Method for calibrating distance between adjacent bonding points based on ultrasonic cold pressing bonding process

Abstract

The invention provides a method for calibrating the distance between adjacent bonding points based on an ultrasonic cold pressing bonding process, and the method comprises the following steps: S1, calculating the distance between the axis of a bonding wire and a substrate according to the radius of the bonding wire and the height of a wire arc, and calculating a first minimum distance according to the distance between the axis of the bonding wire and the substrate; s2, collecting and designing a bonding wire angle; if the designed bonding wire angle is 0 degree, taking the first minimum spacing in the step S1 as a theoretical minimum spacing; if the designed bonding wire angle is not 0 degree, entering the step S3; s3, calculating a second minimum interval according to the diameter of the bonding wire and the line arc height during intersection, and selecting the maximum value of the second minimum interval and the first minimum interval as a theoretical minimum interval; and S4, if the theoretical minimum spacing is not smaller than the design spacing, determining that production can be performed, otherwise, determining that production cannot be performed. The method has the beneficial effects that the minimum spacing of the adjacent bonding points with the angle is quantitatively calculated, the proofreading process is accurate, the effect does not need repeated trial and error, and the working efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microelectronic packaging, and particularly relates to a method for spacing correction between adjacent bonding points based on an ultrasonic cold pressure bonding process. BACKGROUND

[0002] In the field of microelectronic packaging, a bonding process is a key step for connecting a chip and an external circuit. Traditional bonding point spacing design is mainly based on empirical values or simple geometric calculations, and the influence of different bonding angles and arc heights on the minimum spacing is often not fully considered. As a result, quality problems such as mutual interference or line loss of adjacent bonding wires may occur due to the excessively large bonding angle or excessively high arc height designed. Since there is a lack of quantitative correction each time, repeated trial and error and layout revision are required during bonding, which leads to low work efficiency. SUMMARY

[0003] Therefore, the present application aims to provide a method for spacing correction between adjacent bonding points based on an ultrasonic cold pressure bonding process, so as to solve at least one of the above technical problems.

[0004] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows: The present application provides a method for spacing correction between adjacent bonding points based on an ultrasonic cold pressure bonding process, which comprises the following steps: S1, calculating the spacing between the bonding wire axis and the substrate according to the radius of the bonding wire and the wire arc height, and calculating the first minimum spacing according to the spacing between the bonding wire axis and the substrate; S2, collecting the designed bonding wire angle; If the designed bonding wire angle is 0°, the first minimum spacing of step S1 is taken as the theoretical minimum spacing; If the designed bonding wire angle is not 0°, step S3 is entered; S3, calculating the second minimum spacing according to the diameter of the bonding wire and the wire arc height when intersecting, and selecting the maximum value between the second minimum spacing and the first minimum spacing as the theoretical minimum spacing; S4, if the theoretical minimum spacing is not smaller than the designed spacing, it is determined that production is possible, otherwise it is determined that production is not possible.

[0005] Further, the S1 comprises the following steps: S11, collecting the wedge diameter, the wedge tip diameter and the wedge head length according to the wedge model;

[0006] S12, calculating the wedge head inclination angle according to the collected wedge diameter, wedge tip diameter and wedge head length; S13, calculating the first height difference between the wire arc height and the bonding wire axis according to the wedge head inclination angle and the radius of the bonding wire, and calculating the second height difference between the bonding wire axis and the substrate according to the first height difference and the wire arc height; When the second height difference is not less than the length of the chopping head, the first minimum spacing is the radius of the chopping blade; When the second elevation difference is less than the length of the chopping head, the first minimum spacing is calculated based on the second elevation difference and the tilt angle of the chopping head.

[0007] Furthermore, in step S11, the corresponding cleaver and bonding wire are selected according to the chip model and substrate model in the design drawing.

[0008] Furthermore, S3 includes the following steps: S31. Calculate the minimum spacing between welding heads in front of the welding head; S32. When the arc intersects with the welding head, calculate the height of the arc at the intersection. If the arc height at intersection is less than the length of the lead tip, then the second minimum spacing is calculated based on the arc height at intersection, the diameter of the bond wire, and the minimum spacing of the welding heads. If the arc height of the intersecting wires is not less than the length of the wire tip, then the second minimum spacing is calculated based on the diameter of the bonding wire and the minimum spacing of the welding heads.

[0009] Furthermore, in S31: If the arc height is less than the length of the lead tip, the minimum spacing of the welding head is calculated based on the tilt angle of the lead tip and the diameter of the bonding wire. If the arc height is not less than the length of the lead tip, the minimum spacing between the welding heads is calculated based on the lead tip diameter and the bonding wire diameter.

