High-temperature-resistant power type conformal resistor and additive assembling method thereof

Abstract

The invention discloses a high-temperature-resistant power type conformal resistor and an additive assembling method thereof, and belongs to the field of electronic component processing and manufacturing, and the method comprises the following steps: S1, calculating the sheet resistance value or resistivity of a required resistor material according to a required resistance value of a resistor device and a set assembling space size, and selecting a high-temperature-resistant resistor material; s2, carrying out surface treatment on a region on which a resistor is to be assembled on the circuit bearing substrate; s3, assembling a resistor on the circuit bearing substrate through an additive manufacturing process; s4, performing thermocuring on the resistor along with the bearing substrate to form a stable resistor body; and S5, the resistance value of the resistor is tested, and the resistance value of the resistor with large resistance value deviation is adjusted. According to the invention, the conformal resistor can be directly assembled on the special-shaped non-expandable curved surface bearing substrate in an additive manner, the method has the excellent performances of easy processing, flexible design, adjustable resistance value and bendable cladding, and the power resistance of the resistor is improved.

Description

Technical Field

[0001] The present invention relates to the field of electronic component processing and manufacturing, and more specifically, to a high-temperature resistant power conformal resistor and an additive assembly method thereof. Background Art

[0002] Resistors are one of the most commonly used electronic components in electronic products and electronic equipment, among which thin film resistors, thick film resistors and metal foil resistors are the most common resistor forms. Chip resistors are usually deposited on insulating substrates by screen printing, template printing, vacuum evaporation, magnetron sputtering, metal foil rolling bonding and other processes, and then formed into resistor devices after photolithography shaping and packaging, and then assembled into board-level circuits by welding equipment such as automated placement and reflow soldering.

[0003] The above traditional methods cannot meet the needs of preparing conformal resistors on curved substrates, because welding and assembling resistors on curved substrates will cause welding defects due to the height difference between the two end solder joints. If the method of assembling the resistor components on a flat flexible printed circuit board and then bending it to conform to the curved substrate is adopted, there are problems such as local high temperature during welding that damages the flexible board and causes bonding failure, the pads are contaminated by co-cured resin or protective glue, and the stress during the bending and curing of the solder joints is large, causing cracking and damage. At the same time, the resistor components are usually large in size and thick in thickness, which does not meet the needs of small-size assembly on the flexible board. When the flexible board is bent, it is easy to cause interference, bumping and falling, and bulging after curing.

[0004] Additive manufacturing has a wide range of uses in the field of electronic assembly, with a wide range of technical types, a wide range of applicable materials, and a high degree of flexibility and intelligence. Through material extrusion methods such as fused deposition modeling and ink direct writing printing, on-demand material injection methods such as piezoelectric inkjet printing, aerosol printing, and electrohydrodynamic printing, as well as special methods such as laser-induced micro-additive, combined with different electronic functional materials such as nanosilver ink, silver paste, resin ink, and carbon paste, circuit patterns, interconnects, interlayer interconnects, sensors, resistors and other electronic components, and even multi-layer printed circuit boards can be directly assembled on demand on two-dimensional or three-dimensional substrates. The assembly accuracy can reach the nanometer level, which is very suitable for miniaturization and conformal manufacturing needs.

[0005] The temperature resistance of resistors is one of the most important performance indicators of resistors, which directly determines the reliability of resistors when they are subjected to power loads. Common resistor materials that can be used for additive manufacturing are limited by material properties. When the temperature is higher than 200°C, the resistance value deviates seriously or even the resistor breaks and burns. They are usually unable to withstand a power exceeding 0.1w, and their practical application range is limited. At present, reports on additive assembly resistors basically emphasize the feasibility of the assembly process. The lack of high-temperature resistant resistors has become a bottleneck restricting the development of resistor additive assembly technology. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a high-temperature resistant power conformal resistor and an additive assembly method thereof, which can directly assemble the conformal resistor on a special-shaped non-expandable curved surface carrier substrate, and has the excellent performance of easy processing, flexible design, adjustable resistance, and bendable conformability, thereby improving the power resistance performance of the resistor.

