Cadence PCB Best Practices

Allegro/OrCAD Rigid Flex Design Creation Best Practices _______________________________________________________________________ Learn more at Cadence Online Support - https://support.cadence.com Page 9 © 2016 Cadence Design Systems, Inc. All rights reserved worldwide. Exam ple o f a M ask L ay er Site file D ata S ho wn in M ask L ay er Subc lass Site File E dito r The Mask Layer file provides the following data: Function: The assignment of IPC Layer Function Type as defined by IPC-2581. The value set for this field is from a pull down menu of legal values. Choose the type that fits closest to the intended use of the layer. Name: This is the name of the subclass used in the design database. The default name is MASK_0. This name may be any legal subclass name. Class Name: There are four legal classes to which a layer can be assigned. Surface Finishes, Rigid Flex, Package Geometry, and Board Geometry. The class selected should best fit the intended use of the subclass being created. Default Material: A pull down list of available material as defined in the materials.dat file. The value selected becomes the default material value for this layer. Building and maintaining an accurate Mask Layer Site file will save time when initially setting up a new design, and provide accurate data for manufacturing. Working with the fabricator to define the materials will assist in creating a well-defined set of materials. Rigid Flex Design Structure Example Rigid flex designs consist of multiple materials and thickness across the entire design. Each of these materials is represented by different layers in the PCB Editor cross section. Various mask types, dielectrics, stiffeners, and copper layers are combined in different ways to build up the various thicknesses determining which zone is flexible and which zone is rigid. The following diagram is an example of a rigid flex design structure, where the buildup of materials create the various rigid and flex zones.

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