Estimation method of semiconductor wafer scribing blade quota

Abstract

The invention relates to a method for estimating the quota of a scribing blade of a semiconductor wafer. The method comprises the following steps of: calculating the total area swept by the blade after completing cutting of a wafer to be cut by utilizing a cutting software theory; actual scribing cutting is conducted on the standard wafer, and the abrasion loss, namely the unit abrasion loss, of a blade used for cutting the wafer of the unit area is obtained; calculating the actual abrasion loss of the blade for cutting one wafer to be cut according to the total area and the unit abrasion loss, dividing the thickness capable of being consumed by one blade by the actual abrasion loss to obtain the number of wafers capable of being cut by one blade, and finally calculating the BOM amount of the blade. According to the estimation method, the blade cost of different products of customers can be accurately measured and calculated, and the accuracy of measuring and calculating the unit price of the customer products is improved.

Description

Technical Field

[0001] The present application relates to wafer processing technology, and in particular to a method for estimating the quota of a semiconductor wafer dicing blade. Background Art

[0002] In the semiconductor packaging process, wafer dicing is the front process of the packaging process. The materials and auxiliary materials used in the process include dicing film, pure water for dicing washing, dicing cooling water, dicing knife, etc. Among them, dicing film, pure water, cooling water can correspond to the number of wafers, the time when the equipment is turned on, and the water flow meter can be used to allocate the amount to each product without difference. And there are not many categories, which can be allocated according to the number of chips contained in the wafer.

[0003] The evaluation of dicing blades is much more complicated. The consumption of blades will change with different characteristics of wafers, different thicknesses, different sizes, different wafer materials, different process cutting parameters, and different blades used. Blades are one of the main costs of material consumption in this process. Accurately determining the cost consumption of products is of great reference significance for customer pricing, etc.

[0004] However, due to the above factors, blade cost evaluation has always been roughly calculated based on unified consumption, and it is impossible to accurately calculate different products of customers, which affects the accuracy of the unit price calculation of customers' products. Summary of the invention

[0005] In order to overcome the above-mentioned defects, the present application provides a method for estimating the quota of semiconductor wafer dicing blades, which can accurately calculate the blade costs for different customers' products and improve the accuracy of calculating the unit price of customers' products.

[0006] The technical solution adopted by this application to solve its technical problems is:

[0007] A method for estimating the quota of a semiconductor wafer dicing blade comprises the following steps:

[0008] Calculate the area of ​​the wafer to be cut: Use the cutting software to theoretically calculate the total area S that the blade sweeps over when cutting a wafer to be cut;

[0009] Obtaining unit wear amount: Performing actual dicing and cutting on a standard wafer to obtain the wear amount of the blade used to cut a unit area of ​​the wafer, i.e., unit wear amount A;

[0010] Calculate the blade wear: Calculate the actual blade wear C for cutting a disc based on the total area S and the unit wear A, C = S*A;

[0011] Calculate the number of cuts by the blade: Divide the thickness D that a blade can consume by the actual wear amount C to obtain the number of wafers that a blade can cut Q, Q = D / C, where D is the exposed amount of the blade edge minus the thickness of the wafer to be cut;

[0012] Calculate the blade BOM quantity: The blade BOM quantity is the number of blades consumed per thousand chips. The number of chips contained in a wafer is counted as X, and BOM = 1000 / (X*Q).

[0013] Optionally, in calculating the area of ​​the wafer to be cut, the operation logic of the cutting software includes the following steps:

[0014] Obtain parameters: Input the diameter of the wafer to be cut, the parameters of the chip on the wafer and the thickness of the blade in the CAD program, where the parameters of the chip include the X-direction size, Y-direction size and thickness of the chip;

[0015] Simulation cutting: Draw a circle according to the diameter of the wafer, and simulate cutting the circle according to the X-direction and Y-direction dimensions of the chip;

[0016] Calculate the area: Calculate the total length L of the blade cutting and combine it with the thickness M of the chip to calculate the total area S, S = L*M.

[0017] Optionally, the theoretical calculation process of the total length L of the blade cutting includes:

[0018] Use the CAD program to draw a circle of the corresponding size according to the diameter of the disc;

[0019] Draw a straight line on the circle that intersects the circle;

[0020] Find the distance G between the line segment and the two intersection points on the circle 1 , and mark the straight line number, enter the distance G 1 ;

[0021] According to the given chip X-direction size, draw a straight line step by step to find G 2 , and so on, until the X direction is completed, and the total length ∑G in the X direction is obtained;

[0022] In the same way, according to the given chip Y-direction dimensions, calculate the total length ∑I in the Y-direction;

[0023] The total length of the blade cutting is L=∑G+∑I.

