The production method of copper alloy special-shaped copper strip for electronic lead frame has certain advantages, so it is widely used. Lead frame is actually the chip carrier of integrated circuit. The function of the lead frame is to "connect with external wires". There are many types of raw materials for lead frames, including "KFC, C194, c7025, feni42, tamac-15, pmc-90", etc. Lead frame material is one of the packaging materials for semiconductor discrete devices and integrated circuits.

The copper alloy special-shaped copper strip for electronic lead frame has the advantages of "high conductivity, suitable processability, electrical brazing, stress corrosion cracking resistance, necessary strength and tightness of resin packaging", so it is very popular. However, the cost rate of domestic copper alloy special-shaped copper strip for electronic lead frame is not high, and the cost is high, so a new method is needed, so the production method of copper alloy special-shaped copper strip for electronic lead frame has been invented.

The traditional production process of copper alloy special-shaped copper strip for lead frame: the flat ingot is heated under positive pressure micro oxidation atmosphere, the heated flat ingot is rolled on the hot rolling mill for several passes, leveled after online cooling, and the upper and lower surfaces are milled and rolled into coils. The milled strip is repeatedly cold rolled on the cold rolling mill, accompanied by annealing to eliminate the cold work hardening effect. In order to improve the surface of products, mineral oil is used as lubricating and cooling medium;

Strips in various hard states need to be degreased before they can be used by users. Degreasing treatment is mainly "degreasing brushing drying" operation, so that there is no rolling oil residue on the surface of the strip; The thin strip with thickness less than 0.6mm is leveled by continuous stretch bending, so that the longitudinal bending and transverse bending can be eliminated, and the coil after cutting the finished product is packed and put into storage. If the product is a special-shaped belt, it can only be packed and put into storage after the process of "forming electroplating".

Production status of copper alloy special-shaped copper strip for lead frame: at present, the copper strip for lead frame cannot be mass produced in China. Even the products with small amount of trial production still have some problems, which is far from the requirements of users and foreign counterparts. Mainly manifested in

1. More than 90% of copper strip factories in China use small ingots for production, which has large geometric losses and low yield, and the length of the strip can not meet the requirements of users for continuous high-speed punching. In foreign countries, long-length coil is generally used, which has high processing yield and is easy to realize high-speed and stable rolling. The product quality is good, the efficiency is high, and the rate of head and tail precision decline is very small.

2. The vast majority of domestic factories use small ingots after hot rolling to 4.6mm without strip milling. However, foreign plants, large or small, adopt the process of milling the surface of hot rolled strip, which has the advantage that it can not only eliminate the deep subcutaneous defects of ingots, but also eliminate the surface defects caused by hot rolling, and also omit the pickling process of Ingot Milling and some products after hot rolling.

3. The accuracy of the existing rolling and shearing equipment in China is extremely poor, there is no advanced control means, and the width and thickness deviations are quite different from those in foreign countries.

4. Although the accuracy of rolling mills in a few factories is very good, due to the lack of equipment, such as continuous stretch bending leveling, degreasing, precision shearing, packaging and other equipment, they still can not produce high-quality qualified products.

What are the advantages of the production method of copper alloy special-shaped copper strip for electronic lead frame? The production efficiency is improved, the production cost is reduced, and the bandwidth length and specification change freely.

The production method of copper alloy special-shaped copper strip for electronic lead frame is as follows: copper alloy blank → smelting → ingot casting → heating → water seal extrusion → forming → pass rolling → bright annealing → shearing.

Precautions for production method of copper alloy special-shaped copper strip for electronic lead frame:

1. The copper alloy blank is selected according to the weight percentage: fe:0.05 ~ 0.15%; P：0.015～0.04％； Cu: allowance;

2. The heating reaches the extrusion temperature of the blank;

3. The extrusion temperature is 850 ~ 900 ℃;

4. The bright annealing temperature is 450 ~ 550 ℃;

5. The pass is bright annealed after rolling, and the process is repeated four times;

6. The roll with "t" structure is selected for the pass rolling, and the copper alloy special-shaped copper strip with "t" structure is rolled;

7. The roll with "U" structure is selected for the pass rolling, and the copper alloy special-shaped copper strip with "U" structure is rolled.

Production method of copper alloy special-shaped copper strip for electronic lead frame specific case: take the weight percentage, containing: fe:0.05%; P：0.015％； Cu: the residual copper alloy blank, which is treated according to the traditional smelting and ingot casting process, is heated at the temperature of 850 ℃ to reach the extrusion temperature and soften it;

In order to prevent its oxidation, the softened raw materials are directly squeezed into the water for water sealing. The formed copper alloy material is transported to the roll 2 with "t" structure for pass rolling, and the copper alloy special-shaped copper strip prototype 1 with "t" structure is rolled. The obtained copper alloy special-shaped copper strip prototype 1 is bright annealed at 450 ℃, and then the pass rolling and bright annealing processes are repeated three times to obtain the copper alloy special-shaped copper strip, Cut it according to the requirements to get the copper alloy special-shaped copper strip for electronic lead frame with the required specifications, and then pack it into the warehouse.

Source: Changjiang nonferrous metals network