Component arrangement with at least two components and method for producing a component arrangement

Abstract

A component arrangement comprising a first component which has a first joining surface and a second component which has a second joining surface. The first joining surface is connected to the second joining surface using an integrated reactive material system. The integrated reactive material system comprises at least one coating of at least one of the joining surfaces, and the integrated reactive material system comprises an activation region on one surface. The integrated activation region is arranged outside of the joined together regions of the first or second joining surfaces and adjoins the regions which are joined together.

Claims

1. A component arrangement, comprising: a first component, which has a first joining surface; a second component, which has a second joining surface; and an integrated reactive material system, wherein: said first joining surface is connected to said second joining surface at connected regions of the first and second joining surfaces using said integrated reactive material system; said integrated reactive material system comprises at least one coating of at least one of said first and second joining surfaces; said integrated reactive material system further comprises a surface having an activation region thereon; and said activation region is arranged outside of said first or said second joining surface regions which are joined together, and adjoins the connected regions, wherein the surface having the activation region thereon is tilted with respect to a plane, which is defined by the connected regions of the first and second joining surfaces, by an angle , which is not less than 45.

2. The component arrangement according to claim 1, wherein: said integrated reactive material system comprises at least one alternating layer sequence selected from the following material combinations: Al, in combination with one of the following materials CuOx, Fe2O3, Ni, Pd, Pt, and Zr; and/or Ti, in combination with B, or Si; and/or Zr, Ni, or Pd, in combination with Si; and/or Pd or Pt, in combination with Sn or Zn.

3. The component arrangement according to claim 1, wherein: a first of the first and second joining surfaces for joining the components is coated with said integrated reactive material system; and a second of the first and second joining surfaces comprises a wetting layer, which, especially, contains gold.

4. The component arrangement according to claim 1, wherein: at least one of the first and second components contains glass or a semiconductor as a material.

5. The component arrangement according to claim 1, wherein said angle is not less than 60.

6. The component arrangement according to claim 1, wherein said angle is not less than 80.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained on the basis of the exemplary embodiments shown in the drawings. Illustrated are:

(2) FIG. 1: is a schematic representation of a component arrangement according to the invention at different points in time during the joining of the components of the component arrangement;

(3) FIG. 2: is a schematic longitudinal view through a first exemplary embodiment of a pressure sensor according to the invention;

(4) FIG. 3: is a schematic longitudinal view through a first exemplary embodiment of a pressure sensor according to the invention; and

(5) FIG. 4: shows the method steps during the preparation of components of the component arrangement according to the invention in the wafer composite.

DETAILED DISCUSSION IN CONJUNCTION WITH THE DRAWINGS

(6) The component arrangement illustrated in FIG. 1 comprises a first component 10 and a second component 20, which are joined together using an integrated reactive material system 30. For this purpose, a typical process flow for producing a joining connection by means of the exothermically reacting integrated material system is illustrated. The second component 20 is positioned in a first step(I) with a second joining surface 21 on a first joining surface 11 of the first component 10, wherein the first joining surface 11 of the first component 10 and an adjoining surface region 12 of the first component 10 are coated with an integrated reactive material system 30. The coating of the adjoining surface region forms an activation region, which is not covered by the second component 20. The reactive material system 30 comprises a layer sequence of alternating layers 31, 32 of two reactants, wherein the first reactant is, for example, Al, and wherein the second reactant is selected from the following materials: CuO.sub.x, Fe.sub.2O.sub.3, Ni, Pd, Pt, or Zr. The respective layer thickness is approximately 20 nm and the total thickness of the layer sequence is approximately 1 m. Preferably, the second component comprises a wetting layer made of gold, not shown separately here.

(7) The first component 10 and the second component 20 can be both macroscopic and microscopic components, which contain glass, ceramics, metals, semiconductors, and/or plastics as materials.

(8) In a second step (II), a force is applied to the components 10 and 20 in order to achieve a defined surface pressure between the joining surfaces 11, 21 of the components 10, 20, and an exothermic reaction is initiated outside the joining surfaces in the activation region of the integrated reactive material system. This initiation may take place electrically, thermally, electromagnetically, magnetically, mechanically, and/or via laser pulses. A great advantage of the invention is that, as a result of the provision of the activation region outside the space between the joining surfaces of the first and second component, the joining region between the joining surfaces must not be directly accessible for the initiation, and complex joining geometries, or joining geometries that are difficult to reach, can thus be produced. By initiating or activating an exothermic reaction between the layers 31, 32 of the integrated reactive material system 30, the layers are fused, such that interdiffusion between the layers occurs so that a mixed phase 33 is formed, by means of which the joining surfaces are joined. As shown in the images (III) and (IV)of FIG. 1, the exothermic reaction front runs through the entire integrated reactive material system, until it is completely converted by the reaction into the new mixed phase 33. In the process, the complete conversion is finished within a few milliseconds. Due to the low heat input, the joined components can be processed further immediately after the joining process.

(9) The produced joining connection between the first and second components 10, 20 is preferably hermetically sealed, i.e., it has leakage rates of less than 110.sup.8 Pa m.sup.3/L or 110.sup.8 mbar L/s. Furthermore, the joints are mechanically sturdy,with shear with shear strengths between 30 MPa and 400 MPa. They may be bio-compatible and/or resistant to aggressive media, e.g., oils or acids.

