Novel green circuit board disassembling method

Abstract

The invention provides a novel circuit board green disassembling method, and belongs to the technical field of electronic waste disposal, the novel circuit board green disassembling method comprises the steps of circuit board pretreatment, information recording and electrostatic dust collection; preheating at low temperature, controlling the heating rate and ventilating; nondestructive desoldering is carried out, and infrared heating is matched with ultrasonic vibration; components are classified and recycled, and proper clamps are used; substrate material separation and biological enzyme treatment; metal refining and organic material recovery; according to the method, various innovative technologies and processes are adopted, parameters are accurately controlled, and special equipment tools such as an electrostatic dust collection device, preheating equipment, an infrared heating device, a biological enzyme treatment system and an adaptive clamp are used; the problems that according to a traditional disassembling method, environmental pollution is serious, the resource recovery rate is low, and damage to circuit boards and components is large are solved, green and efficient disassembling is achieved, the resource recovery rate is increased, and the integrity of the circuit boards and the components is protected.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic waste treatment, and in particular relates to a novel green disassembly method for circuit boards. Background Art

[0002] With the rapid development of electronic technology, electronic products are updated more and more frequently, and a large number of waste circuit boards are generated. The traditional circuit board disassembly methods mainly have the following problems: serious environmental pollution: some traditional disassembly methods adopt chemical treatment methods and use a large amount of chemical reagents, which is not only costly, but also causes serious environmental pollution, such as the discharge of wastewater, waste gas and waste residue, which poses a threat to the ecosystem and human health. The resource recovery rate is low: traditional physical disassembly methods often find it difficult to finely separate the various materials in the circuit board, resulting in a large amount of valuable metals and organic materials that cannot be effectively recycled, causing waste of resources and great damage to the circuit board and components: whether it is physical crushing or some rough chemical treatment methods, it is easy to cause irreversible damage to the components on the circuit board, reducing the reusable value of the components.

[0003] Therefore, based on the above technical problems, it is necessary to design a new green disassembly method for circuit boards. This method will adopt a series of innovative technologies and processes, and fully consider environmental protection requirements and resource recovery efficiency in all aspects from circuit board pretreatment, disassembly to material recovery and post-processing. By precisely controlling various parameters in the disassembly process, such as temperature, pressure, chemical reagent concentration, etc., and using special equipment and tools, such as special infrared heating devices, bio-enzyme treatment systems, and adapted fixtures, etc., the green and efficient disassembly of waste circuit boards can be achieved, environmental pollution can be minimized, resource recovery rate can be improved, and the integrity of circuit boards and components can be protected, so that they have higher reuse value. Summary of the invention

[0004] The purpose of the present invention is to provide a new green disassembly method for circuit boards, aiming to solve the problems in the prior art that traditional chemical disassembly methods use a large amount of chemical reagents, causing serious environmental pollution, traditional physical disassembly is prone to dust pollution, some heating operations in the disassembly process may produce waste gas emissions, and traditional physical crushing and some inappropriate chemical treatment methods are prone to damage circuit boards and components.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A novel green disassembly method for a circuit board, characterized by comprising the following steps:

[0007] Step 1: PCB pretreatment:

[0008] Conduct a visual inspection of the scrap circuit boards and record in detail information such as their brand, model, size, and the general layout of components;

[0009] Use an electrostatic vacuum cleaner to remove dust and debris from the circuit board surface, where the electrostatic voltage of the electrostatic vacuum cleaner should be controlled within the range of [X1] to [X2] volts to ensure effective dust removal without causing electrostatic damage to the circuit board;

[0010] Step 2: Low temperature preheating:

[0011] Place the pretreated circuit board into the preheating equipment, raise the temperature to 80℃-100℃ at a heating rate of [Y1]℃ / min to [Y2]℃ / min, and maintain for 10-15 minutes;

[0012] The ventilation device in the preheating equipment should ensure an air flow rate of [Z1] cubic meters per hour to [Z2] cubic meters per hour, so that the hot air flows evenly over the circuit board and at the same time exhausts any small amount of organic gas that may be generated;

[0013] Step 3: Non-destructive desoldering:

[0014] Use a special infrared heating device to locally heat the solder joints on the circuit board, quickly raising the temperature of the solder joints to the melting point of the solder (usually 180℃-220℃), but ensure that the temperature of other parts of the circuit board does not exceed 120℃ to prevent thermal damage to components. The infrared lamp power of the infrared heating device should be [W1] watts to [W2] watts, and the dimensional accuracy of the heating area should be controlled within the range of [millimeter level accuracy parameter];

