Review questions for ipc j std 001g free#

The thickness of the coating is to be measured on a flat, unencumbered, cured surface of the printed circuit assembly or a coupon that has been processed with the assembly.

Review questions for ipc j std 001g free#

Mating surfaces as well as other mounting devices such as connectors should also be free of such coating materials. The new standard elaborates on the keep out areas of the coating material and the associated. Part of the standard warns about not leaving any residue due to whatever masking material is being used as well what kind of tolerances one should expect to have when applying masking materials during the conformal coating process. The J-STD-001 revision вЂњFвЂќ also weighs in on these conformal coating changes in numerous ways. In version вЂњFвЂќ the following has been added as a process indicator for all lasses: вЂњno bridging or exposed conductive surfaces from loss of adhesion, voids and bubbles.вЂќ These are the major conformal coating standards changes in the new A-610 version. The newer spec has a more complete section description on the coating thickness as well as on bubbles and voids in conformal coating. The new standard has revised information on conformal coatings. It is a non-inspectable surface and therefore X-ray imaging and process validation needs to be performed in order to meet this criteria. There already has been some push back from users with power electronics in this new interpretation of the standard. In version вЂњFвЂќ Class III defect conditions exist when vertical hole fill is less than 75%. Formerly, the вЂњEвЂќ revision had defect conditions for both Classes 2 and 3when the vertical hole fill was less than 75%.For Class II in the new revision, vertical fill of solder of component now stands at 75% when component are less than 14 leads or 50% when 14 leads or greater. The Class II hole fill criteria have been updated and are described in Table 7.4 of the new A610 document. The supported holes with component leads sections of the revised standard have had some significant changes. This discussion includes foreign object debris (FOD) which in the previous вЂњEвЂќ version called these same objects вЂњparticulate matter.вЂќДЇigure 1: Example of Foreign Object DebrisД¬lass II Supported Hole Fill Requirements The new revision has in section 10.6.2 a discussion on cleanliness.

The newest version of IPC-A-610 standard has added definitions and clarifications of FOD (Foreign Object Damage, Figure 1).

When agreed between manufacturer and user.

QFNs/LGAs where the designed land extends past the component termination area.

Connectors, provided solder does not go into the cavity.

Space from the top of the lead to the bottom of a plastic component is 0.15 mm (6 mils) or less.

In the new вЂњFвЂќ version of the document, it states: вЂњUnless otherwise specified, solder shall not touch a package body or end seal.вЂќ Exceptions are when a copper lead or termination configuration causes the solder fillet to contact a plastic component body, such as: There are now some exceptions allowed in the new version of the standards for some solder to touch a plastic bodied component for small stand-off distance devices. These decreasing package sizes make it tougher and tougher to retain the geometries of the solder joint correctly for a reliable interconnect and still keep the solder off the component body. There are several changes worth highlighting in the new Revision вЂњFвЂќ of the document:Дispelling past concerns that solder could not touch plastic components for fear of future failure, the standards committee were not presented with any significant data indicating a higher rate of failure when solder touched plastic body components. Changes to both of these documents as well as some updates in IPC certification programs for these and other standards are in store for the OEM and EMS communities in the coming year.

The JSTD-001 is its companion document describing how boards should be assembled. The document that is the most widely circulated by the assembly industry is IPC-A-610, which is the acceptance standard for assembled boards. The recent adoption of the newest versions of the JSTD-001(Requirements for Soldered Electrical and Electronic Assemblies) and the companion document IPC A 610 (Acceptability of Electronic Assemblies) late in the summer of 2014 means that there are several changes ahead for those inspecting boards during assembly, accepting boards at incoming inspection, building boards and training associates on applying the revised standards.

Review questions for ipc j-std-001g