Electrical or electronic component, method for producing same, and use of such a component
Patent Information
- Application Number
- EP2023813589
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-19
- Filing Date
- 2023-11-21
- Publication Date
- 2025-10-29
AI Technical Summary
Electrical or electronic components face mechanical instability and corrosion issues due to the limitations of existing materials used for strain relief and protection of contact pads and wires, particularly at high temperatures, where polymer-based materials have low temperature stability and glass-based materials require baking temperatures above the melting point of glass components, risking oxide layer formation.
A sol-gel process is used to create a ceramic-like cover from an organosilane compound and additional ceramic, metal, or glass materials, forming chemical bonds that enhance mechanical and thermal stability, allowing for a low-temperature baking process that avoids oxide layer formation and provides broad temperature compatibility.
The resulting component achieves mechanical and chemical protection for connections, maintaining stability and functionality across a wide temperature range without changes in the cover's chemical structure, even exceeding the baking temperature, thus overcoming the limitations of previous materials.
Smart Images
Figure 1.1
Abstract
Description
[0001] Electrical or electronic component, method for its manufacture and use of such a component
[0002] The invention relates to an electrical or electronic component. Furthermore, the invention relates to a method for producing an electrical or electronic component. Furthermore, the invention encompasses two alternative uses of an electrical or electronic component produced by the method according to the invention.
[0003] Electrical or electronic components are mass-produced, sometimes in very large quantities. They comprise at least one functional element that serves an electrical or electronic function, as well as a substrate on which the functional element is mounted. Examples of such components include sensor elements, heating elements, and also signal processing and / or transmission elements such as microprocessors or radio modules.
[0004] Sensor elements are used in a wide variety of applications and, depending on their design, are used, for example, to detect a temperature, a flow variable, a gas concentration or composition, a humidity value, a pH value and / or a biological variable (e.g. a concentration of substances), but can also be used, for example, as a heating element.
[0005] Such components predominantly have at least one electrical connection in the form of a metallic contact pad. These contact pads are galvanically connected to the functional elements by means of supply lines on, in, and / or through the substrate. To contact the component, one or more contact wires (e.g., with a round cross-section or a flat conductor) and / or contact strands are connected to the contact pads. The connection of the contact wires or strands and the contact pads is achieved in particular by means of a joining process, for example a welding process, a soldering process, or a bonding process. If reference is made below to "contact wires," the associated technical teaching is always analogously applicable to contact strands or flat strips.
[0006] However, these connections between contact pads and contact wires are mechanically relatively unstable. For this reason, the contact pads, including the connected end sections of the contact wires, are covered with a cover, a so-called strain relief. This serves to strengthen the connection by minimizing shear and tensile forces on the connection point. The cover also protects against environmental substances that could, for example, cause corrosion of the connections. The material of the contact pads, contact wires, and cover is selected according to maximum operating temperature and compatibility with the connection material.
[0007] Specifically, the cover is manufactured by applying a covering paste. The paste consists of a glass-based material that is typically amorphous or semi-crystalline. Alternatively, the paste consists of a polymer from the group of thermoplastics, thermosets, elastomers, or thermoplastic elastomers.
[0008] The masking pastes can be roughly divided into three groups:
[0009] First group: For low application temperatures (up to approximately 250 °C), a coating made of a polymer-based paste, particularly containing polyimides, silicones, epoxies, etc., can be used. The paste contains a solvent content between 0% and 30%.
[0010] Polymer-based materials are of limited use due to their low temperature stability and aging process. The strain relief of the contact wires is rather low compared to other materials.
[0011] Second group: In the application temperature range up to approx. 400 °C, low-melting glasses are used as materials.
[0012] Third group: For higher application temperature ranges (from approx. 400 °C), glass-based materials with a higher glass transition point or melting point are used.
[0013] In glass variants, the combined proportion of solids and solvent is 70 to 90%, with 10% to 30% fillers in the paste. Possible solid components include Al2O3, SiO2, ZrO2, TiO2, cordierite, forsterite, or another glass.