[0007] The object of the present invention is achieved through the following solutions:

[0008] A high temperature resistant power conformal resistor comprises a resistor body, wherein the resistor body comprises: a resin bearing matrix, a conductive functional phase, a heat dissipation functional phase, a surfactant and an antioxidant;

[0009] The resin carrier matrix forms a stable three-dimensional network cross-linked structure after heating and curing, and serves as a carrier matrix for the conductive functional phase, the heat dissipation functional phase, the surfactant and the antioxidant;

[0010] The conductive functional phase is evenly distributed in the resin supporting matrix and interconnected to form a spatial percolation network structure, which serves as a transmission channel for electrons;

[0011] The heat dissipation functional phase is evenly distributed in the resin bearing matrix to improve the heat dissipation capacity of the resin bearing matrix;

[0012] The surfactant is used to reduce the surface tension between heterogeneous materials, inhibit the agglomeration of the nanoparticle materials of the conductive functional phase and the heat dissipation functional phase, promote the dispersion of the nanoparticles in the resin carrier matrix, and enhance the wettability of the resistor material and the carrier substrate;

[0013] The antioxidant is used to inhibit the oxidative decomposition of the resin in a high temperature or oxygen environment and to improve the heat resistance of the resin-bearing matrix.

[0014] Further, the resin bearing matrix includes any one of benzoxazine resin, cyanate resin, polyimide resin, polysiloxane resin, phthalonitrile resin, and polyarylacetylene resin;

[0015] The conductive functional phase includes one or more materials selected from graphene, carbon nanotubes, carbon powder, ruthenium oxide powder, silver powder, and copper powder;

[0016] The heat dissipation functional phase comprises one or more materials selected from aluminum nitride ceramic powder, boron nitride ceramic powder, and aluminum oxide ceramic powder;

[0017] The surfactant includes one or more materials selected from the group consisting of silane coupling agent, polyaminosiloxane, polyvinyl alcohol, polyacrylate, alkyl sulfate, and polyoxyethylene ether;

[0018] The antioxidant includes one or more materials selected from hindered phenol 1010, 1076 primary antioxidants and phosphite 168, 626 secondary antioxidants.

[0019] A method for additively assembling a high temperature resistant power conformal resistor comprises the high temperature resistant power conformal resistor as described in any one of the above items, and comprises the following steps:

[0020] S1: Calculate the square resistance or resistivity of the required resistor material and select high temperature resistant resistor material according to the required resistor value and the set assembly space size;

[0021] S2: Surface treatment is performed on the area on the circuit carrier substrate where the resistor is to be assembled;

[0022] S3: Assembling resistors on a circuit-carrying substrate by an additive manufacturing process;

[0023] S4: thermally curing the resistor together with the carrier substrate to form a stable resistor body;

[0024] S5: Test the resistance value of the resistor and adjust the resistance value of the resistor with large resistance deviation.

[0025] Furthermore, after step S5, the method further includes:

[0026] S6: If the circuit-carrying substrate in step S2 is a curved hard substrate, the additive assembly of the conformal resistor is completed after step S5 is completed; if the circuit-carrying substrate in S2 is a flat flexible substrate, step S6 is performed to conform the resistor along with the flexible circuit-carrying substrate onto the curved structural component through a co-curing process to complete the assembly of the conformal resistor.

[0027] Further, in step S1, the square resistance or resistivity of the required resistor material is calculated according to the required resistance value of the resistor device and the set assembly space size, and the high temperature resistant resistor material is selected, which specifically includes the following sub-steps:

[0028] The square resistance or resistivity of the resistor material is controlled by adjusting the ratio of the five components of the resin carrier matrix, the conductive functional phase, the heat dissipation functional phase, the surfactant, and the antioxidant. At this time, the resistor material is a stable and uniform colloidal mixture, in which the resin carrier matrix is ​​in the form of a prepolymer. According to the required temperature resistance and power resistance requirements of the resistor and the material type of the carrier substrate, a material from the high-temperature resistant thermosetting resin is selected as the resistor resin carrier matrix.

[0029] Further, in step S2, the surface treatment of the area on the circuit-bearing substrate where the resistor is to be assembled specifically includes the sub-steps: the circuit-bearing substrate includes a curved hard substrate and a flat flexible substrate;

[0030] First, a laser etching process is used to perform regional selective pretreatment on the surface of the circuit-bearing substrate. By adjusting the laser etching parameters, an array of physical microstructures is processed on the substrate surface to increase the surface roughness.

[0031] Secondly, the surface physical microstructure is electrostatically modified by an electrowetting process to form an electronic transition layer on the surface of the microstructure, thereby increasing the wettability of the resistor material on the physical microstructure.

