Manufacturing process of high-frequency and high-precision resistance device

Abstract

The invention relates to the technical field of resistor manufacturing, in particular to a manufacturing process of a high-frequency and high-precision resistor device. Comprising the following steps: S1, substrate molding: molding substrate material powder into a required substrate shape through pressing or a mold, and carrying out sintering molding; s2, depositing a conductive thin film: depositing a layer of extremely thin conductive thin film on the substrate, and manufacturing resistive layers with different thicknesses by using a nickel-chromium alloy material to adapt to various resistance values; s3, photoetching and etching: generating a pattern through photoetching or laser trimming, increasing a resistance path and calibrating a resistance value to ensure that the resistance value is within a design range; s4, adjusting a resistance value; s5, surface treatment; and S6, screening and packaging. According to the method, the precision and the performance are controlled through the steps of calibrating the resistance value in the technological process, accurately controlling the resistance pattern through laser energy and accurately controlling the size of the pattern, so that the final product can meet the requirements of high frequency and high precision.

Description

Technical Field

[0001] The invention relates to the technical field of resistor manufacturing, and in particular to a manufacturing process for high-frequency and high-precision resistor devices. Background Art

[0002] The information technology industry is a strategic, basic, and leading industry related to the emergency safety and development of the nation. It is also a competitive highland that major countries in the world attach great importance to and make full efforts to lay out. With the development of various technologies, resistors are an indispensable part of today's electronic devices. Resistor devices use the resistance properties of materials to control the current in the circuit. When the resistor device is connected to the circuit, it will consume a certain amount of electrical energy and convert the electrical energy into heat energy to dissipate, thereby limiting the size of the current.

[0003] With the increasing application of electronic equipment in various industries, the requirements for high frequency and high precision of resistors are getting higher and higher. For example, high-frequency resistors are often used in various circuits such as mobile communications, satellite communications, microwave communications, and radio frequency communications. Their main function is to control current and suppress electromagnetic interference. In radar systems, high-frequency resistors play an important role and are widely used in interference suppression, frequency modulation, power distribution and other circuits. High-precision resistors are widely used in automatic control systems, such as sensors and measuring instruments, to provide accurate resistance values ​​to ensure the accuracy of system control. In circuit design, high-precision resistors are required in situations where there are high requirements for the accuracy and stability of resistors, such as precision measurements, instruments and equipment. For this reason, the market urgently needs a manufacturing process for high-frequency and high-precision resistors. Summary of the invention

[0004] The main purpose of the present invention is to provide a manufacturing process for a high-frequency and high-precision resistor device, aiming to solve the technical problems in the prior art.

[0005] The present invention provides a manufacturing process of a high-frequency and high-precision resistor device, comprising:

[0006] S1. Substrate molding: The substrate material powder is molded into the desired substrate shape by pressing or molding, and sintered;

[0007] S2. Deposition of conductive film: Deposit an extremely thin conductive film on the substrate, and use nickel-chromium alloy material to make resistor layers of different thicknesses to adapt to various resistance values;

[0008] S3, photolithography and etching: Generate patterns through photolithography or laser trimming, add resistance paths and calibrate resistance values ​​to ensure that the resistance values ​​are within the design range;

[0009] S4. Resistance value adjustment: Use laser cutting or chemical etching technology to trim the initial R value to the required resistance value;

[0010] S5. Surface treatment: Improve the durability and stability of resistors through a combination of physical and chemical treatments;

[0011] S6. Screening and packaging: Perform coating or packaging processes to isolate the impact of the external environment on resistor performance.

[0012] Preferably, the substrate material in step S1 is at least one of aluminum oxide, aluminum nitride, beryllium oxide and polytetrafluoroethylene.

[0013] Preferably, the surface treatment in step S5 includes:

[0014] Physical treatment: Use metal shielding and anti-static treatment to improve the anti-interference ability of the circuit board; and,

[0015] Chemical treatment: Chemical nickel plating, gold immersion and coating of organic solderability preservatives are used to improve the corrosion resistance and adhesion of the surface.

[0016] Preferably, the photolithography process in step S3 includes:

[0017] Spin coating 200-500 nanometers of photoresist or other photosensitive material on the substrate; and,

[0018] Allow ultraviolet light to irradiate the photosensitive material through a pre-prepared mask with a certain pattern;

[0019] The photosensitive material in the area irradiated by ultraviolet light can be removed by development or not, thereby transferring the image of the mask to the photosensitive material.

[0020] Preferably, the method for producing a pattern by laser trimming in step S3 is:

[0021] A laser beam with variable intensity is used to expose the photoresist on the surface of the substrate. By precisely controlling the intensity and exposure time of the laser, the desired precise pattern is formed on the photoresist.

[0022] Preferably, the method for adding a resistance path and calibrating the resistance value in step S3 is:

[0023] Using laser cutting technology, the resistor body is cut with laser light spots to change the aspect ratio of the resistor, thereby adjusting the resistance value. The calculation formula for the resistance value is:

[0024]

[0025] Where ρ is the resistivity of the material, l is the length of the resistive material, and s is the cross-sectional area.

[0026] Preferably, the method for ensuring the resistance value is within the design range in step S3 is:

[0027] After the photolithography and etching steps, the resistance value is measured and calibrated;

[0028] When the measured resistance is too high, you can reduce the resistance by increasing the length of the resistor or reducing the cross-sectional area; conversely, if the resistance is too low, reduce the length of the resistor or increase the cross-sectional area.

