Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
  • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
  • H01L23/3735—Laminates or multilayers, e.g. direct bond copper ceramic substrates
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
  • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
  • H01L23/3736—Metallic materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/46—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids
  • H01L23/473—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids by flowing liquids
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/0001—Technical content checked by a classifier
  • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Definitions

• the invention relates to a process for the preparation of hollow bodies according to
• the preamble of claim 1 to a hollow body, in particular radiator according to the preamble of claim 1 9 and to an assembly according to the preamble of claim 20.
• DCB method direct copper bond technology
• metal layers or sheets eg copper sheets or sheets
• ceramic or ceramic layers using metal sheets.
• copper sheets or metal or copper foils which have on their surface sides a layer or a coating (reflow layer) of a chemical compound of the metal and a reactive gas, preferably oxygen
• this layer or coating forms a eutectic with a melting temperature below the melting temperature of the metal (eg copper), so that by placing the film on the ceramic and by heating all the layers they can be connected to each other, namely by melting the metal or copper in W1 genentlich only in the region of the melting or oxide layer.
• the metal eg copper
• This DCB method then indicates e.g. the following process steps:
• active soldering method (DE 22131 1 5, EP-A-153 618), e.g. for joining metallization-forming metal layers or metal foils, in particular also copper layers or copper foils or aluminum layers or aluminum foils with ceramic material.
• this method which is also used especially for the production of metal-ceramic substrates, at a temperature between about 800 - 1000 ° C, a connection between a metal foil, such as copper foil, and a ceramic substrate, such as aluminum nitride ceramic, using a brazing filler metal, which also contains an active metal in addition to a main component such as copper, silver and / or gold.
• This active metal which is, for example, at least one element of the group Hf, Ti, Zr, Nb, Ce, establishes a chemical bond between the solder and the ceramic, while the bond between the solder and the metal is a metallic braze joint ,
• hollow bodies in the form of active heat sinks or coolers consisting of a plurality of stacked metal layers or metal foils (stacking) which are formed by bonding or bonding, e.g. by soldering, diffusion bonding or by means of the DMB method are interconnected.
• bonding e.g. by soldering, diffusion bonding or by means of the DMB method.
• the disadvantage here is, inter alia, that the entire stack of the metal l Hornen for bonding or bonding heated to high temperature and the diffusion welding must also be additionally subjected to high pressure, whereby the structure of the metal layers at least partially changed and in particular the hardness the metal layers decreases.
• bonding material such as e.g. the solder or the eutectic melt in solder joints in
• Openings and / or recesses flow, which are introduced into the metal layers in the interior of the stack for the formation of cavities or cooling channels, and these openings or depressions or the cavities or cooling channels formed by these flows clogged.
• Galvanic or other methods to be produced on the metal layers or metal foils corrosion protection layers can not be applied before stacking, since these layers are changed during bonding or bonding by alloying and lose their protective effect in the rule. Applying the anticorrosion coatings after the Joining is not possible or insufficiently possible. Incompletely applied
• Corrosion protection coatings often even increase the corrosion by forming local electrical elements between different metals.
• Another disadvantage of previous methods consists in long process times, which are necessary for the joining and caused by the heating and cooling process.
• the object of the invention is to provide a method which avoids the aforementioned disadvantages and simplifies the production of hollow bodies from at least two arranged in a stack and interconnected metal layers or metal foils.
• a method according to claim 1 is formed.
• a hollow body, in particular a cooler, is the subject matter of patent claim 19.
• An assembly with such a cooler is the subject matter of patent claim 20.
• Bonding layers are produced by sintering or are sintered layers and there are no melting processes during the bonding process, significantly finer structures can be achieved. As a result, u.a. an enlargement of the inner surface of the respective
• Anticorrosive coatings can be applied prior to bonding and will not change properties due to the relatively low sintering temperature.
• the sintered material sinters only at those areas where the sintering pressure is effective and the sintering flow flows. Residual or excess and unsintered sintered material can be washed out after sintering.
• the sintering material used is preferably a metal powder made of copper or a copper alloy or a material containing this metal powder.
• the sintering temperature is then significantly below the melting point of the copper or copper alloy of both the metal layer and the sintered material.
• metal layers of aluminum or an aluminum alloy and a sintered material in the form of a metal powder of aluminum or an aluminum alloy or a sintered material containing this metal powder is well below the melting point of the aluminum or aluminum alloy of both the metal layer and the sintered material.
