【国外标准】 Standard Practice for Controlling Quality of Radiographic Examination of Electronic Devices

4.1 This practice establishes the basic minimum requirements for establishing quality control in radiographic examination of electronic components or devices, or both. Considerations addressed herein include definition of image quality indicator (IQI) features, procedures for imaging of IQI, and reporting.4.2 This practice is written so it can be specified on the engineering drawing, specification, or contract. It is not a detailed how-to procedure and must be supplemented by a detailed examination technique/procedure.AbstractThis practice is intended to control the quality and repeatability of the radiological examination of electronic devices for internal discontinuities, extraneous material, missing components, crimped or broken wires, and defective solder joints in cavities, in the encapsulating materials, or the boards. However, this practice is not intended to control the acceptability or quality of the electronic devices imaged. The quality of the radiological examination shall be determined by image quality indicators (IQIs), which shall be manufactured from clear acrylic plastic with steel covers serving as shims, lead spheres, gold or tungsten wires, and lead numbers, and shall be permanently identified with the appropriate IQI number. The IQI shall simulate as closely as possible the device being examined. For example, the IQI shall have a radiographic density or grey level nearest to that of the device being examined. Two IQIs shall be used for each radiograph, with each IQI located at diagonally opposite corners of the film, and the radiographic image free of blemishes. To identify the image, in both radiography and radioscopy, a system of positive identification of the image shall be provided, which may include any or all of the following: the name of examining laboratory, the date, the part number, the serial number, the data code, the view, and whether original or subsequent exposure.1.1 This practice relates to the radiographic examination of electronic devices for internal discontinuities, extraneous material, missing components, crimped or broken wires, and defective solder joints in cavities, in the encapsulating materials, or the boards. Requirements expressed in this practice are intended to control the quality and repeatability of the radiographic images and are not intended for controlling the acceptability or quality of the electronic devices imaged.1.2 There are areas in this practice that may require agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. These items should be addressed in the purchase order, contract, or inspection technique. Specific applications may require adherence to this practice in part or in full. Deviations from this practice shall be enumerated in inspection plan and approved by both cognizant engineering organization and the supplier.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.