How many parts need to be ordered for your assembled boards? This is a question we hear on nearly every PCB assembly project we undertake.
Establishing the correct quantities is especially important for time-sensitive projects and high-reliability circuit boards.It’s not common for your engineering and design team to know how tape and reel is mounted and used on automated SMT equipment. Consigned component kit shortages is the one of the biggest, if not the biggest, impedance to scheduled delivery and processing. If possible, we recommend full turnkey assembly for all your PCBA projects to ensure the best quality end-product.
It is important to have a sufficient amount of extra components for each project to avoid delays in the case of a loss or attrition of parts.
Our overage cheat sheet below will help you know how many of each component size need to be ordered and at what quantity.
|Component Size||Need less than 20 pieces||Need less than 50 pieces||Need less than 100 pieces|
|01005||Order 150 or more||Order 200 or more||Order 250 or more|
|0201||Order 100 or more||Order 150 or more||Order 200-250 or more|
|0402||Order 100 or more||Order 150 or more||Order 200-250 or more|
|0603||Order 100 or more||Order 150 or more||Order 200-250 or more|
|0805||Order 50 or more||Order 100 or more||Order 150 or more|
|1206||Order 50 or more||Order 100 or more||Order 150 or more|
Many resistors and capacitors are a penny each or less.
A few hundred of these kind of parts will cost less than $5 and the length of the strip can go into a feeder without any problem. Paying an additional $7 for a digi-reel is unnecessary.
However, if the parts are particularly expensive the following can be used as a guide for overages:
There are also some thinner tape widths for the 01005 size parts that are 4mm as opposed to 8mm, most commonly supplied by Murata and TDK. These tape widths are not always able to be used as they don’t fit in the cassette feeder, so avoiding these thinner tape widths is recommended.
Learn more about PCB assembly here.