[0015] During the heating process, use tiny ultrasonic vibrations with a frequency between [F1] Hz and [F2] Hz and an amplitude of [micrometer amplitude parameter] to reduce the adhesion between the solder and the component pins and the circuit board pads, thereby achieving non-destructive desoldering of the components;

[0016] Step 4: Components classification and recycling:

[0017] Use a vacuum pen or mechanical clamp to carefully remove the desoldered components one by one, and place them according to the type (such as resistors, capacitors, integrated circuits, etc.), size and function of the components. The suction force of the vacuum pen should be between [P1] Pascal and [P2] Pascal to ensure that the components can be stably sucked without damaging their pins. For mechanical clamps, the clamping force should be controlled in the range of [Q1] Newton to [Q2] Newton to avoid excessive squeezing of the components;

[0018] For some special and easily damaged components (such as precision sensors, etc.), specially designed flexible fixtures are used for disassembly. The material of the flexible fixture should have a certain elastic modulus within the [elastic modulus range] to ensure that it can provide sufficient clamping force and buffer the impact of external forces on the components during the disassembly process;

[0019] Step 5: Separation of substrate materials:

[0020] Place the circuit board substrate after removing the components into a solution containing a specific biological enzyme that can specifically decompose the organic resin material in the substrate and has little effect on the metal part. The concentration of the biological enzyme should be controlled between [C1] g / L and [C2] g / L, and the pH value of the solution should be maintained in the range of [pH1] to [pH2];

[0021] At a suitable temperature (e.g., 30°C-40°C), the substrate is subjected to degradation treatment to separate the metal foil layer from the organic resin layer. The stirring speed during the treatment should be [R1] rpm to [R2] rpm to ensure that the biological enzyme is in full contact with the substrate;

[0022] Step 6: Metal Refining and Organic Material Recovery:

[0023] The separated metal foil layer is further refined to recover valuable metals such as copper, gold, and silver by electrolysis or chemical precipitation to a certain purity standard. The current density during the electrolysis process should be controlled between [A1] amperes per square meter and [A2] amperes per square meter, and the amount of chemical precipitant added should be accurately calculated based on the metal ion concentration to ensure that the metal recovery rate is above [recovery rate percentage range];

[0024] For the degraded organic resin solution, a series of treatment processes (such as flocculation, precipitation, evaporation, etc.) are used to recover the organic components and convert them into reusable organic materials or energy. The type and amount of flocculant added during the flocculation process should be determined according to the properties of the solution, the precipitation time should be between [T1] hours and [T2] hours, and the evaporation temperature should be controlled within the range of [V1]℃ to [V2]℃;

[0025] Step 7: Disassembly and quality inspection:

[0026] After disassembly, the circuit boards and components should be thoroughly cleaned to remove residual solder, impurities and pollutants on the surface. The cleaning agents used in the cleaning process should meet environmental protection standards, and the content of harmful substances in their ingredients should be lower than [limit standards for harmful substances];

[0027] Use professional testing equipment to perform performance testing and quality assessment on recycled components, screen out components that can be directly reused and those that need further repair, and perform environmentally friendly treatment on unusable components. The accuracy of the testing equipment should meet the [testing accuracy requirements], and accurately measure and judge the various performance indicators of components (such as resistance value accuracy, capacitance value deviation, integrated circuit functional integrity, etc.);

[0028] Conduct quality monitoring and data analysis on the entire disassembly process, summarize experience and lessons learned, continuously optimize disassembly processes and parameters, and improve disassembly efficiency and resource recovery rate. A corresponding indicator system should be established for quality monitoring, including but not limited to disassembly time, component damage rate, resource recovery rate, etc. These indicators should be regularly counted and analyzed, and process parameters should be adjusted based on the analysis results. The disassembly time should be controlled within [time range], and the component damage rate should be lower than [damage rate percentage].

[0029] As a preferred solution of the present invention, the electrostatic dust collection device is an industrial-grade or small-scale high-efficiency electrostatic dust collection device, and the specific type is selected according to the size of the circuit board and the amount of dust.

[0030] As a preferred solution of the present invention, the preheating device is a heating box or a heating chamber that can accurately control the temperature and the heating rate, and the interior of the heating box or the heating chamber should have a uniform heat distribution structure.

[0031] As a preferred solution of the present invention, the infrared heating device should have precise temperature control and heating area positioning functions, and can be flexibly adjusted according to the layout and size of different solder joints on the circuit board.

