How to improve solder paste printing yield?

To improve solder paste printing yield, you can start from the following aspects:

I. Quality control of solder paste

Select high-quality solder paste:

In addition to selecting solder paste from a reliable manufacturer, the shelf life and batch stability of the solder paste should be considered.

Select specialised solder pastes for different application requirements (e.g. high temperature, high humidity, high frequency, etc.).

Storage and use environment:

Set up a special solder paste storage room to maintain a constant temperature and humidity environment.

Follow the "first-in-first-out" principle to ensure the use of the latest production of solder paste.

Stir the paste thoroughly before use to eliminate particle settling and agglomeration.

Equipment and process optimisation

Equipment calibration:

Perform regular equipment maintenance, including cleaning, lubrication and adjustments.

Use precision measuring tools to calibrate the printing machine to ensure that the accuracy meets the requirements.

Printing parameter adjustment:

Adjust squeegee angle and pressure according to PCB board material and thickness.

Printing speed should be adjusted according to the viscosity and fluidity of the solder paste.

Printing gap should be slightly larger than the diameter of solder paste particles to avoid clogging.

High precision stencil:

Select laser cutting stencil to improve the precision of opening and edge clarity.

Regularly check the wear and tear of the stencil and replace it in time.

Third, the stencil and paste characteristics of matching

Stencil selection:

Select the appropriate stencil material and thickness according to the PCB board design.

The shape of the stencil opening should match the shape of the pad to reduce printing errors.

Solder paste particle size:

Select solder paste with different particle sizes for different PCB board pitches and pad sizes.

Fine particle solder paste is suitable for high-density, fine-pitch PCB board.

Fourth, environmental control

Temperature and humidity:

The printing workshop should be equipped with a constant temperature and humidity system to maintain suitable environmental conditions.

Avoid printing operations under extreme weather conditions.

Cleanliness:

Clean the stencil, squeegee and printing press table regularly to prevent contamination.

Use special cleaners and tools for cleaning.

V. Process Monitoring and Inspection

Implement automatic optical inspection (AOI):

Select high-precision AOI equipment for real-time monitoring of printing quality.

Set reasonable detection parameters and alarm thresholds to detect and deal with printing defects in a timely manner.

Personnel training:

Regularly train and assess operators on solder paste printing techniques.

Emphasise the awareness of safety production and quality control, and improve the responsibility and operation skills of the staff.

VI. Continuous Improvement and Innovation

Data Analysis:

Collect and analyse data from the printing process to identify potential problems and improvement points.

Use statistical process control (SPC) and other methods for data analysis.

Technology Innovation:

Focus on industry dynamics and technological development, introduce new technologies and equipment.

Carry out research and development activities to improve the independent innovation ability of solder paste printing technology.

In summary, to improve the yield of solder paste printing needs to consider the quality of solder paste, equipment and process optimisation, stencil and paste characteristics matching, environmental control, process monitoring and testing, as well as continuous improvement and innovation and other aspects.Through the implementation of these strategies, can significantly improve the yield of solder paste printing and product quality.