[0032] Furthermore, in step S3, the step of assembling the resistor on the circuit-carrying substrate by an additive manufacturing process specifically includes the following sub-steps:

[0033] Select additive manufacturing process technology for resistor assembly based on the viscosity range and molding accuracy requirements of the resistor material;

[0034] During the assembly process, the carrier substrate is fixed on the workbench, and the resistor material is deposited at the required position on the carrier substrate by spraying or extrusion as needed. The resistor material is controlled to form the required three-dimensional structure by adjusting the printing parameters. The overlap length between the resistor and the electrodes at both ends is 0.1 to 0.5 times the effective length of the resistor. During the assembly process, the resistor material is pre-dried by heating the carrier substrate to reduce the fluidity of the resistor material after deposition and improve the accuracy of the three-dimensional structure. The heating temperature is controlled between 60°C and 180°C.

[0035] Furthermore, in step S4, the resistor is thermally cured together with the carrier substrate to form a stable resistor body, which specifically includes the following sub-steps:

[0036] Use an oven to thermally cure the resistor. Select the thermal curing temperature and curing time according to the type of the resistor resin carrier matrix. The maximum temperature shall not exceed the thermal decomposition temperature of the resin carrier matrix and the circuit carrier substrate material. During curing, put the resistor and the carrier substrate into the oven together at room temperature and heat them to the set temperature. After curing, take them out as the oven cools down to room temperature.

[0037] Further, in step S5, the resistance of the resistor is tested, and the resistance of the resistor with a large resistance deviation is adjusted, which specifically includes the following sub-steps:

[0038] If the test resistance value is too large, the resistance value is adjusted by an additive method in which additional resistor material is deposited on the top surface of the resistor and then solidified; if the test resistance value is too small, the resistance value is adjusted by a subtractive method in which part of the material is removed in the width or thickness direction of the resistor by laser etching or mechanical engraving, and ultimately the resistance value of all resistors is controlled within the required accuracy.

[0039] Furthermore, in step S6, the surface of the curved structural part is an expandable curved surface. In the co-curing process, a layer of adhesive film of a set thickness is sandwiched between the curved structural part and the flexible circuit carrier substrate. The three are fixed together in a mold and placed in an autoclave or press. Under high temperature and high pressure, the flexible circuit carrier substrate is reliably conformed to the curved structural part, and the resistor remains conformal to the surface of the curved structural part.

[0040] The beneficial effects of the present invention include:

[0041] (1) The conformal resistor obtained by the technical solution of the present invention can be used to prepare resistor materials that meet different additive manufacturing process technologies and performance requirements by mixing various components. The resistor uses a high-temperature resistant high-performance thermosetting resin as a resin carrier matrix, and with the heat dissipation function, it can suppress the thermal damage of the resistor under high power load, and significantly improve the power resistance performance of the resistor.

[0042] (2) The present invention improves the additive manufacturing process for resistors. The resistors are assembled using the improved additive manufacturing process technology solution, and have excellent properties such as easy processing, flexible design, adjustable resistance, and bendable conformability. They are suitable for additive manufacturing processing methods such as direct writing printing and inkjet printing, and can be applied to the additive assembly of small-size, high-reliability, and high-performance resistors on flat printed circuits and flexible film substrates.

[0043] (2) The technical solution of the present invention is combined with a four-axis or more multi-degree-of-freedom additive manufacturing device or a robotic arm device, which can directly assemble conformal resistors on a special-shaped non-expandable curved surface carrier substrate, which is helpful for the realization of various advanced electronic functional products. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0045] Figure 1 It is composed of a flat flexible circuit carrying substrate;

[0046] Figure 2 It is a resistor assembled on a flat flexible circuit carrier substrate;

[0047] Figure 3 It is the conformal resistor after co-curing is completed;

[0048] Figure 4 Assemble resistors on curved hard special-shaped circuit-bearing substrates;

[0049] Figure 5 is a flowchart of the steps of the method according to the embodiment of the present invention;

[0050] In the figure, 1-flexible thin film dielectric board; 2-printed circuit pattern; 3-first conformal resistor; 4-array microstructure; 5-regular curved surface structural member; 6-curved hard special-shaped dielectric board; 7-conformal circuit pattern; 8-second conformal resistor. DETAILED DESCRIPTION

[0051] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0052] The specific conception and implementation process of the present invention is as follows:

[0053] On the one hand, the present invention provides a high temperature resistant power conformal resistor, wherein the resistor body includes the following parts: a resin supporting matrix, a conductive functional phase, a heat dissipation functional phase, a surfactant, and an antioxidant.

