阅读说明：本技术 一种键合金带及其制备方法 (Bonding gold belt and preparation method thereof ) 是由 周钢 范传勇 张知行 于 2020-05-20 设计创作，主要内容包括：本发明公开了一种键合金带及其制备方法,所述键合金带包括如下重量百分含量的成分：99.99％≤Au＜100％、0＜Be≤0.001％、0＜Cu≤0.003％、0＜Fe≤0.001％、0＜Mg≤0.001％和0＜Ag≤0.003％。本发明对键合金带的配方进行了优化,显著提升了键合金带的机械性能,使其具有适宜的拉伸强度和延伸率,满足键合要求。本发明制备的键合金带传输稳定可靠,耐电流高,连接牢固,尺寸精确度高,宽度公差为±1％,厚度公差为±0.0002mm,属于高精度产品。(The invention discloses a bonding gold belt and a preparation method thereof, wherein the bonding gold belt comprises the following components in percentage by weight: more than 99.99 percent and less than 100 percent of Au, more than 0 and less than 0.001 percent of Be, more than 0 and less than 0.003 percent of Cu, more than 0 and less than 0.001 percent of Fe, more than 0 and less than 0.001 percent of Mg, and more than 0 and less than 0.003 percent of Ag. The formula of the bonding alloy belt is optimized, the mechanical property of the bonding alloy belt is obviously improved, the bonding alloy belt has proper tensile strength and elongation, and the bonding requirement is met. The bonding gold belt prepared by the invention has stable and reliable transmission, high current resistance, firm connection and high dimensional accuracy, has a width tolerance of +/-1 percent and a thickness tolerance of +/-0.0002 mm, and belongs to a high-precision product.)

1. A bonding gold belt is characterized by comprising the following components in percentage by weight: more than 99.99 percent and less than 100 percent of Au, more than 0 and less than 0.001 percent of Be, more than 0 and less than 0.003 percent of Cu, more than 0 and less than 0.001 percent of Fe, more than 0 and less than 0.001 percent of Mg, and more than 0 and less than 0.003 percent of Ag.

2. The bonding gold strip of claim 1 wherein the bonding gold strip comprises the following composition in weight percent: au is more than or equal to 99.99% and less than 100%, Be is more than or equal to 0.001% and less than or equal to 0.0003%, Cu is more than or equal to 0.003% and less than or equal to 0.0003%, Fe is more than or equal to 0.001% and less than or equal to 0.0003%, Mg is more than or equal to 0.001% and less than or equal to 0.0003%, and Ag is more than or equal to 0.003%.

3. The bonding gold strip of claim 2 wherein the bonding gold strip comprises the following composition in weight percent: au 99.9984%, Be 0.0003%, Cu 0.0003%, Fe 0.0003%, Mg 0.0003% and Ag0.0003%.

4. The bonding gold strip of claim 2 wherein the bonding gold strip comprises the following composition in weight percent: au 99.9979%, Be 0.0006%, Cu 0.0004%, Fe 0.0003%, Mg 0.0003% and ag 0.0005%.

5. The bonding gold strip of claim 2 wherein the bonding gold strip comprises the following composition in weight percent: au 99.9971%, Be 0.0009%, Cu 0.0005%, Fe 0.0003%, Mg 0.0003% and ag 0.0009%.

6. The gold bonding tape of any one of claims 1 to 5, wherein the total impurity content of the gold bonding tape is 0.01% or less.

7. The method of producing a bonding alloy strip according to any one of claims 1 to 6, comprising the steps of:

(1) putting gold into a continuous casting furnace, adding trace elements Be, Cu, Fe, Mg and Ag, and casting an alloy rod;

(2) drawing the alloy rod to process into a wire rod with a target size;

(3) rolling the wire rod to process a gold strip with a target size;

(4) annealing the gold strip;

(5) and winding the annealed gold belt at a fixed length to obtain the bonding alloy belt.

8. The method for producing a bonding alloy strip according to claim 7, wherein the continuous casting temperature in the step (1) is 1150-1250 ℃.

9. The method for producing a bonding alloy ribbon according to claim 7, wherein in the step (2), the elongation of the die in the drawing process is 8% to 15%, and the drawing speed is 7 to 10 m/s.

10. The method for producing a bonding alloy ribbon according to claim 7, wherein in the step (4), the annealing temperature is 350 to 500 ℃ and the annealing speed is 0.5 to 1.0 m/s.

Technical Field

The invention belongs to the technical field of bonding materials, and particularly relates to a bonding gold belt and a preparation method thereof.

Background

Bonding is an important step in the production of integrated circuits, and is the operation of connecting a circuit chip to a lead frame. The bond ribbon and the gold bond wire are both inner leads used to electrically connect the input/output bond pads of the on-chip circuitry to the inner contacts of the lead frame during assembly of the semiconductor device and the integrated circuit. But the use effect of the bonding alloy strip is different from that of the bonding gold wire. Because of the current skin effect, the gold wire and the gold belt with the same cross section are different in current magnitude, and the maximum current born by the gold belt is far higher than that of the gold wire. Particularly in the military industry, the battlefield environment is special, the reliability and the transmission requirements are much higher than those of civil products, and gold wires often cannot meet the requirements, so that the gold wires are mainly applied to the military industry at present. The bonding alloy belt has more processing difficulty than the bonding gold wire, and the research on the bonding alloy belt is less at present. The indexes require that the dimensional tolerance of the gold strip in the width direction is within +/-5 percent, and the dimensional tolerance of the gold strip in the thickness direction is within +/-10 percent. The tolerance of the existing commercially available gold strip is much larger than the range, for example, the width of the gold strip is required to be 500 microns, but the actual width is less than 450 microns, which affects the weldability and the product size of the product.