[0010] Furthermore, in step S31, the corresponding wire guide nozzle model is selected according to the blade model, and the length of the wire guide nozzle head and the diameter of the wire guide nozzle are collected according to the wire guide nozzle model.

[0011] Furthermore, the design bonding line angle is in the range of -90° to 90°.

[0012] A second aspect of the present invention provides an electronic device including a processor and a memory communicatively connected to the processor and used to store processor-executable instructions, the processor being used to perform the method described in the first aspect above.

[0013] A third aspect of the present invention provides a server including at least one processor and a memory communicatively connected to the processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the processor to cause the at least one processor to perform the method as described in the first aspect.

[0014] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method described in the first aspect.

[0015] Compared with existing technologies, the adjacent bonding point spacing calibration method based on ultrasonic cold pressing bonding process described in this invention has the following advantages: The present invention discloses a method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process. This method quantifies and calculates the minimum spacing between adjacent bonding points with angles, ensuring accurate calibration without repeated trial and error, thus improving work efficiency. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the method described in an embodiment of the present invention; Figure 2 This is a schematic diagram of the head structure of the cleaver according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the first height difference between the arc height and the bonding wire axis as described in an embodiment of the present invention; Figure 4 This is a schematic diagram of the wire nozzle head structure according to an embodiment of the present invention. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Example 1

[0022] like Figure 1 As shown, a method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding technology includes the following steps: S1. Calculate the distance between the bonding wire axis and the substrate based on the radius and arc height of the bonding wire, and calculate the first minimum distance based on the distance between the bonding wire axis and the substrate. S1 includes the following steps: S11. Collect the diameter of the chopping blade, the diameter of the tip of the chopping blade, and the length of the head of the chopping blade according to the model of the chopping blade.

[0023] The difference between the diameter of the chopping blade and the diameter of its tip, divided by 2, equals the distance between the outer edge of the chopping blade tip and the outer wall of the chopping blade. Figure 2 As shown in the median value of 1.3, Figure 2 The value 4.6 in the figure represents the length of the cleaver head; S12. Calculate the tilt angle of the chopping head based on the collected chopping diameter, chopping tip diameter, and chopping head length; the tilt angle of the chopping head is the taper of the chopping head's conical surface.

[0024] The tilt angle β of the chopping head can be calculated based on the distance between the outer edge of the chopping tip and the outer wall of the chopping head, and the length of the chopping head. S13. Calculate the first height difference between the arc height and the axis of the bonding wire based on the tilt angle of the cleaver head and the radius of the bonding wire, and calculate the second height difference between the axis of the bonding wire and the substrate based on the first height difference and the arc height. When the second height difference is not less than the length of the chopping head, the first minimum spacing is the radius of the chopping blade; When the second elevation difference is less than the length of the chopping head, the first minimum spacing is calculated based on the second elevation difference and the tilt angle of the chopping head.

[0025] In step S11, the appropriate cleaving blade and bonding wire are selected according to the chip model and substrate model in the design drawing.

[0026] S2. Collect the design bond line angle; If the design bonding wire angle is 0°, then the first minimum spacing in step S1 is taken as the theoretical minimum spacing. If the bond line angle is not 0°, proceed to step S3; S3. Calculate the second minimum spacing based on the diameter of the bonding wire and the arc height when the wires intersect, and select the maximum value between the second minimum spacing and the first minimum spacing as the theoretical minimum spacing. S3 includes the following steps: S31. Calculate the minimum spacing between welding heads in front of the welding head; S32. When the arc intersects with the welding head, calculate the height of the arc at the intersection. If the arc height at intersection is less than the length of the lead tip, then the second minimum spacing is calculated based on the arc height at intersection, the diameter of the bond wire, and the minimum spacing of the welding heads. If the arc height of the intersecting wires is not less than the length of the wire tip, then the second minimum spacing is calculated based on the diameter of the bonding wire and the minimum spacing of the welding heads.

[0027] In S31: If the arc height is less than the length of the lead tip, the minimum spacing of the welding head is calculated based on the tilt angle of the lead tip and the diameter of the bonding wire. If the arc height is not less than the length of the lead tip, the minimum spacing between the welding heads is calculated based on the lead tip diameter and the bonding wire diameter.

[0028] In step S31, the corresponding wire guide nozzle model is selected according to the blade model, and the length of the wire guide nozzle head and the diameter of the wire guide nozzle are collected according to the wire guide nozzle model.

