Contents
How to size through hole pads?
Determine the Plated-Thru-Hole Diameter IPC suggests that you can take the lead diameter, add a certain value to it, and this will end up being your plated-thru-hole diameter. For Density A, this extra margin is 0.25mm. So if your lead diameter was 0.5mm then your plated-thru-hole would be 0.75mm diameter.
What shape should a through hole pin solder joint have?
concave fillet
The ideal solder joint for through-hole components is a “concave fillet”, which has a smooth and shiny concave surface at an angle of 40 to 70 degrees from the horizontal, which looks just like the shape of a Hershey’s kiss.
How big are pcb holes?
Recommended PCB Hole Sizes
| Lead Size | Hole Size |
|---|---|
| (0.46) .018 Sq. | (0.76) .030 Dia. |
| (0.51) .020 Sq. | (0.81) .032 Dia. |
| (0.64) .025 Sq. | (1.02) .040 Dia. |
| (1.14) .045 Sq. | (1.75) .069 Dia. |
What is barrel fill?
“Wetable” surfaces are those that will wet with solder and are free from contamination. Solder will not wet a surface that is not hot enough. You need to run a thermal profile of the area where the barrels do not fill, measuring the top side of the board to make sure it’s hot enough for your solder alloy.
How big should a plated thru hole be?
IPC suggests that you can take the lead diameter, add a certain value to it, and this will end up being your plated-thru-hole diameter. For Density A, this extra margin is 0.25mm. So if your lead diameter was 0.5mm then your plated-thru-hole would be 0.75mm diameter.
How big of a hole do I need for a square lead?
For square or rectangle leads – add 0.1mm to the diagonal of the rectangle. For very big flat/square/rectangle leads, better use slot/square holes, not round. (because of the reliability reasons). You need to allow for both the lead size and tolerance and the hole size tolerance.
How to calculate PTH hole and pad diameter sizes according to?
Pad Diameter = Minimum Hole Size + 0.1mm + 0.60mm (for Level A of IPC-2221) Pad Diameter = Minimum Hole Size + 0.1mm + 0.50mm (for Level B of IPC-2221) Pad Diameter = Minimum Hole Size + 0.1mm + 0.40mm (for Level C of IPC-2221) Example: Maximum Lead Diameter = 0.55mm. According to Level A Minimum Hole Size = 0.80mm; Pad Diameter = 1.50mm.
Which is the best way to determine the size of a hole?
First, you look at the specs from your board house. They will give you the tolerance of final finished hole diameters from what you specify. In some cases, they will round to the nearest drill size, with then a resulting diameter range for each such drill. In other words, it is best to stick to a set of discrete hole sizes.