Base island exposed type and embedded type base island lead frame structure and first-engraving last-plating method thereof

Abstract

The invention relates to a base island exposed type and embedded type base island lead frame structure and a first-engraving last-plating method thereof. The structure comprises base islands (1) and pins (2), wherein two groups of base islands (1) are provided, and one group consists of first base islands (1.1), while the other group consists of second base islands (1.2); the front sides of the first base islands (1.1), the second base islands (1.2) and the pins (2) are provided with a first metal layer (4), and the back sides of the first base islands (1.1) and the pins (2) are provided witha second metal layer (5); areas on the periphery of the pins (2), areas between the pins (2) and the base islands, areas between the first base islands and the second base islands, the back sides of the second base islands (1.2) and areas between the pins are embedded with packless plastic package materials (3); and the sizes of the back sides of the first base islands (1.1) and the pins (2) are smaller than the sizes of the front sides of the first base islands and the pins so as to form a first base island and pin structure which is big on the top and small at the bottom. The invention has the advantage of large constraint capacity of the plastic package body and the metal pins.

Description

(1) Technical field [0001] The invention relates to a base island exposed type and embedded type base island lead frame structure and a method for engraving first and then plating. It belongs to the technical field of semiconductor packaging. (2) Background technology [0002] The traditional lead frame structure is described in detail as follows: [0003] After chemical etching and surface electroplating are carried out on the front side of the metal substrate, the production of the lead frame is completed (such as Figure 14 shown). The backside of the lead frame is then etched during the packaging process. [0004] However, the above-mentioned lead frame has the following disadvantages in the packaging process: [0005] This kind of lead frame structure is half-etched on the front of the metal substrate, because half-etching is only performed on the front of the metal substrate, and the plastic encapsulant only covers the height of half a foot during the plastic encaps...

AI Technical Summary

Problems solved by technology

[0005] This kind of lead frame structure is half-etched on the front of the metal substrate, because half-etching is only carried out on the front of the metal substrate, and the molding compound only covers the height of half a foot during the molding process, so the plastic package and the metal The binding ability of the feet becomes smaller. If the plastic package is not well attached to the PCB board, and then reworked and re-attached, it is easy to cause the problem of falling feet (such as Figure 15 shown)

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