An adjacent bonding point spacing correction method based on ultrasonic cold press bonding process

Abstract

The application provides an adjacent bonding point spacing correction method based on an ultrasonic cold pressure bonding process, comprising the following steps: S1, calculating the spacing between the bonding wire axis and the substrate according to the radius and the wire arc height of the bonding wire, and calculating the first minimum spacing according to the spacing between the bonding wire axis and the substrate; S2, collecting the design bonding wire angle; if the design bonding wire angle is 0 DEG, the first minimum spacing of step S1 is taken as the theoretical minimum spacing; if the design bonding wire angle is not 0 DEG, step S3 is entered; S3, calculating the second minimum spacing according to the diameter and the wire arc height when intersecting, and selecting the maximum value of 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 design spacing, it is determined that production can be carried out, otherwise it is determined that production cannot be carried out. The application has the beneficial effects that the minimum spacing of adjacent bonding points with angles is quantitatively calculated, the correction process is accurate, the effect does not need to be repeatedly tried and wrong, and the work 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 experience 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 lines may occur due to the excessively large bonding angle or excessively high arc height designed. Each time, quantitative correction is lacked, and 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:

[0005] The present application provides a method for spacing correction between adjacent bonding points based on an ultrasonic cold pressure bonding process, comprising the following steps:

[0006] S1, calculating the spacing between the bonding line axis and the substrate according to the radius of the bonding line and the line arc height, and calculating the first minimum spacing according to the spacing between the bonding line axis and the substrate;

[0007] S2, collecting the designed bonding line angle;

[0008] If the designed bonding line angle is 0°, the first minimum spacing of step S1 is taken as the theoretical minimum spacing;

[0009] If the designed bonding line angle is not 0°, step S3 is entered;

[0010] S3, calculating the second minimum spacing according to the diameter of the bonding line and the line arc height when intersecting, and selecting the maximum value between the second minimum spacing and the first minimum spacing as the theoretical minimum spacing;

[0011] S4, if the theoretical minimum spacing is not smaller than the designed spacing, it is determined that production can be carried out, otherwise it is determined that production cannot be carried out.

[0012] Further, the S1 comprises the following steps:

[0013] S11, collecting the wedge diameter, wedge tip diameter and wedge head length according to the wedge model;

[0014] S12, calculating the wedge head inclination angle according to the wedge diameter, the wedge tip diameter and the wedge head length;

[0015] 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;

[0016] When the second height difference is not less than the wedge head length, the first minimum distance is the radius of the wedge;

[0017] When the second height difference is less than the wedge head length, the first minimum distance is calculated according to the second height difference and the wedge head inclination angle.

[0018] Further, the S11 selects the corresponding wedge and bonding wire according to the chip model and the substrate model in the design drawing.

[0019] Further, the S3 comprises the following steps:

[0020] S31, calculating the minimum distance of the welding head in front of the welding head;

[0021] S32, the wire arc intersects in front of and behind the welding head, and the wire arc height at the intersection is calculated;

[0022] If the wire arc height at the intersection is less than the length of the wire nozzle head, then the second minimum distance is calculated according to the wire arc height at the intersection, the diameter of the bonding wire and the minimum distance of the welding head;

[0023] If the wire arc height at the intersection is not less than the length of the wire nozzle head, then the second minimum distance is calculated according to the diameter of the bonding wire and the minimum distance of the welding head.

[0024] Further, in the S31,

[0025] If the wire arc height is less than the length of the wire nozzle head, then the minimum distance of the welding head is calculated according to the wire nozzle inclination angle and the diameter of the bonding wire;

[0026] If the wire arc height is not less than the length of the wire nozzle head, then the minimum distance of the welding head is calculated according to the diameter of the wire nozzle and the diameter of the bonding wire.

[0027] Further, in the S31, the corresponding wire nozzle model is selected according to the wedge model, and the length of the wire nozzle head and the diameter of the wire nozzle are collected according to the wire nozzle model.

[0028] Further, the design bonding wire angle is in the range of -90° to 90°.