• metal layers and sintered material made of aluminum or an aluminum alloy results in a significant simplification compared to conventional joining or bonding method, since the connection of the metal layers takes place without vacuum and without special flux.
• active coolers are, in particular, hollow bodies whose cavities form cooling channels which contain or are traversed by a heat-transporting medium or cooling medium.
• Fig. 1 in a simplified representation and in section a hollow body in the form of an active cooler or an active heat sink;
• FIG. 2 is a schematic representation of various method steps of the method for producing the hollow body of FIG. 1;
• FIG. 3 shows in a simplified representation and in section a hollow body in the form of an active cooler according to another embodiment of the invention.
• FIG. 4 shows a schematic illustration of different method steps of the method for producing the hollow body of FIG. 3;
• FIG. 5 shows in a simplified representation and in section a hollow body in the form of an active cooler according to another embodiment of the invention.
• FIG. 6 is a schematic representation of various method steps of the method for producing the hollow body of FIG. 5;
• FIG. 5 shows in a simplified representation and in section a hollow body in the form of an active cooler according to another embodiment of the invention.
• FIG. 8 is a schematic representation of various method steps of the method for producing the hollow body of FIG. 7;
• FIG. 9 is a schematic representation of various partial steps of the method for producing the hollow body of FIGS. 1, 3, 5 and 7 in a further embodiment of the invention; Fig. 10 and 1 1 each time the course of the sintering current Is in the manufacture of
• 1 is a hollow body in the form of a cooler.
• the hollow body consists of a plurality of stack-like stacked metal layers 2-5, which are each formed by metal foils and are bonded to one another via bonding layers in the form of sintered layers 6-8 by sintering.
• the sinter layers 6 - 8 are part of
• Stack arrangement ie in each case a sintered layer 6 - 8 is between two metal layers 2-5 arranged.
• the two metal layers 2 and 5 form the outer layers and the upper and
• the arranged between the metal layers 2 and 5 metal layers 3 and 4 form cavities 9 of the hollow body 1, d. H. when using the hollow body 1 as an active cooler the flowed through by a vapor and / or gaseous or preferably by a liquid heat transport medium or cooling medium cooling structure of the radiator.
• the cavities or cooling er réelle is closed at the top and bottom of the hollow body 1 by the local metal layers 2 and 5.
• connections which are indicated in the figure 1 schematically with 1 .1.
• the metal layers 3 and 4 are provided to form the cavities 9 and the radiator structure with a plurality of openings 10, of which in the illustrated embodiment, each opening 10 is continuous, d. H. from the one
• the formation and / or arrangement of the openings 10 is basically arbitrary, provided that the required radiator structure results, preferably a cooler structure with ever-branching cooling channels and / or with continuous posts 1 .2, which connect the metal layers 2 and 5 and made of the material Metal layers 2 and 4 and the sintered layers 6 - 8 exist.
• the openings 10 in the metal layers 3 and 4 are produced for example by punching, cutting (also laser cutting) or by etching in an etching masking process.
• FIG. 2 shows in the positions a - i the essential steps of the method for
• the upper metal layer 2 is provided.
• the metal layers 3 and 4 provided with the openings 10 are provided and then subsequently provided on a surface side with a layer 6.1 or 7.1 of sintered material according to the positions d and f, the sintered layer 6 after sintering later or 7 forms.
• the application of the layers 6.1 and 7.1 preferably takes place in such a way that the respective layer does not cover the openings 10.
• the metal layer 5 is provided and then provided according to the position h on a surface side with a layer 8.1 of the sintered material, which forms the sintered layer 8 after sintering.
• the individual metal layers 2-5 provided with the sintered material are stacked one above the other in accordance with the position i such that the metal layers 2-5 following one another in this stack abut each other over a layer 6.1, 7.1 or 8.1 from the sintered material. Subsequently, the stack thus formed between two electrodes 1 1 and 12 is arranged, of which the electrode 1 1 against the metal layers 3 and 4 facing away from the surface side
• Metal layer 2 and the electrode 12 against the metal layers 3 and 4 facing away from the surface side of the metal layer 5 is applied, in such a way that the respective electrode 1 1 or 12 with its electrode surface, the respective metallization 2 or 5 completely covered, but preferably protrudes beyond the edge of the stack formed by the metal layers 2-5.
• the electrode 1 1 is for example part of a press ram of a press, for example a hydraulic press for generating a high pressure or sintering pressure Ps.
• the electrode 12 is then part of a workpiece support of this press.