[0054] The resin carrier matrix is ​​composed of a material selected from high temperature resistant thermosetting resins such as benzoxazine resin, cyanate resin, polyimide resin, polysiloxane resin, phthalonitrile resin, polyarylacetylene resin, etc. The glass transition temperature of the high temperature resistant resin is T g >200℃, thermal decomposition temperature T d5％ >350°C. The resin has a stable prepolymer form and forms a stable three-dimensional network cross-linked structure after heating and curing, serving as the supporting matrix for the remaining components.

[0055] The conductive functional phase is composed of one or more materials selected from graphene, carbon nanotubes, carbon powder, ruthenium oxide powder, silver powder, copper powder, etc., and the particle size D90 of the conductive functional material is less than 10 μm. The conductive functional material is evenly distributed in the resin support matrix and interconnected to form a spatial percolation network structure, which serves as a transmission channel for electrons.

[0056] The heat dissipation functional phase is composed of one or more materials selected from aluminum nitride ceramic powder, boron nitride ceramic powder, alumina ceramic powder, etc. The heat dissipation functional material is required to have good insulation performance and a material particle size D90 of less than 10μm. The heat dissipation functional material is evenly distributed in the resin bearing matrix to improve the heat dissipation capacity of the resin bearing matrix.

[0057] The surfactant is composed of one or more materials selected from silane coupling agent, polyaminosiloxane, polyvinyl alcohol, polyacrylate, alkyl sulfate, polyoxyethylene ether, etc. The surfactant can significantly reduce the surface tension between heterogeneous materials, inhibit the agglomeration of nanoparticle materials of the conductive functional phase and the heat dissipation functional phase, promote the dispersion of nanoparticles in the resin carrier matrix, and enhance the wettability of the resistor material and the carrier substrate.

[0058] The antioxidant is composed of one or more materials selected from hindered phenol 1010, 1076 main antioxidants and phosphite 168, 626 auxiliary antioxidants. The antioxidant can inhibit the oxidative decomposition of the resin under high temperature or oxygen environment and improve the heat resistance of the resin-bearing matrix.

[0059] On the other hand, Figure 5 As shown, the present invention provides an additive assembly method for a high temperature resistant power conformal resistor, comprising the following steps:

[0060] S1: According to the required resistance value of the resistor device and the set assembly space size, calculate the square resistance or resistivity of the required resistor material and select the appropriate high temperature resistant resistor material.

[0061] In step S1, the square resistance or resistivity of the resistor material is controlled by adjusting the ratio of five components, namely, a resin carrier matrix, a conductive functional phase, a heat dissipation functional phase, a surfactant, and an antioxidant. At this time, the resistor material is a stable and uniform colloidal mixture, in which the resin carrier matrix is ​​in the form of a prepolymer. According to the required temperature resistance and power resistance requirements of the resistor and the type of material of the carrier substrate, a material selected from high-temperature resistant thermosetting resins such as benzoxazine resin, cyanate resin, polyimide resin, polysiloxane resin, phthalonitrile resin, and polyarylacetylene resin is used as the resistor resin carrier matrix. The viscosity of the resistor material is 0.1 to 100 Pa·s, and the viscosity of the resistor material can be adjusted by adding a solvent. Conventional solvents include acetone, NN dimethylformamide, tetrahydrofuran, toluene, and the like.

[0062] S2: Surface treatment is performed on the area on the circuit carrier substrate where the resistor is to be assembled.

[0063] In step S2, the circuit-bearing substrate includes a curved hard substrate and a flat flexible substrate. The dielectric materials of the curved hard substrate include polyetheretherketone (PEEK), polyimide (PI), polytetrafluoroethylene (PTFE), alumina ceramics, etc., and the dielectric materials of the flat flexible substrate include polyimide (PI), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP) film, etc. First, a laser etching process is used to perform regional selective pretreatment on the surface of the circuit-bearing substrate. By adjusting the laser etching parameters, an array-arranged physical microstructure is processed on the surface of the substrate to increase the surface roughness. Secondly, an electrowetting process is used to electrostatically modify the surface physical microstructure, form an electronic transition layer on the surface of the microstructure, and increase the wettability of the resistor material on the physical microstructure. The above surface treatment can significantly enhance the bonding force between the resistor material and the circuit-bearing substrate.