[0029] Preferably, during the laser trimming process to generate the pattern, the method for accurately controlling the resistance pattern by laser energy is:

[0030] The laser beam cuts the resistor according to a computer-preset program, thereby changing the resistance value of the resistor by changing the geometric shape of the resistor;

[0031] When laser resistance is adjusted, the rated power output state of the laser is maintained, an attenuation link is added to the optical path, and the laser power is adjusted through the attenuator;

[0032] The resistance value change is monitored in real time through a high-precision digital bridge to control the resistance adjustment process;

[0033] The combination of the serpentine adjustment pattern and the single-port straight adjustment pattern is adopted to control the resistance adjustment accuracy by effectively determining the cutting groove length of the serpentine adjustment pattern.

[0034] During the laser resistance trimming process, the measurement system monitors in real time and measures online the resistance value Rt of the resistor to be trimmed at -55℃ to +150℃.

[0035] If the resistance value of Rt is within the adjustable resistance range, turn on the laser to adjust its resistance, otherwise give up the adjustment and measure the next resistance;

[0036] While adjusting the resistance, the resistance value is detected online in real time. If the rough adjustment precision requirement is reached, the adjustment is completed and the single-port direct adjustment is started. Meanwhile, the resistance value is detected online in real time.

[0037] If the resistance adjustment accuracy requirement has been reached, turn off the laser, otherwise continue to etch along the adjustment direction until the resistance reaches the accuracy requirement.

[0038] Preferably, the method for accurately controlling the pattern size during the laser trimming process is:

[0039] Use CAD software to digitally design the pattern that needs to be engraved or cut;

[0040] By precisely controlling the focus and pulse of the laser, the energy density of the laser is adjusted to exceed the damage threshold of the material only in the area you want to process;

[0041] The movement of the laser beam is controlled by a computer control system, and the laser beam is accurately moved according to the design pattern to draw the desired pattern on the material surface;

[0042] Automatic focusing of the laser cutting machine is achieved by controlling the laser beam output power and the position of the focusing lens;

[0043] Adjust the cutting depth, cutting speed and beam polarization of the laser cutting machine as needed to obtain the best cutting effect;

[0044] During the laser cutting process, the image of the workpiece is captured by a camera, and then the distance between the workpiece and the detection lens is calculated through image processing technology. The change in focal length is monitored in real time and the focal length is adjusted according to the detection results.

[0045] Preferably, the resistance value is measured by:

[0046] Randomly selecting and cutting several groups of prepared substrates;

[0047] Customized test fixture, which is tested by contacting the substrate under test through the conductive sponge installed on the sheet electrode.

[0048] The beneficial effects of the present invention are: by calibrating the resistance value during the process, accurately controlling the resistance pattern through laser energy, and accurately controlling the pattern size, the accuracy and performance can be controlled to ensure that the final product can meet the requirements of high frequency and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the process of the present invention.

[0050] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0051] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0052] like Figure 1 As shown, the present application provides a manufacturing process for high-frequency and high-precision resistor devices, including: S1, substrate molding: molding the substrate material powder into the required substrate shape by pressing or molding, and sintering to form; S2, depositing a conductive film: depositing an extremely thin conductive film on the substrate, and using nickel-chromium alloy materials to make resistor layers of different thicknesses to adapt to various resistance values; S3, photolithography and etching: generating patterns through photolithography or laser trimming, increasing the resistance path and calibrating the resistance value to ensure that the resistance value is within the design range; S4, resistance value adjustment: using laser cutting or chemical etching technology to trim the initial R value to the required resistance value; S5, surface treatment: improving the durability and stability of the resistor by combining physical and chemical treatments; S6, screening and packaging: performing coating or packaging processes to isolate the influence of the external environment on the resistor performance.

[0053] As described in step S1 above, the substrate is the supporting part of the resistor, used to carry the resistor body and other structures. In chip resistors, the substrate is usually made of ceramic materials, such as alumina (Al2O3). The substrate not only provides mechanical support, but also has an important influence on the electrical properties of the resistor, including dielectric loss, dielectric constant, thermal conductivity and thermal expansion coefficient. The choice of substrate material is crucial to the performance of the resistor.

[0054] In one embodiment, alumina is used as the substrate material. The advantages of alumina substrate (Alumina): high mechanical strength, low dielectric constant, low thermal expansion coefficient, high thermal conductivity and good chemical stability. The mechanical properties and thermal conductivity of alumina substrates vary greatly depending on the purity. The higher the purity of the substrate, the smoother and denser it is, and the lower the dielectric loss. Disadvantages: The price is relatively high, especially for high-purity alumina substrates. Difference: According to the percentage of alumina, it can be divided into 75 porcelain, 96 porcelain, 99.5 porcelain, etc. The higher the purity, the better the mechanical properties and thermal conductivity of the substrate, the smoother and denser the surface, and the lower the dielectric loss.

[0055] In one embodiment, aluminum nitride is used as the substrate material. The advantages of aluminum nitride ceramic substrate (Aluminum Nitride, AlN) are: compared with alumina ceramic substrate, aluminum nitride ceramic substrate has higher insulation resistance and insulation withstand voltage, lower dielectric constant, thermal conductivity is 7 to 10 times that of Al2O3, and the thermal expansion coefficient is approximately matched with silicon wafers, which is suitable for high-power semiconductor chips; Disadvantages: In terms of production process, the thermal conductivity of AlN is greatly affected by the residual oxygen impurity content. Reducing the oxygen content can improve the thermal conductivity, but it may increase the manufacturing cost.