[0014] The curing temperatures of such pastes are at least 400 °C. The paste, or the resulting coating, must have a thermal expansion coefficient compatible with the substrate.
[0015] The challenge in producing glass-based materials using glass pastes is that they require a firing temperature that exceeds the melting temperature of the glass components. This requires that the contact wires be resistant to the glass's melting temperature and that no oxide layers form. Oxide layers are undesirable because they complicate final measurements and subsequent joining techniques in the assembly. Conversely, this means that, on the one hand, the maximum operating temperature in the application is always below the firing temperature during production, and, on the other hand, that the firing temperature must be below the oxidation temperature of the contact wires.
[0016] The invention is therefore based on the object of providing an electrical or electronic component which overcomes the above-mentioned challenges.
[0017] The object is achieved by an electrical or electronic component according to patent claim 1, by a method for producing an electrical or electronic component according to patent claim 16, by a first use according to patent claim 20 and by a second use according to patent claim 21.
[0018] With regard to the electrical or electronic component, it is provided that it comprises: a substrate having a first side and a second side opposite the first side;
[0019] At least one functional element applied to the first side or the second side or to another side of the substrate;
[0020] One or more contact pads applied to the first side of the substrate on a partial area of the substrate for electrically contacting the at least one functional element;
[0021] At least one contact wire per contact pad, which is / are connected to the respective contact pad at one end region; and a cover, which covers at least the contact pad(s) and the respective end region of the contact wire(s), wherein the cover is produced by firing a paste, which paste contains a starting material consisting of an organosilane compound produced by means of a sol-gel process, and at least one additional material from the group consisting of ceramics, metals and / or glasses.
[0022] According to the invention, the cover consists of two components: a starting material in the form of an organosilane compound and an additional material. The particles of the starting material form chemical bonds with each other during firing. This creates a ceramic-like structure that is mechanically and thermally stable and provides mechanical and chemical protection for the connections between the contact pads and the contact wires.
[0023] A sol-gel process is a method for producing solid non-metallic, inorganic, or hybrid polymer materials from colloidal dispersions, known as sols. The term "contact wire" has a broad definition. In addition to a conventional wire with a round cross-section, the term also encompasses, for example, one or more flat ribbons or strands.
[0024] In addition, chemical bonds form with the added particles of the additional material, significantly increasing the strength of the coating when cured. Furthermore, the starting material can also form chemical bonds with the substrate material, significantly increasing the bond to the substrate.
[0025] Baking (= curing the paste by exposure to a baking temperature) is performed at a relatively low baking temperature. This can reduce changes or damage, or the formation of oxide layers, on the contact wires or other components of the component.
[0026] An advantageous embodiment of the component provides that the organosilane compound contains methylphenylpolysiloxanes. The starting materials of this compound are linked by the sol-gel process to form methylphenylpolysiloxanes, which, for example, have the following structural formula:
[0027] During the burnout, the oxygen groups enable the formation of the chemical bond between the methylphenylpolysiloxanes, to the particles of the additional material and, if applicable, to the substrate material.
[0028] In one embodiment, the substrate comprises a ceramic material, a metallic material, a semiconductor material, or a composite material. Aluminum oxide, magnesium oxide, aluminum nitride, mullite, or other mixtures of ceramic compounds, such as zirconium oxide, can preferably be used as ceramic materials. Examples of metallic materials that can be considered are stainless steel, copper, or aluminum. Examples of suitable semiconductor materials are silicon or gallium arsenide. According to an advantageous embodiment of the component, the contact pad(s) consists / consists of a metallic material, in particular platinum. The contact pads consist of a layer that is applied to the substrate using a thin-film or thick-film technique.
[0029] According to an advantageous embodiment of the component, the functional element serves as a sensor element for detecting at least one physical, chemical, or biological parameter of a medium. In this case, the sensor element can be used to detect the temperature, humidity, conductivity, and / or flow rate of the medium.