[0064] S3: Assembling resistors on the circuit-carrying substrate by additive manufacturing process.

[0065] In step S3, the additive manufacturing process includes aerosol printing, piezoelectric inkjet, current jet printing, micro-pen direct writing and other process technologies. One of the additive manufacturing process technologies is selected for resistor assembly according to the viscosity range and molding accuracy requirements of the resistor material. During the assembly process, the carrier substrate is fixed on the workbench, and the resistor material is sprayed or extruded and deposited on the required position on the carrier substrate as required. The resistor material is controlled to form the required three-dimensional structure by adjusting parameters such as printing speed, layer height, line width, air pressure, deposition direction and nozzle size. The overlap length between the resistor and the electrodes at both ends is 0.1 to 0.5 times the effective length of the resistor. During the assembly process, the resistor material is pre-dried by heating the carrier substrate to reduce the fluidity of the resistor material after deposition and improve the accuracy of the three-dimensional structure. The heating temperature is 60℃ to 180℃.

[0066] S4: Thermally cure the resistor together with the carrier substrate to form a stable resistor body.

[0067] In step S4, the resistor is thermally cured in an oven. The thermal curing temperature and curing time are selected according to the type of the resistor resin substrate. The maximum temperature must not exceed the thermal decomposition temperature of the resin substrate and the circuit substrate. During curing, the resistor and the substrate are placed in an oven at room temperature and heated to a set temperature. After curing, the resistor is taken out of the oven after the oven cools down to room temperature.

[0068] S5: Test the resistance value of the resistor and adjust the resistance value of the resistor with large resistance deviation.

[0069] In step S5, if the test resistance value is too large, the resistance value is adjusted by depositing additional resistance material on the top surface of the resistor and then solidifying it. If the test resistance value is too small, the resistance value is adjusted by removing part of the material in the width or thickness direction of the resistor through laser etching or mechanical engraving. Finally, the resistance value of all resistors is controlled within the required accuracy.

[0070] S6: If the circuit substrate in S2 is a curved hard substrate, then the additive assembly of the conformal resistor is completed after S5 is completed. If the circuit substrate in S2 is a flat flexible substrate, then S6 is performed to conform the resistor to the curved structural component along with the flexible circuit substrate through a co-curing process to complete the assembly of the conformal resistor.

[0071] In step S6, the surface of the curved structural part is a developable curved surface. In the co-curing process, a layer of adhesive film of a specific thickness is sandwiched between the curved structural part and the flexible circuit carrier substrate, and the three are fixed together in a mold and placed in an autoclave or press. Under high temperature and high pressure, the flexible circuit carrier substrate is reliably conformed to the curved structural part, and the resistor is also completely conformal to the surface of the curved structural part.

[0072] Example 1

[0073] This embodiment uses a planar flexible substrate as a circuit bearing substrate for resistor assembly. This embodiment provides an additive assembly method for a high-temperature resistant power conformal resistor, including the following steps:

[0074] SS1: The circuit carrier substrate is a flat flexible printed circuit board, such as Figure 1 As shown, the substrate includes a polyimide (PI) flexible film dielectric board 1, a printed circuit pattern 2 and a first conformal resistor 3 assembled by additive manufacturing. Figure 2 As can be seen, the space size for assembling resistors on the substrate is 1.5mm×1.5mm×0.1mm (L×W×D), and the resistance value of the resistor device is required to be 200Ω. According to the above requirements, polyimide resin is selected as the resin carrier matrix of the resistor material, NN dimethylformamide is used as the solvent, and the proportion of the five components of the resin carrier matrix, the conductive functional phase, the heat dissipation functional phase, the surfactant, and the antioxidant is adjusted to make the viscosity of the gel-like resistor material 10Pa·s and the square resistance 200Ω / sq. Figure 2 In the embodiment, an array microstructure 4 is provided between the flexible thin film dielectric plate 1 and the first conformal resistor 3 .

[0075] SS2: First, a laser etching process is used to process an array of physical microstructures 4 in the resistor area to be assembled on the surface of the circuit carrier substrate to increase the surface roughness. The laser wavelength is 1064nm, the output power is 5W, the laser pulse frequency is 50kHz, the laser processing rate is 1000-5000mm / s, and the number of processing times is 1-5 times. Secondly, the electrowetting process is used to electrostatically modify the surface physical microstructure, form an electronic transition layer on the microstructure surface, and increase the wettability of the resistor material on the physical microstructure.