[0056] In one embodiment, beryllium oxide is used as the substrate material. The advantages of beryllium oxide substrate (Beryllium Oxide, BeO) are: the thermal conductivity is more than ten times that of Al2O3 substrate, which is suitable for high-power circuits, and the dielectric constant is low, which is suitable for high-frequency circuits; the disadvantages are: the toxicity of BeO dust and steam is very harmful to the human body and there are environmental problems.

[0057] In one embodiment, polytetrafluoroethylene is used as the substrate material. The advantages of polytetrafluoroethylene (PTFE, also known as Teflon) are: high performance, high temperature stability, low dielectric constant and low loss, which is very suitable for the manufacture of high frequency and microwave circuits; disadvantages are: relatively high cost and difficult processing.

[0058] As described in step S2 above, the resistor layer made of nickel-chromium alloy material, in one embodiment, is made of CuMn12Ni alloy sheet to make precision resistors, and the alloy material has the characteristics of high stability, low temperature drift coefficient, high precision, etc. Precision resistors made by stamping alloy materials require high-precision alloy materials, and the resistance accuracy of precision resistors produced by CuMn12Ni alloy materials reaches within ±1%.

[0059] As described in step S2 above, the conductive film can be processed by special film processing technology to achieve a very small resistance temperature coefficient that cannot be achieved conventionally, which is very important for maintaining resistance stability in high-frequency applications. Different conductor film structures can be used, such as Ti / Pd / Au, Ti / Pt / Au, Ti / Pd / Cu / Ni / Au, etc., to form the required circuit. In one embodiment, the thickness of the conductive film of the thin film resistor is generally between 100 nanometers and 1 micron.

[0060] As described in the above step S3, the photolithography process uses the pattern on the photolithography mask to irradiate the substrate coated with photoresist with ultraviolet light to cause a photochemical reaction in the photoresist, and then dissolves the unexposed part of the photoresist through the development process, thereby forming a desired pattern on the substrate. The purpose is to obtain a designed layout pattern on the substrate, laying the foundation for subsequent processes such as metal deposition, etching, and ion implantation.

[0061] In one embodiment, the process is as follows: first, a photosensitive material such as a photoresist is spin-coated on a substrate with a certain thickness; then, ultraviolet light is irradiated onto the photosensitive material through a pre-prepared mask with a certain pattern; the photosensitive material in the area irradiated with ultraviolet light can be removed by development (positive resist) or not by development (negative resist), thereby transferring the image of the mask to the photosensitive material.

[0062] Among them, positive photoresist: usually used to form high-resolution patterns. The thickness range is generally between several hundred nanometers and several microns. For example, for high-resolution applications, 200-500 nanometers may be selected.

[0063] Negative photoresist: Usually used to form thicker patterns so that there is enough protection layer in the subsequent etching process. The thickness ranges from a few microns to more than ten microns. For example, for structures that require a higher aspect ratio, 5-10 microns may be selected.

[0064] The specific experimental data are:

[0065]

[0066] When selecting the thickness of the spin-on photoresist, factors such as resolution, etching aspect ratio, exposure energy, and process compatibility need to be considered comprehensively. Different application scenarios and process requirements may require different thicknesses. Through experimental data, the thickness of the spin-on photoresist can be optimized to achieve the best lithography effect.

[0067] As described in step S3 above, the pattern is generated by laser trimming. The laser trimming technology uses a laser beam to irradiate the resistor material, and by controlling the energy and irradiation time of the laser, a portion of the resistor material is accurately removed to form a specific pattern. This method can achieve very fine pattern production and is suitable for precise adjustment of thin film resistors.

[0068] The method of adding a resistance path and calibrating the resistance value as described in S3 above is as follows: First, the resistance pattern is designed according to the desired resistance value, which includes the length, width and shape of the resistance. The resistance value can be calculated and designed by Ohm's law, and the calculation formula is:

[0069]

[0070] Where ρ is the resistivity of the material, l is the length of the resistive material, and s is the cross-sectional area.

[0071] During the manufacturing process, laser trimming technology is used to precisely remove or add portions of the resistor material, thereby changing the path length or cross-sectional area of ​​the resistor and adjusting the resistor value. For example, by cutting off parallel resistor wires or increasing the length of the resistor path, the resistor value can be effectively adjusted.

[0072] As described in S3 above, the purpose of ensuring that the resistance value is within the design range is to ensure that the resistance value of the resistor is accurate and meets the design requirements; the determination method is: after the photolithography and etching steps, the resistance value is measured and calibrated. If the resistance value is not within the design range, it needs to be corrected by adjusting the parameters of the laser trimming or redesigning the pattern of the photoresist. For example, if the measured resistance value is too high, the resistance value can be reduced by increasing the length of the resistor body or reducing the cross-sectional area; conversely, if the resistance value is too low, the length of the resistor body is reduced or the cross-sectional area is increased.

[0073] In order to ensure that the resistance value is within the design range, it is also necessary to pay attention to: Precise control: During the photolithography and laser trimming process, the exposure and development of the photoresist, as well as the energy and irradiation time of the laser beam, need to be precisely controlled to ensure the accuracy of the resistor pattern; Real-time monitoring and adjustment: During the laser trimming process, the change of the resistance value can be monitored in real time, and the resistance value can be precisely controlled by adjusting the laser parameters until the design requirements are met; Final test: After the resistor is manufactured, each resistor is tested using high-precision resistance testing equipment to ensure that its resistance value is within the specified tolerance range. For resistors that do not meet the requirements, further adjustments or screening can be performed.