[0029] S4. If the theoretical minimum spacing is not less than the design spacing, then production is deemed possible; otherwise, production is deemed impossible.

[0030] The design bonding line angle is in the range of -90° to 90°, and the absolute value of the design bonding line angle is used for subsequent calculations.

[0031] The following are specific examples: When bonding 15mil diameter aluminum wire, take 2mm arc height, 4mm arc length, and 20° arc angle as an example.

[0032] The diameter of the chopping blade is 3.4mm, the diameter of the tip is 0.8mm, and the height of the blade head is 4.6mm. The distance between the guide tip and the center line of the chopping blade is 6.3 + gap, and the height of the guide tip is 8.5 mm; gap is the distance from the front end of the guide tip to the center line of the chopping blade.

[0033] like Figure 1 , 2As shown in Figure S1, the first height difference between the arc height and the axis of the bonded line is calculated based on the tilt angle of the cutter head and the radius of the bonded line. The formula for calculating the first height difference is: ;

[0034] Where A1 is the first height difference, r is the radius of the bond line, 4.6 is the height of the chopping head, and 1.3 is the difference between the radius of the chopping tip and the radius of the chopping blade.

[0035] The second height difference between the bonding line axis and the substrate is calculated based on the first height difference and the arc height. The formula for calculating the second height difference is as follows: ; Where A2 is the second elevation difference; H is the highest height of the arc; When the second height difference is not less than the length of the chopping head, the first minimum spacing is the radius of the chopping blade; When the second elevation difference is less than the length of the chopping head, the first minimum spacing is calculated based on the second elevation difference and the tilt angle of the chopping head.

[0036] The formula is as follows: When 0 < A2 < 4.6 mm, W LR =tanβ*A2-1.3+1.7; When 4.6mm≤A2, W LR =1.7; W LR β is the first minimum spacing, and β is the tilt angle of the cleaver head; S2. Collect the design bond line angle; If the design bonding wire angle is 0°, then the first minimum spacing in step S1 is taken as the theoretical minimum spacing. If the bond line angle is not 0°, proceed to step S3; When the arc is 0°, calculate the arc equation based on the arc height (H) and arc length (L); When the arc is α°, calculate the equation of the arc by rotating the circle with the point (x=0, y=0, z=0) in the x and y planes by an angle of α.

[0037] S31. Calculate the minimum spacing between welding heads in front of the welding head; In S31: If the arc height is less than the length of the lead tip, the minimum spacing of the welding head is calculated based on the tilt angle of the lead tip and the diameter of the bonding wire. If the arc height is not less than the length of the lead tip, the minimum spacing between the welding heads is calculated based on the lead tip diameter and the bonding wire diameter.

[0038]

[0039] Where D is the diameter of the bonding wire; z is the height of the wire arc when the wire nozzle intersects with the wire arc, WF is the minimum head pitch, 3.367D 0.755 is the gap, i.e., the distance from the front end of the wire nozzle to the center line of the劈刀, 63 / 85 is tanb, b is the tilt angle of the wire nozzle head, as Figure 4 shown.

[0040] S32. When the wire arc intersects with the head before and after, calculate the height of the wire arc at the intersection; As Figure 4 shown, if the height of the wire arc at the intersection is less than the length of the wire nozzle head, calculate the second minimum pitch according to the height of the wire arc at the intersection, the diameter of the bonding wire, and the minimum head pitch; If the height of the wire arc at the intersection is not less than the length of the wire nozzle head, calculate the second minimum pitch according to the diameter of the bonding wire and the minimum head pitch.

[0041]

[0042] Where d is the second minimum pitch, 63 / 85 is tanb, b is the tilt angle of the wire nozzle head, D is the diameter of the bonding wire; z is the height of the wire arc when the wire nozzle intersects with the wire arc, 3.367D 0.755 is the gap, i.e., the distance from the front end of the wire nozzle to the center line of the劈刀, α is the designed bonding wire angle.

[0043] The derivation process is as follows: When the wire arc intersects with the wire nozzle head (0 < z < 8.5), (the plane where the wire arc is located); Let , combined with , we get , substituting it into the wire arc equation, we get: , that is: , substituting into it, we get a quadratic equation about z: ; If 0 < z < 8.5, then ; The pitch [[ID=5​​​​​​​​​​​​​​​When bonding 15mil diameter aluminum wire, with an arc height of 2mm, an arc length of 4mm, and an arc angle of 20°, the calculated values ​​are z=1.56mm and d=1.21mm. When the bond line angle is 0°, W LR =0.79mm; Taking the maximum value of 1.21mm as the theoretical minimum spacing, the designed spacing is 1mm, which is not feasible for production. At this time, we can choose to reduce the number of bond wires to increase the spacing, or we can adjust the bond wire angle. By adjusting the angle to 10°, we can calculate d=0.69mm. Taking the maximum value of 0.79mm as the theoretical minimum spacing, which satisfies the design spacing of 1mm, production is possible.