[0029] The second aspect of the present application provides an electronic device, comprising a processor and a memory connected with the processor and used for storing executable instructions of the processor, and the processor is used for executing the method of the first aspect.

[0030] The third aspect of the present application provides a server, comprising at least one processor and a memory connected with the processor, and the memory stores executable instructions of the at least one processor, and the instructions are executed by the processor to make the at least one processor execute the method of the first aspect.

[0031] The fourth aspect of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the method of the first aspect.

[0032] Compared with the prior art, the method for correcting the spacing between adjacent bonding points based on the ultrasonic cold pressure bonding process has the following beneficial effects:

[0033] The method for correcting the spacing between adjacent bonding points based on the ultrasonic cold pressure bonding process quantitatively calculates the minimum spacing of adjacent bonding points with angles, and the correction process is accurate and does not need to be repeatedly tried and corrected, thereby improving the work efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0034] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description are used to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0035] Figure 1 The method flowchart described in the embodiments of the present application;

[0036] Figure 2 The wedge head structure schematic diagram described in the embodiments of the present application;

[0037] Figure 3 The first height difference schematic diagram of the wire arc height and the bonding wire axis described in the embodiments of the present application;

[0038] Figure 4 The wire guide nozzle head structure schematic diagram described in the embodiments of the present application. DETAILED DESCRIPTION

[0039] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0040] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0041] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0042] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0043] Embodiment one

[0044] As Figure 1 shown, a method for calibrating the spacing between adjacent bonding points based on the ultrasonic cold pressure bonding process, comprising the following steps:

[0045] 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;

[0046] The S1 comprises the following steps:

[0047] S11, collecting the wedge diameter, wedge tip diameter and wedge head length according to the wedge model.

[0048] The wedge tip diameter is subtracted from the wedge diameter and divided by 2 to equal the distance between the wedge tip outside and the wedge outside wall, as Figure 2 shown in value 1.3 in the middle, Figure 2 value 4.6 in the middle represents the wedge head length;

[0049] S12, calculating the wedge head inclination angle according to the wedge diameter, the wedge tip diameter and the wedge head length; the wedge head inclination angle is the taper of the wedge head conical surface.

[0050] According to the distance between the wedge tip outside and the wedge outside wall and the wedge head length, the wedge head inclination angle β can be calculated,

[0051] 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;

[0052] When the second height difference is not less than the wedge head length, the first minimum distance is the radius of the wedge;

[0053] When the second height difference is less than the wedge head length, the first minimum distance is calculated according to the second height difference and the wedge head inclination angle.

[0054] In the S11, the corresponding wedge and bonding wire are selected according to the chip model and the substrate model in the design drawing.

[0055] S2, collecting the design bonding wire angle;

[0056] If the design bonding wire angle is 0°, the first minimum distance in step S1 is taken as the theoretical minimum distance;

[0057] If the design bonding wire angle is not 0°, step S3 is entered;

[0058] S3, calculating the second minimum distance according to the diameter of the bonding wire and the wire arc height when intersecting, and selecting the maximum value between the second minimum distance and the first minimum distance as the theoretical minimum distance;

[0059] The S3 includes the following steps:

[0060] S31, calculating the minimum distance of the welding head in front of the welding head;

[0061] S32, the wire arc intersects in front of and behind the welding head, and the wire arc height when intersecting is calculated;

[0062] If the wire arc height when intersecting is less than the length of the lead wire nozzle head, the second minimum distance is calculated according to the wire arc height when intersecting, the diameter of the bonding wire and the minimum distance of the welding head;

[0063] If the wire arc height when intersecting is not less than the length of the lead wire nozzle head, the second minimum distance is calculated according to the diameter of the bonding wire and the minimum distance of the welding head.

[0064] In the S31,

[0065] If the wire arc height is less than the length of the wire guide head, the minimum distance of the welding head is calculated according to the wire guide tilt angle and the diameter of the bonding wire;

[0066] If the wire arc height is not less than the length of the wire guide head, the minimum distance of the welding head is calculated according to the wire guide diameter and the diameter of the bonding wire.

