What should be paid attention to in the installation and debugging of surface treatment equipment for semiconductor lead frame rear package?
The installation and debugging of surface treatment equipment for semiconductor lead frame rear package directly affects product quality (such as coating uniformity and adhesion), equipment stability and production efficiency, and it is necessary to strictly follow industry norms and technical requirements. The following are the key points for attention, which are classified according to pre-installation, during installation, commissioning stage and subsequent verification:
First, preparation before installation: basic guarantee and risk prediction
Equipment and site matching verification
Site environment: it shall meet the requirements of cleanliness (recommended Class 1000 or above), temperature and humidity (temperature 20-25℃ 1℃, humidity 40-60% 5%), shockproof (ground bearing ≥ 1.5 times of equipment weight, away from vibration sources such as stamping equipment), ventilation (equipped with waste gas treatment system, aiming at volatiles of electroplating solution such as acid mist and organic gas).
Matching of public system: confirm that the interface specifications, flow rate and pressure of power supply (three-phase 380 V 10%, grounding resistance ≤4Ω), pure water (resistivity ≥ 18.2 m Ω cm), compressed air (pressure 0.5-0.8MPa, oil content ≤0.01ppm) and chemical supply pipeline (materials compatible with liquid medicine, such as PP and PVDF) meet the requirements of equipment.
Technical data and personnel preparation
Thoroughly understand the equipment drawings (mechanical assembly drawing, electrical schematic diagram, pipeline direction drawing) and operation manual, and make clear the installation accuracy requirements of key components (such as electroplating bath, spray system and drive roller).
Debugger should have knowledge of semiconductor packaging process (such as material characteristics of lead frame, surface treatment target: anti-oxidation and improving bonding), and train equipment safety operation in advance (such as chemical leakage emergency and high voltage protection).
Material and tool preparation
Prepare qualified auxiliary materials: chemicals matching the process (such as nickel plating solution and gold salt solution, whose purity needs to be verified in advance), pure water for cleaning and lead frame samples for testing (same batch and same material).
Equipped with high-precision measuring tools: laser interferometer (measuring transmission precision), micrometer (measuring coating thickness), surface roughness meter, pH meter and conductivity meter (monitoring liquid parameters).
Second, the installation process: precision control and compliance
Mechanical structure installation: strictly control tolerance and stability
Core component positioning:
The transmission system (such as conveying roller and chain) should ensure levelness (error ≤0.05mm/m) and coaxiality (error ≤0.02mm) to avoid uneven coating caused by lead frame deviation during operation;
The treatment tank body (electroplating bath and cleaning tank) shall be installed horizontally, with no accumulated liquid at the bottom drain, and the spacing between the tank wall and the spraying/spraying device shall be uniform (the error shall be ≤1mm) to ensure the consistent spraying pressure.
Pipeline connection:
Chemical pipeline joints shall be free of leakage (connected by clamping sleeve or welding to avoid contamination of liquid medicine by thread sealant), and pressure test shall be conducted (for example, there is no pressure drop after holding the pressure at 0.3MPa for 30 minutes);
Distinguish pipelines with different functions (such as acid liquor, alkali liquor and pure water), label them and distinguish them with different colors to prevent cross-contamination.
Electrical and control system installation: safety and signal stability
Electrical wiring: wiring in strict accordance with the schematic diagram, and separate the power line from the signal line (spacing ≥30cm) to avoid electromagnetic interference; Sensors (such as position sensors and liquid level gauges) are firmly installed, the detection range covers the running path of the lead frame, and the signal feedback delay is ≤10ms.
Safety devices: emergency stop button, overload protection, liquid level alarm (such as liquid medicine shortage/overflow), waste gas concentration monitoring, etc. need to be linked reliably, and can immediately stop and cut off the chemical supply when triggered.
Environmental protection and safety compliance
The waste gas/waste liquid treatment system shall be installed synchronously with the main equipment: electroplating bath shall be equipped with a local exhaust hood (wind speed ≥0.5m/s), the waste liquid pipeline shall be connected to the waste water treatment station, and the direction of valve opening and closing shall be clear to prevent waste liquid from flowing backwards.
The chemical storage area is isolated from the equipment area, and an anti-leakage cofferdam (height ≥15cm) is set up, equipped with emergency neutralizer (such as calcium carbonate for sulfuric acid leakage), eye washer and shower device (distance from equipment ≤10m).
3. Commissioning stage: step-by-step verification and process optimization.
Single machine debugging: functional verification and parameter calibration
No-load test:
Transmission system: run for 24 hours without load, check whether there is abnormal sound or jamming, and record the error of roller speed (≤±1rpm) to ensure the lead frame to be transported smoothly (no scratches or wrinkles).
Liquid medicine system: test the liquid inlet/outlet speed and liquid level control accuracy of each tank (error ≤±2mm), the specification error of spraying/soaking time ≤0.1s, and the temperature fluctuation of heating system (such as electroplating solution temperature control) ≤ 0.5℃.
Electrical and control system: verify the PLC program logic (such as "cleaning-electroplating-drying" process switching), whether the sensor response is accurate (such as the frame in place signal triggering the subsequent process), and the setting of HMI parameters is consistent with the actual implementation.
Process parameter debugging: benchmarking product requirements
Preliminary parameter setting: Set key parameters (current density, electroplating time, concentration of chemical solution, cleaning pressure) according to process specifications (such as nickel plating thickness of 5-8μm and gold plating thickness of 0.1-0.3μm).
Sample testing and optimization:
10-20 samples are produced continuously, and the coating uniformity (thickness difference on the same frame is less than or equal to 5%), adhesion (grid test, no shedding) and surface smoothness (no pinhole and color difference) are tested.
If there is any abnormality (such as local coating is too thin), investigate the reason: uneven transmission speed? Uneven current distribution (adjust anode position)? Abnormal concentration of liquid medicine (replenishing or replacing liquid medicine)?
Stability verification: continuously produce more than 500 tablets under the optimal parameters, and count the defective rate (target ≤0.1%) to ensure the long-term operation of the equipment without drift.
Safety and environmental performance debugging
Simulation of abnormal scene: test the emergency response (such as automatic liquid cut-off, alarm and shutdown) in case of "liquid leakage", "power failure" and "frame sticking" to ensure no safety risk.
Exhaust emission detection: when the equipment is running at full load, detect the concentration of harmful substances (such as nickel ion ≤ 0.5 mg/m) at the exhaust port, which is in line with the Emission Standard of Pollutants in Semiconductor Industry.
Iv. acceptance and follow-up: documentation and continuous monitoring
Confirmation of acceptance criteria
Equipment performance: meet the design capacity (such as ≥50 pieces /min), process indicators (coating thickness, uniformity, adhesion up to standard) and failure rate (≤1%/ month).
Document delivery: provide installation and commissioning report (including key parameter records and test data), spare parts list and operation and maintenance manual, which shall be signed by both parties for confirmation.
Personnel training and maintenance plan
Training for operators and maintenance personnel: routine inspection items (such as roller cleanliness, liquid level and filter pressure difference), and common troubleshooting (such as transmission slip and abnormal coating).
Make maintenance cycle: for example, replace the filter element every week, calibrate the sensor every month and check the pipeline corrosion every quarter to ensure the long-term stability of the equipment.
summary
The installation and debugging of semiconductor lead frame surface treatment equipment should focus on "accuracy, cleanliness, safety and compliance", and control the whole process from preliminary preparation to later verification, with special attention to the influence of mechanical accuracy on process uniformity, chemical compatibility on product quality and environmental protection and safety on production compliance. By strictly implementing the above matters, the failure rate in the trial production stage can be effectively reduced, providing reliable guarantee for mass production.
