You must be wondering whether it is simple to reduce the size of the SMT PCB assembly? Ongoing trends of double-sided board assembly while putting high-density interconnect technique to use through shrinking trace widths or via-in-pad. You need to follow a strategic component placement that ends up reducing routing space. This helps to shrink the major board footprint while ensuring better electrical performance.
Major Points in PCB Panel Size Optimisation for SMT Assembly
To manage the size of the SMT PCB assembly, one needs to take several factors into consideration.
Compatibility of the Selected Equipment for Automated Assembly
Without checking with the manufacturing equipment specifications, you should never move ahead to reduce the size of the SMT PCB assembly. Trying to pick-and-place systems and other automated assembly machines are always bound by size limitations for the panels. Sizes vary from 50mm X 50mm X 510mm X 460 mm, and SMT equipment sizes are highly dependent on the manufacturer and machine model. It is always advisable to understand the higher and lower panel sizes which your assembly line can support. In some cases, when panels were incredibly small, adjusting processing was challenging and vice versa. Understand the pattern beforehand to pocket the right design.
Edge Clearing and Board Spacing
If you think one can process size reduction without learning about board spacing on the panel and edge clearance, remember that poor spacing might obstruct smooth access to the board. Proper spacing, on the other hand, ensures automated tools have smooth access without interference. A spacing of 5 mm is considered ideal between boards and 10 mm from the panel edges so that tooling rails can be smoothly placed. It helps in the alignment of SMT machines. Insufficient spacing often attracts damage to the component or depanelization. Do not opt for too much spacing, as it will unnecessarily increase costs and waste panel space.
Ideal Efficient Panel Size for Pick and Place
Optimisation is essential here, especially for PCB panels in pick-and-place machines. If the components can be placed correctly in a single step without frequent repositioning, it works best. After checking the machine’s working area, one needs to align the panel size so that one does not waste much time during assembly. It also reduces the possibility of any human error while finishing the setup.
Reflow Soldering Features
Reflow ovens, when heating the panel, help the solder paste and other secure components to pocket the expected results. If it is done without optimising the overall panel size, the heat distribution will be uneven, which might result in unwanted defects. It might also result in insufficient solder joints. Never miss rechecking that the panel size is in line with the oven conveyor’s width. The width often ranges from 300 mm to 500 mm, but may vary depending on the design. Try to manage uniform board density throughout the board density. It helps to work on even heating. If the empty spaces are large or the board layouts are not efficiently customised, it might result in thermal imbalance and poor soldering quality.
Learning About the Standard Size of PCB Panel for SMT Assembly
Though standard sizes cannot be claimed to be universal, as they change with project needs, there are some industry-standard dimensions that are followed by manufacturers for SMT assembly. These standards check compatibility with streamlined production and automated equipment.
- Small Panels are around 100mm X 100mm, which is often suggested for small-batch production. These sizes are highly recommended for testing designs before scale-up.
- Medium panels vary in size from 200 mm x 300 mm. It is advisable for SMT equipment and mid-volume runs.
- Large panels of 500mm X 400mm, or sometimes more, can be employed, especially for high-volume productions, which increases efficiency and at the same time reduces time wastage.
The mantra for selecting the correct panel size is to understand the set production volume and the extent to which your assembly partner can stretch.
Use Smaller Components
Try switching to smaller alternatives to the bigger ones, like 0805 to 0201. Try a 60-90% lighter, smaller component.
Double-Sided Assembly
These days, the top and bottom sizes of assemblies are becoming popular. It saves time and doubles the possible surface area.
Reduced the size of SMT Components
You can try adding through-hole components, which are available alongside surface-mount devices. You will be surprised by the reduced area occupied and the weight exerted.
Panelization Specification
Plan and draw the PCB shape so it fits perfectly into a smaller, standard panel. It will help control excessive manufacturing costs caused by smaller, improperly shaped boards.
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Advantages of Reduced PCB SMT Assembly Size
If you think that reducing size has less advantage, you need to think twice. A list of benefits is associated with its smaller size, which will increase the product quality too.
- With a great panel design, material waste is reduced, and at the same time, the cost per board is also controlled. If you are doing high-volume production and you manage to save even 4% of the total cost, it can yield substantial savings.
- When you process panels compatible with automated equipment, you reduce setup time and save time. It will help with fast turnover.
- If you practice proper panel design, it results in consistent soldering and assembly. It will also check for fewer defects and great reliability.
- Completely optimising panels helps scale production from traditional to ongoing, quick production without drastic design alterations.
Wrapping Up
You need to follow the right approach when making any alteration to the design of your PCB, and you will see how seamlessly it will fit the space for the SMT assembly. Indeed, the outcomes for your product will be much better, and you can check for a smooth production flow.