[0032] As a preferred solution of the present invention, the vacuum suction pen, mechanical clamp and flexible clamp should be selected and designed according to the shape, size and material of the components to ensure stable operation without damaging the components during the disassembly process.

[0033] As a preferred solution of the present invention, the bio-enzyme treatment system should include a reaction tank, a stirring device, a bio-enzyme adding device and a product separation device, and each part should work together to achieve efficient separation of substrate materials and recovery of organic materials.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. In this scheme, the use of chemical reagents is reduced: by adopting green technologies such as bio-enzyme treatment systems, the use of a large number of chemical reagents is avoided, and the pollution to the environment is reduced from the source. For example, bio-enzymes can specifically decompose the organic resin materials in the substrate, but have little effect on the metal part, reducing the use of chemical reagents in the process of separating substrate materials;

[0036] Control dust and waste gas emissions: Use electrostatic dust collection equipment to remove dust in the pretreatment stage, and reasonably design ventilation equipment during preheating and non-destructive soldering processes to effectively control dust and waste gas emissions. For example, ensure that the air flow rate in the preheating equipment is [Z1]-[Z2] cubic meters per hour to exhaust the small amount of organic gas that may be generated.

[0037] 2. In this solution, a series of precisely controlled steps are used to achieve fine separation of materials. In the substrate material separation step, the concentration of the biological enzyme is controlled between [C1]-[C2] g / L, the pH value of the solution is controlled within the range of [pH1]-[pH2], and the stirring speed is controlled within the range of [R1]-[R2] rpm, so that the organic resin material in the substrate is effectively decomposed and the metal foil layer is separated from the organic resin layer. Subsequently, the metal and organic materials are efficiently recovered through various methods such as electrolysis, chemical precipitation, and flocculation, thereby improving the resource recovery rate. For example, during the electrolysis process, the current density is controlled between [A1]-[A2] amperes per square meter to ensure that the metal recovery rate is above [recovery rate percentage range].

[0038] 3. In this solution, gentle and precise disassembly technology: gentle and precise technical means are used in each disassembly step. For example, a special infrared heating device is used in the non-destructive desoldering process with ultrasonic vibration to quickly raise the temperature of the solder point to the melting point of the solder (180℃-220℃), while ensuring that the temperature of other parts of the circuit board does not exceed 120℃ to avoid thermal damage to components;

[0039] Suitable fixture selection: Select appropriate fixtures for disassembly based on the characteristics of components. The suction force of the vacuum pen should be between [P1]-[P2] Pascals, and the clamping force of the mechanical fixture should be within the range of [Q1]-[Q2] Newtons. For special components, use flexible fixtures (elastic modulus within the [elastic modulus range]) to ensure stable operation without damaging components during disassembly, thereby increasing the reusability of components. DETAILED DESCRIPTION

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] The present invention provides the following technical solutions:

[0043] A novel green disassembly method for circuit boards, characterized in that it comprises the following steps: circuit board pretreatment:

[0044] Conduct a visual inspection of the scrap circuit boards and record in detail information such as their brand, model, size, and the general layout of components;

[0045] Use an electrostatic vacuum cleaner to remove dust and debris from the circuit board surface, where the electrostatic voltage of the electrostatic vacuum cleaner should be controlled within the range of [X1] to [X2] volts to ensure effective dust removal without causing electrostatic damage to the circuit board;

[0046] Step 2: Low temperature preheating:

[0047] Place the pretreated circuit board into the preheating equipment, raise the temperature to 80℃-100℃ at a heating rate of [Y1]℃ / min to [Y2]℃ / min, and maintain for 10-15 minutes;

[0048] The ventilation device in the preheating equipment should ensure an air flow rate of [Z1] cubic meters per hour to [Z2] cubic meters per hour, so that the hot air flows evenly over the circuit board and at the same time exhausts any small amount of organic gas that may be generated;

[0049] Step 3: Non-destructive desoldering:

[0050] Use a special infrared heating device to locally heat the solder joints on the circuit board, quickly raising the temperature of the solder joints to the melting point of the solder (usually 180℃-220℃), but ensure that the temperature of other parts of the circuit board does not exceed 120℃ to prevent thermal damage to components. The infrared lamp power of the infrared heating device should be [W1] watts to [W2] watts, and the dimensional accuracy of the heating area should be controlled within the range of [millimeter level accuracy parameter];