• the sintering or the formation of the metal layers 2-5 connecting and dense sintered layers 6 - 8 is carried out under sintering pressure Ps, on the electrodes 1 1 and 12 and thus on the metal layers 2-5 and the intermediate layer 6.1, 7.1 and 8.1 perpendicular to their surface sides is applied, and by a sintering current Is, which is provided by a current source 1 3, wherein the voltage between the electrodes 1 1 and 12 is low, for example in the range between 2V and 25V.
• the metal layers 2 - 5 as well as the sintering material used for the layers 6.1, 7.1 and 8.1 are electrically conductive, the formation of the sintered layers 6 - 8 by current or Sparksintern possible, the sintering current Is is of course adjusted so that the required sintering temperature is reached will, but will not melt.
• the sintered layer 8 is shown in FIGS. 1 and 2 as a continuous layer. Since, however, the sintering takes place only at those areas where the sintering pressure Ps is sufficiently effective and also the sintering flow Is flows, ie at the bottom of the
• Metal layer 4 outside the openings 10, and further residual or excess and not sintered sintered material can be washed out after sintering, is the
• Sintered layer 8 in the finished hollow body 1 also structured, i. not present at the openings 10 of the metal layer 4 or only with reduced thickness.
• FIG. 3 again shows, in section, a hollow body 1 a, which differs from the hollow body 1 essentially only in that the sintered layer 8 connecting the lower metal layer 5 to the overlying metal layer 4 is structured by already structured application of the layer 8 the cavities 9 at the of the
• Sintered layer 8 but are limited by the metal layer 5.
• FIG. 4 again shows in the positions a-i the essential steps of the method for producing the hollow body 1 a, whereby this method differs from the method of FIG. 2 only in that according to the position h the later
• Sintered layer 8 forming sintered material is already applied structured in the layer 8.1, in such a way that this material is located only where the metal layer 4 outside its openings 10 abuts against the layer 8.1. According to position i, the formation of the medium, in particular for the heat flowing through the cavities 9, is carried out by means of dense sintering layers 6 - 8 by application of the sintering pressure Ps and of the
• FIG. 5 shows, in a simplified sectional illustration as a further embodiment, a hollow body 1 b, which consists of an upper metal layer 14 and a lower metal layer 15. Both metal layers 14 and 15 are again metal foils.
• the lower metallization 1 5 is provided with indentations or depressions 17.
• the two metal layers 14 and 15 are in turn connected to one another by a dense sinter layer 18 dense at least for the heat-transporting medium or cooling medium.
• FIG. 6 shows, in the positions a-f, essential method steps in the production of the hollow body 1b.
• the metal layer 14 is provided and corresponding to the positions c and d, the metal layer 1 5 with the recesses 17 is formed from a metal layer corresponding to the metal layer 14, for example by pattern etching by means of a masking-etching method.
• a structured layer 18.1 of sintered material forming the later sinter layer 18 is then applied to the metal layer 1 5 in accordance with the position e, in such a way that the recesses 1 7 of the sintering layer 1
• a stack is then formed between the two metal layers 14 and 15 with the layer 18. 1 between the electrodes 1 1 and 12 and subjected to the sintering pressure P and through the stack by pressurizing the stack
• Sintering current I generates the two metal layers 14 and 1 5 connecting dense sinter layer 18.
• Figure 7 shows in section a hollow body 1 c, which differs from the hollow body of Figure 5 in that the metal layer 14 is provided with the recesses 1 7, in such a way that the recesses 1 7 in both metal layers 14 and 15th to the closed to the outside cavities 1 6 or to the closed to the outside radiator structure.
• the two metal layers 14 and 15 are in turn connected to one another via the structured, dense sintered layer 18.
• FIG. 8 shows, in the positions a-g, essential method steps of the method for producing the hollow body 1c, this method differing from the method of FIG. 6 only in that, corresponding to the positions a and g, the metal layer 14 with the recesses 17 is provided.
• the sintered layers 6 - 8 and 18 each extend over the entire surface of the adjacent metal layers 2 - 5, 14 and 1 5, although in the illustrated
• the respective metal layer before applying the layer 6.1, 7.1, 8.1 or 18.1 from the sintered material to be provided with a metallic intermediate layer 1 9, as in the figure 9 is exemplified for the metal layer 5 in the positions a and b.
• the structured or continuous layer 8.1 made of sintered material (positions c and d) is then applied to this metallic intermediate layer 19.
• the intermediate layer 1 9 may also be a corrosion protection layer or part of such a layer, which then extends for example over the entire exposed surface of the metal layer.
