designated by the same references.

Figure 1 is a schematic perspective view of an electronic module. This module has two parts: a cooling device M 1 and a plug-in unit M2.

The cooling device M 1 constitutes an element intended to be permanently mounted in electronic equipment. It has a frustoconical base, C, with, inside, a pipe in the form of a serpentine, F, whose representation, reduced to a dashed line, indicates the path; at the level of the large base of the frustoconical base, this pipe is connected to two tubes: a tube Te for the entry of heat transfer liquid and a tube Ts for discharging this liquid after it has passed through the pipe. A guide plate H 1, made of a small plate pierced with a hole, constitutes a lateral protuberance at the frustoconical base C, at the periphery of the large base of this frustoconical base. The frustoconical base C and the plate H 1 are made of the same metal which is a good conductor of heat.

The M2 plug-in unit comprises a metal block, D, in the form of a right parallelepiped pierced with a recess E and surmounted by a guide finger H2. The recess E, of frustoconical shape, has its largest base which constitutes an opening in one of the faces of the block D. The plug-in unit M2 comprises electronic circuits, not shown in FIG. 1, which are pressed against the faces of the block D other than the face into which the recess E opens.

The frustoconical shapes of the base and the recess have the same profile, which makes it possible to achieve a mechanical junction with good contact between the facing surfaces of the base C and the recess E when the unit M2 , female part of the junction, is plugged into the cooling device M 1, male part. In Figure 1 the module is shown with the longitudinal axes of the base and the recess combined along the same line XX. Furthermore, the plug-in unit has been turned around this axis in such a way that its guide finger H2 is directed towards the hole drilled in the guide plate H 1. Under these conditions, it suffices to subject the plug-in unit M2 to a translation parallel to XX and directed towards the device M 1 so that the recess E comes over the base C. It should be noted that a variant of embodiment consists in having the guide finger which forms part of the cooling device and the plate which forms part of the plug-in unit.

FIG. 2 is a schematic side view which shows the module shortly before the unit M2 has come to completely plug into the device M 1. In this figure, as in Figure 1, the circuits electronics carried by the M2 unit have not been shown; moreover the serpentine pipe was not indicated. On the other hand, this figure shows a tapped blind hole V1 and a screw, V2, intended to penetrate into the hole V1; the blind hole is drilled in the base C of the cooling device M 1, along the longitudinal axis marked by the line XX, and this blind hole opens out through the small base of the frustoconical base; the screw V2, the head of which is located outside the metal block D, enters this block through a smooth hole and opens into the recess E; the axis of the screw coincides with the longitudinal axis of the recess E identified by the line XX.

As shown in FIG. 2, the plug-in unit M2 is not totally "impaled" on the frustoconical base M 1: it remains to bring the unit M2 closer to the base M 1 a little more 1 0% of the value of the depth of the recess E; the screw V2 then enters the hole V1, provided that the screw head is turned to ensure screwing.

It should be noted that the screw V2 has, in the vicinity of its head, a circular groove, Vc. A plate Cv, made of two half-plates screwed into the base D, prevents the screw V2 from moving along the axis XX, transforming it into captive screw; for this, the two half-plates have a notch in a semicircle and are joined so that the notches form a circle the periphery of which is inside the groove of the screw V2. Thus the screw V2 makes it possible not only to achieve by screwing it, a good contact between the cooling device M 1 and the unit M2 but also, by unscrewing it, to separate the unit M2 from the device M 1.

It is the good contact between trunks of cones with on one side the cooling device M 1 and on the other the unit M2, which ensures an efficient drainage of the calories from the unit M2 towards the heat-transfer liquid which circulates in the device M 1. This contact can be further improved if the surfaces intended to come into contact between the device M 1 and the unit M2 are greased with a grease with good thermal conduction.

In the example described with the aid of FIGS. 1 and 2, the frustoconical walls have a circular director; other frustoconical walls can be used provided of course that the male part formed by the cooling device and the female part formed by the plug-in unit have the same profile for their facing surfaces after plugging in. Figure 3 is a more detailed view than the previous figures; it corresponds to the plug-in unit of an amplifier module with power transistors for transmitters working in VHF, that is to say in VHF according to the English acronym commonly used. In FIG. 3, as in the following figure, the electronic components arranged on the printed circuits have not been shown to simplify the drawing.

