Backward GPP (Glass Passivation Pellet) high voltage diode chip in automobile module, and production technology

Abstract

The invention discloses a backward GPP (Glass Passivation Pellet) high voltage diode chip in an automobile module, and a production technology. The technology comprises the following steps of oxidation pretreatment, oxidation, photoetching, single-side oxidation layer removal, diffusion pretreatment, boron diffusion predeposition, boron diffusion, once phosphorus source / boron source diffusion, diffusion aftertreatment, N<+> surface mesa etching, electrophoresis, sintering, oxidation layer removal, nickel plating, gold plating and chip cutting. The obtained chip is in a P<++>-P<+>-N-N<+> type structure. According to the high voltage diode chip and the production technology, the defect of great electric leakage of a geminate axial diode is improved, damage to glass passivation protection during welding of a backward diode in a geminate GPP diode is avoided, an effective welding area is increased, and the whole heat dissipation function of the geminate diode is improved. An N-type substrate slice replaces a P-type substrate slice, and a backward GPP high voltage diode is manufactured in a deep N<+> surface corrosion groove, so that the backward GPP high voltage diode in the automobile module fills a gap in the technical field of domestic automobile modules.

Description

technical field [0001] The invention relates to the technical field of production of symmetrical high-voltage diodes in automobile modules, in particular to a reverse GPP high-voltage diode chip in automobile modules and a production process. Background technique [0002] The module used for rectification and protection on automotive control devices is usually composed of two diodes connected in opposite directions. The circuit diagram is as follows Figure 4 shown. At present, automotive modules in the semiconductor industry are generally composed of two axial diodes. The axial diodes have disadvantages: the mesa is usually formed by an acid corrosion process, which will cause a large leakage current of the diodes; and the subsequent assembly is complicated and the process Contamination easily occurs in the medium, resulting in poor performance. GPP diodes have the characteristics of small leakage, simple subsequent assembly, and little impact on performance. Therefore, th...

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Problems solved by technology

At present, automotive modules in the semiconductor industry are generally composed of two axial diodes. The axial diodes have disadvantages: the mesa is usually formed by an acid corrosion process, which will cause a large leakage current of the diodes; and the subsequent assembly is complicated and the process Contamination easily occurs in the medium, resulting in poor performance

GPP diodes have the characteristics of small leakage, simple subsequent assembly, and little impact on performance. Therefore, the industry hopes to use GPP diodes instead of axial diodes to make modules, but the pair of tubes composed of GPP diodes needs to be welded on the frame in the opposite direction, such as Figure 5 As shown, this connection will cause the glass passivation protection of the reverse diode to be damaged, which will affect the performance. At the same time, the welding area will be reduced, which will cause poor heat dissipation.

Some people in the general industry think of using P-type substrates to make reverse GPP diodes in modules, but to make high-voltage reverse GPP diodes, P-type substrates with high resistivity are required, but the production of P-type high-resistivity substrates The process is complicated, difficult, and the cost is too high, so it is difficult to purchase in the market

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