阅读说明：本技术 一种弹坑超敏感产品生产参数优化方法 (Production parameter optimization method for crater super-sensitive product ) 是由 韩波 于 2020-07-31 设计创作，主要内容包括：本发明公开了一种弹坑超敏感产品生产参数优化方法,该方法通过将产品生产过程中的各个参数加大,进行弹坑的验证,当在该工艺参数生产下的芯片不会产生弹坑时,认定该参数为生产芯片的工艺参数,同时对生产机器进行验证。通过本发明的方法设计产品的生产过程各个参数,能够提高生产线的良品率。(The invention discloses a crater hypersensitive product production parameter optimization method, which is characterized in that each parameter in the production process of a product is increased to verify the crater, and when a chip produced by the process parameters cannot generate the crater, the parameters are determined as the process parameters for producing the chip, and meanwhile, a production machine is verified. By designing all parameters of the production process of the product through the method, the yield of the production line can be improved.)

1. A production parameter optimization method for a crater hypersensitive product is characterized by comprising the following steps:

step 1, producing chips by bonding special equipment, controlling process parameters including ultrasonic power, bonding pressure, bonding time and bonding temperature in a production process, increasing the upper limit value of each existing production process parameter range, setting the ultrasonic power to increase to an A value, increasing the bonding pressure to a B value, increasing the bonding time to a C value, and increasing the bonding temperature to a D value; starting to produce the chip from the increased upper limit value of the production process parameter, gradually reducing the production process parameter to the upper limit value of the existing production process parameter, and if the chip has a crater in the period, determining the chip as a crater sensitive product;

step 2, continuously reducing the production process parameters to the range of the existing production process parameters, reducing one process parameter each time, fixing other three process parameters, and when the chip does not generate a crater, performing a tensile test, a thrust test and an IMC test on the chip, wherein the tests meet the requirements to obtain a group of production process parameters which are the upper limit value of the range of the optimized production process parameters; and continuously reducing the process parameters until the tension test, the thrust test and the IMC test do not meet the requirements, and obtaining the lower limit value of the optimized production process parameter range.

2. The method for optimizing the production parameters of the crater ultra-sensitive product according to claim 1, wherein the ultrasonic power is controlled by controlling the current, the current control range is 50-80mA, and the existing pressure control range is 15-23 g; the existing temperature control range is 140-200 ℃; the bonding time is 5-30 ms.

3. The method for optimizing production parameters of a crater ultra-sensitive product according to claim 1, wherein the defects caused by the tensile test comprise: neck broken wire, fish tail broken wire, middle section, ball falling off and outer welding point falling off.

4. The method for optimizing production parameters of a crater super-sensitive product according to claim 1, wherein the defects caused by the thrust test comprise ball falling, ball mid-shear and aluminum pad falling.

5. The method of claim 1, wherein the alloy area requirement is greater than 80% in the IMC test.

6. The method for optimizing the production parameters of the crater ultra-sensitive product according to claim 1, wherein the method comprises a step 3 after the step 2, wherein each machine produces chips by using the determined process parameters, then the yield test is performed, the machine sorting is performed by using the yield as a standard, and the machine with the previous yield is selected for use;

and 3, selecting each machine for production, and increasing the frequency of replacing the riving knife.

7. The method for optimizing production parameters of a crater super-sensitive product according to claim 1, wherein the value A is the upper limit of the existing ultrasonic power + the upper limit of the existing ultrasonic power x 30%, the value B is the upper limit of the existing bonding pressure + the upper limit of the existing bonding pressure x 30%, the value C is the upper limit of the existing bonding time + the upper limit of the existing bonding time x 30%, and the value D is the upper limit of the existing bonding temperature + the upper limit of the existing bonding temperature x 30%.

8. The method for optimizing production parameters of a crater super-sensitive product according to claim 1, wherein the special bonding equipment comprises KNS, ASM and SKW.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of packaging, and particularly relates to a production parameter optimization method for a crater super-sensitive product.

[ background of the invention ]

The crater is a phenomenon generated when the chip is bonded in the packaging process, and the crater is generated mainly because of overlarge output energy, so that an aluminum pad in a bonding area of the chip is damaged and a small hole is left. In the production process, the craters are generated for a plurality of reasons, for example, the process parameters are improperly set in the bonding process, the bonding area of the chip is polluted before bonding, and the aluminum cushion layer in the bonding area is thin.