[0024] Optionally, in the step of obtaining the unit wear amount, the cutting software obtains a video of cutting a standard wafer, calculates the total length of the blade cutting according to the video, and calculates the total cutting length S according to the total cutting length S. t 、Chip thickness D 1 and total blade wear C t, calculate the wear of the blade used to cut the unit area of ​​the wafer, that is, the unit wear A, A = C t / (S t *D 1 ).

[0025] Optionally, the total blade wear C t The calculation method includes: recording the wear amount C of the blade for each Y-meter cutting. 1 , C 2 ...C n , total blade wear C t =C 1 +C 2 +...+C n ; Total length of blade cutting S t The calculation method includes: recording the length S of the disc cut by each blade 1 , S 2 ...S n , the total length of the blade cutting S t =S 1 +S 2 +...+S n .

[0026] The beneficial effects of the present application are as follows: in the present application, the CAD cutting software is used to accurately calculate the area swept by the blade when cutting the wafer to be cut, so that the basic data of the subsequent new products can be known without actual cutting, and it is simpler and faster to obtain the basic data of the products. When simulating cutting, the cutting path passes through the coordinate points and is accurately and automatically calculated, which greatly simplifies the actual measurement process and measurement accuracy; the cutting video is used to obtain the unit wear amount, and combined with the cutting software, the measurement process is relatively simple to implement, and finally the blade BOM quantity can be obtained through simple calculations, thereby greatly improving the estimation accuracy of the blade BOM quantity and simplifying the estimation process, so that the blade cost of different customers' products can be accurately calculated, and the accuracy of the customer product unit price calculation is improved. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] A method for estimating the quota of a semiconductor wafer dicing blade comprises the following steps:

[0029] Calculate the area of ​​the wafer to be cut: use the cutting software theory to calculate the total area S that the blade sweeps through when cutting a wafer to be cut; the wafer to be cut is the customer's new wafer, and its specifications are different from those of the standard wafer, such as the length, thickness, and chip size of the wafer; the cutting software is a CAD program software developed using the AutoLisp language; the operating principle of the cutting software is: accept the feature information of the wafer, draw a circle based on the feature information and simulate the cutting of the circle, and obtain the total cutting area based on the cutting path and chip thickness.

[0030] Obtain unit wear: Perform actual dicing and cutting on standard wafers to obtain the wear of the blade used to cut a wafer per unit area, i.e., unit wear A. Standard wafers are typical wafers of customers. When a blade of the same specification is used to cut a standard wafer, it only needs to be cut once. After obtaining the unit wear A, it can be used in the estimation process of different wafers to be cut in the future.

[0031] Calculate the blade wear: Calculate the actual blade wear C for cutting a disc based on the total area S and the unit wear A, C = S*A;

[0032] Calculate the number of cuts by the blade: Divide the thickness D that a blade can consume by the actual wear amount C to obtain the number of wafers that a blade can cut Q, Q = D / C, where D is the exposed amount of the blade edge minus the thickness of the wafer to be cut;

[0033] Calculate the blade BOM quantity: The blade BOM quantity is the number of blades consumed per thousand chips. The number of chips contained in a wafer is counted as X, and BOM = 1000 / (X*Q).

[0034] In this application, the simulated cutting software is used to accurately calculate the distance that the blade runs in the process of cutting the wafer to be cut, and the cutting area of ​​the blade of the wafer is calculated in combination with the thickness of the chip. Then, the standard wafer is actually cut to obtain the wear amount of the blade used to cut the wafer per unit area, that is, the unit wear amount. According to the total area and the unit wear amount, the actual wear amount of the blade used to cut a wafer to be cut is calculated, and finally the blade BOM amount is calculated. In this application, the CAD cutting software is used to accurately calculate the area swept by the blade cutting the wafer to be cut, so that the basic data of the subsequent new products can be known without actual cutting, and the basic data of the product is obtained more simply and quickly. When simulating cutting, the cutting path passes through the coordinate points and is accurately and automatically calculated, which greatly simplifies the actual measurement process and measurement accuracy; the cutting video is used to obtain the unit wear amount, which is combined with the cutting software, and the measurement process is relatively simple. Finally, the blade BOM amount can be obtained by simple calculation, which greatly improves the estimation accuracy of the blade BOM amount and simplifies the estimation process, so that the blade cost can be accurately calculated for different products of customers, and the accuracy of the unit price calculation of customers' products is improved.

