Apart from all types of Printed Circuit Boards (PCBs) such as Prototype PCB, Standard PCB, Aluminum PCB, HDI PCB, Flex PCB, Flex-Rigid PCB, High-Frequency PCB, Thick copper PCB, High-Tg PCB and Halogen-Free PCB, PCBCart also manufactures solder paste stencils to meet Surface Mount Technology (SMT) requirements.
Stencils, also called SMT stencils, play a key role in transferring accurate amount of solder paste to correct positions on bare circuit boards ready for assembly. In other words, stencils can fast and efficiently ensure the most accurate solder paste amount and optimal electrical connection. With solder stencils, it is possible to use metal squeegee blades to apply solder paste easily over the openings on PCBs and make stencil to be well aligned with the surface of the advanced circuit board.
According to SMT stencil manufacturing technologies, we provide two types of stencils: laser-cut stencils and chemical-etch stencils.
The openings are lasered on 100% stainless steel. Generally speaking, this kind of stencil can be produced with high quality and a high degree of precision within a short time.
• Advantages: high accuracy; barely influenced by objective elements; trapezoid opening beneficial for demoulding; suitable for accurate cutting; reasonable price;
• Disadvantages: relative low manufacturing speed.
The openings are etched into the metal using acid. Usually this kind of stencil offers better protection on material temper and hardness.
• Advantages: one-time formation; relatively high manufacturing speed; low cost;
• Disadvantages: tending to form sand clock shape or large openings; numerous manufacturing stages and accumulating errors; unsuitable for fine pitch stencils; bad for environmental protection.
How to Determine Stencil Size?
Stencil size is composed by two parts: internal size and overall size. Internal size is the size compatible with that of PCB ready to be assembled while overall size refers to the size compatible with printer parameter limit. As long as both sizes are accurately designed, stencil will be able to make full use of its functions.
Internal size of stencil can be figured out conforming to the following rule:
• Width of Framed Stencil = width of PCB + 100mm while its Length = length of PCB + 100mm
• Width of Frameless stencil = width of PCB + 200mm while its Length = length of PCB + 200mm
For example, if one circuit board size is 50*50mm, then the size of its framed stencil should be around 150*150mm and the size of its frameless stencil should be around 250*250 mm.
It's easy to remember and operate so it worked for manual solder paste printing in SMT assembly prior to the advent of automatic printer. It can be said that different PCB sizes lead to generations of different internal sizes of stencil.
When it comes to automatic solder paste printer, however, it's relatively solid. Overall size of stencil has to be determined by parameter limit of the equipment, that is, printer, because stencil has to work within the range of printer with a frame. Different printers feature different parameter regulations. As far as PCBCart is concerned, the stencil size compatible with our printer can be either 650mm*650mm or 736mm*736mm.
PCB designers have to focus on internal size of stencil, they don't need to care about its overall size since it is generally determined by the parameters of printer in your contract assembler workshop.
How to Order Stencils
Here at PCBCart, you can order stencil alone or buy together with PCBs.
• Purchase stencil together with PCBs. Enter Standard PCB Quote page or Prototype PCB Quote page, fill in your custom PCB spec, then check the Laser Stencil option at the bottom part, and enter your required stencil parameters. As soon as these gaps end up being filled, the stencil will be contained in your order list.
Once all necessary parameters are filled in, a rough production cost will show in the right column. Click the Add to Cart button if you're happy with the price. Then follow our online guide to place the order and upload files. We'll start to process your order once your payment was received.
• Purchase laster stencil only. Click the following button to submit your stencil spec, then follow our online guide to submit the order and issue the payment. Once order has been submitted, please keep an eye for email sent from us, we will be in touch to confirm stencil production file before manufacturing.
Quote and Order for Laser Stencil within Seconds
If your demands go beyond the items displayed on line, reach us by email for detailed quote.