Therefore, how to avoid the crater phenomenon in the production of such products is now desired.

[ summary of the invention ]

The invention aims to overcome the defects of the prior art and provide a production parameter optimization method of a crater super-sensitive product, which is used for solving the problem of how to set process parameters in the production of the product and improving the yield of a production line.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a production parameter optimization method for a crater hypersensitive product comprises the following steps:

step 1, producing chips by bonding special equipment, controlling process parameters including ultrasonic power, bonding pressure, bonding time and bonding temperature in a production process, increasing the upper limit value of each existing production process parameter range, setting the ultrasonic power to increase to an A value, increasing the bonding pressure to a B value, increasing the bonding time to a C value, and increasing the bonding temperature to a D value; starting to produce the chip from the increased upper limit value of the production process parameter, gradually reducing the production process parameter to the upper limit value of the existing production process parameter, and if the chip has a crater in the period, determining the chip as a crater sensitive product;

step 2, continuously reducing the production process parameters to the range of the existing production process parameters, reducing one process parameter each time, fixing other three process parameters, and when the chip does not generate a crater, performing a tensile test, a thrust test and an IMC test on the chip, wherein the tests meet the requirements to obtain a group of production process parameters which are the upper limit value of the range of the optimized production process parameters; and continuously reducing the process parameters until the tension test, the thrust test and the IMC test do not meet the requirements, and obtaining the lower limit value of the optimized production process parameter range.

The invention is further improved in that:

preferably, the ultrasonic power is controlled by controlling the current, the current control range is 50-80mA, and the existing pressure control range is 15-23 g; the existing temperature control range is 140-200 ℃; the bonding time is 5-30 ms.

Preferably, the defects caused by the tensile test include: neck broken wire, fish tail broken wire, middle section, ball falling off and outer welding point falling off.

Preferably, the defects caused by the thrust test include ball drop, ball mid-shear, and aluminum pad drop.

Preferably, the alloy area requirement in the IMC test is > 80%.

Preferably, step 2 is followed by step 3, each machine uses the determined process parameters to produce chips, then the yield test is carried out, the machines are sorted by taking the yield as the standard, and the machine with the previous yield is selected to use;

and 3, selecting each machine for production, and increasing the frequency of replacing the riving knife.

Preferably, the value a is the existing upper limit of ultrasonic power + the existing upper limit of ultrasonic power × 30%, the value B is the existing upper limit of bonding pressure + the existing upper limit of bonding pressure × 30%, the value C is the existing upper limit of bonding time + the existing upper limit of bonding time × 30%, and the value D is the existing upper limit of bonding temperature + the existing upper limit of bonding temperature × 30%.

Preferably, the special bonding equipment comprises KNS, ASM and SKW.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a crater hypersensitive product production parameter optimization method, which primarily judges whether a product to be produced is a crater sensitive product or not by increasing each parameter in the production process of the product, verifies the crater by continuously adjusting process parameters after the determination, determines the parameters as the process parameters for producing chips when the chips produced by the process parameters do not generate craters and do not generate other defects, and determines the production range of the process parameters by repeated tests. By designing all parameters of the production process of the product through the method, the yield of the production line can be improved.

Furthermore, the technological parameters comprise ultrasonic power, pressure welding pressure, pressure welding time and pressure welding temperature, and the defect of craters cannot occur in the product while the parameters are adjusted by optimizing the four main parameters.

Further, after the process parameters are determined, in order to ensure that the produced product is the optimal product, the production machine is determined according to the yield.

[ description of the drawings ]

FIG. 1 is a flow chart of the present invention;

