Mistakes within kits of components supplied to us by clients as free issue kits are the single most frequent cause of production delay for us. Clients are advised to open every package received from distributors and to check the contents are exactly as ordered in terms of substance and quantities. Our experience is that 1 item in 50 received from distributors has an error. Our working assumption is that client supplied kits are correct. We cannot guarantee to identify wrong components. We will use our best efforts to report errors to clients. If significant additional costs arise as a consequence, then these will be additional to our quoted prices.
Take a look at the pros & cons of supplying free issue kits. Send your BOM to us for a quote
We will always try our best to place problematic parts. For example, sub-optimal SMD pad size can be tolerated by adjusting the amount of paste delivered by the solder stencil. We cut our own solder stencils so, if necessary, we can revise the stencil design and cut a new stencil the same day. If economic, we will consider modifying components to fit. Components that we are unable to fit will be returned to clients unfitted. When fitting standard Rs and Cs, unless instructed otherwise in the client’s BOM, we will fit the nearest E24 value e.g. 122 ohms will be fitted as 120 ohms. Badly labeled components, ambiguous placement locations, and unclear drawings may result in non-fitment of parts if such issues cannot be resolved by direct contact with clients.
BOMs usually have the normal default information such as reference designator, description, manufacturer and manufacturer part number. In addition, it is highly desirable to include Farnell part numbers, and columns to indicate whether the parts are client supplied, Newbury supplied or not fitted.
We typically need 5% extra parts to allow for losses and wastage. Most parts will be assembled using automated pick & place machines. It is inevitable that some parts will be lost from the tape at the beginning and end of production runs due to trial runs and miss-picks. This will not occur on every part, but it could happen on any part. Large parts, and manually placed parts may be supplied to us in the exact quantity.
All components, where possible, should be supplied on tapes and reels. Anti-static precautions should be observed with all packaging. Component packages or bags must be marked as follows:
It is essential to send us the pick & place machine component placement data. This data will include the component x/y coordinate data in .prn, .csv, or .xls file formats. All CAD design software will output a standard pick & place machine component placement file which will be suitable for our needs. There will be columns for:
We assemble PCBs to commercial quality based on IPC-A-610 Rev C – Class 1 specification, “Acceptability of Electronic Assemblies”. If other levels of build quality are required such as class 2, class 3, military, or medical ask us to quote.
Because of the short runs, most electronic assemblies we manufacture are not tested by us. They will be inspected on a visual basis. Any defects identified during final test may be returned to NEL for re-work. We can test electronic assemblies either using flying probe test, functional test, power up test, or customer supplied test routines and test rigs. Please ask us to quote.
2% silver loaded solder wire will be used for hand soldered components. This colophony- free flux leaves a slight “white-powdery” inert residue around the solder joints and is non-corrosive. This is acceptable for all commercial applications.
The normal pad foot-print design guidelines apply. In particular, ensure that via holes adjacent to BGA pads are covered with solder resist so that solder is not “wicked” away. Via pads should not be placed within BGA pads or SMD pads for the same reason.