[0035] In calculating the area of ​​the wafer to be cut, the operating logic of the cutting software includes the following steps:

[0036] Obtain parameters: Input the diameter of the wafer to be cut, the parameters of the chip on the wafer and the thickness of the blade in the CAD program, where the parameters of the chip include the X-direction size, Y-direction size and thickness of the chip;

[0037] Simulation cutting: Draw a circle according to the diameter of the wafer, and simulate cutting the circle according to the X-direction and Y-direction dimensions of the chip;

[0038] Calculate the area: Calculate the total length L of the blade cutting and combine it with the thickness M of the chip to calculate the total area S, S = L*M.

[0039] The theoretical calculation process of the total length L of the blade cutting includes:

[0040] Use the CAD program to draw a circle of the corresponding size according to the diameter of the disc;

[0041] Draw a straight line on the circle that intersects the circle;

[0042] Find the distance G between the line segment and the two intersection points on the circle 1 , and mark the straight line number, enter the distance G 1 ;

[0043] According to the given chip X-direction size, draw a straight line step by step to find G 2 , and so on, until the X direction is completed, and the total length ∑G in the X direction is obtained;

[0044] In the same way, according to the given chip Y-direction dimensions, calculate the total length ∑I in the Y-direction;

[0045] The total length of the blade cutting is L=∑G+∑I.

[0046] In the step of obtaining unit wear, the cutting software obtains a standard disc cutting video, calculates the total length of the blade cutting based on the video, and calculates the total cutting length S according to the total cutting length. t 、Chip thickness D 1 and total blade wear C t , calculate the wear of the blade used to cut the unit area of ​​the wafer, that is, the unit wear A, A = C t / (S t *D 1 ). The wafer cutting video is based on the customer's typical chip products as the cutting target.

[0047] Total blade wear C t The calculation method includes: recording the wear amount C of the blade for each Y-meter cutting.1 , C 2 ...C n , total blade wear C t =C 1 +C 2 +...+C n ; Total length of blade cutting S t The calculation method includes: recording the length S of the disc cut by each blade 1 , S 2 ...S n , the total length of the blade cutting S t =S 1 +S 2 +...+S n The actual cutting distance has a large error because the blade will cut a certain distance outside the entire wafer. Therefore, according to the number of cuts on the corresponding screen of the machine, find the distance calculated by the corresponding software, and finally calculate the total wear C t The total length S calculated by the following software t .

[0048] Embodiment 1: A method for estimating the quota of a semiconductor wafer dicing blade comprises the following steps:

[0049] Step 1: Calculate the area of ​​the wafer to be cut: Use the cutting software to theoretically calculate the total area S that the blade sweeps over when cutting a wafer to be cut; the specific process is as follows:

[0050] 1.1 Load the simulation cutting software program in the CAD environment, that is, load the BOMSAW program in AutoCAD or Haocheng CAD;

[0051] 1.2 Enter the BOMSAW command;

[0052] 1.3 Input the file name of the data to be output, test.txt;

[0053] 1.4 Enter the name of the product to be evaluated;

[0054] 1.5 Input the size of the disc to be cut, such as the diameter of the disc is 8 inches;

[0055] 1.6 Input the pure step size of the chip, input the X-direction size of the wafer chip as 1.32mm and the Y-direction size as 1.05mm;

[0056] 1.7 Input the pure thickness of the chip and the thickness of the blade;

[0057] 1.8 Draw a circle of corresponding size according to the diameter of the disc;

[0058] 1.9 After selecting the circle, simulate scribing and complete scribing in the X and Y directions respectively;

[0059] 1.10 Determine the total length of the dicing and the area swept by the blade, and record the data in the output file, which includes the product name, X and Y dimensions, total number of chips, total length, total area S swept by the blade, number of simulated cutting columns and rows, etc.;

[0060] Step 2: Obtain unit wear amount: Perform actual dicing and cutting on the standard wafer to obtain the wear amount of the blade used to cut the wafer per unit area, i.e., the unit wear amount A; the specific process is as follows:

[0061] 2.1 Video recording of the typical wafer cutting process of the designated customer;

