Know your Customers Desires
By Mark Thompson | Published on May 5, 2010 - 10:00 AM PST
Now, More than ever we need to pay special attention to our customersÕ desires and Idiosyncrasies. Over the years of building parts for the same customer, the Fabricator generally amasses a certain amount of additional knowledge about the customer. Things like special features on the artwork that would cause delays at other fabricators that are known as intentional features by a fabricator who has already asked the questions... It is therefore crucial that these small details are documented and archived in a Customer specific requirements type database. Having said that, there are certainly times that deviations from "what has been" and "what is" warrant that the question be asked again. Here, it is good to have that background knowledge of previous dispositions of the same kind with the customer so that the questions can be answered easily and with fewer delays.
10 Things to Review Prior to Release to a Fabricator
By Mark Thompson | Published on April 5, 2010 - 10:00 AM PST
Hello all. In this month’s "Engineering Spotlight" I will go over 10 things that should be reviewed prior to releasing a PCB to be fabricated. I want to stress that depending upon the application some of these things may not be feasible in a given design.
Keep them on the Inside - Why Fabricators prefer Impedance Lines on Internal Layers
By Mark Thompson | Published on February 26, 2010 - 10:00 AM PST
Greeting‘s all. In this month’s “The Bare (board) Truth” I will be talking about some of the reasons both Fabricators and Customers may benefit by keeping any Impedance controlled lines on the internal layers. So let me dive right in.
Are we on the same page? - Design Vs. Manufacturing
By Mark Thompson | Published on January 30, 2010 - 10:00 AM PST
In This month’s column I will talk about tolerances and drawing callouts and the questions that arise in fabrication due to vague or incomplete notes on drawings or read me files. In a fabrication environment we frequently say we deal with anyone from a customer that provides detailed 14 page drawings all the way to the proverbial “ball point pen on a cocktail napkin”. This means we see drawing notes that can sometimes be incomplete or misleading. In this column, I will give examples of both complete and relevant drawing notes those that are less complete requiring clarification from the customer.
Engineering Spotlight: More Standard Manufacturing edits revealed...
By Mark Thompson | Published on November 19, 2009 - 10:00 AM PST
Previously, I talked about etch compensations for copper features based on the known loss at the Etch process, about Inner layer scale factors based on core thickness to achieve optimum layer-to layer registration. I have also talked about altering dielectrics to achieve desired Impedances staying as close to the intended original line sizes and edits or tweaks to line and space values to achieve Impedances if altering dielectrics is not enough.
Engineering Spotlight: Basic Impedance Fabrication Guidelines | Part 2
By Mark Thompson | Published on October 22, 2009 - 10:00 AM PST
In this column I will talk more about Co-planar structures and unique reference plane scenarios as they relate to PCB fabrication. In the first part, I will talk about Co-planar type structures and the effect of un-intentional co-planar coupling on Impedances. In the second part, I will talk about the use of unique reference plane scenarios for multiple impedance’s. What benefits they may have vs. any drawbacks.
Engineering Spotlight: Solder Mask and Surface Finish
By Mark Thompson | Published on September 10, 2009 - 10:00 AM PST
In today's RoHS environment, immersion silver and gold replaces tin-lead. What does this mean to your mask artwork files? Interestingly, when tin-lead finishes were the norm, most solder mask clearances associated with surface mount devices were "gang relieved," which is to say there were no webs of solder mask material between the mounts. This tended to create situations where solder wicking occurred, shorting mounts together.
Engineering Spotlight: What Really Happens to Your CAM Files...
By Mark Thompson | Published on July 27, 2009 - 10:00 AM PST
Have you ever wondered exactly what happens to your CAM files once they go to a fabricator? In today’s column I will attempt to explain a few of the standard edits made by a fabricator and what that means to the end user. So what types of edits get done to the artwork files before processing?
Engineering Spotlight: Net-Lists and Net-List Generation
By Mark Thompson | Published on June 28, 2009 - 10:00 AM PST
A net-list compare is required for IPC Class 3 6012 jobs and any other job that the customer has supplied a net-list on, typically the net lists are IPCD356, IPCD356A or some other ASCII type file such as a mentor neutral file. The purpose of the net-list is to verify the design criteria against the output Gerber files to make sure there are no differences between the desired design and the generated Gerber files. Many times over the years We here at Prototron have been asked to Generate a net-list file from the provided Gerber’s
Engineering Spotlight: Basic Impedance Fabrication Guidelines | Part 1
By Mark Thompson | Published on June 9, 2009 - 10:00 AM PST
Hello All, Today’s column will be on some very basic impedance guidelines for fabrication. As a very brief recap of what I said in my previous audio column, prior to trace routing, pre-establish the effective Dk’s of each sub section with your chosen fabricator. (Remembering, generally the thinner the dielectric the thinner the pre preg or b-stage, the thinner the b-stage the higher resin content, the higher the resin content the lower the Dk.)
Engineering Spotlight: Dielectric Constant Mismatches
By Mark Thompson | Published on May 13, 2009 - 10:00 AM PST
How many times have you had a part go from Prototype to production only to get a whole lot of ‘door stops’? These inconsistencies between prototype and production type board shops are only the beginning! There are variances between prototype shops themselves, and even shops under the same Company name can have inconsistencies.