[0076] SS3: Use the micro-pen direct writing process to additively assemble resistors on the circuit carrier substrate. The carrier substrate is fixed on the workbench by vacuum adsorption, and the resistor material is extruded and deposited at the desired position on the carrier substrate through the micro-pen direct writing needle. The printing speed is 360mm / min, the layer height is 0.1mm, the line width is 0.2mm, the air pressure is 0.6MPa, the deposition direction is 0°, the needle diameter is 0.2mm, and the overlap length between the resistor and the electrodes at both ends is 0.4 times the effective length of the resistor (that is, H is 0.6mm). During the assembly process, the carrier substrate is heated by heating the workbench to pre-dry the resistor material. The heating temperature is 80°C. The assembled resistor is shown as follows Figure 2 shown.

[0077] SS4: Use an oven to heat cure the resistor at a temperature of 220°C for 12 hours. During curing, place the resistor and the carrier substrate in the oven at room temperature and heat them up to the set temperature. After curing, cool them down to room temperature and take them out.

[0078] SS5: Test the resistance value of the resistor. For resistors with large resistance values, the resistance value is adjusted by an additive method of depositing additional resistance material on the top surface of the resistor and then solidifying it. For resistors with small resistance values, the resistance value is adjusted by a subtractive method of removing part of the material in the width or thickness direction of the resistor by laser etching. Finally, the resistance value of all resistors is controlled within the required accuracy.

[0079] SS6: The resistor is conformed to the regular curved surface structure 5 along with the flexible circuit substrate through the co-curing process. The surface of the curved surface structure is a developable curved surface. In the co-curing process, a layer of adhesive film of a specific thickness is sandwiched between the curved surface structure and the flexible circuit substrate. The three are fixed together in a mold and put into an autoclave. Under high temperature and high pressure, the flexible circuit substrate is reliably conformed to the curved surface structure, and the resistor is completely conformal with the surface of the curved surface structure. The conformal resistor after co-curing is as follows: Figure 3 shown.

[0080] For this embodiment, 10 resistors were randomly selected to test their resistance values ​​after additive assembly, shaping adjustment, and co-curing. The recorded data are shown in the following table. It can be seen that the final resistance accuracy is within ±5% of the design value of 200Ω, and the consistency is good. The 10 resistors were tested for power resistance, and a 0.3W power load was loaded at both ends of each resistor through a DC power supply. The results showed that the resistors remained stable within 4 hours of the load, indicating that the conformal resistors prepared by this method have excellent power resistance performance.

[0081] Table 1

[0082]

[0083] Example 2

[0084] This embodiment uses a curved hard special-shaped substrate as a circuit bearing substrate for resistor assembly. This embodiment provides an additive assembly method for a high-temperature resistant power conformal resistor, including the following steps:

[0085] SSS1: The circuit-carrying substrate is a curved hard special-shaped circuit substrate, such as Figure 4 As shown, the substrate includes a polyetheretherketone (PEEK) curved hard shaped dielectric plate 6, a conformal circuit pattern 7 and a second conformal resistor 8 assembled by additive manufacturing. The space size for assembling the resistor on the substrate is about 1.5mm×1.5mm×0.1mm (L×W×D), and the resistance value of the resistor device is required to be 300Ω. According to the above requirements, benzoxazine resin is selected as the resin bearing matrix of the resistor material, acetone is used as the solvent, and the proportion of the five components of the resin bearing matrix, the conductive functional phase, the heat dissipation functional phase, the surfactant, and the antioxidant is adjusted so that the viscosity of the gel-like resistor material is 1Pa·s and the square resistance is 300Ω / sq.

[0086] SSS2: First, a laser etching process is used to process an array of physical microstructures in the resistor area to be assembled on the surface of the circuit carrier substrate to increase the surface roughness. The laser wavelength is 1064nm, the output power is 5W, the laser pulse frequency is 50kHz, the laser processing rate is 1000-5000mm / s, and the number of processing times is 1-5 times. Secondly, the electrowetting process is used to electrostatically modify the surface physical microstructure, form an electronic transition layer on the microstructure surface, and increase the wettability of the resistor material on the physical microstructure.