[0045] The minimum spacing between adjacent bond points with angles is quantized and calculated, resulting in high bonding programming efficiency and speed, eliminating the need for repeated trial and error.

[0046] Example 2

[0047] An electronic device includes a processor and a memory communicatively connected to the processor and used to store processor-executable instructions, the processor being used to execute the method described in Embodiment 1 above.

[0048] Example 3

[0049] A server includes at least one processor and a memory communicatively connected to the processor, the memory storing instructions executable by the at least one processor to cause the at least one processor to perform the method as described in Embodiment 1.

[0050] Example 4

[0051] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding technology, characterized in that, Includes the following steps: S1. Calculate the distance between the bonding wire axis and the substrate based on the radius and arc height of the bonding wire, and calculate the first minimum distance based on the distance between the bonding wire axis and the substrate. S2. Collect the design bond line angle; If the design bonding wire angle is 0°, then the first minimum spacing in step S1 is taken as the theoretical minimum spacing. If the bond line angle is not 0°, proceed to step S3; S3. Calculate the second minimum spacing based on the diameter of the bonding wire and the arc height when the wires intersect, and select the maximum value between the second minimum spacing and the first minimum spacing as the theoretical minimum spacing. S4. If the theoretical minimum spacing is not less than the design spacing, then production is deemed possible; otherwise, production is deemed impossible.

2. The method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process according to claim 1, characterized in that: S1 includes the following steps: S11. Collect the diameter of the chopping blade, the diameter of the tip of the chopping blade, and the length of the head of the chopping blade according to the model of the chopping blade; S12. Calculate the tilt angle of the chopping head based on the collected chopping diameter, chopping tip diameter, and chopping head length. S13. Calculate the first height difference between the arc height and the axis of the bonding wire based on the tilt angle of the cleaver head and the radius of the bonding wire, and calculate the second height difference between the axis of the bonding wire and the substrate based on the first height difference and the arc height. When the second height difference is not less than the length of the chopping head, the first minimum spacing is the radius of the chopping blade; When the second elevation difference is less than the length of the chopping head, the first minimum spacing is calculated based on the second elevation difference and the tilt angle of the chopping head.

3. The method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process according to claim 2, characterized in that: In step S11, the appropriate cleaving blade and bonding wire are selected according to the chip model and substrate model in the design drawing.

4. The method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process according to claim 1, characterized in that: S3 includes the following steps: S31. Calculate the minimum spacing between welding heads in front of the welding head; S32. When the arc intersects with the welding head, calculate the height of the arc at the intersection. If the arc height at intersection is less than the length of the lead tip, then the second minimum spacing is calculated based on the arc height at intersection, the diameter of the bond wire, and the minimum spacing of the welding heads. If the arc height of the intersecting wires is not less than the length of the wire tip, then the second minimum spacing is calculated based on the diameter of the bonding wire and the minimum spacing of the welding heads.

5. The method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process according to claim 4, characterized in that, In S31: If the arc height is less than the length of the lead tip, the minimum spacing of the welding head is calculated based on the tilt angle of the lead tip and the diameter of the bonding wire. If the arc height is not less than the length of the lead tip, the minimum spacing between the welding heads is calculated based on the lead tip diameter and the bonding wire diameter.

6. The method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process according to claim 5, characterized in that: In step S31, the corresponding wire guide nozzle model is selected according to the blade model, and the length of the wire guide nozzle head and the diameter of the wire guide nozzle are collected according to the wire guide nozzle model.

7. The method for calibrating the spacing between adjacent bonding points based on ultrasonic cold pressing bonding process according to claim 1, characterized in that: The design bond line angle is to be within the range of -90° to 90°.

8. An electronic device comprising a processor and a memory communicatively connected to the processor and used for storing processor-executable instructions, characterized in that: The processor is used to execute the method described in any one of claims 1-7.

9. A server, characterized in that: The method includes at least one processor and a memory communicatively connected to the processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the processor to cause the at least one processor to perform the method as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it implements the method described in any one of claims 1-7.

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