[0062] 2.2 Record the wear of the blade every 10 meters of cutting. 1 , C 2 ...C n , total blade wear C t =C 1 +C 2 +...+C n ; Record the length S of the disc cut by each blade 1 , S 2 ...S n , the total length of the blade cutting S t =S 1 +S 2 +...+S n ;

[0063] 2.3 According to the total cutting length S t 、Chip thickness D 1 and total blade wear C t , calculate the wear of the blade used to cut the unit area of ​​the wafer, that is, the unit wear A, A = C t / (S t *D 1 );

[0064] Step 3: Calculate the blade wear: Calculate the actual blade wear C for cutting a wafer according to the total area S and the unit wear A, C = S*A;

[0065] Step 4: Calculate the number of cuts by the blade: Divide the thickness D that a blade can consume by the actual wear amount C to obtain the number of wafers that a blade can cut Q, Q = D / C, where D is the exposed amount of the blade edge minus the thickness of the wafer to be cut;

[0066] Step 5: Calculate the blade BOM quantity: The blade BOM quantity is the number of blades consumed for every thousand chips. The number of chips contained in a wafer is counted as X, and BOM = 1000 / (X*Q).

[0067] It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these modifications and improvements are all within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for estimating the quota of a semiconductor wafer dicing blade, characterized in that: The steps include: Calculate the area of ​​the wafer to be cut: Use the cutting software to theoretically calculate the total area S that the blade sweeps over when cutting a wafer to be cut; Obtaining unit wear amount: Performing actual dicing and cutting on a standard wafer to obtain the wear amount of the blade used to cut a unit area of ​​the wafer, i.e., unit wear amount A; Calculate the blade wear: Calculate the actual blade wear C for cutting a disc based on the total area S and the unit wear A, C = S*A; Calculate the number of cuts by the blade: Divide the thickness D that a blade can consume by the actual wear amount C to obtain the number of wafers that a blade can cut Q, Q = D / C, where D is the exposed amount of the blade edge minus the thickness of the wafer to be cut; Calculate the blade BOM quantity: The blade BOM quantity is the number of blades consumed per thousand chips. The number of chips contained in a wafer is counted as X, and BOM = 1000 / (X*Q).

2. The method for estimating the semiconductor wafer dicing blade quota according to claim 1, characterized in that: In calculating the area of ​​the wafer to be cut, the operating logic of the cutting software includes the following steps: Obtain parameters: Input the diameter of the wafer to be cut, the parameters of the chip on the wafer and the thickness of the blade in the CAD program, where the parameters of the chip include the X-direction size, Y-direction size and thickness of the chip; Simulation cutting: Draw a circle according to the diameter of the wafer, and simulate cutting the circle according to the X-direction and Y-direction dimensions of the chip; Calculate the area: Calculate the total length L of the blade cutting and combine it with the thickness M of the chip to calculate the total area S, S = L*M.

3. The method for estimating the semiconductor wafer dicing blade quota according to claim 2, characterized in that: The theoretical calculation process of the total length L of the blade cutting includes: Use the CAD program to draw a circle of the corresponding size according to the diameter of the disc; Draw a straight line on the circle that intersects the circle; Find the distance G1 between the line segment and the two intersection points on the circle, mark the line number, and enter the distance G1; According to the given chip X-direction dimension, draw a straight line step by step to find G2, and so on, until the X-direction is completed, and the total length ∑G in the X-direction is obtained; In the same way, according to the given chip Y-direction dimensions, calculate the total length ∑I in the Y-direction; The total length of the blade cutting is L=∑G+∑I.

4. The method for estimating semiconductor wafer dicing blade quota according to claim 1, characterized in that: In the step of obtaining unit wear, the cutting software obtains a standard disc cutting video, calculates the total length of the blade cutting based on the video, and calculates the total cutting length S according to the total cutting length. t , chip thickness D1 and total insert wear C t , calculate the wear of the blade used to cut the unit area of ​​the wafer, that is, the unit wear A, A = C t / (S t *D1).

5. The method for estimating the semiconductor wafer dicing blade quota according to claim 4, characterized in that: Total blade wear C t The calculation method includes: recording the wear of the blade C1, C2, ..., C per cutting Y meters respectively. n , total blade wear C t =C1+C2+...+C n ; Total length of blade cutting S t The calculation method includes: recording the lengths S1, S2, ..., S of the discs cut by each cut of the blade respectively. n , the total length of the blade cutting S t =S1+S2+...+S n .