SMT Stencils or calls SMT Laser Stencils are used to print solder paste on the PCBs for assembly components. They are often made of Stainless Steel and are manufactured by processes of laser cut or etching.Stencil Printing is the process of depositing solder paste on the PCB to establish electrical connections. it is to achieve through a single material namely solder paste which consists of solder metal and flux.The equipment and materials used in this stage are laser stencil,solder paste, and Paste printer.In order to meet a good solder joint,the right volume of solder paste needs to be printed,the component needs to be placed in the right solder PADs, the solder paste needs to wet well on the board and also must be clean enough for SMT stencil printing. |
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Solder Paste Printing is a very important link in SMT process, Printing quality will effect the 1st yield of SMT, so the stencil design is very important for actual production.The main function of stencil is help to release solder paste to flex pad, The purpose is release exact quantity solder paste to flex pad, There are three technic to build stencil: chemical-etching , laser cutting+electropolish and electroforming, current our company mainly use laser stencil+electropolish. |
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SMT Laser Stencil technology allows having tighter dimention tolerances and greater location accuracy.All of the aperture walls after laser cutting can be smoothed through electro-polishing. The repeatability of aperture dimensions in laser-cutting stencils is generally better than that of chemical etching stencils. Due to the need for fine pitch components, the size design of the aperture becomes smaller and smaller that lead to PCB laser stencil becomes more and more impotrant,With SMT laser cutting, there is no photo films requiring precise alignment from moisture.The laser cutting stencil process results in trapezoidal apertures that can create better solder paste for pcb SMT assembly.
Panda PCB used the LPKF SLG 6080 stencil laser system to cut foils for our solder paste stencils. It has superior positional accuracy and cutting tolerances. it can even be operated automatically with two different cutting gases in the same job. The selection of the gas type, as well as pressure adjustment and monitoring is done fully automatically.Please send us the files you need cut for stencil printing. the Vector files can be e.g Gerber RS-274X, DXF,SVG,EPS,HPGL,AutoCad,.ai. Bitmap files can not be identified for stencils e.g jpg,png,bmp . |
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| SMT Stencils Thickness Recommendation: |
Laser Stencil Advantages: |
Components |
Pads Pitch (mm) |
Stencil Thickness(mm) |
QFP, SOIC, SOP,TSOP, Connector
|
1.27 |
0.18/0.12 |
0.8 |
0.15/0.18 |
0.65 |
0.15 |
0.5 |
0.10/0.12/0.15 |
0.4 |
0.10 |
0.3 |
0.08 |
BGA |
1.50 |
0.15 |
1.27 |
0.15 |
1.00 |
0.13 |
0.80 |
0.12 |
0.65 |
0.10 |
0.50 |
0.10 |
0.40 |
0.08 |
0603 |
* |
0.12/0.15/0.18 |
0402 |
* |
0.10/0.12/0.15 |
0201 |
* |
0.1 |
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1.Allows having tighter dimention tolerances and greater location accuracy.
2.All of the aperture walls after laser cutting can be smoothed through electro-polishin.
3.Repeatability of aperture dimensions in laser-cutting stencils is generally better than that of chemical etching stencils.
4. No photo films requiring precise alignment from moisture.
5.The laser cutting stencil process results in trapezoidal apertures that can create better solder paste for pcb SMT assembly .
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| Technical Data: StencilLaser G 6080: |
Laser Stencil Capabilities : |
Cutting range (X/Y) |
600 mm x 800 mm (23.6” x 31.5”) |
Maximum frame size (X/Y) |
740 mm x 950 mm x 40 mm (29.1” x 39.4” x 1.6”) |
Maximum loose sheet size (X/Y) |
650 mm x 850 mm (25.6” x 33.5”) |
Material thickness |
Up to 1 mm (0.04”) |
Laser repetition rate |
Max. 45 kHz |
Axial precision |
±2 μm |
Right-angle precision |
4 angular seconds |
Repeatability |
±2 μm |
Power consumption |
Max. 2 800 VA over all |
Dimension System(W x H x D) |
1 575 mm x 1 920 mm x 1 820 mm (61’’ x 75” x 64”) |
Weight |
Less than 2 000 kg (4 400 lbs) |
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1. 100% Laser cut stencils up to x= 24" y=28"
2. Foil thicknesses from 2mil to 20mil
3. Frame size:10x10",12x12",15x15",12x17",20x20",29x29"
4. Axial precision (X/Y axis) +/- 4 micron over full working area
5. Cut Features as narrow as .002"
6. Utilizing the finest grain stainless material
7. Ultra fine pitch
8. 9000 apertures/hour capability
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