[0087] SSS3: Additively assemble resistors on circuit carrier substrates using piezoelectric valve jet additive manufacturing process. The carrier substrate is fixed on the workbench of the five-axis linkage printing equipment by a fixture, and the resistor material is deposited on the required position on the carrier substrate by jetting through the piezoelectric valve nozzle. The printing speed is 300mm / min, the layer height is 0.1mm, the line width is 0.1mm, the jet frequency is 800Hz, the deposition direction is 0°, the nozzle diameter is 0.05mm, and the overlap length between the resistor and the electrodes at both ends is 0.3 times the effective length of the resistor. During the assembly process, the carrier substrate is heated by heating the workbench to pre-dry the resistor material, and the heating temperature is 120℃.

[0088] SSS4: Use an oven to heat cure the resistor at a temperature of 220°C for 12 hours. During curing, place the resistor and the carrier substrate in the oven at room temperature and heat them up to the set temperature. After curing, cool them down to room temperature and take them out.

[0089] SSS5: Test the resistance value of resistors. For resistors with large resistance values, the resistance value is adjusted by an additive method of depositing additional resistance material on the top surface of the resistor and then solidifying it. For resistors with small resistance values, the resistance value is adjusted by a subtractive method of removing part of the material in the width or thickness direction of the resistor by laser etching. Finally, the resistance value of all resistors is controlled within the required accuracy.

[0090] For this embodiment, the final additive assembly conformal resistor is obtained after SSS5 is completed. 10 resistors are randomly selected to test their resistance values ​​after additive assembly and trimming adjustment. The recorded data are shown in the following table. It can be seen that the final resistance accuracy is within ±3% of the design value of 300Ω, and the consistency is good.

[0091] Table 2

[0092]

[0093]

[0094] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0095] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0096] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. A high temperature resistant power conformal resistor, comprising a resistor body, characterized in that: The resistor comprises: a resin bearing matrix, a conductive functional phase, a heat dissipation functional phase, a surfactant and an antioxidant; The resin carrier matrix forms a stable three-dimensional network cross-linked structure after heating and curing, and serves as a carrier matrix for the conductive functional phase, the heat dissipation functional phase, the surfactant and the antioxidant; The conductive functional phase is evenly distributed in the resin supporting matrix and interconnected to form a spatial percolation network structure, which serves as a transmission channel for electrons; The heat dissipation functional phase is evenly distributed in the resin bearing matrix to improve the heat dissipation capacity of the resin bearing matrix; The surfactant is used to reduce the surface tension between heterogeneous materials, inhibit the agglomeration of the nanoparticle materials of the conductive functional phase and the heat dissipation functional phase, promote the dispersion of the nanoparticles in the resin carrier matrix, and enhance the wettability of the resistor material and the carrier substrate; The antioxidant is used to inhibit the oxidative decomposition of the resin in a high temperature or oxygen environment and to improve the heat resistance of the resin-bearing matrix.

2. The high temperature resistant power conformal resistor according to claim 1, characterized in that: The resin bearing matrix includes any one of benzoxazine resin, cyanate resin, polyimide resin, polysiloxane resin, phthalonitrile resin and polyarylacetylene resin; The conductive functional phase includes one or more materials selected from graphene, carbon nanotubes, carbon powder, ruthenium oxide powder, silver powder, and copper powder; The heat dissipation functional phase comprises one or more materials selected from aluminum nitride ceramic powder, boron nitride ceramic powder, and aluminum oxide ceramic powder; The surfactant includes one or more materials selected from the group consisting of silane coupling agent, polyaminosiloxane, polyvinyl alcohol, polyacrylate, alkyl sulfate, and polyoxyethylene ether; The antioxidant includes one or more materials selected from hindered phenol 1010, 1076 primary antioxidants and phosphite 168, 626 secondary antioxidants.

3. An additive assembly method for a high temperature resistant power conformal resistor, characterized in that: The invention comprises the high temperature resistant power conformal resistor according to any one of claims 1 to 2, and comprises the following steps: S1: Calculate the square resistance or resistivity of the required resistor material and select high temperature resistant resistor material according to the required resistor value and the set assembly space size; S2: Surface treatment is performed on the area on the circuit carrier substrate where the resistor is to be assembled; S3: Assembling resistors on a circuit-carrying substrate by an additive manufacturing process; S4: thermally curing the resistor together with the carrier substrate to form a stable resistor body; S5: Test the resistance value of the resistor and adjust the resistance value of the resistor with large resistance deviation.

