PCB & Assembly Turn Time - How to Expedite Your Order
Factors Affecting Turn Time
Turn time is always among the most significant concerns in the world of PCB fabrication and
assembly; in fact, it is often just as important as the cost or quality of a project. At Bittele Electronics, we
understand that our clients have deadlines to meet, so we strive always to minimize the turn time of
your orders, and to get your boards to you as quickly as possible. Still, many of our clients ask if there is
anything that they can do from their side of the equation to help in further reducing the turn time of
their order. This handy reference is intended to answer such questions as succinctly as possible, giving
our clients a clear picture of each potential source of additional turn time on their quote.
Standard Turn Time
For PCB fabrication, we begin with a standard 5-day turn time, which is offered at lower
volumes for 2-layer boards with 1.0 oz Copper Weight. An increase in the number of layers or the
copper weight will cause an increase in turn time. This standard turn time could also be significantly
affected by the presence of blind or buried vias, as well as vias in pads, and also very large or very small
For PCB assembly, we begin with a standard 7-day turn time. This can increase in the presence
of difficult component packages, such as BGA, QFN, or 0201. A board whose components are majority
THT, rather than SMT, will also effect an increase in turn time. Special assembly requirements will also
add to the standard turn; such requirements might be the addition of standoffs to a board, or the gluing
down of a battery holder.
Together, and with a 2-day shipping allowance for components to reach our production
facilities, this totals a 14-day standard turn time for Turnkey PCB orders. We hope that by sharing these
causes of increased turn time, we can help you to understand the turn time listed on your particular
quote and also help you to minimize turn time in your future designs.
Avoiding Common Delays
We realize that it is not always possible to avoid those design elements, mentioned above, that
effect an increase in turn time; your design might require 6 copper layers, or a BGA package. In these
cases, you can still help to expedite your PCB assembly project if you have a clear understanding of our
ordering and manufacturing processes. There are a few common causes of delay, outlined below, that
can be easily avoided through organization in the early stages of the project.
Preparing Your Design Files
To complete the fabrication and assembly of your boards, we require your Gerber files in RS
274X format, your Bill of Materials (BoM), your NETLIST file, and your Centroid file. One of the most
common sources of delay is a missing Centroid file; this is the file that describes the actual location and
orientation of each component on your PCB to our placement machines. It is normally a .CSV or .XLSX
file. The Centroid is often overlooked when clients send their design files for a quotation, and valuable
time can be lost if the Centroid file has not been received by the time your PCBs are ready for assembly.
For assistance in generating a Centroid file, please see our guide at http://blog.7pcb.com/procedure-creating-centroid-file/.
Consignment and Parts Procurement
In order for your components to reach our production facilities, you may choose to allow our
parts procurement department to handle purchasing, or you may choose to purchase the parts yourself
and ship them to our Toronto offices. In either case, a common cause of delay in PCB assembly orders
occurs when one or more of your parts runs out of stock between the time that your BoM was created
and the time that your order was placed. Suppliers such as Digi-Key or Mouser see very high demand,
and so it is quite the gambit to select parts which show only minimal stock from these suppliers. Your
part may show 500 pieces of stock when you create your BoM, but by the time your order is placed, that
stock could be depleted, and you could be looking at a 15 week factory lead time.
We also see delays come from difficulty in shipping consigned parts to our Toronto offices. If
you have decided to consign your parts to us, we recommend that you prepare the shipment as early as
possible so that we can work with you to resolve any shipping issues within your project timeline. If your
order is very rushed, it may be best to allow our parts procurement team to handle purchasing for you
in order to avoid such issues altogether.
Other Turn Time Questions
We hope that this guide has been able to answer all of your questions regarding turn time for
your PCB Assembly project. If you find yourself with any lingering questions, please do not hesitate to
contact us through email at firstname.lastname@example.org. One of our specialists will respond promptly, and will be
happy to take you through the process in detail.