Island expose and multi-salient-point island expose lead frame structure and carving and plating method thereof

Abstract

The invention relates to an island expose and multi-salient-point island expose lead frame structure and a carving and plating method thereof. The island expose and multi-salient-point island expose lead frame structure comprises two groups of islands (1) and pins (2); the first group of islands are first islands (1.1), and the other group of islands are second islands (1.2), the front faces of which are set to be in a multi-salient-point structure; the front faces and the back faces of the islands (1) and the pins (2) are respectively provided with a first metal layer (4) and a second metal layer (5); plastic package material (3) containing no fillings is embedded in a region at the peripheries of the pins (2), a region between each island (1) and each pin (2), a region between each first island (1.1) and each second island (1.2) and a region between the pins (2); and the sizes of the back faces of the islands and the pins are less than those of the front faces of the islands and the pins, thereby forming an island and pin structure with a large upper part and a small lower part. The invention has the advantages that the plastic package body and the metal pin have high binding capacity.

Description

(1) Technical field [0001] The invention relates to a base island exposed and multi-bump base island exposed 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] There are two main types of traditional lead frame structures: [0003] The first: [0004] After chemical etching and surface electroplating are carried out on the front of the metal substrate, a layer of high-temperature-resistant adhesive film is pasted on the back of the metal substrate to form a lead frame carrier that can be packaged (such as Figure 14 shown). [0005] The second type: [0006] 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 15 shown). The backside of the lead frame is then etched during the packaging process. [0007] However, the above two lead frame...

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Problems solved by technology

So directly increased the high cost

[0010] 2) Also because the back of this kind of lead frame must be affixed with a layer of high-temperature-resistant adhesive film, so the chip loading process in the packaging process can only use conductive or non-conductive resin technology, and can not be used at all. Chip-mounting process and soft solder process, so the types of products that can be selected are relatively limited.

[0011] 3) Because the back of this kind of lead frame must be pasted with a layer of high temperature resistant adhesive film, and in the ball soldering bonding process in the packaging process, because the high temperature resistant adhesive film is a soft material, Therefore, the instability of ball bonding parameters is caused, which seriously affects the quality of ball bonding and the stability of product reliability.

[0014] This kind of lead frame structure has a half-etching process on the front of the metal substrate. Although it can solve the problem of the first lead frame, because only the half-etching work is performed on the front of the metal substrate, the plastic encapsulation compound only covers The height of half a foot is used, so the binding ability between the plastic package and the metal foot becomes smaller. If the plastic package is not attached to the PCB board very well, it is easy to cause the problem of foot drop (such as Figure 17 shown)

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