The performance of the integrated circuit is directly affected by the quality of the bonding effect, so that the bonding alloy strip needs to meet the bonding requirement, has high dimensional accuracy, uniformity, no bending, smooth surface, no contamination, no scratch, and proper tensile strength and elongation. The gold belt processed by pure gold only has the advantages of very soft property, lower strength and poor weldability, and can not meet the bonding requirement. Therefore, it is desirable to provide a gold ribbon that meets the bonding requirements.

Disclosure of Invention

In order to solve the defects and shortcomings in the prior art, the invention aims to provide a gold bonding strip and a preparation method thereof.

In order to realize the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a bonding gold belt, which comprises the following components in percentage by weight: more than 99.99 percent and less than 100 percent of Au, more than 0 and less than 0.001 percent of Be, more than 0 and less than 0.003 percent of Cu, more than 0 and less than 0.001 percent of Fe, more than 0 and less than 0.001 percent of Mg, and more than 0 and less than 0.003 percent of Ag.

Different trace elements have different degrees of influence on the mechanical properties of the gold belt, the shape of a solder ball, the radian of an arch wire, the allowance of a tail wire and the like. The invention preferably selects the gold belt formula according to various basic tests, namely the results of the influence of a single element on the base material and the mutual influence among the elements. Wherein Be can improve the processing fatigue resistance of gold and increase part strength simultaneously. Cu and Fe can improve the strength of gold in a large range and increase the tensile force. Mg can enhance the wetting performance during welding and enhance the thrust. Ag can increase the strength and workability of gold.

Further preferably, the bonding alloy strip comprises the following components in percentage by weight: au is more than or equal to 99.99% and less than 100%, Be is more than or equal to 0.001% and less than or equal to 0.0003%, Cu is more than or equal to 0.003% and less than or equal to 0.0003%, Fe is more than or equal to 0.001% and less than or equal to 0.0003%, Mg is more than or equal to 0.001% and less than or equal to 0.0003%, and Ag is more than or equal to 0.003%. The total amount of trace elements added cannot exceed 90ppm, so the kinds of added elements cannot be excessive, and the elements are mutually affected, resulting in the need for an equilibrium state. The invention confirms that the addition amount of each element in the range is relatively proper through repeated tests.

If the single element is adjusted too much, the balance is broken, and the product is not good, the wire is broken, the ball is slippery, and the wire arc is not good. Therefore, the present invention further preferably provides the following formulation.

The bonding alloy belt comprises the following components in percentage by weight: au 99.9984%, Be 0.0003%, Cu0.0003%, Fe 0.0003%, Mg 0.0003% and Ag 0.0003%.

The bonding gold belt comprises the following components in percentage by weight: au 99.9979%, Be 0.0006%, cu 0.0004%, Fe 0.0003%, Mg 0.0003% and Ag 0.0005%.

The bonding gold belt comprises the following components in percentage by weight: au 99.9971%, Be 0.0009%, cu 0.0005%, Fe 0.0003%, Mg 0.0003% and Ag 0.0009%.

Preferably, the total content of impurities in the bonding alloy strip is less than or equal to 0.01 percent.

The invention also provides a preparation method of the bonding alloy strip, which comprises the following steps:

(1) putting gold into a continuous casting furnace, adding trace elements Be, Cu, Fe, Mg and Ag, and casting an alloy rod;

(2) drawing the alloy rod to process into a wire rod with a target size;

(3) rolling the wire rod to process a gold strip with a target size;

(4) annealing the gold strip;

(5) and winding the annealed gold belt at a fixed length to obtain the bonding alloy belt.

Preferably, the continuous casting temperature of the step (1) is 1150-1250 ℃. The continuous casting is carried out in the temperature range, the gold solution has good fluidity, the casting is facilitated, the trace elements cannot be sintered, the content of the trace elements is conveniently and accurately controlled, and meanwhile, the temperature range has low requirement on equipment, and common continuous casting furnace equipment can be achieved. If the continuous casting temperature is too low, the fluidity of the gold solution is insufficient, and casting defects are caused. If the continuous casting temperature is too high, the added trace elements are sintered, so that the content of the trace elements cannot be accurately controlled, the temperature is too high, the requirement on equipment is high, and the rated temperature of common continuous casting furnace equipment is 1400 ℃.

Preferably, in the step (2), the elongation of the die in the wire drawing process is 8% -15%, and the wire drawing speed is 7-10 m/s.

Preferably, in the step (4), the annealing temperature is 350-500 ℃, and the annealing speed is 0.5-1.0 m/s.

Compared with the prior art, the invention has the following advantages: the formula of the bonding alloy belt is optimized, the mechanical property of the bonding alloy belt is obviously improved, the bonding alloy belt has proper tensile strength and elongation, and the bonding requirement is met. The bonding gold belt prepared by the invention has stable and reliable transmission, high current resistance, firm connection and high dimensional accuracy, has a width tolerance of +/-1 percent and a thickness tolerance of +/-0.0002 mm, and belongs to a high-precision product.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention is further illustrated by the following examples. It is apparent that the following examples are only a part of the embodiments of the present invention, and not all of them. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention.