Introduction
The role of solder paste printing to protect the printed board, improve the quality of soldering and improve the efficiency of assembly, its importance is reflected in the improvement of product quality, reduce manufacturing defects and improve production efficiency.
I. The basic principles of solder paste printer
1. The workflow of the solder paste printer
1.1 Fixed stencil and squeegee
Fix the correct stencil to the printing machine and adjust to the best condition. Adjust the angle between squeegee and stencil (generally 45-60 °, automatic and semi-automatic printing machine mostly use 60 °).
1.2 Adding solder paste
1.3 Printing operation
Put in the PCB for printing, make sure the PCB is firmly fixed.
Squeegee down to the SMT printing position, press the setting to start printing. During the printing process, pay attention to monitor the printing effect, check whether there is less tin, even tin, pull the tip, shift, leakage and other bad phenomena.
After printing, the squeegee returns to the original position and the PCB board is separated from the stencil.
1.4 Inspection and Cleaning
The first 5PCS boards are required to be fully inspected, after the printing quality is OK, notify the IPQC for the first inspection, confirm that there is no abnormality in the printing quality, and then notify the line operator to start production.
1.5 Abnormal handling
During the production process, if you find 3PCS in a row with bad printing, notify the technician to debug and clean the PCB board with bad printing.
If there is printing abnormality during printing, please inform the staff immediately to deal with it.
1.6 End work
Turn off the machine according to the operation procedure and clean the worktable.
2. Key factors affecting printing quality
Viscosity and adhesion of solder paste, particle size of solder paste, manufacturing process of stencil, temperature and humidity, equipment precision.
II. The impact of key parameters on yield
1. Viscosity and type of solder paste
The impact of viscosity: the viscosity of the paste directly affects the material flow in the printing process.
Selection of solder paste type: the appropriate solder paste can effectively improve the soldering performance.
2. Printing pressure setting
Relationship between pressure and yield: An optimal pressure range should be found to ensure uniform distribution of solder paste.
Adjustment method: By gradually adjusting the pressure parameters and observing the actual printing effect, we can find the best pressure setting.
3. Squeegee angle and speed
Squeegee Angle: The angle between squeegee and substrate affects the coating effect of solder paste.
Squeegee speed: It is recommended to test different speeds to find the best speed for specific production requirements.
4. Adjustment of printing layer thickness
Importance of layer thickness: Layer thickness can be effectively controlled by adjusting the opening size of the printing template.
Recommended thickness range: According to industry standards and specific product requirements, it is recommended to set the appropriate layer thickness range and regularly monitor its consistency to ensure yield.
III. The steps to optimize the printing parameters
1. Evaluation of existing parameters
1.1 Data collection and analysis
First collect past production data, including the yield of each batch, the type of defects, customer feedback and so on. This data can help you identify the weak links in the current parameter settings.
Use statistical tools to analyze the data to see which parameters have a strong correlation with product quality and identify potential areas for optimization.
1.2 Identify room for improvement
Based on the results of the analysis, make a list of parameters that need to be focused on for improvement, such as paste viscosity, print pressure, squeegee speed, etc. Create a prioritized list to help rationally allocate resources and time.
2. Experimentation and Adjustment
2.1 Implement small-scale testing
Select one or more parameters that have a large impact to conduct small-scale experiments. For example, first adjust the paste viscosity and printing pressure to observe the yield changes in each group.
Record the settings and results of each experiment for subsequent analysis.
2.2 Adjust the parameters according to the results
Analyze the experimental data to find the parameter combinations that give the best results. For example, if a particular combination of viscosity and pressure results in a significant yield improvement, consider applying these parameters to mass production.
During the adjustment process, make sure to change only one parameter at a time to better understand the specific impact.
3. Continuous Monitoring and Feedback
3.1 Set monitoring metrics
Determine key performance indicators (KPIs), such as yield rate, defect rate, and product return rate in production. These metrics will help you monitor the effects of your optimization.
Set up a schedule of regular checkups to ensure that the evaluation process is ongoing so that problems can be identified in a timely manner.
3.2 Periodic review and optimization
Conduct periodic reviews of printing parameters based on monitoring data. If new issues or yield rate drops are detected, take immediate action to reassess the relevant parameters.
Encourage the team to share feedback and form a good communication mechanism to ensure that all relevant personnel have input into the improvement of the printing process.
4. Employee Training and Awareness Raising
4.1 Education and Training
Provide regular training for operators and related personnel to ensure they understand the importance of optimizing parameters to improve production yields.
Share success stories and lessons learned so that team members are aware of best practices and common mistakes.
4.2 Build an optimization culture
Encourage full participation in the optimization process so that every employee feels important in improving quality. Increase employee motivation and responsibility through incentives.
Company Profile
Zhejiang NeoDen Technology Co., Ltd. has been manufacturing and exporting various small pick and place machines since 2010. Taking advantage of our own rich experienced R&D, well trained production, NeoDen wins great reputation from the world wide customers.
In our global Ecosystem, we collaborate with our best partners to deliver a more closing sales service, high professional and efficient technical support.
We believe that great people and partners make NeoDen a great company and that our commitment to Innovation, Diversity and Sustainability ensures that SMT automation is accessible to every hobbyist everywhere.
Post time: Mar-18-2025