PCB & Assembly Turn Time - How to Expedite Your Order
Factors Affecting Turn TimeTurn 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 TimeFor 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 board dimensions.
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 DelaysWe 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 FilesTo 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 https://www.7pcb.com/blog/procedure-creating-centroid-file.php.
Consignment and Parts ProcurementIn 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.