[0067] In the S31, the corresponding wire guide model is selected according to the batch tool model, and the length of the wire guide head and the diameter of the wire guide are collected according to the wire guide model.

[0068] In the S4, if the theoretical minimum distance is not less than the design distance, it is determined that production is possible, otherwise it is determined that production is not possible.

[0069] The design bonding wire angle is in the range of -90° to 90°, and the absolute value of the design bonding wire angle is used for subsequent calculation.

[0070] The following is a specific example:

[0071] 15mil wire diameter aluminum wire bonding, for example, 2mm arc height, 4mm arc length, wire arc angle 20°.

[0072] The wedge diameter is 3.4mm, the wedge tip diameter is 0.8mm, and the wedge head height is 4.6mm;

[0073] The distance between the wire guide and the wedge center line is 6.3+gap, and the wire guide height is 8.5mm; gap is the distance from the front end of the wire guide to the wedge center line.

[0074] As shown in Figure 1 、 2 In the S1, the first height difference between the wire arc height and the bonding wire axis is calculated according to the wedge head tilt angle and the radius of the bonding wire, and the calculation formula of the first height difference is:

[0075] ;

[0076] Wherein A1 is the first height difference, r is the radius of the bonding wire, 4.6 is the wedge head height, and 1.3 is the difference between the wedge tip radius and the wedge radius.

[0077] The second height difference between the bonding wire axis and the substrate is calculated according to the first height difference and the wire arc height, and the calculation formula of the second height difference is:

[0078] ;

[0079] Wherein A2 is the second height difference; H is the highest height of the wire arc;

[0080] When the second height difference is not less than the length of the wedge head, the first minimum distance is the radius of the wedge;

[0081] When the second height difference is less than the wedge head length, the first minimum distance is calculated according to the second height difference and the wedge head inclination angle.

[0082] The formula is as follows:

[0083] When 0 LR = tanb * A2 - 1.3 + 1.7;

[0084] When 4.6mm LR = 1.7;

[0085] W LR is the first minimum distance, and b is the wedge head inclination angle.

[0086] S2, the design wire bonding angle is collected;

[0087] If the design wire bonding angle is 0°, the first minimum distance in step S1 is taken as the theoretical minimum distance;

[0088] If the design wire bonding angle is not 0°, step S3 is entered.

[0089] When the wire arc is 0°, the wire arc equation is calculated according to the wire arc height (H) and the wire arc length (L);

[0090] When the wire arc is a°, the wire arc equation is calculated by rotating the point (x = 0, y = 0, z = 0) in the x and y planes by an angle of a.

[0091] S31, the minimum distance of the welding head in front of the welding head is calculated;

[0092] In the S31,

[0093] If the wire arc height is less than the wire guide head length, the minimum distance of the welding head is calculated according to the wire guide inclination angle and the diameter of the wire bonding line;

[0094] If the wire arc height is not less than the wire guide head length, the minimum distance of the welding head is calculated according to the wire guide diameter and the diameter of the wire bonding line.

[0095]

[0096] Where D is the diameter of the wire bonding line; z is the height of the wire arc when the wire guide intersects the wire arc, WF is the minimum distance of the welding head, 3.367D 0.755 is the gap, i.e. the distance from the front end of the wire guide to the center line of the wedge, and 63 / 85 is tanb, b is the inclination angle of the wire guide head, as shown in Figure 4 .

[0097] S32, the wire arc intersects the welding head in front and back, and the height of the wire arc when intersecting is calculated.

[0098] As Figure 4 shown, if the height of the wire arc when intersecting is less than the length of the wire nozzle head, the second minimum distance is calculated according to the height of the wire arc when intersecting, the diameter of the bonding wire, and the minimum distance of the welding head;

[0099] If the height of the wire arc when intersecting is not less than the length of the wire nozzle head, the second minimum distance is calculated according to the diameter of the bonding wire and the minimum distance of the welding head.

