A process method for non-inverted forming of bottom lead-out devices

Abstract

The invention discloses a process method for non-inverted formation of a bottom lead-out device. Firstly the formed device is put in a lead flattening tool to flatten the device lead; then the device of which the lead is flattened is reversely fixed on a cutting edge, and first time formation of the device is performed by using formation equipment upper and lower moulds; and finally the device is fixed on the cutting edge in a non-inverted way, and second time formation of the device is performed by using the formation equipment upper and lower moulds. According to the process method for non-inverted formation of the bottom lead-out device, the formed device is put in the lead flattening tool to flatten the device lead, and then formation is completed through forward and backward processing so that formation of the domestic bottom lead QFP and SOP packaging device can be realized through combination of the specificity of the domestic bottom lead QFP and SOP packaging device according to the idea of the non-inverted formation method with cooperation of the designed lead flattening moulds and the special formation cutting edge.

Description

technical field [0001] The invention belongs to the technical field of safety and reliability of electronic components, and in particular relates to a non-inverted forming method for bottom lead-out devices. Background technique [0002] According to the requirements of Article 4.4 of the QJ 3171 "Technical Requirements for Forming Components of Aerospace Electronic and Electrical Products", QFP and SOP packaged devices need to be formed before their leads are soldered. Various environmental test requirements after the printed board. [0003] The common practice now is to invert the device by the operator according to the requirements, so that its leads form an inverted cantilever beam junction, such as figure 1 As shown, the leads from the bottom of the existing domestic QFP and SOP packaged devices are relatively short, which cannot meet the inversion forming specified in the standard, such as figure 2 As shown, if figure 2 In the later stage of the test, the stress o...

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Problems solved by technology

[0003] The common practice now is to invert the device by the operator according to the requirements, so that its leads form an inverted cantilever beam junction, such as figure 1 As shown, the leads from the bottom of the existing domestic QFP and SOP packaged devices are relatively short, which cannot meet the inversion forming specified in the standard, such as figure 2 As shown, if figure 2 In the later stage of the test, the stress of the lead solder joints cannot be released, resulting in solder joint problems. In order to avoid the release of the stress of the lead solder joints of the bottom lead QFP and SOP packaged devices in the later stage, the leads must be non-inverted.

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