(10) The pressure sensor 100 shown in FIG. 2 comprises a semiconductor pressure transducer 110 made of silicon, which comprises a measuring diaphragm 112 retained by a counter body 114. The measuring diaphragm 112 is formed by anisotropic etching of a measuring chamber 118 in a silicon wafer, wherein the edge region remaining around the measuring chamber 118 forms the counter body 114. The semiconductor pressure transducer 110 further comprises resistor elements, which are doped in the measuring diaphragm 112. The pressure sensor 100 moreover comprises a supporting body 120, which contains borosilicate glass, wherein the supporting body 120 is joined to a bottom side 116 of the counter body 114 by means of anodic bonding. Through the supporting body 120 extends a reference pressure channel 122, through which the measuring chamber 118 can be loaded with a reference pressure. On a bottom side of the supporting body 120 facing away from the pressure transducer 110, an integrated reactive material system 124 is prepared, which continues on a side of the supporting body 120, which extends orthogonally to the bottom side, in an activation region 126. The bottom side of the supporting body rests on a metallic base 130, wherein a channel 132 that communicates with the reference pressure channel 122 extends through the base 130, wherein the reactive material system 124 seals a reference pressure path, which is formed by the reference pressure channel 122 and the channel 132, with respect to the surroundings between the supporting body 120 and the base 130. The base 130 contains a metallic materialespecially, Kovar. By activating the reactive material system in the activation region 126, an exothermic reaction is initiated, which completely converts the reactive material system 124 between the supporting body 120 and the base 130, whereby the two components are joined in a tight manner. Since the joining takes place without significant heating of the volumes of the base 130 and the supporting body 120, hardly any thermomechanical stresses were put on the components by the joining of the components to each other.

(11) The exemplary embodiment of a pressure sensor shown in FIG. 3 comprises a differential pressure sensor 200 with a differential pressure transducer, which comprises a measuring diaphragm 210 made of silicon between a first counter body 220-1 and a second counter body 220-2. The two counter bodies respectively comprise a measuring chamber 218-1, 218-2, which is respectively delimited by a diaphragm bed, against which the measuring diaphragm 210 can rest in case of an overload. In addition, the counter bodies respectively comprise a pressure channel 222-1, 222-2, through which the measuring diaphragm 210 can be loaded with pressures acting against each other, so that the measuring diaphragm is moved as a function of the difference between the two pressures. In order to detect a pressure-dependent movement of the measuring diaphragm 210, the differential pressure transducer comprises at least one capacitive transducer, which comprises at least one electrode on a counter body and one electrode on the diaphragm side. The counter bodies 220-1, 220-2 contain silicon and are joined to the measuring diaphragm 210, which also contains silicon, by means of anodic bonding, wherein a silicon oxide layer is provided between the measuring diaphragm 210 and each of the counter bodies. The counter bodies 220-1, 220-2 are respectively supported on the rear side by a connecting body 230-1, 230-2, wherein through each connecting body extends a pressure line 232-1, 232-2, which communicates with the pressure channel 222-1, 222-2 of the adjoining counter body. The connecting bodies contain, especially, a ceramic material, the thermal expansion coefficient of which deviates by no more than 5 ppm/K from the thermal expansion coefficient of the material of the counter bodies. The joining surface of the counter bodies 220-1, 220-2 facing the supporting bodies is respectively coated with a reactive material system 224-1, 224-2, which respectively continues in an activation region 226-1, 226-2, which is arranged outside a joining surface between the counter bodies and the connecting bodies. The joining surfaces of the connecting bodies facing the counter bodies additionally comprise a wetting layer made of gold, not shown separately here. By activating an exothermic reaction in the activation regions 226-1, 226-2, the integrated reactive material systems 224-1, 224-2 between the counter bodies and the connecting bodies are completely converted in an exothermic reaction, whereby the counter bodies are respectively joined to the adjoining connecting body in a pressure-tight and pressure-retaining manner, wherein the converted reactive material systems at the same time seal the pressure paths that are formed by the pressure lines 232-1, 232-2 with the respectively adjoining pressure channels 222-1, 222-2. The pressure-resistant joint between the counter bodies and the connecting bodies stabilizes the differential pressure measuring cell against static overloads. In addition, compared to traditional soldering methods, the joining by means of an integrated reactive material system reduces the introduction of thermomechanical stresses in the joining partners. This significantly improves the measurement precision and the repeatability of the differential pressure sensor, since stress-related hysteresis effects are largely eliminated.

(12) FIG. 4 shows a sequence of method steps for depositing the integrated reactive material systems, including the subsequent isolation into separate components.

(13) In a first step (I), the substrate 301 is provided and, if needed, a cleaning step is performed.

(14) In a second step (II), the substrate 301 is structured, wherein component flanks 303 are formed, for example, by recesses 302 in one surface of the substrate 301. In the process, the structuring can be carried out, for example, by a sawing, etching, wet etching, dry etching, erosion or ablation process. Typically, such a component flank is structured, which is coated in the subsequent steps with the exothermically reacting integrated reactive materials.

(15) In a third step (III), the structured substrates 301 are coated with the integrated reactive material system 304. For this purpose, the coating processes can be carried out by means of physical vapor deposition, electrochemical deposition, as well as deposition using printing techniques. The integrated reactive material system 301 comprises, on the one hand, a joining surface coating 305 on the upper side of the substrate and an activation region coating 306 on the previously structured flanks 303, wherein the joining surface coating 305 transitions into the activation region coating 306 so that a reaction of the joining surface coating can be activated by a reaction of the activation region coating.

(16) In a fourth step (IV), the substrates 301 are separated into individual components (308). For this purpose, the separation may be carried out, for example, by a sawing, etching, wet etching, dry etching, erosion, or ablation process, especially, also from the bottom side of the substrate.