9 Common Issues During Component Selection

The importance of component selection is too often overlooked by clients preparing a PCB Assembly project. Design and layout of the board itself are of course very demanding tasks, but it is important to pay some attention to the actual parts that will be soldered to that new board of yours. Projects with a lot of component issues will often run up against delay or additional cost, complicating the experience for all parties involved.

At Bittele Electronics, we have years of experience working in Parts Management, and we are ready to help you ensure that your PCB Assembly project is fully optimized. The nine most common issues we notice that can delay the quoting and/or purchasing stage of the project are listed below for your reference. If you refer to this handy guide while building the Bill of Materials (BOM) for your next PCB design, your parts should be worry-free!

1. Low-to-No Stock

This one is fairly straightforward, but easy to overlook in some cases. Many clients fill in their BOM before the PCB layout is completely finished, and stock levels have completely changed by the time our purchasing team receives your order. For this reason, we recommend that you give your BOM a once-over to catch any stock issues just before sending in your order, or you could move the BOM building process to a later stage in the design.

Keep in mind that vendor listings are not always fully up to date. You might only need 100 out of the 132 that are marked “Available”, but the actual quantity in the warehouse might not agree. It is always better to choose parts that have a significant amount of extra vendor stock.

For parts that simply are not available in high stock levels, some clients will provide approved substitute part numbers in a separate column of their BOM. Also, be sure to check out our database of Free Passive Parts, available for all turnkey PCB orders.

2. Incomplete Part Number

We often see clients who include only partial part numbers in their BOM, which requires some back-and-forth to sort out exactly what model should be purchased. For example:

GRM0335C1E101 – Refers to a family of capacitors by Murata Electronics

GRM0335C1E101JA01D – Refers to a specific capacitor

Even if our vendor search for the partial part number turns up only one result, we still have to request your confirmation in order to purchase a different part number than the exact one listed on your BOM; orders with multiple partial part numbers can see some significant delay. Again, the optional substitute part number column on your BOM could be used to list multiple family variants, or you could include a note “Any suffix for GRM0335C1E101 is okay”.

3. Incomplete BoM Line

Sometimes it can be difficult to judge What Exactly Needs to be Included on Your Bill of Materials, and important information can end up left out. Generally, the following fields will be required for any BoM:
  1. Item Number
  2. Reference Designator
  3. Quantity
  4. Manufacturer Part Number
Additional columns, such as Description, Manufacturer, Notes, or Alternate P/Ns, can help to make the process more efficient, but the four listed above are absolutely required in any project.

To help you with the process, we provide a Sample BOM on our website that can be quickly populated with your project’s information.

4. Typos!

So simple, but so very deadly! We certainly would not want your project to run into any trouble just because someone missed a “0” in the quantity column, or the typed a wrong letter in a part number’s suffix. Our parts procurement team is extremely skilled at catching these types of errors, but you can help to boost the efficiency of your project by simply giving your BOM a quick proofread before you submit your designs.

5. Lead Times

This is more often an issue for orders with Consigned Parts, where our clients need to get all of the parts to our Toronto location by a given date in order for production times to line up properly. In our Full Turnkey service, you can trust all of the purchasing to our experienced team. We can leverage our long-standing business relationships to get your parts shipped faster, and have them better organized for receiving, often for a lower cost than client-directed purchasing would require.

Our advice on this topic is mainly to give our parts procurement team a shot, and we are sure you will be impressed. For orders where consigned parts are a necessity, make sure to budget at least an extra day or two for unforeseen circumstances. We will of course work with you at every step to help you get things on track as soon as possible.

6. Unreliable Vendors

At Bittele, we purchase only from reputable North American parts vendors with whom we have formed long-standing business relationships. As such, we can depend on these vendors to quote accurate lead times for us, and to always supply the right components. Unfortunately, not all vendors are so reliable, and we have seen issues with long delays, missing parts, or wrong / fake parts in the past. This is the reason for Bittele’s strict policy to only purchase from vendors that have fully earned our trust.

Clients will commonly ask us to purchase parts for their order from a lesser-known vendor for larger price breaks, but we strongly discourage this practice. If our clients prefer to make the purchase and consign the parts to us, we can certainly accommodate, but we very much recommend sticking with our approved vendors, even if it means a part change or two.

Our most frequently used vendors are: Digi-Key, Mouser, Avnet, Newark Element 14, Future Electronics, and Arrow Electronics

7. Obsolete Parts

Obsolete parts are mainly a concern for repeat orders, where there has been some time between production runs. In these cases, it is helpful for clients to give their BOM a once-over to check for any obsolete parts. We can work with you to find replacement parts for any obsolete components, and in some situations, we might be able to source a limited quantity to help you out with your next run. The important thing with obsolete parts is simply that you are aware of them as early as possible.

8. Minimum Order Quantities (MOQ)

When browsing for parts to suit your project, you should always make sure to keep an eye on the “Minimum Quantity”, “Minimum Order”, or “Minimum Order Quantity” listing for each component. A part with an MOQ listing of 100 can only be ordered in quantities of 100 pieces or more, which might not be economical for your 10 piece PCB Assembly project.

Make sure to check if your part must be ordered in specific multiples as well, since this is sometimes the case. We need to order some extras of each part to protect us against production loss, so if your part must be ordered in multiples of 100, and we require exactly 100 for the order, we either have to order a lot of extras, or find a different solution.

9. Samples

The most cutting-edge Prototype PCB Assembly projects use the most cutting-edge IC technology, and sometimes that means going directly to the manufacturer. Bittele’s PCB Assembly Process can certainly support sample parts as long as we have a datasheet for the physical attributes of the component in question. The only potential issue here is that component manufacturers can be notably slow in shipping out those sample parts.

We recommend that our clients place any orders for samples with the manufacturer as soon as possible, and certainly well in advance of submitting your PCB Design Files to Bittele for a quotation.

So these have been the 9 most common issues that occur during component selection. With this information in mind, we hope that you will be able to work with us to create an efficient and straightforward BOM that allows your PCB Assembly project to finish quickly and for a low cost. If you find yourself with any further questions about our policies around electronic components, please feel free to Contact Us any time. We can be reached via email at sales@7pcb.com, or toll-free at 1-888-812-1949.


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