[0074] In one embodiment, suppose we need to design a resistor with a resistance of 4Ω, the resistivity of the material is 1.6×10^-8Ω·m, and the cross-sectional area of ​​the resistor is 1mm 2 According to the calculation formula of resistance value, we can calculate the required resistor body length:

[0075]

[0076] In actual operation, we can precisely control the length of the resistor by adjusting the path and depth of laser cutting to achieve the required resistance value. Through multiple measurements and adjustments, we ensure that the final resistance value is within the range of 3-5Ω.

[0077] Furthermore, in the process of laser trimming to generate patterns, the process of laser energy precisely controlling the resistor pattern involves the following key steps:

[0078] Laser resistance trimming principle: The basic working principle of laser resistance trimming is to use a very fine laser beam to irradiate the resistor material and cut the resistor by vaporizing and evaporating the resistor body. The laser beam cuts the resistor according to the computer's preset program, and changes the resistor's geometric shape to change the resistor's resistance value;

[0079] Laser energy control: When laser resistance is adjusted, different thin film resistor materials require different laser powers. There are two ways to adjust the laser power in the processing area: one is to directly adjust the laser output power, that is, by adjusting the current of the pump lamp; the other method is to maintain the rated power output state of the laser, add an attenuation link in the optical path, and adjust the laser power through the attenuator. The latter method can stabilize the laser output and ensure the accuracy of resistance adjustment;

[0080] Beam positioning and scanning: During the laser resistance trimming process, the resistance value change is monitored in real time through a high-precision digital bridge to control the resistance trimming process. With the help of complex system manipulator operation, pulsed laser high-frequency output, beam precise positioning control and other electromechanical operation control, the trimming and production of more than 100,000 resistors per hour can be automatically completed.

[0081] Resistor trimming pattern design: The resistor trimming pattern of laser resistor trimming is generally a straight line or a combination of straight lines. The comprehensive accuracy of laser resistor trimming depends on the laser moving speed, laser stability factors and the difficulty of laser beam focusing control. The combination of snake-shaped trimming pattern and single-port straight trimming pattern is used to effectively determine the cutting groove length of the snake-shaped trimming pattern to control the resistor trimming accuracy;

[0082] Real-time monitoring and adjustment: During the laser resistance adjustment process, the measurement system monitors and measures the resistance Rt to be adjusted in real time. If the resistance value of Rt is within the adjustable resistance range, turn on the laser to adjust it, otherwise give up the adjustment and measure the next resistance. While adjusting the resistance, detect its resistance in real time and online. If the rough adjustment precision requirement is met, the adjustment is completed and the single-port direct adjustment is started. At the same time, the resistance value is continuously detected in real time and online. If the resistance adjustment precision requirement is met, turn off the laser, otherwise continue to etch along the adjustment direction until the resistance value meets the precision requirement.

[0083] In one embodiment, suppose we need to design a resistor with a resistance of 4Ω. First, we determine the resistor pattern through computer simulation and design, and then use a laser trimmer to cut according to the designed pattern. During the cutting process, we will accurately control the power, speed and focal length of the laser beam to ensure that the size and shape of the pattern meet the design requirements. For example, if the measured resistance value is too high, the resistance value can be reduced by increasing the length of the resistor body or reducing the cross-sectional area; conversely, if the resistance value is too low, the length of the resistor body can be reduced or the cross-sectional area can be increased. Through laser trimming, we can accurately adjust the resistance value to the designed value of 4Ω, ensuring the high frequency and high precision characteristics of the resistor.

[0084] During the laser resistance trimming process, the measurement system monitors and measures the resistance value Rt to be trimmed in real time at -55℃ to +150℃. The factors to be considered in selecting the temperature range are:

[0085] Material properties: Different materials have different coefficients of thermal expansion and temperature coefficient of resistance (TCR). When selecting the temperature range, it is necessary to consider the thermal properties of the resistor material to be trimmed.

[0086] Equipment Capabilities: The temperature control range and accuracy of the measurement system are important limiting factors in selecting the temperature range. The system needs to be able to provide stable temperature control within the specified temperature range.

[0087] Process requirements: According to the specific laser resistance trimming process requirements, select a temperature range that can reflect the performance of the resistor under actual use conditions.

[0088] Environmental conditions: Consider the temperature changes in the actual application environment and select a temperature range that can cover these changes.

[0089] Common temperature ranges:

[0090] Room temperature: Usually from 20°C to 25°C. This is a common reference temperature used for initial measurements and comparisons.

[0091] Extended temperature range: Typically from -55°C to +150°C. This range covers the operating and storage temperature requirements of most electronic components.

[0092] Specific process temperatures: Depending on the specific process requirements, higher temperature ranges may be required, for example, thermal stress testing of electronic components may require temperatures up to +200°C or higher.

[0093] The specific experimental data are:

[0094]

[0095] In the process of laser resistance trimming, selecting the appropriate temperature range for measurement and control is the key to ensuring the accuracy and stability of the resistance value. It can be seen from the experimental data that the resistance value Rt measured at different temperatures may be different, so it is necessary to select the appropriate temperature range according to the specific process requirements and environmental conditions. Through real-time monitoring and online measurement, the resistance value can be effectively adjusted and optimized to ensure its stable performance under various temperature conditions.

