A kind of preparation method of lead frame with rough side wall

Abstract

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. In the present invention, one-side brown oxidation is performed on the upper surface of the lead frame, and then the half-etched area and the side wall are subjected to super-roughening treatment after electroplating and etching, and the side wall and the half-etched area are formed by controlling the ultra-roughening process conditions. The rough surface with good roughness increases the bonding force between the lead frame and the contact area of ​​the molding resin, while the lower surface of the lead frame is not roughened, and only a smooth pre-plating layer is formed on the exposed pad area, which reduces surface roughness At the same time, the bottom surface is not easy to adhere to the flash generated during the plastic sealing process, which reduces the difficulty of cleaning, facilitates the simplification of the process, and saves the cost of roughening and electroplating. The side wall of the lead frame of the invention has good roughness, improves the airtightness and reliability of the integrated circuit packaging body, and reduces defects such as delamination and cracking.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and particularly relates to a preparation method of a lead frame with rough sidewalls. 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, realizes the connection between the chip and the electrical signal of the external circuit board by means of bonding materials, and also provides 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), square flat no-lead package (QFN / DFN), small outline package (SOP), etc. . The reliability of the package body of an integrated circuit is the main indicator for testing the quality of its products, which is usually determined by i...

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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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