[0030] Alternatively, the functional element may serve as a heating element.
[0031] For both alternatives, it is advantageously provided that the functional element consists of a, in particular meander-shaped, resistor structure, or has such a resistor structure, wherein the resistor structure consists in particular of platinum, nickel, or an alloy containing platinum or nickel, e.g., PtTh or NiCr. The resistor structure is manufactured by applying a metallic layer, which is subsequently patterned. The layer is applied using a thin-film or thick-film process. By measuring the resistance value, a temperature value, for example, can be determined. By applying electrical power, the resistor structure is heated and emits heat.
[0032] Alternatively, the functional element can be used for signal processing and / or signal transmission. For this purpose, the functional element consists of an electrical circuit with one or more electronic elements (resistor, capacitor, coil, transistor, (light-emitting) diodes, etc.). It can also be provided that the functional element is an ASIC or a microprocessor, or contains additional components, such as an antenna (e.g., if the functional element is intended to function as a radio module).
[0033] In one embodiment of the component, it is provided that the contacting wire or wires consist of a metallic material, in particular nickel, copper, gold, stainless steel, aluminum or molybdenum, or of an alloy. In particular, the contacting wire or wires is / are coated with an insulating material. Preferably, the contacting wires are additionally coated with a galvanic metallization, wherein the insulating material surrounds the contacting wires. Typical insulating materials include polymers, ceramic compounds or metal oxides. The connection of the contacting wires and the contact pads is effected in particular by means of a joining process, for example a welding process, a soldering process or a bonding process.
[0034] The component may comprise at least two contact pads, wherein the contact pads are arranged on a common sub-region on the first side or the second side of the substrate, or wherein the contact pads are arranged on two separate end regions of the first side or the second side of the substrate. If the contact pads are not arranged in the same sub-region of one side of the substrate, not one but several covers are required, so that each of the connections between contact pads and contact wires is covered by a cover.
[0035] In one embodiment of the component, the device comprises a passivation layer applied to the first side and / or the second side of the substrate in such a way that it covers at least the functional element. The passivation layer consists of a glass, a glass ceramic, or a polymer. The passivation layer serves to mechanically and chemically protect the substrate and the components applied thereto, such as the functional element, the contact pads, and / or the leads from the contact pads to the functional element.
[0036] With regard to the method for producing such an electrical or electronic component, it is provided that this method comprises:
[0037] Providing a substrate having a first side and a second side opposite the first side, having at least one functional element applied to the first side or the second side or to a further side of the substrate, having a functional layer, and having one or more contact pads applied to a partial area of the first side of the substrate for electrically contacting the at least one functional element, wherein at least one contacting wire is provided per contact pad, which is / are connected to the respective contact pad at an end area;
[0038] Applying a paste, which paste contains a starting material consisting of an organosilane compound produced by a sol-gel process, and at least one additional material from the group consisting of ceramics and / or glasses, wherein, after application, the paste covers at least the contact pad(s) and the respective end region of the contact wire(s); and firing the paste to produce a covering layer at a firing temperature for at least a predetermined firing time.
[0039] The manufacturing process produces a component with a cover made of a ceramic-like structure. This structure is both mechanically and thermally stable and protects the connections between the contact pads and the contact wires mechanically and chemically. During the firing, or curing, of the paste, chemical bonds are formed at least in the starting material of the paste, thereby achieving the described properties.
[0040] An advantageous embodiment of the method provides that the paste is applied by a dispersion process.
[0041] The parameters for curing, or paste curing, are selected so that the curing temperature is above 250 °C. The curing time is at least 2 hours. This evaporates the paste's solvents, thus drying the paste, and also creates the described chemical compounds (i.e., the paste is cured, or baked).
[0042] With regard to the first use of an electrical or electronic component produced by means of a method according to the invention, it is provided that this component is used at an operating temperature which is higher than the baking temperature of the paste.