It is a plug-in unit of 1 5 X 1 5 X 35 cm in overall dimensions, working in the range 1 70-230 MHz and capable of supplying 750 W in peak power; it is intended for a transmitter. This plug-in unit comprises, in addition to a metal block D with a recess E and a guide finger H2, as described with the aid of FIGS. 1 and 2, a DC power supply J, two couplers at 3 dB at 90 °, Ka , Kb, two amplifiers Aa, Ab, a management circuit G, various plugs I, S, Gi, J 1, J2, conductors such as Li and a screw, not visible in the figure; this screw corresponds to the screw V2 according to FIG. 2.

The power supply J is fixed on the rear face of the block D, that is to say on the face opposite to the face into which the recess E opens; it receives a DC input voltage from the two plugs J 1, J2 which are banana plugs arranged, like the other plugs, on the front face of block D. The power supply J is entirely contained in a sort of frame whose outer periphery matches the outer periphery of the rear face of the block D and whose inner periphery is large enough so that the head of the screw V2, described with the aid of FIG. 2, is easily accessible.

On the upper face of the block D, that is to say on that which carries the guide finger H2, is fixed the amplifier Aa and on the lower face the amplifier Ab while the couplers Ka, Kb are fixed on a face vertical and that the circuit G for the management of the amplifiers and the power supply is fixed on the other vertical face.

The signal to be amplified by the module according to FIG. 3 arrives, via the plug I and the conductor Li, on one of the ports of the first pair of conjugate ports of the coupler Ka; the second port of this first pair is connected to a suitable load placed on the same support as the coupler Ka and not shown. The two amplifiers Aa and Ab have their signal inputs respectively connected to the two ports of the second pair of conjugate ports of the coupler Ka. The signal outputs of these two amplifiers are respectively connected to the two ports of the first pair of conjugate ports of the coupler Kb. The accesses of the second access pair of the Kb coupler are respectively connected to the plug S and to a suitable load arranged on the same support as the Kb coupler and not shown. The Gi plug is connected to the management circuit G by conductors.

FIG. 4 corresponds to FIG. 3 but in the case of a plug-in unit of an amplifier module with power transistors for a transmitter working in UHF waves, that is to say in UHF according to the English acronym commonly used.

It is a plug-in unit of 1 5 x 1 5 x 35 cm in overall dimensions, working in the range 470 - 860 MHz and capable of supplying 750 W in peak power; it is intended for a transmitter. This plug-in unit comprises, in addition to a metal block D with a recess E and a guide finger H2, as described with the aid of FIGS. 1 and 2, a DC power supply J, a preamplifier P, three management circuits G 1 at G3, six 3 dB couplers at 90 °, K1 to K6, four amplifiers A1 to A4, various plugs I, S, Gi, J 1, J2, conductors such as Li and a screw not visible in FIG. 4; here again this screw corresponds to the screw V2 according to FIG. 2.

FIG. 5 is an electrical diagram which represents the connections between the preamplifier P, the couplers K 1 to K6 and the amplifiers A1 to A4. The preamplifier P receives, via the plug I and the conductor Li, a signal to be amplified; it has its output connected to one of the ports of the first pair of conjugate ports of the coupler K 1.

The output signals of the accesses of the second pair of conjugate accesses of the coupler K 1 are delivered respectively to the couplers K2 and K3 on an access of their first pair of conjugate accesses.

The four amplifiers A 1 to A4 have their inputs respectively connected to the four ports of the two second pairs of conjugate access relating to the couplers K2, K3 and their outputs respectively connected to the four ports of the first two pairs of conjugate access relating to the couplers K4, K5.

One of the ports of the second pair of conjugate ports of the coupler K4 is connected to one of the ports of the first pair of conjugate ports of the coupler K6 while one of the ports of the second pair of conjugate ports of the coupler K5 is connected to the other port of the first pair of conjugate ports of the coupler K6.

One of the ports of the second pair of conjugate ports of the coupler K6 is connected, via a conductor, to the plug S.

In FIG. 5, the couplers K 1 to K6 each have one of their four ports which is not connected, in reality on each of these ports is connected a suitable load; these six charges, also not shown in FIG. 4, are placed respectively in the same places as the couplers K1 to K6.

The choice of connections made with the couplers K1 to K6 is determined, in a conventional manner, to achieve sharing of the input signal followed, after amplification, by phase recombination of the four amplified signals.

The power supply J according to FIG. 4 is arranged in the same way as the power supply J according to FIG. 3.

Significantly halfway between its front and rear faces on the one hand and in the vicinity of its front face on the other hand the block D is surrounded by sorts of frames with rectangular cross section. These frames are shown respectively in Figures 6a, 6b in schematic sectional views. The frame located halfway between the front and rear faces of the block D and shown alone in FIG. 6a, contains the couplers K1 to K3 which each occupy a quarter of the length of the frame, the fourth quarter being empty; in the same way, the frame located in the vicinity of the front face of the block D and shown alone in FIG. 6b, contains the couplers K4 to K6 which each occupy a quarter of the length of the frame, the fourth quarter being empty.

