Your PCB Assembly Documentation is Key to a Smooth Quoting Process

Posted on November 05, 2015
by Toby Klusmeyer

When it comes to getting a PCB Assembly quote, having a great documentation package goes a long way to getting your quote fast — complete with an accurate price and delivery that will not change after you place your order.

PCB Assembly Documentation: Your EMS provider is an expert at finding errors
Have you recently had a PCB Assembly quoted, then placed the order and soon discovered your Electronic Manufacturing Service (EMS) provider can’t deliver on time, or needs to upcharge for documentation discrepancies? Or upcharges for a detail that you forgot to include?
You know very well that the devil is in the details of your PCB Assembly documentation and he will come out to haunt you even if you only sin once. So, what can you do to prevent detail-devils from possessing your PCB Assembly project? One answer is to work closely, as a partner, with your EMS provider.
Here’s why:
Your EMS provider is an expert at scrubbing your
PCB Assembly documentation to find errors.
This is a great thing for you. I can’t tell you how many times we’ve quoted an assembly only to find errors lurking in the details. I know that we’ve saved our customers countless dollars over the years by finding the errors before they go to production.
Your Quote Package: Accurate PCB Assembly Documentation eliminates risk
Here are the MINIMUM requirements we need from our customers. Consider this list a simple overview just to get us on the same page:
* PCB Assembly Specifications
* Bare PCB Gerber Files
* Bare PCB Specifications
* Bill of Material with Quantity, Reference Designators, Description, Manufacturer Name and Manufacturer’s Part Number
* Quantity of Boards to Build
* Delivery date(s)
As an EMS provider, it’s our job to estimate the cost of materials, labor and tooling required and the time required to build your assembly. All quotes include these, plus a risk factor based on the complexity of the assembly. Eliminating risk is an opportunity for reducing cost.
I’ve been in this industry for over 20 years. PCB Assembly documentation that prospects have provided range from pitiful to absolutely remarkable. People come and go from this industry so it is important for me to train you how to create a great PCB assembly documentation set so that risk is eliminated for you and for me.
Your Bare PCB: Utmost quality begins here, so get it right
So, you’ve designed your PCB following all the IPC rules. You’ve created all of your Gerber files (output files) and then you performed a DFM check (Design for Manufacturing) using some of the online tools available.
Now… take the time to create a Bare PCB Specification (PCB Fabrication Drawing) and include it with your Gerber Files. Review all the specifications to be sure you have all the required details. Don’t make any assumptions.
If you are new to this, be sure you take the time to learn the important details of this step. There are many references available online so be sure to talk to people who understand this information.
The bottom line is this: Your job is to get the details written permanently in your documentation so that any changes made to the assembly, or with suppliers in the future, will result in exactly what you want — every time.

Your Bill of Materials: Save time by removing errors and checking component availability
I talked to my quoting team about our prospects’ Bill of Materials (BOM) submitted for quotation. They told me that almost every BOM they received had at least one error on it. I couldn’t believe it. How could this be?
Well, an error by my team’s standards might be different than yours. Here’s a list of challenges they have to deal with:
1. Parts might be on the PCB but not on the BOM
2. Parts have long lead-times — and the Customer won’t accept such a deal
3. Parts are obsolete or will be discontinued in the near future
4. Incorrect Manufacturer’s name or part number
5. Incorrect quantity
6. Incorrect package type — won’t fit on board land pattern.
These are the top six issues that we find. Imagine how an automated, online quote can deal with these issues? Again, support for my claim that a great relationship with your EMS provider is so important.
That’s why I urge you to take the time to review your BOM for errors in advance before you find yourself up against the clock. Better yet, have our team review it for you here.
The Devil is in the Details, and PCB Heaven is in getting them all right
As an engineer, I sometimes drive people crazy with my detail-oriented style. I can’t help it. I’m not always perfect, but I strive for perfection. It’s in my blood. Besides, my obsession with detail saves money and improves delivery for my customers.
I love checklists. Here’s a list of questions that really helps my quote team hone in on the price and delivery that we provide in our quotes. Your answer to these questions (in advance) really helps streamline the quoting process and prevent errors from propagating into your assemblies.
PCB Assembly Specifications
* Lead-free Assembly (yes/no)
* RoHs Compliant Assembly (yes/no)
* Top Side Surface Mount Components (yes/no)
* Top Side Solder Paste Layer Provided (yes/no)
* Top Side Thru-Hole Components (yes/no)
* Bottom Side Surface Mount Components (yes/no)
* Bottom Side Solder Paste Layer provided (yes/no)
* PCB Scoring/Routing
* IPC Specification Requirements IPC-A-600 Class 1, 2 or 3
Order Specifications
* Number of Boards
* Delivery Date/Schedule
* Customer Providing Parts (all/some/none)
* Board Quantities to Quote
* First Article Provided Before Entire Order Built?
* Estimated Annual Usage (EAU)
Bare PCB Specifications
* PCB Size & Shape
* Number of Layers
* Material Type
* Thickness
* Outer Layer Copper Thickness
* Inner Layer Copper Thickness
* Solder Mask Color
* Silk Screen Color
* Finish/Plating Type
* Panelization Requirements
Providing the ideal PCB Assembly documentation to your EMS provider for quoting will get you the price and delivery you need. It will help prevent surprises down the road and will build a rewarding, responsive partnership with your EMS provider.
Happy quoting to all.
See you next time, next blog.

Tags: PCB Assembly Communication PCB Assembly Quote

Welcome to the Pro-Active Engineering Blog!

Insights on improving manufacturing PCB lead time without sacrificing quality.

Recent Posts