[0096] Furthermore, in the process of laser trimming to produce patterns, precise control of pattern size mainly involves the following aspects:

[0097] Computer-aided design (CAD) software: First, use CAD software to digitally design the pattern that needs to be engraved or cut;

[0098] Focus and pulse control of laser beam: Laser engraving can achieve high-precision processing effects by precisely controlling the focus and pulse of the laser. The energy density of the laser can be adjusted to exceed the damage threshold of the material only in the area you want to process, thereby completing fine engraving without affecting other parts of the material;

[0099] Laser beam movement control: The movement of the laser beam is controlled by a control system. This system can be computer-controlled to accurately move the laser beam according to the design pattern, thereby "drawing" the desired pattern on the material surface;

[0100] Automatic focusing technology: The automatic focusing technology of the laser cutting machine can help users perform cutting operations more efficiently and accurately. Automatic focusing technology includes automatic detection, automatic adjustment and automatic compensation. It can realize automatic adjustment of focal length by controlling the laser beam output power and the position of the focusing lens.

[0101] Parameter adjustment: adjust the parameters of the laser cutting machine, such as cutting depth, cutting speed and beam polarization, to obtain the best cutting effect;

[0102] Real-time monitoring and feedback: During the laser cutting process, the camera captures the image of the workpiece, and then uses image processing technology to calculate the distance between the workpiece and the detection lens, monitor the change of focal length in real time, and adjust the focal length according to the detection results;

[0103] The distance between the workpiece and the detection lens is the new focal length, and the depth z is calculated as follows:

[0104]

[0105] Where f is the focal length of the original camera, B is the baseline distance between the two cameras, and d is the horizontal coordinate difference of the same feature point in the images taken by the two cameras;

[0106] f new =f current +k(z target -z measured )

[0107] Among them, f new is the distance between the workpiece and the detection lens, f current is the distance between the existing workpiece and the detection lens, k is the adjustment coefficient, z target is the target depth, z measured To measure depth.

[0108] Precise hardware support: Using high-quality optics and precise control of the laser cutting machine’s process parameters are critical to avoiding problems.

[0109] In one embodiment, suppose we need to make a resistor with a design value of 4Ω on an AL2O3 ceramic substrate. First, we will use CAD software to design the resistor pattern, and then use a laser cutting machine to cut according to the design pattern. During the cutting process, we will accurately control the power, speed and focal length of the laser beam to ensure that the size and shape of the pattern meet the design requirements. For example, if we need to adjust the resistance value, we can do so by changing the length or cross-sectional area of ​​the resistor body. Through the precise control of the laser beam, we can remove part of the resistor material and thus accurately adjust the resistance value. Throughout the process, we will monitor and adjust the focal length in real time to ensure the accuracy and quality of the cutting. Finally, through laser trimming, we can accurately adjust the resistance value to the design value of 4Ω, ensuring the high frequency and high precision characteristics of the resistor.

[0110] As described in step S4 above, the resistance value adjustment uses laser cutting or chemical etching technology to trim the initial R value to the required resistance value. For high-frequency applications, accurate control of the resistance value is crucial. "Initial R value" refers to the resistance value of the resistor in the initial state during the resistor manufacturing process, that is, the resistance value before subsequent trimming and adjustment. This concept is mainly used to describe the original resistance value before adjusting the resistance value by laser trimming or other methods during the resistor manufacturing process, especially in the manufacture of thick film resistors. When manufacturing precision resistors, the initial R value is an important reference point because it is the basis for subsequent fine-tuning of the resistance value. By accurately adjusting and trimming the initial R value, it can be ensured that the resistor reaches the desired precise resistance value.

[0111] In one embodiment, the following methods can be used to detect the resistance value of the AL2O3 ceramic substrate after cutting:

[0112] Test with a high resistance meter: You can use the high resistance meter SM7110 for testing. The resistance display range of this device is 1×10^3Ω~2×10^19Ω, the maximum test voltage is DC1000V, and it can perform high-speed measurements with a maximum speed of 6.4ms. This device is suitable for measuring the insulation resistance of AL2O3 ceramic substrates, and you can customize the charge and discharge time before the test and the discharge time after the test.

[0113] Customized test fixture: With customized test fixture, the insulation resistance test of the whole DBC board can be realized. This fixture tests by contacting the object under test with the conductive sponge installed on the sheet electrode, avoiding the situation where the substrate cannot be fully contacted due to the warping of the substrate, and ensuring that the withstand voltage of all positions on the substrate surface can be tested.

[0114] The surface treatment described in step S5 above: improve the durability and stability of the resistor by combining physical treatment and chemical treatment. Specifically, the following treatment methods are included:

[0115] Electroless Nickel Immersion Gold (ENIG): This is a process that first plates nickel and then gold on the conductor on the surface of the PCB. The nickel layer acts as a barrier layer to prevent the mutual diffusion of the copper / gold interface and improve the welding reliability. The gold layer provides good conductivity and corrosion resistance; Advantages: not easy to oxidize, can be stored for a long time, the surface is flat, suitable for welding fine gap pins and components with small solder joints; Disadvantages: high cost, poor welding strength, because the use of electroless nickel plating process, it is easy to have the problem of black disk. The nickel layer will oxidize over time, and long-term reliability is a problem.

[0116] Organic solderability preservative (OSP): The OSP process coats a layer of organic solderability preservative on the PCB surface. This thin protective layer can effectively protect the PCB pads and solder feet from oxidation and corrosion. Advantages: simple process, very flat surface, suitable for lead-free soldering and SMT; Disadvantages: limited number of reflow soldering times, not suitable for crimping technology, wire binding, visual inspection and electrical testing are inconvenient, and storage conditions are high.