[0043] With regard to the second use of an electrical or electronic component produced by means of a method according to the invention, it is provided that this component is used at an operating temperature which is lower than the baking temperature of the paste.
[0044] The component according to the invention, thanks to the specially manufactured cover, allows operation over a wide application temperature range. The formation of the "quasiceramic" structure (through the formation of chemical compounds in at least the starting material of the paste) enables application temperatures above and below the firing temperature without any further changes to the chemical structure of the cover.
[0045] The invention is explained in more detail with reference to the following figures.
[0046] Fig. 1: a first embodiment of a component according to the invention; and Fig. 2: a second embodiment of the component according to the invention.
[0047] A first embodiment of the proposed electrical or electronic component 100 according to the invention is depicted in Fig. 1. The upper view shows the component 100 in plan view, whereas the upper view shows a section along a longitudinal axis of the component 100.
[0048] In the present embodiment, the component consists of a planar substrate 110. In other embodiments, the substrate can also be non-planar, for example, in a thicker configuration or curved. The material of the substrate 110 can be chosen arbitrarily, but must be suitable for applying the components described below. For example, the substrate 110 consists of a metallic material, a ceramic material, a composite material, a polymaterial, or a semiconductor material.
[0049] A functional element 120 is applied to a first side of the substrate. In the present case, this is a platinum resistor structure, which was applied to the substrate 110 using a thick-film or thin-film process and which serves to detect a temperature or as a heating element. However, the functional element 120 can also be configured differently and, for example, be designed as a sensor element for detecting a physical quantity other than temperature, or a chemical quantity, or a biological quantity.
[0050] Two contact pads 131, 132 are applied to a partial area, more precisely an edge area, of the first side. These are made of a metallic material and are also applied to the substrate 110 using a thick-film or thin-film process. It may also be provided to apply the contact pads 131, 132 to another side of the substrate 110.
[0051] The contact pads 131, 132 are conductively connected to the functional element 120 via supply lines. The contact pads 131, 132 serve to externally electrically contact the functional element 120.
[0052] Furthermore, a passivation layer can be provided, which is applied to the substrate 110 in such a way that it covers at least parts of the substrate and parts of the functional element 120. The passivation layer consists in particular of a glass or glass composite and serves to mechanically and chemically protect the substrate 110 and components applied thereto, such as the functional element 120, the contact pads 131, 132 and / or the leads from the contact pads 131, 132 to the functional element 120. A contacting wire 141, 142 is provided for each contact pad 131, 132, which is to be connected to the respective contact pad 131, 132. The term "contacting wire" encompasses wires with various cross-sectional geometries. Flat conductors, which have a rectangular cross-section with a very large aspect ratio, also fall under the term "contacting wire" in the context of the component according to the invention.It may also be provided to provide a so-called contacting stranded wire instead of a single wire, which consists of a plurality of thin bundled wire fibers. In an alternative embodiment, it is also possible to connect two or more such contacting wires or stranded wires to a single contact pad 131, 132.
[0053] The contact wires 141, 142 consist of one or more materials from the group consisting of copper, gold, nickel, platinum, or alloys containing one or more of the aforementioned elements, in particular CuNi, CuAg, NiPt, PtRth, or stainless steel. The contact wires 141, 142 are preferably coated with a galvanic metallization. In the present exemplary embodiment, the contact wire 142 is surrounded, at least in sections, by a material with insulating properties. Typical insulating materials include polymers, ceramic compounds, or metal oxides.
[0054] The contact wires 141, 142 are connected to the respective contact pads 131, 132 at their end regions, which are not insulated, by means of a joining process. The joining process is, for example, a welding process, a soldering process, or a bonding process.
