Direct chip placing lead frame structure and production method thereof

Abstract

The invention relates to a direct chip placing lead frame structure and a production method thereof. The structure comprises pins (2). A first metal layer (4) is arranged on the front surface of each pin (2). A second metal layer (5) is arranged on the back surface of each pin (2). The front surface of each pin (2) extends as much as possible to a position below a chip which is subsequently attached. Encapsulation material (3) with no packing is embedded in the peripheral area of each pin (2) and an area between the pin (2) and the pin (2). The encapsulation material (3) with no packing connects the periphery of the lower part of the pin (2) and the lower part of the pin (2) with the lower part of the pin (2) into a whole body. The dimension of the back surface of the pin (2) is enabled to be smaller than the dimension of the front surface of the pin (2) to form a pin structure with a large upper part and a small lower part. The invention has the advantages that the binding capacity between the encapsulation body and the pin is high, the cost is reduced, the energy is saved, the carbon emission is reduced and the waste is reduced.

Description

(1) Technical field [0001] The invention relates to a lead frame structure and a production method thereof. 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 frames have the following disadvantages in the packaging process: [0008] Th...

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Problems solved by technology

So directly increased the high cost

[0010] 2) Also because the back of the lead frame must be affixed with a layer of high-temperature-resistant adhesive film, the chip loading process in the packaging process can only use conductive or non-conductive resin technology, and eutectic cannot be used at all. Process and soft solder process for chip mounting, 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, so It caused the instability of ball bonding parameters, which seriously affected the quality of ball bonding and the stability of product reliability.

[0013] 5) The general lead frame has a design of the base island, which causes the size of the chip to be limited by the size of the base island. If the size of the chip is relatively large, the area of ​​the package will also be enlarged accordingly.

[0017] In addition, due to the long distance between the chip and the metal pin, the length of the metal wire is relatively long, such as Figures 18-19 As shown, the cost of metal wires is high (especially expensive pure gold metal wires); also due to the long length of metal wires, the signal output speed of the chip is slow (because it is a storage product and requires a large amount of data) The calculation is more prominent); also because the length of the metal wire is longer, the parasitic resistance / capacitance of the metal wire and the interference of the parasitic pole to the signal are also high; The longer the distance, the larger the volume and area of ​​the package, the higher the material cost, and the more waste

[0018] In addition, the general lead frame has a base island design, which causes the size of the chip to be limited by the size of the base island. If the size of the chip is relatively large, the area of ​​the package will also be enlarged accordingly.

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