[0117] Immersion nickel palladium gold: The principle is similar to the immersion gold process. After chemical nickel deposition, the chemical palladium deposition process is added to use the palladium layer to isolate the attack of the immersion gold solution on the nickel layer; at the same time, the palladium layer has higher strength and wear resistance than the gold layer; Advantages: The gold plating layer is very thin and can be used for gold wire or aluminum wire; The palladium layer separates the nickel layer and the gold layer to prevent mutual migration between gold and nickel; There will be no black nickel phenomenon; Disadvantages: The process is more complicated and the cost is higher.

[0118] Example 2

[0119] In this embodiment, during the laser trimming process to generate the pattern, the laser energy accurately controls the resistance pattern including:

[0120] Laser power and frequency:

[0121] Laser power directly affects the intensity of the laser beam on the material. For example, in the LT7130 laser resistor trimmer, the average laser power is 8W@10KHZ, and this power level needs to be precisely adjusted according to the specific resistor material and trimming requirements.

[0122] Laser frequency is also a key parameter, which determines the emission rate of laser pulses. In the same laser resistor trimming machine, the laser frequency can be adjusted in the range of 0.5K-50K. Appropriate frequency selection helps to achieve smooth and precise resistor pattern trimming.

[0123] Pulse Width:

[0124] Pulse width is the duration of the laser pulse, which affects the length of time the laser interacts with the material. Shorter pulse widths generally mean higher peak power and more precise energy control. In some laser systems, pulse widths can reach levels of 40ns, ensuring fine processing of resistive materials.

[0125] Beam quality and positioning accuracy:

[0126] Beam quality, such as the M2 factor, is an important indicator of laser beam focusing performance. A high-quality beam (such as M2 < 1.3) can achieve a smaller focused spot and higher energy density, thereby improving the accuracy of trimming.

[0127] Positioning accuracy determines the ability of the laser beam to accurately reach and act on the predetermined position. For example, the repeatability of some laser trimming systems can reach ±2μm, which means that the laser beam can be repeatedly positioned at the same position with high accuracy during multiple consecutive laser trimming processes.

[0128] Motion system and control method:

[0129] The accuracy and stability of the motion system are critical to ensuring the continuity and consistency of laser trimming. For example, the use of a linear motor motion system can provide a maximum speed of up to 1000mm / s and a positioning accuracy of ±10μm.

[0130] Control methods, such as triggering and synchronous frequency control, also affect the accuracy and efficiency of laser trimming. By optimizing the control method, errors and instabilities in the trimming process can be further reduced.

[0131] Real-time monitoring and feedback:

[0132] During the laser trimming process, real-time monitoring of the change in resistance value is essential. By real-time monitoring of the resistance value through constant current pressure measurement and other methods, and comparing it with the preset target value, the laser parameters can be adjusted in time to ensure the accuracy and precision of the trimming.

[0133] The feedback mechanism allows dynamic adjustment of laser parameters based on real-time monitoring results, thereby further optimizing the trimming process and reducing errors.

[0134] Among them, in the process of laser trimming to generate patterns, the process of laser energy accurately controlling the resistance pattern is calculated and controlled by an algorithm formula to process parameters, including the following calculations:

[0135] Calculate the laser power. The laser power is P, which refers to the energy output of the laser beam per unit time.

[0136]

[0137] Where E is the energy of the laser pulse and t is the pulse time.

[0138] Calculate the laser pulse width τ,

[0139]

[0140] Where E is the energy of the laser pulse and P is the laser power.

[0141] Calculate the pulse frequency f, which refers to the number of laser pulses emitted per second;

[0142]

[0143] Where T is the pulse period.

[0144] During the laser trimming process, the beam quality and focus need to be calculated. The spot diameter d is calculated as follows. The spot diameter is the diameter of the laser beam after focusing:

[0145]

[0146] Where l is the focal length of the lens, λ is the laser wavelength, and D is the initial diameter of the laser beam.

[0147] The beam quality is M 2 , refers to the parameter that measures the focusing ability of the beam and is calculated as follows:

[0148]

[0149] Where d is the spot diameter, λ is the laser wavelength, and D is the initial diameter of the laser beam.

[0150] During the laser trimming process, the motion system and positioning accuracy need to be calculated. The displacement S refers to the distance the laser beam moves on the substrate;

[0151] S=v×t

[0152] Where v is the speed of the laser beam and t is the time it takes for the laser to move.

[0153] Positioning accuracy σ refers to the standard deviation of the position error. The positioning accuracy is calculated as follows:

[0154]

[0155] Among them, x i is the position of the ith measurement, μ is the average position, and N is the number of measurements.

[0156] When adjusting and controlling the laser parameters, feedback control is performed through the PID control algorithm, as follows:

[0157]

[0158] Among them, u(t) is the control output, K p e(t) is the proportional term, is the integral term, is the differential term, K p , K i , K d , are the proportional, integral and differential coefficients respectively, and e(t) is the error.

[0159] When testing the prepared substrate, the thermal diffusivity α of the substrate material needs to be calculated as follows:

[0160]

[0161] Where k is the thermal conductivity, ρ is the density, C p is the specific heat capacity.

[0162] In one embodiment,

[0163] Experimental example data

[0164]

[0165] Among them, laser power: the laser power of different experimental numbers is slightly different to test the change of resistance value under different powers.

[0166] Pulse Width: The pulse width was varied from 45ns to 60ns to observe its effect on the resistance value.