[0055] Subsequently, a cover 150 is produced, which covers at least the contact pads 131, 132 and the end regions of the contact wires 141, 142. The cover is produced by applying a paste to an area on the substrate intended for the application of the cover 150. The paste contains a starting material comprising an organosilane compound. The organosilane compound contains methylphenylpolysiloxanes synthesized by a sol-gel process. The sol-gel process creates a so-called "wet gel," which forms the starting material. Before the dispersion process, at least one additional material from the group consisting of ceramics, metals, and / or glasses is added to the paste containing the starting material.
[0056] The paste is then cured, or baked. For this purpose, the component 110 is exposed to a baking temperature of at least 250 °C for at least two hours. This causes liquid components, such as solvents, of the paste to evaporate. On the other hand, the curing process causes chemical bonds to form between the components of the paste—the methylphenylpolysiloxanes contained in the starting material—and the additional material, which ensures the paste's high strength in the cured state.
[0057] In addition, the starting material can also form chemical bonds with the material of the substrate 110, thereby increasing the mechanical adhesion of the cover 150 to the substrate 110. A ceramic-containing material such as corundum, ZiO2, etc., is preferably suitable for this purpose, as this promotes the formation of these bonds.
[0058] The additional material provides or controls further properties of the cover 150. For example, the addition of an additional metallic material increases the thermal conductivity of the cover 150. Ceramics and glasses as additional materials in the paste significantly increase the thermal resistance of the cover (up to approx. 600°C, possibly even higher for glasses).
[0059] The cover 150 manufactured in this way exhibits high mechanical and thermal stability. The component 110 can therefore be operated over a wide application temperature range. The baked or annealed cover 150 allows application temperatures above and below the baking temperature without any further changes to the chemical structure of the cover 150.
[0060] A second embodiment of the proposed electrical or electronic component 200 according to the invention is depicted in Fig. 1. The upper view shows the component 200 in plan view, whereas the upper view shows a section along a longitudinal axis of the component 200.
[0061] The basic structure of component 200 corresponds to component 100 described in Fig. 1. The difference from component 100 shown in Fig. 1 is that functional element 220 is arranged in the center of substrate 210. A contact pad 231, 232 is located at each of two end regions of substrate 210. Each of contact pads 231, 232 is connected to a respective contact wire 241, 242. Contact wires 241, 242 are each insulated.
[0062] Due to the special arrangement of the contact pads 231, 232, two covers 250, 250' are required. The production of the covers 250, 250' corresponds to the production of the cover 150 described in Fig. 1. However, two partial areas of the substrate 210 are coated with the paste before firing or curing.
[0063] 100, 200 components
[0064] 110, 210 substrate 120,220 functional element
[0065] 131, 132, 231, 232 contact pads
[0066] 141, 142, 241, 242 contact wire
[0067] 150, 250, 250' coverage
Claims
Patent claims 1 . Electrical or electronic component (100,200) comprising: A substrate (110, 210) having a first side and a second side opposite the first side; At least one functional element (120, 220) applied to the first side or the second side or to another side of the substrate (110, 210); One or more contact pads (131, 132, 231, 232) applied to the first side of the substrate (110, 210) on a partial area of the substrate (110, 210) for electrically contacting the at least one functional element (120, 220); At least one contacting wire (141, 142, 241, 242) per contact pad (131, 132, 231, 232), which is connected at one end region to the respective contact pad (131, 132, 231, 232); and at least one cover (150, 250, 250') which covers at least the contact pad (131, 132, 231, 232), or the contact pads, and the respective end region of the contacting wire (141, 142, 241, 242), or the contacting wires, wherein the cover (150, 250, 250') is produced by firing a paste, which paste contains a starting material consisting of an organosilane compound produced by means of a sol-gel process, and at least one additional material from the group of ceramics, metals and / or glasses.
2. Component according to claim 1, wherein the organosilane compound contains methylphenylpolysiloxanes.
3. Component according to one of the preceding claims, wherein the substrate (110, 210) comprises a ceramic material, a metallic material, a semiconductor material or a composite material.