• Suitable materials for the metal layers 2 - 5, 14 and 1 5 include copper, aluminum, iron, nickel, titanium, molybdenum, tungsten, tantalum, silver, gold and alloys of the aforementioned metals, such as copper alloys, iron alloys,
• Silver alloys aluminum alloys, titanium alloys, but also multi-layer materials with layers of different metals, e.g. from the aforesaid metals or metal alloys.
• Suitable sintered material for the layers 6.1, 7.1, 8.1 and 18.1 is a sinterable particulate or powdered metallic material or a metal powder, for example of copper, silver, gold, aluminum, nickel, iron, titanium or alloys of the aforementioned metals, for example of copper alloys, iron alloys, silver alloys,
• the particle size of the sinterable particulate or powdery metallic material is, for example, in the range between 0.1 ⁇ and 50 ⁇ .
• the sintered material is present for example in monomodal, bimodal or trimodal form.
• the layers 6.1, 7.1, 8.1 and 18.1 each consist of the same material in the respective method and are applied, for example, with a layer thickness in the range between 5 ⁇ and 300 ⁇ .
• the application of the layers 6.1, 7.1, 8.1 and 18.1 takes place, for example, in a printing process, e.g. Screen printing process, by dispensing,
• Spraying / spraying, electrostatic or using applicator rollers are possible.
• Interlayer-bearing metal layers 2 - 5, 14 or 15 differs are suitable for example, copper, nickel, chromium, silver, gold, palladium, platinum or alloys of the aforementioned metals.
• the intermediate layer 19 can be applied in different ways, for example galvanically, by chemical deposition or by a CVD method, by sputtering, by plasma spraying, by cold gas spraying, etc.
• the thickness of the intermediate layer 1 9 is for example in the range between 0.05 ⁇ and 100 ⁇ .
• the sintering pressure Ps used during sintering is, for example, in the range between 0.5 kN / cm 2 to 6.0 kN / cm 2 .
• the sintering current Is is preferably chosen such that the current density in the region of the sintering layers 6 - 8, 18 to be produced, ie where the sintering process takes place, is in the range between 10 A / cm 2 and 300 A / cm 2 .
• Current maxima or current peaks is furthermore, as shown in FIG. 10, the use of a pulse-shaped sintering current Is, wherein the pulse width t1 of the respective current pulse lies in the range between 1 msec and 500 msec and the pulse interval t2 is in the range between 0 msec and 400 msec. It may also be appropriate according to the Figure 1 1, to superimpose the current pulses in addition with an alternating current or with smaller current pulses.
• the sintering pressure Ps is also impulsively applied, specifically in accordance with FIG. 12 in the form that a constant sintering pressure Psmin is superimposed on a pulse-shaped increase in the sintering pressure, so that the sintering pressure Ps changes in a pulse shape between a pressure Psmax and a value Psmin.
• the pressure Psmin is then for example between 0.05 Psmax and 0.98 Psmax, wherein Psmax is selected in the range between 0.5 kN / cm 2 and 6 kN / cm 2 .
• the period duration tp of the pulse-shaped pressurization is, for example, in the range between 0.5 msec and 3000 msec.
• the sintering pressure Ps increases during the sintering process from a sintering pressure Psmin and reaches the value Psmax before the end of the sintering process or the sintering phase, as shown in broken lines in FIG.
• a rising sintering pressure Ps is superimposed on a pulse-shaped changing sintering pressure.
• the increasing sintering pressure has the advantage, for example, that at the beginning of the sintering phase pre-sintering and thus at least some stabilization of the sintered material or of the sintered layers formed by this material takes place, while in the course of the sintering phase, in addition to the sintering, an increasing compression of the sintering layer Sintering material takes place so as to seal the at least for the heat-transporting medium
• these preferably also contain organic additives, such as, for example, cellulose.
• organic additives such as, for example, cellulose.
• drying and heating of the organic additives can be carried out by electric current even when arranged between the electrodes 1 1 and 12 stacking arrangement, with appropriate adjustment of the current density and the pressure P.
• the respective hollow body 1, 1 a - 1 c preferably forms an active cooler for electrical or electronic components 20, for example, for opto-electrical components, for example for diode laser bars.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Ceramic Engineering (AREA)
• Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

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• 2012
  • 2012-08-17 DE DE102012107570.0A patent/DE102012107570B4/de active Active
• 2013
  • 2013-08-12 WO PCT/DE2013/100290 patent/WO2014026675A2/de active Application Filing
  • 2013-08-13 TW TW102128974A patent/TW201424900A/zh unknown

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