Preparation method of lead frame with rough side wall

Abstract

The invention belongs to the technical field of semiconductor devices, and particularly relates to a preparation method of a lead frame with a rough side wall. According to the invention, the upper surface of the lead frame is firstly subjected to single-sided brown oxidation, then a semi-etched region and the side wall are subjected to super-roughening treatment after electroplating and etching,and the side wall and the semi-etched region form a rough surface with good roughness by controlling super-roughening process conditions, so that the binding force of the contact region of the lead frame and plastic packaging resin is increased. The lower surface of the lead frame is not roughened, and the pre-electroplated layer with the smooth surface is only formed in the exposed bonding pad area, so that the surface roughening area is reduced; meanwhile, the lower surface is not prone to adhering to overflowing materials generated in the plastic package process, the cleaning difficulty isreduced, the process is simplified, and the roughening and electroplating cost is saved. The side wall of the lead frame has good roughness, the air tightness and reliability of an integrated circuitpackaging body are improved, and the defects of layering, cracking and the like are reduced.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a preparation method of a lead frame with rough side walls. Background technique [0002] The lead frame is the basic component for the manufacture of integrated circuit semiconductor components. It provides a carrier for the chip of the integrated circuit, and realizes the connection of the chip and the electrical signal of the external circuit board by means of the bonding material. It can also provide a heat dissipation channel together with the package shell to release heat. Most of the current integrated circuits are in the form of plastic packages, mainly including plastic dual in-line package (PDIP), quad flat package (QFP), quad flat no-lead package (QFN / DFN), small outline package (SOP), etc. . The reliability of the package of an integrated circuit is the main index to test its product quality, usually determined by its package performance. W...

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Problems solved by technology

Among them, the surface treatment method of micro-etching is relatively common, but the current roughening process is to micro-etch the whole lead frame substrate, such as the ultra-roughening lead frame electroplating pretreatment process proposed in the invention patent with the publication number CN109989083A, Directly use organic acid roughening solution to spray the lead frame, so that the front and back of the lead frame obtained in this way will form a rough copper layer, and in the subsequent packaging and injection molding process, it is inevitable that the molding compound will overflow. After being tightly combined with the brown oxide layer on the back of the lead frame, it is difficult to remove it by ordinary cleaning processes, and additional high-pressure water washing or polishing processes are required, which not only complicates the process, prolongs the production cycle, but also affects the integrity of the integrated circuit package Sex, reduce product qualification rate

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