[ detailed description ] embodiments

The invention is described in further detail below with reference to the accompanying drawings:

in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and encompass, for example, both fixed and removable connections; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention discloses a production parameter optimization method for a crater hypersensitive product, which specifically comprises the following steps with reference to fig. 1:

step 1, according to the information of a chip to be produced, including the thickness of an aluminum layer and the type of a wire, a special welding device (such as KNS, ASM and SKW) is used for production, a crater sensitive product is screened out by a method of verifying craters after test parameters of ultrasonic power, pressure, welding time and welding temperature are increased by welding in a debugging process, the ultrasonic power is set to be increased to be an A value, the welding pressure is increased to be a B value, the welding time is increased to be a C value, and the welding temperature is increased to be a D value, wherein the preferred A value is the upper limit of the existing ultrasonic power plus the upper limit of the existing ultrasonic power multiplied by 30%, the B value is the upper limit of the existing welding pressure plus the upper limit of the existing welding pressure multiplied by 30%, the C value is the upper limit of the existing welding time plus the upper limit of the existing welding time multiplied by 30%, and the D value is the upper limit of the existing welding temperature. Starting to produce the chip from the increased upper limit value of the production process parameter, gradually reducing the production process parameter to the upper limit value of the existing production process parameter, and if the chip has a crater in the period, determining the chip as a crater sensitive product; and if the chip does not have craters after exceeding the range, determining that the product is not a crater sensitive product, and preparing the product according to the production method of the non-crater sensitive product.

In the parameter reducing process, one process parameter is reduced every time, but the ultrasonic power is reduced for one time instead of continuously reducing a certain parameter, then the pressure welding pressure is reduced, then the pressure welding time is reduced, and then the pressure welding temperature is reduced, and the process is subjected to four times of tests; then the ultrasonic power is reduced, and the pressure welding pressure is reduced again …; because the crater sensitive chip is very sensitive to the process parameters in the production process, if a certain parameter is reduced too much at one time, other process parameters can not be synchronously adjusted, and the production is influenced. The above-described parameter decreasing order may be adjusted.

During the above test, the existing parameter ranges may change with the replacement of chip materials and the replacement of production equipment.

Step 2, continuously reducing the production process parameters to the range of the existing production process parameters, reducing one process parameter each time, fixing other three process parameters, and when the chip does not generate a crater, performing a tensile test, a thrust test and an IMC test on the chip, wherein the tests meet the requirements to obtain a group of production process parameters which are the upper limit value of the range of the optimized production process parameters; and continuously reducing the process parameters until the tension test, the thrust test and the IMC test do not meet the requirements, and obtaining the lower limit value of the optimized production process parameter range.

In the parameter reducing process, one process parameter is reduced every time, but the ultrasonic power is reduced for one time instead of continuously reducing a certain parameter, then the pressure welding pressure is reduced, then the pressure welding time is reduced, and then the pressure welding temperature is reduced, and the process is subjected to four times of tests; then the ultrasonic power is reduced, and the pressure welding pressure is reduced …; the above-described parameter decreasing order may be adjusted.

On the basis of the step 1, firstly reducing the ultrasonic power, preferably controlling the ultrasonic power by controlling the current, wherein the current is controlled to be 50-80mA, the pressure control range is 15-23g, the temperature control range is 140-.

During the adjustment of various parameters, the produced chips are verified through the integrated circuit bonding quality standard, and the verification content of each chip comprises the following steps: and after the four tests of tension, thrust, craters and IMC are all in accordance with standards, selecting an optimal machine from the four tests to define a special press-welding machine and special line operation.

In the inspection process, the bonding wire is subjected to tension test, and the conditions of neck wire breakage, fishtail wire breakage, middle section, ball falling and outer welding point falling of the bonding wire are ensured to be avoided.

When the welding spot is used for a thrust test, the conditions of ball falling, ball middle shearing and aluminum pad falling of the welding ball are ensured to be avoided.

When the crater test is carried out, the crater condition can not appear in the whole chip.

When the alloy area (IMC) test is carried out, the alloy area is ensured to be more than 80 percent, and more preferably more than or equal to 85 percent.

The 100 chips produced by each machine are detected through the four detection processes, and the test data of each chip is recorded; and calculating the yield of chips produced by each machine, selecting machines with high yield for production, specifically sorting the machines by taking the yield of the machines as a measurement standard, and selecting the machines with the previous yields for production according to the required number of the machines.

And 3, in the pressure welding operation process, the abnormality can be found and solved in time by increasing the monitoring frequency (for example, the normal product riving knife service life is 2000K, 36H needs to be changed once, a crater is made once when the riving knife is changed, the crater sensitive product riving knife service life is reduced to 1000K, the crater sensitive product riving knife service life is reduced to 18H and is made once when the riving knife is changed), and the number of crater samples can be avoided from flowing out abnormally.