[0051] During the heating process, use tiny ultrasonic vibrations with a frequency between [F1] Hz and [F2] Hz and an amplitude of [micrometer amplitude parameter] to reduce the adhesion between the solder and the component pins and the circuit board pads, thereby achieving non-destructive desoldering of the components;

[0052] Step 4: Components classification and recycling:

[0053] Use a vacuum pen or mechanical clamp to carefully remove the desoldered components one by one, and place them according to the type (such as resistors, capacitors, integrated circuits, etc.), size and function of the components. The suction force of the vacuum pen should be between [P1] Pascal and [P2] Pascal to ensure that the components can be stably sucked without damaging their pins. For mechanical clamps, the clamping force should be controlled in the range of [Q1] Newton to [Q2] Newton to avoid excessive squeezing of the components;

[0054] For some special and easily damaged components (such as precision sensors, etc.), specially designed flexible fixtures are used for disassembly. The material of the flexible fixture should have a certain elastic modulus within the [elastic modulus range] to ensure that it can provide sufficient clamping force and buffer the impact of external forces on the components during the disassembly process;

[0055] Step 5: Separation of substrate materials:

[0056] Place the circuit board substrate after removing the components into a solution containing a specific biological enzyme that can specifically decompose the organic resin material in the substrate and has little effect on the metal part. The concentration of the biological enzyme should be controlled between [C1] g / L and [C2] g / L, and the pH value of the solution should be maintained in the range of [pH1] to [pH2];

[0057] At a suitable temperature (e.g., 30°C-40°C), the substrate is subjected to degradation treatment to separate the metal foil layer from the organic resin layer. The stirring speed during the treatment should be [R1] rpm to [R2] rpm to ensure that the biological enzyme is in full contact with the substrate;

[0058] Step 6: Metal Refining and Organic Material Recovery:

[0059] The separated metal foil layer is further refined to recover valuable metals such as copper, gold, and silver by electrolysis or chemical precipitation to a certain purity standard. The current density during the electrolysis process should be controlled between [A1] amperes per square meter and [A2] amperes per square meter, and the amount of chemical precipitant added should be accurately calculated based on the metal ion concentration to ensure that the metal recovery rate is above [recovery rate percentage range];

[0060] For the degraded organic resin solution, a series of treatment processes (such as flocculation, precipitation, evaporation, etc.) are used to recover the organic components and convert them into reusable organic materials or energy. The type and amount of flocculant added during the flocculation process should be determined according to the properties of the solution, the precipitation time should be between [T1] hours and [T2] hours, and the evaporation temperature should be controlled within the range of [V1]℃ to [V2]℃;

[0061] Step 7: Disassembly and quality inspection:

[0062] After disassembly, the circuit boards and components should be thoroughly cleaned to remove residual solder, impurities and pollutants on the surface. The cleaning agents used in the cleaning process should meet environmental protection standards, and the content of harmful substances in their ingredients should be lower than [limit standards for harmful substances];

[0063] Use professional testing equipment to perform performance testing and quality assessment on recycled components, screen out components that can be directly reused and those that need further repair, and perform environmentally friendly treatment on unusable components. The accuracy of the testing equipment should meet the [testing accuracy requirements], and accurately measure and judge the various performance indicators of components (such as resistance value accuracy, capacitance value deviation, integrated circuit functional integrity, etc.);

[0064] Conduct quality monitoring and data analysis on the entire disassembly process, summarize experience and lessons learned, continuously optimize disassembly processes and parameters, and improve disassembly efficiency and resource recovery rate. A corresponding indicator system should be established for quality monitoring, including but not limited to disassembly time, component damage rate, resource recovery rate, etc. These indicators should be regularly counted and analyzed, and process parameters should be adjusted based on the analysis results. The disassembly time should be controlled within [time range], and the component damage rate should be lower than [damage rate percentage].

[0065] In a specific embodiment of the present invention, 1. Circuit board pretreatment: Appearance inspection A detailed appearance inspection of the waste circuit board is performed. For example, for a waste computer motherboard, its brand is recorded as [brand name], model is [specific model], and size is [specific value of length × width × thickness]. It is observed that its main components are distributed in specific areas of the motherboard, such as a large number of capacitors and resistors concentrated around the CPU, and there are specific chips near the graphics card interface.

[0066] The electrostatic dust collector used was an industrial-grade electrostatic dust collector (selected based on the large size of the circuit board and the moderate amount of dust), and the electrostatic voltage was controlled within the range of [X1] to [X2] volts (the actual value was [specific value] volts). The device effectively removed dust and debris from the surface of the circuit board without causing electrostatic damage to the circuit board.

[0067] 2. Low-temperature preheating: Place the pretreated circuit board in a heating box (as a preheating device, it meets the requirements of accurately controlling the temperature and heating rate and having a uniform heat distribution structure inside), and raise the temperature to 80℃-100℃ (actually raise the temperature to [specific temperature value]℃) at a heating rate of [Y1]℃ / min (actual value is [specific heating rate value]℃ / min) to [Y2]℃ / min, and keep it for 10-15 minutes (actual holding time is [specific holding time value] minutes);

[0068] The ventilation device in the preheating device ensures that the air flow rate is [Z1] cubic meters per hour to [Z2] cubic meters per hour (the actual air flow rate is [specific flow rate value] cubic meters per hour), so that the hot air flows evenly through the circuit board, and at the same time, a small amount of organic gas that may be generated is discharged. In the embodiment, a small amount of odorous gas can be smelled being discharged;

[0069] 3. Non-destructive desoldering: A special infrared heating device is used, the infrared lamp power of which is [W1] watts to [W2] watts (the actual power is [specific power value] watts), and the dimensional accuracy of the heating area is controlled within the range of [millimeter-level accuracy parameter] (the actual accuracy reaches [specific accuracy value] mm). The solder joints on the circuit board are locally heated, and the temperature of the solder joints is quickly raised to the melting point of the solder (for example, 180°C-220°C, actually raised to [specific solder joint temperature value]°C), while ensuring that the temperature of other parts of the circuit board does not exceed 120°C (in the embodiment, the highest temperature of other parts monitored by the temperature monitoring device is [specific temperature value]°C), effectively preventing thermal damage to components;

[0070] During the heating process, a tiny ultrasonic vibration is used, the frequency of which is between [F1] Hz and [F2] Hz (the actual frequency is [specific frequency value] Hz) and the amplitude is [micrometer-level amplitude parameter] (the actual amplitude is [specific amplitude value] micrometer), which reduces the adhesion between the solder and the component pins and the circuit board pads, thereby achieving non-destructive desoldering of the components. In the embodiment, the solder of most solder joints is successfully separated from the component pins and pads under this combined action;

[0071] 4. Components classification and recycling:

[0072] Use a vacuum suction pen (suction force between [P1] Pascal and [P2] Pascal, actual suction force is [specific suction force value] Pascal) and a mechanical clamp (clamping force between [Q1] Newton and [Q2] Newton, actual clamping force is [specific clamping force value] Newton) to carefully remove the desoldered components one by one, and classify and place them according to the type, size and function of the components. For example, resistors, capacitors, etc. are placed in different storage boxes according to different specifications, and integrated circuit chips are also classified according to their functions and models;

[0073] For some special and easily damaged components (such as precision sensors, etc.), a specially designed flexible clamp is used for disassembly. The material elastic modulus of the flexible clamp is within the [elastic modulus range] (the actual elastic modulus is [specific elastic modulus value]), ensuring that it can provide sufficient clamping force and buffer the impact of external forces on the components during the disassembly process. In the embodiment, the precision sensor is smoothly disassembled without damage under the action of the flexible clamp;

[0074] 5. Substrate material separation:

[0075] Place the circuit board substrate after removing the components into a solution containing a specific biological enzyme, the concentration of the biological enzyme is controlled between [C1] g / L and [C2] g / L (the actual concentration is [specific concentration value] g / L), and the pH value of the solution is maintained in the range of [pH1] to [pH2] (the actual pH value is [specific pH value]). Degrade the substrate at a suitable temperature (e.g., 30°C-40°C, the actual temperature is [specific temperature value]°C), and the stirring speed during the treatment process is [R1] rpm to [R2] rpm (the actual stirring speed is [specific stirring speed value] rpm), so that the biological enzyme is fully in contact with the substrate, and finally the metal foil layer and the organic resin layer are separated;

[0076] The metal foil layer and the degraded organic resin solution are separated by a filtration device (as part of the product separation device), thereby achieving a preliminary separation of the substrate material. In the embodiment, it can be observed that the metal foil layer and the solution are clearly separated;

[0077] 6.Metal refining and organic material recycling:

[0078] The separated metal foil layer is further refined by electrolysis (the current density during the electrolysis process is controlled between [A1] amperes per square meter and [A2] amperes per square meter, and the actual current density is [specific current density value] amperes per square meter) to recover valuable metals such as copper, gold, and silver therein to a certain purity standard (in the embodiment, the purity of the recovered metal is detected by a detection device to meet the requirements of relevant industrial applications);

[0079] The degraded organic resin solution is treated through a series of processes such as flocculation, precipitation, and evaporation. The type and amount of flocculant added during the flocculation process are determined according to the properties of the solution (in the example, [specific flocculant name] flocculant is used, and the amount added is [specific amount added value]), the precipitation time is between [T1] hours and [T2] hours (the actual precipitation time is [specific precipitation time value] hours), and the evaporation temperature is controlled within the range of [V1]°C to [V2]°C (the actual evaporation temperature is [specific evaporation temperature value]°C), and the organic components therein are recovered and converted into reusable organic materials or energy. In the example, some organic components were successfully recovered and subsequent utilization attempts were made;

[0080] 7. Post-disassembly processing and quality inspection:

[0081] The disassembled circuit boards and components are thoroughly cleaned, and the cleaning agents used meet environmental standards (the harmful substance content in its ingredients is lower than [harmful substance limit standard], and the actual detected harmful substance content is [specific content value]), effectively removing residual solder, impurities and pollutants on the surface;

[0082] Use professional testing equipment (with accuracy meeting [test accuracy requirements] and actual test equipment accuracy of [specific accuracy value]) to perform performance testing and quality assessment on the recycled components. For example, measure the resistance accuracy of resistors, detect the capacitance deviation of capacitors, and judge the functional integrity of integrated circuits. Filter out components that can be directly reused and those that need further repair, and treat unusable components in an environmentally friendly manner. In the embodiment, approximately [specific proportion value] of components can be directly reused, some components can be used after repair, and unusable components are treated in accordance with environmental protection requirements;

[0083] The entire disassembly process is quality monitored and data analyzed, and a corresponding indicator system is established, including disassembly time (controlled within [time range], the actual disassembly time is [specific time value]), component damage rate (lower than [damage rate percentage], the actual damage rate is [specific damage rate value]), resource recovery rate, etc. These indicators are regularly counted and analyzed, and the process parameters are adjusted according to the analysis results. In the embodiment, the process parameters such as the heating rate and the concentration of the enzyme are optimized and adjusted by monitoring and analyzing the indicators.

[0084] Specifically in this solution, the electrostatic dust collection equipment is an industrial-grade or small-scale high-efficiency electrostatic dust collection device, and the specific type is selected according to the size of the circuit board and the amount of dust.

[0085] In this embodiment: the electrostatic dust suction device is used to remove dust and debris on the surface of the circuit board. During the circuit board disassembly process, dust may interfere with subsequent operations, such as affecting the observation and removal of components, and may also have adverse effects during heating and other processes. Through electrostatic dust suction, the surface of the circuit board can be ensured to be clean and tidy, providing a good foundation for subsequent steps.

[0086] Specifically in this solution, the preheating device is a heating box or heating chamber that can accurately control the temperature and heating rate, and the interior of the heating box or heating chamber should have a uniform heat distribution structure.

[0087] In this embodiment: the preheating device (heating box or heating chamber) can raise the temperature of the circuit board to 80℃-100℃ and maintain it for a certain period of time (10-15 minutes) at a precisely controlled heating rate ([Y1]℃ / min-[Y2]℃ / min). This uniform heating method can heat the entire circuit board evenly and avoid local overheating or overcooling. This is very important for subsequent non-destructive desoldering operations, because uneven heating may cause problems such as circuit board deformation, component damage, or uneven solder melting.

[0088] Specifically in this solution, the infrared heating device should have precise temperature control and heating area positioning functions, and can be flexibly adjusted according to the layout and size of different solder joints on the circuit board.

[0089] In this embodiment: the infrared heating device can precisely locally heat the solder joints on the circuit board. It can quickly raise the temperature of the solder joints to the melting point of the solder (180°C-220°C) while ensuring that the temperature of other parts of the circuit board does not exceed 120°C. This precise temperature control is essential for lossless desoldering. By heating only the solder joints, the solder can be melted without causing thermal damage to surrounding components and circuit boards, thereby ensuring the integrity and reusability of the components.

[0090] Specifically in this solution, the vacuum suction pen, mechanical clamp and flexible clamp should be selected and designed according to the shape, size and material of the components to ensure stable operation without damaging the components during the disassembly process.

[0091] In this embodiment: the suction force of the vacuum suction pen is between [P1] Pascal and [P2] Pascal, which can generate sufficient suction force to stably pick up components. During the disassembly process, components need to be removed accurately, and appropriate suction force can ensure that components will not fall during the suction process, thereby ensuring the continuity and accuracy of the disassembly operation;

[0092] The clamping force of the mechanical clamp is in the range of [Q1] Newton to [Q2] Newton, and it can provide a stable clamping force to fix the components. For some larger or heavier components, the vacuum pen may not provide sufficient support force. At this time, the mechanical clamp can play a role to ensure that the components will not move during the disassembly process, ensuring the safety and accuracy of the disassembly operation;

[0093] For some special and easily damaged components (such as precision sensors, etc.), the flexible fixture is made of a material with a certain elastic modulus (within the [elastic modulus range]). This elastic property enables the flexible fixture to provide sufficient clamping force to fix the components during the disassembly process, and to buffer the impact of external forces on the components, thereby effectively protecting the integrity and performance of special components and ensuring that they can still be used normally after disassembly.

[0094] Specifically in this solution, the bio-enzyme treatment system should include a reaction tank, a stirring device, a bio-enzyme adding device and a product separation device, and each part should work together to achieve efficient separation of substrate materials and recovery of organic materials.

[0095] In this embodiment: the reaction tank is the core container of the bio-enzyme treatment process, which provides a closed space for the reaction between the circuit board substrate and the bio-enzyme solution. In this space, the bio-enzyme can fully contact with the organic resin material in the substrate, thereby performing an effective decomposition reaction;

[0096] The stirring device stirs the bio-enzyme solution and the substrate in the reaction tank at a certain stirring speed ([R1] rpm to [R2] rpm). This allows the bio-enzyme to be more evenly distributed in the solution and fully contact with all parts of the substrate, avoiding incomplete local reactions, thereby improving the decomposition effect of the bio-enzyme on the organic resin material of the substrate;

[0097] The bio-enzyme adding device can accurately control the amount of bio-enzyme added to keep its concentration between [C1] g / L and [C2] g / L. The appropriate enzyme concentration is crucial to the efficiency and effect of the decomposition reaction. If the amount of enzyme is too much, it may cause waste and may also have an adverse effect on the subsequent separation and recycling process; if the amount of enzyme is too little, it may lead to incomplete decomposition and fail to achieve effective separation of the substrate material;

[0098] The product separation equipment is used to separate the metal foil layer after the reaction and the organic resin solution after degradation. Through filtration or centrifugation, it can effectively separate the two substances of different properties, providing pure raw materials for subsequent metal refining and organic material recovery, ensuring the efficiency and accuracy of the recovery process.

[0099] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A new green disassembly method for circuit boards, characterized in that: The following steps are involved: Step 1: PCB pretreatment: Conduct a visual inspection of the scrap circuit boards and record in detail information such as their brand, model, size, and the general layout of components; Use an electrostatic vacuum cleaner to remove dust and debris from the circuit board surface, where the electrostatic voltage of the electrostatic vacuum cleaner should be controlled within the range of [X1] to [X2] volts to ensure effective dust removal without causing electrostatic damage to the circuit board; Step 2: Low temperature preheating: Place the pretreated circuit board into the preheating equipment, raise the temperature to 80℃-100℃ at a heating rate of [Y1]℃ / min to [Y2]℃ / min, and maintain for 10-15 minutes; The ventilation device in the preheating equipment should ensure an air flow rate of [Z1] cubic meters per hour to [Z2] cubic meters per hour, so that the hot air flows evenly over the circuit board and at the same time exhausts any small amount of organic gas that may be generated; Step 3: Non-destructive desoldering: Use a special infrared heating device to locally heat the solder joints on the circuit board, quickly raising the temperature of the solder joints to the melting point of the solder (usually 180℃-220℃), but ensure that the temperature of other parts of the circuit board does not exceed 120℃ to prevent thermal damage to components. The infrared lamp power of the infrared heating device should be [W1] watts to [W2] watts, and the dimensional accuracy of the heating area should be controlled within the range of [millimeter level accuracy parameter]; During the heating process, use tiny ultrasonic vibrations with a frequency between [F1] Hz and [F2] Hz and an amplitude of [micrometer amplitude parameter] to reduce the adhesion between the solder and the component pins and the circuit board pads, thereby achieving non-destructive desoldering of the components; Step 4: Classification and recycling of components: Use a vacuum pen or mechanical clamp to carefully remove the desoldered components one by one, and place them according to the type (such as resistors, capacitors, integrated circuits, etc.), size and function of the components. The suction force of the vacuum pen should be between [P1] Pascal and [P2] Pascal to ensure that the components can be stably sucked without damaging their pins. For mechanical clamps, the clamping force should be controlled in the range of [Q1] Newton to [Q2] Newton to avoid excessive squeezing of the components; For some special and easily damaged components (such as precision sensors, etc.), specially designed flexible fixtures are used for disassembly. The material of the flexible fixture should have a certain elastic modulus within the [elastic modulus range] to ensure that it can provide sufficient clamping force and buffer the impact of external forces on the components during the disassembly process; Step 5: Separation of substrate materials: Place the circuit board substrate after removing the components into a solution containing a specific biological enzyme that can specifically decompose the organic resin material in the substrate and has little effect on the metal part. The concentration of the biological enzyme should be controlled between [C1] g / L and [C2] g / L, and the pH value of the solution should be maintained in the range of [pH1] to [pH2]; At a suitable temperature (e.g., 30°C-40°C), the substrate is subjected to degradation treatment to separate the metal foil layer from the organic resin layer. The stirring speed during the treatment should be [R1] rpm to [R2] rpm to ensure that the biological enzyme is in full contact with the substrate; Step 6: Metal Refining and Organic Material Recovery: The separated metal foil layer is further refined to recover valuable metals such as copper, gold, and silver by electrolysis or chemical precipitation to a certain purity standard. The current density during the electrolysis process should be controlled between [A1] amperes per square meter and [A2] amperes per square meter, and the amount of chemical precipitant added should be accurately calculated based on the metal ion concentration to ensure that the metal recovery rate is above [recovery rate percentage range]; For the degraded organic resin solution, a series of treatment processes (such as flocculation, precipitation, evaporation, etc.) are used to recover the organic components and convert them into reusable organic materials or energy. The type and amount of flocculant added during the flocculation process should be determined according to the properties of the solution, the precipitation time should be between [T1] hours and [T2] hours, and the evaporation temperature should be controlled within the range of [V1]℃ to [V2]℃; Step 7: Disassembly and quality inspection: After disassembly, the circuit boards and components should be thoroughly cleaned to remove residual solder, impurities and pollutants on the surface. The cleaning agents used in the cleaning process should meet environmental protection standards, and the content of harmful substances in their ingredients should be lower than [limit standards for harmful substances]; Use professional testing equipment to perform performance testing and quality assessment on recycled components, screen out components that can be directly reused and those that need further repair, and perform environmentally friendly treatment on unusable components. The accuracy of the testing equipment should meet the [testing accuracy requirements], and accurately measure and judge the various performance indicators of components (such as resistance value accuracy, capacitance value deviation, integrated circuit functional integrity, etc.); Conduct quality monitoring and data analysis on the entire disassembly process, summarize experience and lessons learned, continuously optimize disassembly processes and parameters, and improve disassembly efficiency and resource recovery rate. A corresponding indicator system should be established for quality monitoring, including but not limited to disassembly time, component damage rate, resource recovery rate, etc. These indicators should be regularly counted and analyzed, and process parameters should be adjusted based on the analysis results. The disassembly time should be controlled within [time range], and the component damage rate should be lower than [damage rate percentage].

2. The novel green disassembly method of circuit board according to claim 1 is characterized by: The electrostatic dust collection equipment is an industrial-grade or small-sized high-efficiency electrostatic dust collection device, and the specific type is selected according to the size of the circuit board and the amount of dust.

3. The novel green disassembly method of circuit board according to claim 2 is characterized in that: The preheating device is a heating box or a heating chamber that can accurately control the temperature and the heating rate, and the interior of the heating box or the heating chamber should have a uniform heat distribution structure.

4. The novel green disassembly method of circuit board according to claim 3 is characterized by: The infrared heating device should have precise temperature control and heating area positioning functions, and can be flexibly adjusted according to the layout and size of different solder joints on the circuit board.

5. The novel green disassembly method of circuit board according to claim 4 is characterized in that: The vacuum suction pen, mechanical clamp and flexible clamp should be selected and designed according to the shape, size and material of the components to ensure stable operation and no damage to the components during the disassembly process.

6. The novel green disassembly method of circuit board according to claim 5 is characterized by: The bio-enzyme treatment system should include a reaction tank, a stirring device, a bio-enzyme adding device and a product separation device, and each part should work together to achieve efficient separation of substrate materials and recovery of organic materials.