4. Component according to one of the preceding claims, wherein the contact pad (131, 132, 231, 232) or the contact pads consist of a metallic material, in particular platinum.
5. Component according to one of the preceding claims, wherein the functional element (120, 220) serves as a sensor element for detecting at least one physical measurement variable of a medium.
6. Component according to claim 5, wherein the sensor element serves to detect the temperature, humidity, conductivity and / or flow of the medium.
7. Component according to one of claims 1 to 4, wherein the functional element (120, 220) serves as a heating element.
8. Component according to one of claims 5 to 7, wherein the functional element (120, 220) consists of a, in particular meander-shaped, resistance structure, or has such a resistance structure, wherein the resistance structure consists in particular of platinum, nickel, or of an alloy containing platinum or nickel, for example PtTh or NiCr.
9. Component according to one of claims 1 to 4, wherein the functional element (120, 220) serves for signal processing and / or signal transmission.
10. Component according to one of the preceding claims, wherein the contacting wire (141, 142, 241, 242) or the contacting wires has / have a round cross-section, or wherein the contacting wire (141, 142, 241, 242) or the contacting wires is / are a flat strip.
11. Component according to one of the preceding claims, wherein the contacting wire (141, 142, 241, 242) or the contacting wires consist of a metallic material, in particular nickel, copper, gold, stainless steel, aluminum or molybdenum, or of an alloy.
12. Component according to one of the preceding claims, wherein the contacting wire (141, 142, 241, 242) or the contacting wires is / are coated with an insulating material.
13. Component according to one of the preceding claims, wherein the connection of each of the contacting wires (141, 142, 241, 242) to the corresponding contact pad (131, 132, 231, 232) is produced by means of a joining process, in particular a welding process, a soldering process or a bonding process.
14. Component according to one of the preceding claims, wherein the component (100,200) has at least two contact pads (131, 132, 231, 232), wherein the contact pads (131, 132, 231, 232) are arranged on a common partial area on the first side or the second side of the substrate (110, 210), or wherein the contact pads (131, 132, 231, 232) are arranged on two separate end regions of the first side or the second side of the substrate (110, 210).
15. Component according to one of the preceding claims, comprising a passivation layer which is applied to the first side and / or the second side of the substrate (110, 210) in such a way that it covers at least the functional element (120, 220), wherein the passivation layer consists of a glass, a glass ceramic or a polymer.
16. A method for producing an electrical or electronic component (100,200), comprising: Providing a substrate (110, 210) with a first side and a second side opposite the first side, with at least one functional element (120, 220) applied to the first side or the second side or to a further side of the substrate (110, 210), with a functional layer, and with one or more contact pads (131, 132, 231, 232) applied to a partial area of the first side of the substrate (110, 210) for electrically contacting the at least one functional element (120, 220), wherein at least one contacting wire (141, 142, 241, 242) is provided per contact pad (131, 132, 231, 232), which at one end area is connected to the respective contact pad (131, 132, 231, 232) is / are connected; Applying a paste, which paste contains a starting material consisting of an organosilane compound produced by means of a sol-gel process, and at least one additional material from the group consisting of ceramics and / or glasses, wherein, after application, the paste covers at least the contact pad (131, 132, 231, 232) or the contact pads, and the respective end region of the contacting wire (141, 142, 241, 242) or the contacting wires; and firing the paste to produce a cover (150, 250, 250') at a firing temperature for at least a predetermined firing time.
17. The method according to claim 16, wherein the paste is applied by a dispersion process.
18. The method according to claim 16 or 17, wherein the baking temperature is above 250 °C.
19. A method according to any one of claims 16 to 18, wherein the baking time is at least 2 hours.
20. Use of an electrical or electronic component (100,200) produced by a method according to one of claims 16 to 19 at an operating temperature which is higher than the baking temperature of the paste.
21. Use of an electrical or electronic component (100,200) produced by a method according to one of claims 16 to 19 at an operating temperature which is lower than the baking temperature of the paste.