4. The additive assembly method of the high temperature resistant power conformal resistor according to claim 3, characterized in that: After step S5, the method further includes: S6: If the circuit-carrying substrate in step S2 is a curved hard substrate, the additive assembly of the conformal resistor is completed after step S5 is completed; if the circuit-carrying substrate in S2 is a flat flexible substrate, step S6 is performed to conform the resistor along with the flexible circuit-carrying substrate onto the curved structural component through a co-curing process to complete the assembly of the conformal resistor.

5. The additive assembly method of the high temperature resistant power conformal resistor according to claim 3, characterized in that: In step S1, the required square resistance or resistivity of the resistor material is calculated according to the required resistance value of the resistor device and the set assembly space size, and the high temperature resistant resistor material is selected, which specifically includes the following sub-steps: The square resistance or resistivity of the resistor material is controlled by adjusting the ratio of the five components of the resin carrier matrix, the conductive functional phase, the heat dissipation functional phase, the surfactant, and the antioxidant. At this time, the resistor material is a stable and uniform colloidal mixture, in which the resin carrier matrix is ​​in the form of a prepolymer. According to the required temperature resistance and power resistance requirements of the resistor and the material type of the carrier substrate, a material from the high-temperature resistant thermosetting resin is selected as the resistor resin carrier matrix.

6. The additive assembly method of the high temperature resistant power conformal resistor according to claim 3, characterized in that: In step S2, the surface treatment is performed on the area on the circuit-bearing substrate where the resistor is to be assembled, specifically including the sub-steps: the circuit-bearing substrate includes a curved hard substrate and a flat flexible substrate; First, a laser etching process is used to perform regional selective pretreatment on the surface of the circuit-bearing substrate. By adjusting the laser etching parameters, an array of physical microstructures is processed on the substrate surface to increase the surface roughness. Secondly, the surface physical microstructure is electrostatically modified by an electrowetting process to form an electronic transition layer on the surface of the microstructure, thereby increasing the wettability of the resistor material on the physical microstructure.

7. The additive assembly method of the high temperature resistant power conformal resistor according to claim 3, characterized in that: In step S3, the resistor is assembled on the circuit-carrying substrate by an additive manufacturing process, specifically comprising the following sub-steps: Select additive manufacturing process technology for resistor assembly based on the viscosity range and molding accuracy requirements of the resistor material; During the assembly process, the carrier substrate is fixed on the workbench, and the resistor material is sprayed or extruded and deposited at the required position on the carrier substrate as required. The resistor material is controlled to form the required three-dimensional structure by adjusting the printing parameters. The overlap length between the resistor and the electrodes at both ends is 0.1 to 0.5 times the effective length of the resistor. During the assembly process, the resistor material is pre-dried by heating the carrier substrate to reduce the fluidity of the resistor material after deposition and improve the three-dimensional structure accuracy. The heating temperature is controlled between 60°C and 180°C.

8. The additive assembly method of the high temperature resistant power conformal resistor according to claim 3, characterized in that: In step S4, the resistor is thermally cured together with the carrier substrate to form a stable resistor body, which specifically includes the following sub-steps: Use an oven to thermally cure the resistor. Select the thermal curing temperature and curing time according to the type of the resistor resin carrier matrix. The maximum temperature shall not exceed the thermal decomposition temperature of the resin carrier matrix and the circuit carrier substrate material. During curing, put the resistor and the carrier substrate into the oven together at room temperature and heat them to the set temperature. After curing, take them out as the oven cools down to room temperature.

9. The additive assembly method of the high temperature resistant power conformal resistor according to claim 3, characterized in that: In step S5, the resistance of the resistor is tested and the resistance of the resistor with a large resistance deviation is adjusted, which specifically includes the following sub-steps: If the test resistance value is too large, the resistance value is adjusted by an additive method in which additional resistor material is deposited on the top surface of the resistor and then solidified; if the test resistance value is too small, the resistance value is adjusted by a subtractive method in which part of the material is removed in the width or thickness direction of the resistor by laser etching or mechanical engraving, and ultimately the resistance value of all resistors is controlled within the required accuracy.

10. The additive assembly method of the high temperature resistant power conformal resistor according to claim 4, characterized in that: In step S6, the surface of the curved structural part is an expandable curved surface. In the co-curing process, a layer of adhesive film of a set thickness is sandwiched between the curved structural part and the flexible circuit carrier substrate. The three are fixed together in a mold and placed in an autoclave or press. Under high temperature and high pressure, the flexible circuit carrier substrate is reliably conformed to the curved structural part, and the resistor remains conformal to the surface of the curved structural part.

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