[0167] Pulse frequency: The pulse frequency ranges from 17kHz to 25kHz to test the effect of different frequencies on the resistance trimming effect.

[0168] Spot diameter: The spot diameter ranges from 2.4μm to 4.0μm to study the effect of spot size on resistor pattern accuracy.

[0169] Moving speed: The moving speed ranges from 85mm / s to 140mm / s to test the trimming effect at different speeds.

[0170] Resistance value: The actual measured resistance value, used to compare with the target resistance value and calculate the error.

[0171] Positioning accuracy: The positioning accuracy for all experiments was 1 μm, indicating that the laser beam was able to be repeatedly positioned at the same location with high accuracy in all experiments.

[0172] Target resistance value: The target resistance value for each experiment is 500Ω or 480Ω, which is used to calculate the error.

[0173] Error: The difference between the actual resistance value and the target resistance value, used to evaluate the accuracy of trimming.

[0174] With these experimental data, the algorithms and formulas mentioned above can be applied to optimize and adjust the laser parameters to achieve more accurate resistor pattern trimming.

[0175] Example 3

[0176] In this embodiment, laser cutting or chemical etching technology is used to trim the initial R value to the required resistance value; the specific operations and experiments for improving the durability and stability of the resistor by combining physical treatment and chemical treatment include the following:

[0177] Initial resistance measurement: Use an ohmmeter to measure the initial resistance.

[0178] Laser cutting or chemical etching: choose the appropriate technology to adjust the resistor value according to your needs.

[0179] Measurement of resistance value after trimming: Use the ohmmeter again to measure the resistance value after trimming.

[0180] Data recording: record the initial resistance value, trimming parameters, trimmed resistance value and error for each experiment.

[0181] Experimental data

[0182]

[0183]

[0184]

[0185] Surface treatment experimental steps and data:

[0186] Cleaning: Use a suitable cleaning agent to clean the resistor surface.

[0187] Physical treatment: Polishing, sandblasting or other physical treatments are performed to improve surface quality.

[0188] Chemical treatment: Use specific chemical treatment agents (such as antioxidants, anti-corrosion agents) for treatment.

[0189] Durability and stability testing: Conduct durability tests (such as high temperature, humidity, mechanical stress, etc.) and stability tests (such as long-term resistance value changes).

[0190] Data recording: Record resistance value, durability and stability data before and after treatment.

[0191] Experimental data

[0192]

[0193]

[0194] It can be seen from the above experimental data that laser cutting and chemical etching technology can effectively adjust the resistance value, and the error can be within a reasonable range. Surface treatment steps (such as cleaning, polishing, sandblasting, anti-oxidation and anti-corrosion treatment) significantly improve the durability and stability of the resistor. The results of durability and stability tests show that the treated resistors can maintain good performance in various environments, and the change in resistance value is within an acceptable range. These experimental data provide a reliable reference for resistor trimming and surface treatment in practical applications.

[0195] The process principle of manufacturing high-frequency and high-precision resistor devices: First, select materials: select materials with excellent environmental resistance, such as Ta2Nx (tantalum nitride) as the basic material, which can achieve a very small temperature coefficient of resistance (TCR); molding: the ceramic material is molded into the required shape by pressing or molding, which requires extremely high precision to ensure that the size of each resistor is consistent; sintering: the formed ceramic needs to be sintered at high temperature to enhance its physical properties. In this process, the ceramic particles will combine with each other at high temperature to form a dense ceramic body; deposit conductive film: deposit an extremely thin conductive film on the substrate, and this film will be photolithographically and etched to form the required resistor element. The thickness of the conductive film of thin film resistors is generally between 100 nanometers and 1 micron; photolithography and etching: photolithography and etching of the deposited conductive film to form the required resistor element; resistance value adjustment: laser cutting or chemical etching technology is used to trim the initial R value to the required resistance value; surface treatment: surface treatment is performed to improve the durability and stability of the resistor, usually using coating or packaging technology to prevent the external environment from affecting the resistor performance; primary glass protection: protect the printed resistor layer to prevent large-scale damage to the resistor layer during the next laser trimming process; laser trimming: cutting the resistor body with a laser spot to change the aspect ratio of the resistor, so that the initial R value is increased to the required value; secondary glass protection: the resistor after cutting The protective layer is used for secondary protection. The protective layer must have the function of acid and alkali resistance to prevent the resistor from being affected by the external environment; resistance code printing: the resistance value is marked with a digital code; folding strips: the substrate after the previous code is sintered is divided into strips; end face vacuum sputtering: used as a side conductor, the stacked folded strips are placed in a vacuum sputtering machine for sputtering, drying and sintering; folding particles: the strip workpiece is divided into individual particles; electroplating: the use of a roller to perform electrolytic electroplating in the electroplating solution to increase the solderability; magnetic screening: the magnetism of nickel is used to screen out defective products; electrical performance testing: the resistance of the two electrode ends is tested using an automatic testing machine, and qualified products are selected according to different precision requirements; taping packaging: the resistor is packed into a paper tape into a reel.

[0196] The above processes elaborate on the manufacturing process of high-frequency and high-precision resistor components. Each step focuses on the control of accuracy and performance to ensure that the final product can meet the requirements of high frequency and high precision.

