Lead frame surface treatment process

Abstract

The invention discloses a lead frame surface treatment process, which belongs to the technical field of lead frame surface treatment. In the prior art, a method generally adopted for surface treatmentof the lead frame is sand blasting coarsening or chemical coarsening liquid is used for coarsening, an enough coarsening effect on the lead frame can be achieved by adopting one coarsening mode in existing cognition, but different coarsening degrees on the surface of the lead frame in the coarsening process are not considered. And the phenomenon of poor bonding wire operability due to different coarsening degrees in downstream packaging by different coarsening degrees is avoided. According to the method, the influence of the coarsening consistency on the subsequent process is found, the coarsening consistency is improved while the coarsening effect of the lead frame is improved by additionally arranging one-time physical sand blasting coarsening after chemical coarsening, and the qualityof surface treatment of the lead frame is improved by adding an ultrasonic impurity removal process and an anti-oxidation process.

Description

technical field [0001] The invention discloses a lead frame surface treatment process, which belongs to the technical field of lead frame surface treatment. Background technique [0002] Lead frame is the basic material of semiconductor packaging and the carrier of integrated circuit chips. The main material for producing lead frame is copper alloy, and the production of high-density and multi-pin lead frame is mainly realized by etching the lead frame. In recent years, more and more semiconductor packaging customers require that the reliability of integrated circuit chips must meet the requirements of MSL1 level. The key improvement is to increase the bonding strength between the lead frame and the packaging resin. From the original point of view, the way to improve the reliability of the chip is to increase the roughness of the lead frame surface, through the principle of mechanical interlocking to enhance the bonding force between the lead frame base material and the pack...

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Problems solved by technology

[0003] Chinese patent 201910347487.3 discloses a process of using acid corrosion to roughen the surface of the lead frame. In actual production, the lead frame is in a continuous motion process, and the method of spraying will easily cause the lead frame to be in the direction of the spraying. There is a relatively large degree of corrosion on the surface. In practical applications, the inventors of the present application have found that the current prior art only focuses on the influence of the degree of roughening on the plastic sealing effect, that is, only considering the chemical roughening can cause a large degree of corrosion on the upper and lower parts of the lead frame. Coarsening, while the time and amount of acid received by the other sides and edges are less than those facing the spraying surface, and the degree of roughening is severely divided into two levels, even if it adopts the method of sucking the acid away, It is also difficult to ensure that the roughness of all surfaces of the lead frame has a good consistency. Further, the bonding force of the encapsulating resin to different positions of the lead frame will be different during the lead frame encapsulation process, and the life after encapsulation often depends on the combination. The position where the force is small, so the coarsening effect is greatly reduced

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