PCB stencil

Why SMD PCB stencil?

SMD components growing a higher density and components on the circuit board. The PCB stencil soldering process does not affect using a soldering wave, even in a reflow oven or using vapor phase soldering. The possible tin solder is loosened in the form of a paste using a stencil and squeegee. The components are then listed on the solder paste. The adhesive force of the paste prevents it from falling off. Heavier components are usually Glued to it.

SMD Assembly

MOKO Technology Provides comprehensive services for assembling surface-mounted (SMD) components and components for push-through assembly (THT). Our production facility is technologically flexible, we take on the assembly of various components from the SMD components of size 0201 to the integrated circuits with QFP and BGA & uBGA housings in excellent quality with a lot of experience. Our typical series size is between 1 and 1000 pieces, the normal order period is 5 to 10 days.

SMD assembly PCB stencil

Create solder paste PCB stencil

9 Step:

Step 1: Material and preparation

Step 2: Prepare the PCB layout and determine dimensions

Step 3: Create Gerber files

Step 4: Open Gerber file for conversion

Step 5: Export Gerber to SVG file

Step 6: Cutting software

Step 7: Change The size of the design

Step 8: Prepare transparency and machine

Step 9: Cut your stencil

Use a Cricut cutting machine and Sure-Cuts-A-Lot software to create usable solder paste stencils for electronic prototyping purposes.

The quality and precision of the stencils obtained are good enough, size 0805 and TQFP (0.8 mm pitch) electronic component prototype.

This Instructable on a tutorial I originally wrote based on solder paste stencils.

I would not recommend purchasing a Cricut just to create solder paste stencils. However, if you have a friend or relative who owns one, or at a Cricut store or at the flea market, then buying Sure-Cuts-A-Lot software will turn a Cricut into a very useful device. Functionality then becomes something like a low-end vinyl/craft cutter like its Craft Robo.

Step 1: Material and preparation for PCB stencil

Materials

– Cricut machine
– Sure-Cuts-A-Lot software
– Gerber viewer software
– Transparencies for overhead projectors that you can buy at any office supply store
– A Windows XP / Vista computer

Preparation

Your Cricut must have a specific firmware version. You can update/downgrade the firmware by downloading Cricut Design Studio and following the instructions under Help to update the firmware. See the Sure-Cuts-A-Lot FAQ for more information.

Step 2: Prepare the PCB layout and determine dimensions

It can take some trial and error to create decent solder paste PCB stencils is not very precise. It cuts rounded edges and ignores shapes smaller than about 18mil (0.46mm) by 50mil (1.27mm). That said, you should make sure that all of your component pads are large than these. To make sure a pad still has enough solder paste area, make the pad more. The KiCAD EDA Suite PCB layout program has the ability to change all one footprint pads at a time. Solder has this amazing property that connects to metal parts when reflow finds. As long as your PCB has precise solder resist, solder metal pieces will be found to link. So don’t be too concerned about pads (basically say +/- 20%).

You need the exact dimensions of your PCB template for later. Use your PCB layout software distance tool to determine the distance between the outermost component pads. Not the size of the PCB, but the distance between outermost pad edges. In the example below, the PCB has a width of 2.3 “, but the edge to edge pad distance is 2.142”.

You can measure distances by selecting drawings from the layer pull-down menu and clicking the Dimensions button in the right tool menu. It’s the fourth button from the bottom.

Step 3: Creating Gerber files

Draw your PCB layout using the Gerber solder paste stencil.

When using KiCAD, choose Draw from the File menu. In the plot window, select SoldP_Cmp for the solder paste component layer and click the Plot button.

Step 4: Open Gerber file for conversion

Open the file in Gerber Gerber Viewer. Select Open Layer (s) from the File menu.

Step 5: Export Gerber to SVG file

Then export the file in SVG format. Select Export, then SVG … from the File menu.

Step 6: Cutting software

Create solder paste stencils with Cricut
Import the SVG file into Sure-Cuts-A-Lot by choosing Import SVG … from the File menu.

Step 7: Resize the design

Create solder paste stencils with Cricut
Click Keep Proportions in the Properties window and set the stencil’s width to the value previously noted.

Step 8: prepare transparency and machine

Create solder paste stencils with Cricut
Take a sheet of transparency film and cut it to the size of the Cricut cutting mat. Tack the cut transparency into the cutting mat. Place the cutting mat in the machine and press the insert paper button.

Set the Cricut’s thrust washer up, the speed wheel will turn to High or Medium, and the cutting blade depth to 5 or 6. Detailed instructions can be found in the Cricut manual. You will find some trial-and-error needed. Speed ​​and pressure can change the accuracy of the cuts, and greater cutting knife depth speeds up how quickly you need to replace the cutting mat.

Step 9: Cut your PCB stencil

Create solder paste stencils with Cricut
Go to cut the design. Choose Cut Design from the Cutter menu.

SMD solder paste PCB stencil

SMD stencil at MOKO Technology – everything from a single source!
Reduce your process costs and use the service around our PCB production. We can easily and conveniently provide you with the corresponding SMD stencil to match your PCB order – to you or your assembly partner.

SMD PCB stencils from MOKO Technology – simple, practical, inexpensive!
Regardless of whether laser-cut SMD stencils, adhesive stencils or stencils for clamping systems. This means you have lower process costs and time for other important tasks.

Using the latest technology, MOKO Technology is able to cover all of our customers’ usual requirements and will manufacture your SMD stencils to measure. We offer the following specifications:

• Formats up to 760 x 600 mm
• Depending on the format, up to 2,000 pads included
• Material thicknesses between 50 and 500 µm
• Electropolishing
• Nano sealing
• Edge protection
• Aluminum frame
• Step stencils

With our production preparation, we take over the complete data check of your SMD stencil as well as the handling of the paste data. The entire MOKO team looks forward to your inquiry and is happy to be there for you personally!

PCB Stencil printer and the dispenser

While our automatic stencil printers enable a homogeneous, high-precision paste application, paste application by means of a dispenser can be a cost-effective solution for smaller series (from the components of the housing size 0603 to the integrated circuits with SOP housing).

Another advantage of the stencil printer is that several smaller circuit board stencils can have space on one stencil board by using the maximum printing area of ​​420×445 mm, whereby a further cost reduction is achieved.

SMD assembly

The SMD assembly is carried out by Pick & Place placement machines from Panasonic and Samsung in a full vision system. An important advantage of the Pick & Place system is the extraordinary flexibility with regard to component packaging. The integrated circuit can come in rod magazines, (tube), belts (reel), trays (tray), the automated assembly can be solved in any case.

Accuracy: 50μm
PCB size: 50mm x 40mm – 420mm x 390mm

Soldering SMD

After equipping the SMD, high-quality soldering takes place in a forced convection reflow oven from HELLER with 7 heating zones or a vapor phase soldering system, which can be used to produce a wide range of temperature profiles in accordance with today’s expectations.

SMD repair

The visual inspection and repair of the solder joints using microscopes are carried out by employees with years of experience. Precise, accurate repairs are made possible by the component-adjustable rework stations from ERSA with adjustable temperature and numerous accessories and LEISTER hot air devices.

Final test according to IPC-A-610

A visual 100% final inspection of all of our products is carried out via the intermediate tests and the microscope tests after the SMD have been fitted to ensure high quality. The final inspection is carried out by the certified IPC-A-610 specialists.

 

 

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