How to Choose diode ​ Devices Correctly

How to Choose diode Devices Correctly

Before selecting standard rectifier diode, the following knowledge should be understood:

(1) Packaging form

There are various packaging forms for diode  devices. From the perspective of packaging structure, there are airtight packaging and physical packaging; From the perspective of packaging materials, there are metal packaging, ceramic packaging, glass passivation packaging, glass packaging, glass inner passivation plastic packaging, plastic packaging, etc. There is a space with a certain atmosphere around the chip in the airtight packaging cavity and it is isolated from the outside world; The chip surrounding the physical packaging and the packaging cavity form the entire entity. This packaging form does not have the problem of air leakage and excess packaging material that may occur in airtight packaging, but has high requirements for packaging materials. It must be dense, moisture-resistant, adhere to the chip material, and have good thermal matching, and should not produce harmful gases under high temperature and low pressure conditions.

Miniaturization is the trend of device development. The packaging material for surface mount devices generally uses modified epoxy resin, which has a high level of reliability; The volume of the device is 20% to 80% smaller than that of conventional devices, and the overall use of this device in electronic circuits can significantly reduce the overall volume of the machine. Most of our factory's products also use this packaging form in addition to conventional packaging. Small current devices generally use packaging forms such as SOT-23, SOD-123, SOT-227, and some products use glass packaging surface mount packaging forms such as MELF (DO-213AB) and Mini MELF; Devices with a range of 1-6A typically use packaging forms such as SMA, SMB, and SMC.

(2) General principles for diode  device selection

According to the functional and performance requirements (including electrical performance, volume, weight, etc.), quality requirements, and environmental adaptability requirements of the application part for the device, select the appropriate variety, model, and manufacturer, and determine the quality level of the device and the requirements for the packaging form (shape), lead coating, Radiant intensity assurance level, etc. of the device; For devices with special requirements, other requirements such as internal thermal resistance, anti-static ability, and transient overload resistance should be selected or evaluated.