PCB templates are very important.During the PCB assembly process, the printing quality of the PCB solder paste template will directly affect the processing quality of SMT,
and the quality of solder paste printing is directly related to the quality of the PCB template.
Therefore, correctly designing the SMT template, selecting the appropriate PCB template thickness, and designing the opening size of the
PCB template will be the key to ensuring the quality of solder paste printing.

The key factors affecting the quality of the PCB template include the PCB template material and PCB template thickness, PCB template opening type,

PCB template size, PCB template wall flatness, etc. Therefore, special attention must be paid to the PCB template during the design, processing, inspection, and production of the PCB template.

PCB templates include SMT templates, etching templates, and laser templates. ZBPCB is a template manufacturer.

SMT templates are traditional prototype SMT templates, mainly used for PCB SMT templates. SMT templates have mature
SMT template suppliers, and many customers customize laser cutting templates near me. Etching templates are the process of making templates.

Laser templates use laser cutting templates. In recent years, laser template technology has developed rapidly, and laser template materials have been continuously updated.
There are more and more laser cutting template suppliers, and it is becoming more and more convenient for customers to customize laser cutting templates.

What is PCB stencil?

PCB steel mesh is actually a very thin steel plate. The size of PCB steel mesh is generally fixed to suit the solder paste printer.
The thickness of the PCB steel mesh used ranges from 0.08mm, 0.10mm, 0.12mm, 0.15mm, and 0.18mm.

The steel mesh was originally made of metal mesh, so it is called steel mesh. At first, nylon polyester mesh was used. Later,
Because of its good durability, it was replaced by metal mesh and copper mesh. Now it is stainless steel mesh. But no matter what material the metal mesh is made of,
It has the disadvantages of poor shape and low precision. With the development of SMT technology, the requirements for SMT steel mesh are getting higher and higher.
SMT steel mesh came into being. Stainless steel steel mesh replaced them, which is the current SMT steel mesh.

The main function of PCB steel mesh is to assist solder paste deposition and transfer the exact amount of solder paste to the exact position on the bare PCB.
PCB steel mesh consists of a mesh frame, a screen, and a steel sheet. There are many holes on the steel sheet, and these holes correspond to the positions on the PCB that need to be printed.
When in use, place the PCB under the steel mesh and let the solder paste leak onto the PCB through the holes in the fixed position of the steel mesh.

How to choose an SMT stencil?

1. Minimum required spacing and aperture.

2. Stencil desoldering performance.

3. Reducing and preventing solder paste bridging, short circuits or lack of solder.

4. Cost, yield and cycle time of processing materials.

5. Life and durability of stencil materials.

6. Required solder paste thickness.

How to make a PCB template?

Laser template

Laser template is the most commonly used template in the SMT template industry. Features of laser template:

Directly use data files to reduce production error links; SMT template opening position accuracy is extremely high: the whole process error is <4μm;
SMT template opening has a geometric shape that is convenient for solder paste printing.

PCB and data files are required to make laser templates.

PCB data must be edited correctly and must not be distorted, damaged or broken.

ZBPCB acceptable data files include GERBER, HPGL, JOB, PCB, GWK, CWK, PWK, DXF, PDF, PAD2000, POWER PCB, GCCAM4, PROTEL, AUTOCADR14 (2000), CLIENT98, CAW350W, V2001.
The data must contain SMT solder paste layer and character layer data to check the front and back of the data, component category, etc.

Laser cutting template process flow, Filin makes PCB_gets coordinates_data file_data processing_laser cutting_polishing_network cable

Features of laser template: high data production accuracy, less affected by objective factors; trapezoidal opening is conducive to demolding; can do precision cutting; moderate price.

Disadvantages of laser template: slow cutting speed one by one.

Etching template

ZBPCB uses 301 steel plate to make templates. Etching templates are suitable for PCB printing with angle position and spacing greater than or equal to 0.4MM.
They are suitable for use with copy boards and films. CAD/CAM and exposure mode can also be used at the same time.
They can be scaled according to different parts, and there is no need to calculate the price according to the number of parts.
Etching templates are fast to make, and etching PCB templates are cheaper than laser templates.

Chemical etching template process flow: data file PCB_filming_exposure_development_etching_steel cleaning_wire mesh

Features: Chemical etching templates are formed in one time, with fast speed; cheap.

Disadvantages: Chemical etching templates are easy to form hourglass shapes (not enough etching) or large opening sizes (excessive stretching);
Objective factors (experience, reagents, films) have a great influence, there are many production links, and the cumulative error is large.
It is not suitable for fine pitch Stencil production methods, and the preparation process pollutes the environment.

How to use PCB steel mesh?

1. PCB samples or PCB batches will become bare PCB boards, and then the circuit boards need to be soldered.

2. Cover the PCB steel mesh on the PCB.

3. Use the SMT laser steel mesh to print solder paste on the surface of the PCB disc.

4. Print solder paste and mount SMT components.

5. The PCB with solder paste is soldered through reflow soldering-overheating furnace-semi-cured solder paste.

6. The bare PCB board is now a semi-finished PCBA product.

SMT steel mesh is a “delicate” precision mold, so be careful when using it:

1. Handle with care;

2. Clean (wipe) the steel mesh before use to remove dirt carried during transportation;

3. Stir the solder paste or red glue evenly to avoid clogging the opening;

4. Optimal printing pressure: The best pressure is when the scraper just scrapes off the solder paste (red glue) on the steel mesh;

5. It is best to use self-adhesive printing when printing.

6. When the scraper completes the stroke, it is best to pause for 2-3 seconds before demolding. If conditions permit, the molding speed should not be too fast.

7. Do not hit the PCB steel mesh with hard objects or sharp knives;

8. After use, clean the PCB steel mesh, put it back into the packaging box, and place it on a dedicated storage rack.

The price of SMT steel mesh is mainly calculated by the following requirements:

1. Opening process, including etching, laser, ion cascade, depends on the precision of steel mesh opening and the process requirements of the product.
Etching is the cheapest, with the lowest precision and the lowest price. Laser cutting steel mesh generally requires a spacing of less than 0.35.

2. Steel mesh thickness. The price of steel meshes of different thicknesses is also different. In addition, there are special thickness processes,
Such as chemical ladder steel meshes, which are more expensive.

3. Size. Of course, the larger the size, the more expensive it is.

4. Material, steel mesh frame thickness size, protective coating, etc.

5. Other requirements, such as single-sided mesh, double-sided mesh, etc., have different prices.

The production process of PCB steel mesh has a great influence on the quality of solder paste printing. Which PCB steel mesh to use depends on product characteristics, welding terminal size, component type, component distribution of components on PCB board, etc.

ZBPCB is a one-stop service company specializing in PCB circuit board manufacturing, PCBA OEM materials, and SMT patch processing. We have many years of experience in electronic processing, advanced production equipment, and a complete after-sales service system, and can provide you with high-quality electronic manufacturing services.