Category:PCB PCB Layout

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The connections on a PCB should be identical to its corresponding circuit diagram, but while the circuit diagram is arranged to be readable, the PCB layout is arranged to be functional, so there is rarely any visible correlation.

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PCB Layout cost Reply 2017-02-12 05:45:06
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rosenborisov78

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Determining a price for PCB layout services is conceptually simple: Estimated number of hours times an hourly rate. The trick is estimating how much time, and which rate is applicable.Over the past 24 years we've quoted more than 6,000 designs and evolved a pricing methodology that uses a structured process applied to a baseline formula which is then modified to accommodate exceptional items.
Documents Needed
Probably the most frequent question asked by new customers is “What information do you need to quote a design?” Here are the files required for a quote, and additional files that are helpful (the more information provided the better):
Required
  1. Schematic (Native design file or PDF)
  2. BOM (Bill of Materials)
  3. Mechanical (DXF, IDF, PDF, or simple X-Y dimensions)
Helpful
  1. Netlist
  2. Routing Rules / Constraints Document
  3. Placement Floorplan
  4. Component Datasheets (only for components with Layout Notes)
Additional Things We Need To Know
Below are some common questions we might have, especially for new customers:
  1. General schematic/technology questions?
  2. Manufacturing cost concerns?
  3. CAD tool requirements? (At Optimum we support most tools)
  4. Do you have a corporate library?
  5. Target completion date?
Estimating Time - Baseline
With a general understanding of the design and the basic questions answered, we can estimate the hours required for the project. For layout, the tasks are virtually the same for every board:
  1. Library creation
  2. Placement
  3. Routing
  4. Outputs
To put a time to these tasks, we created a formula based on a count of component pins, components, nets, desired number of layers, and the usable area of the board. Using the documentation you provided a baseline number of hours is generated for each of the layout tasks.
Estimating Time - Adders
The baseline number is then adjusted with “adders”, items which impact the standard time it takes to complete a design. Some common “adders” are:
  1. Component pin density. This is derived from the usable square area (inches) / number of pins. Anything over 400 pins / sq. in. would increase not only the placement time, but the routing as well. This calculation is also used to determine if HDI is necessary from a density standpoint (not package).
  2. Routing density. Based on the number of internal routing layers, number of nets, and shape of the board, a factor is applied to the routing baseline.
  3. Routing Topologies and Timing requirements. DDR memory schemes are good examples of technologies that take a bit longer to successfully incorporate into a layout. Other examples would be; RF designs with shield walls, Power Supplies, large number of differential pairs, PHY’s, etc.
  4. HDI. Necessary due to either package size or component pin density. HDI is a real game changer on what can be accomplished on a PCB as well as differentiator between designers.
  5. Mil / Aero. Technologies used on military / aerospace are typically no different than what we see in the commercial world but because of their stringent design guidelines, review process, complex documentation and project management requirements, these boards take longer to complete in all areas.
Estimating Time - Example
Here's an example time estimate from a recent design quote:
Baseline Inputs
Board Size: 6 x 4”
Layers: 8
Pins: 1848
Comps: 544
Nets: 353
Baseline Time Estimate
Library: .5 days
Placement: 3.5 days
Copper: 4 days
Outputs: 1 day
Adders
DDR3 (1 bank)
Total Time Estimate
64 Hours
In the above example, we have a fairly straight forward design expected to take approximately 64 hours. This considers all aspects of the design process, including library, layout, and project management, required to produce a design that will meet your electrical constraints and manufacturing requirements.
Hourly Rate
To put a price to this example, we would multiply the 64 hours times an hourly rate. US domestic layout rates tend to range from $90-$150 per hour. The factors affecting the rate include turnaround urgency, seniority of designer required, technologies, EDA tool choice, onsite requirements, and business volume.
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Statement: This post is only the personal view of the author and does not represent the opinions of ALLPCB.com.

Buck

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Remarkable.Great help to my learning.
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