This article shows how to calculate PTH (Plated Through-Hole) Hole and Pad Diameter sizes according to IPC, IPC and IPC standards in the . Check out page 39 of IPC (google: “IPC filetype:pdf” to find a free copy:)) Electrical clearance requirements are based on multiple. defined by the IPC generic standard: Level A: General Design Complexity. Level B: Moderate Design Complexity. Level C: High Design Complexity.

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For all these purposes, the nickel underplating must be intact that is, not cracked and must have sufficient thickness to achieve the particular function for which it was intended. During the design testability review meeting, tooling concepts are established, and determinations are made as to the most effective tool-cost versus board layout concept conditions.

Vias, wide conductors, or component lead mounting lands may be considered as probe points provided that sufficient area is available for probing and maintaining the integrity of the via, conductor, or component lead mounting joint. Masking seals must be air-tight. In many cases the bypass capacitors 0. Required compatibility check with solder resist. Polyurethanes are available in almost as many variations as the epoxies.

IPC-2221A – University of Colorado at Boulder

Typical applications are military products where the entire final assembly will be conformal coated. In most applications, there are system level fault isolation and recovery requirements such as mean time to repair, percent up time, operate through single faults, and maximum time to riletype.

IPC – February Users of this publication are encouraged to participate in lpc development of future revisions. Standard discrete components resistors, capacitors, diodes, transistors, etc. This provides a surface for auto-catalyzing the electroless copper deposition.


This is due to a multiplier used for each cross sectional area range. Printed boards and printed board assemblies in this class are suitable for applications where high levels of assurance are required and service is essential. To prevent oxidation of an underlying plating such as nickel and electroless nickel to enhance solderability 21 IPCA May and extend storage life.

Saturn PCB Design Toolkit Version 7.06

See the link if you have this issue. The filler is normally dried aluminum oxide or magnesium oxide powder. See IPC for complete cross-reference and properties of these grades. Changed stipline formula restriction to 0. Calculates the outer and inner layer diameters filetupe a padstack given the drill size. Surface mounted components and their patterns require special consideration for test probe access, especially if components are mounted on both sides of the board filefype have very high lead counts.

Edge clearance to any exposed circuitry i.

IPCA – University of Colorado at Boulder

Etched markings may affect electrical characteristics such as capacitance. These materials generally offer toughness, high elasticity, a wide range of hardness, and good adhesion. Also, when using surface mount technology, the potential usable board area is theoretically doubled. Updated default values for via settings.

C Conductor Patterns The conductor pattern does not need a separate datum reference, provided a minimum annular ring is specified. Component density values higher than these will be a cause for concern. May required over melting metal surfaces, the maximum recommended conductor width, where the coating completely covers the conductor, shall be 1. This will minimize electrical leakage problems resulting from condensed moisture or high humidity. Some components may not have long enough leads for thicker boards.

Silicones are often used as a cushioning overcoat for articles which will be encased in hard potting compounds later.


Removed installer background to reduce file size. Minimize the impedance and radiation loop of the coupling capacitor by keeping capacitor leads as short as possible, and locating them adjacent to the critical circuit.

Contact the via which is connected to the land and visually inspect to ensure continuity from the via to the land. Fixed startup error in Signal Properties calc in metric mode. In addition, crosstalk between adjacent circuits will depend directly upon circuit spacing, the distance to the reference planes, length of parallelism between conductors, and signal rise time see IPC-D This should be based on the maximum size of all parts required by the parts list and the total space they and their lands will require on the board, exclusive of interconnection conductor routing.

Do not allow the component the opportunity to tip during assembly or soldering. They are less resistant to solvent attack than epoxy and are two part systems with other variable properties dependent upon formulation.

Board Thickness to Plated Hole Diameter: The grounding scheme can be used as a part of the distribution system. Time mode selected after user exists Conductor Properties. MIL-S is canceled and listed for reference only.

Taller parts on this side of the board will require cutouts in the test fixture.

Unless otherwise specified on the master drawing, the maximum bow and twist shall be 0. The recommended structural adhesives listed in 4.