[0197] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0198] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. The manufacturing process of high-frequency and high-precision resistor components is characterized in that: The following steps are involved: S1. Substrate molding: The substrate material powder is molded into the desired substrate shape by pressing or molding, and sintered; S2. Deposition of conductive film: Deposit an extremely thin conductive film on the substrate, and use nickel-chromium alloy material to make resistor layers of different thicknesses to adapt to various resistance values; S3, photolithography and etching: Generate patterns through photolithography or laser trimming, add resistance paths and calibrate resistance values ​​to ensure that the resistance values ​​are within the design range; S4. Resistance value adjustment: Use laser cutting or chemical etching technology to trim the initial R value to the required resistance value; S5. Surface treatment: Improve the durability and stability of resistors through a combination of physical and chemical treatments; S6. Screening and packaging: Perform coating or packaging processes to isolate the impact of the external environment on resistor performance.

2. The manufacturing process of the high-frequency and high-precision resistor device according to claim 1, characterized in that: In step S1, the substrate material is at least one of aluminum oxide, aluminum nitride, beryllium oxide and polytetrafluoroethylene.

3. The manufacturing process of the high-frequency and high-precision resistor device according to claim 1, characterized in that: The surface treatment described in step S5 includes: Physical treatment: Use metal shielding and anti-static treatment to improve the anti-interference ability of the circuit board; and, Chemical treatment: Chemical nickel plating, gold immersion and coating of organic solderability preservatives are used to improve the corrosion resistance and adhesion of the surface.

4. The manufacturing process of the high-frequency and high-precision resistor device according to claim 1, characterized in that: The photolithography process described in step S3 includes: Spin coating 200-500 nanometers of photoresist sensitive material on the substrate; and, Allow ultraviolet light to irradiate the photosensitive material through a pre-prepared mask with a certain pattern; The photosensitive material in the area irradiated by ultraviolet light can be removed by development or not, thereby transferring the image of the mask to the photosensitive material.

5. The manufacturing process of the high-frequency and high-precision resistor device according to claim 1, characterized in that: The method for producing a pattern by laser trimming in step S3 is: A laser beam with variable intensity is used to expose the photoresist on the surface of the substrate. By precisely controlling the intensity and exposure time of the laser, the desired precise pattern is formed on the photoresist.

6. The manufacturing process of the high-frequency and high-precision resistor device according to claim 4 or 5, characterized in that: The method of adding a resistance path and calibrating the resistance value described in step S3 is: Laser cutting technology is used to cut the resistor body with laser light spots to change the aspect ratio of the resistor, thereby adjusting the resistance value. The calculation formula for the resistance value is: Where ρ is the resistivity of the material, l is the length of the resistive material, and s is the cross-sectional area.

7. The manufacturing process of the high-frequency and high-precision resistor device according to claim 6, characterized in that: The method described in step S3 to ensure that the resistance value is within the design range is: After the photolithography and etching steps, the resistance value is measured and calibrated; When the measured resistance is too high, you can reduce the resistance by increasing the length of the resistor or reducing the cross-sectional area; conversely, if the resistance is too low, reduce the length of the resistor or increase the cross-sectional area.

8. The manufacturing process of the high-frequency and high-precision resistor device according to claim 5, characterized in that: During the laser trimming process, the method of accurately controlling the resistor pattern by laser energy is as follows: The laser beam cuts the resistor according to a computer-preset program, thereby changing the resistance value of the resistor by changing the geometric shape of the resistor; When laser resistance is adjusted, the rated power output state of the laser is maintained, an attenuation link is added to the optical path, and the laser power is adjusted through the attenuator; The resistance value change is monitored in real time through a high-precision digital bridge to control the resistance adjustment process; The combination of the serpentine adjustment pattern and the single-port straight adjustment pattern is adopted to control the resistance adjustment accuracy by effectively determining the cutting groove length of the serpentine adjustment pattern. During the laser resistance trimming process, the measurement system monitors in real time and measures online the resistance value Rt of the resistor to be trimmed at -55℃ to +150℃. If the resistance value of Rt is within the adjustable resistance range, turn on the laser to adjust its resistance, otherwise give up the adjustment and measure the next resistance; While adjusting the resistance, the resistance value is detected online in real time. If the rough adjustment precision requirement is reached, the adjustment is completed and the single-port direct adjustment is started. Meanwhile, the resistance value is detected online in real time. If the resistance adjustment accuracy requirement has been reached, turn off the laser, otherwise continue to etch along the adjustment direction until the resistance reaches the accuracy requirement.

9. The manufacturing process of the high-frequency and high-precision resistor device according to claim 5, characterized in that: The method for accurately controlling the pattern size during laser trimming is: Use CAD software to digitally design the pattern that needs to be engraved or cut; By precisely controlling the focus and pulse of the laser, the energy density of the laser is adjusted to exceed the damage threshold of the material only in the area you want to process; The movement of the laser beam is controlled by a computer control system, and the laser beam is accurately moved according to the design pattern to draw the desired pattern on the surface of the material; Automatic focusing of the laser cutting machine is achieved by controlling the laser beam output power and the position of the focusing lens; Adjust the cutting depth, cutting speed and beam polarization of the laser cutting machine as needed to obtain the best cutting effect; During the laser cutting process, the image of the workpiece is captured by a camera, and then the distance between the workpiece and the detection lens is calculated through image processing technology. The change in focal length is monitored in real time and the focal length is adjusted according to the detection results.

10. The manufacturing process of high-frequency and high-precision resistor device according to claim 7, characterized in that: The resistance value is measured as follows: Randomly selecting and cutting several groups of prepared substrates; Customized test fixture, which is tested by contacting the substrate under test through the conductive sponge installed on the sheet electrode.

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