In FIGS. 6a, 6b, the volumes occupied by the directional couplers K 1 to K 6 have only been shown. These couplers are, in the example described, conventionally made up of two quarter-wave lines facing each other over their entire length; a dielectric ensures the maintenance of the lines and the spacing between the lines; the positioning of the lines inside the frame is ensured by dielectric washers.

Between the power supply J and the frame with the couplers K1 to K3 are located the preamplifier P on the upper face of the block D and the management circuits G 1 to G3 on the other three faces. These management circuits manage the power supply J of the preamplifier P and the amplifiers A1 to A4.

The Gi card is connected by conductors to the management circuits G 1, G2, G3. When crossing the frame which contains the couplers K1 to K3, these conductors coming from the Gi plug divide into three to go respectively to the three management circuits.

The invention is not limited to the examples described but relates to any embodiment of an electronic semiconductor module where the liquid cooling is done by means of a fixed cooling device, in a truncated cone, where the circuits to be cooled are mounted on a plug-in support which has a frustoconical recess having the same profile as the truncated cone of the cooling device and where the support, when it is inserted, has the wall of its recess in contact with the cooling device.

In particular in the terminal phase of the approximation between the plug-in unit and the base, the guiding can be carried out with other means than those which consist in making a guiding finger penetrate into the hole of a guiding plate. This is how this guidance can be obtained by a key-groove assembly with the groove dug in the frustoconical wall of the recess and the key projecting from the frusto-conical wall of the cooling device or vice versa. The groove and the key can be arranged in a plane passing through the longitudinal axis corresponding to the axis XX in FIGS. 1 and 2.

In both cases, these are guide means which are specifically designed to facilitate positioning of the plug-in unit. However, specific guidance means are not essential. Indeed, guidance in the terminal phase can be obtained by positioning the plugs of the plug-in unit opposite the corresponding fixed plugs; these fixed plugs, not shown in Figures 1 and 2, are permanently mounted in the electronic equipment which includes the cooling device. These are cards arranged around the cooling device; they allow the plug-in unit to be connected to the electronic equipment in question.

The mobile locking system, instead of being constituted by a “screw-nut” type assembly, as described with the aid of FIG. 2, can be constituted by a “quarter-turn handle” type assembly. In both cases, these are blocking systems specifically designed for blocking the module. However, it is conceivable that the module does not have a specific blocking system, since the blocking resulting from contact between the two frustoconical surfaces and connections between the plugs may be sufficient for certain applications.

Similarly, the frustoconical shapes can be oblique frustoconical shapes and / or have a director different from a circle.

Claims

10 CLAIMS

1. Electronic module comprising semiconductor electronic circuits and a device for cooling by circulation of a liquid, characterized by a plug-in unit (M2) which comprises, in addition to the electronic circuits, a metal block (D) covered externally by the electronic circuits and pierced with a frustoconical recess (E), and by the fact that the cooling device (M 1) constitutes an element intended to be permanently mounted in electronic equipment and has a frustoconical base (C), this frustoconical base containing a pipe (F) for the circulation of the liquid and constituting the male part of a mechanical junction whose housing in the female part is constituted by the recess (E).

2. Module according to claim 1, characterized in that the metal block (D) is a straight parallelepiped with a front face and with the frustoconical recess (E) which opens into the front face and in that the electronic circuits (J , G, Ka, Kb, Aa, Ab; J, G 1 -G3, P, K1 - K6, A1 -A4) are arranged on the faces of the parallelepiped other than the front face.

3. Module according to one of the preceding claims, characterized in that it comprises specific guide means (H 1, H2) to facilitate the junction between the recess and the base.

4. Module according to claim 3, characterized in that the guide means are constituted by a guide finger (H2) and by a plate (H 1) pierced with a hole, the hole being intended to be penetrated by the finger , the finger and the plate being part, one of the plug-in unit (M2) and the other of the cooling device (M 1).

5. Module according to one of the preceding claims, characterized in that it comprises specific blocking means (V1, V2, Cv) for blocking the plug-in unit against the cooling device.

6. Module according to claim 5, characterized in that the specific locking means comprise a captive screw (V2, Cr) and a tapped hole (V1), the captive screw passing through the metal block (D) and 1 1

emerging in the recess (E) and the tapped hole being drilled in the base (C).

7. Transmitter, characterized in that it comprises at least one module according to one of the preceding claims.