[0100]

[0101] wherein d is the second minimum distance, 63 / 85 is tanb, b is the inclination 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 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 wedge, and a is the designed bonding wire angle.

[0102] The derivation process is as follows:

[0103] When the wire arc intersects the wire nozzle head (0<z<8.5), (the plane where the wire arc is located);

[0104] Let , combined with , to get , substitute into the wire arc equation to get:

[0105] that is: , and

[0106] Substitute to get a quadratic equation about z:

[0107] ;

[0108] If 0<z<8.5, then ;

[0109] The distance ;

[0110] When the wire arc intersects the upper end of the wire nozzle (z≥8.5), , substitute into the wire arc equation to get:

[0111] ;

[0112] If z≥8.5, then , the distance .

[0113] When bonding 15mil diameter aluminum wire, with 2mm arc height, 4mm arc length, and wire arc angle 20°, z=1.56mm and d=1.21mm are calculated.

[0114] The bonding wire angle is 0°, W LR = 0.79 mm;

[0115] Taking the maximum value 1.21 mm as the theoretical minimum spacing, the design spacing is 1 mm, which cannot be produced. At this time, the number of bonding wires can be reduced to increase the spacing, or the bonding wire angle can be adjusted. By adjusting the angle to 10°, d = 0.69 mm is calculated. Taking the maximum value 0.79 mm as the theoretical minimum spacing, the design spacing of 1 mm can be produced.

[0116] Quantitative calculation of the minimum spacing of adjacent bonding points with angles makes the bonding programming implementation rate high and fast, without repeated trial and error.

[0117] Embodiment two

[0118] An electronic device includes a processor and a memory connected in communication with the processor and configured to store instructions executable by the processor, and the processor is configured to execute the method of embodiment one.

[0119] Embodiment three

[0120] A server includes at least one processor and a memory connected in communication with the processor, the memory storing instructions executable by the at least one processor, and the instructions are executed by the processor to cause the at least one processor to execute the method of embodiment one.

[0121] Embodiment four

[0122] A computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method of embodiment one.

[0123] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

[0124] The above is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An adjacent bond pad pitch alignment method based on an ultrasonic cold press bonding process, characterized by, The method comprises the following steps: S1, calculating the distance 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 distance according to the distance between the bonding wire axis and the substrate; S2, collecting the design bonding wire angle; If the design bonding wire angle is 0°, the first minimum distance in step S1 is taken as the theoretical minimum distance; If the design bonding wire angle is not 0°, step S3 is entered; S3, calculating the second minimum distance according to the diameter of the bonding wire and the wire arc height when intersecting, and selecting the maximum value between the second minimum distance and the first minimum distance as the theoretical minimum distance; S4, if the theoretical minimum distance is not less than the design distance, it is determined that production is possible, otherwise it is determined that production is not possible; 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; S12, calculating the wedge head inclination angle according to the collected wedge diameter, the wedge tip diameter and the 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 wedge head length, the first minimum distance is the radius of the wedge; When the second height difference is less than the wedge head length, the first minimum distance is calculated according to the second height difference and the wedge head inclination angle.

2. The method of claim 1, wherein the method is performed by a computer system. In the S11, the corresponding wedge and bonding wire are selected according to the chip model and the substrate model in the design drawing.

3. The method of claim 1, wherein the method is used in an ultrasonic cold press bonding process. The S3 comprises the following steps: S31, calculating the minimum distance of the welding head in front of the welding head; S32, the wire arc intersects in front of and behind the welding head, and the wire arc height when intersecting is calculated; If the wire arc height when intersecting is less than the length of the lead mouth head, the second minimum distance is calculated according to the wire arc height when intersecting, the diameter of the bonding wire and the minimum distance of the welding head; If the wire arc height when intersecting is not less than the length of the lead mouth head, the second minimum distance is calculated according to the diameter of the bonding wire and the minimum distance of the welding head.

4. The method of claim 3, wherein the method further comprises: In the S31: If the wire arc height is less than the length of the lead mouth head, the minimum distance of the welding head is calculated according to the lead mouth inclination angle and the diameter of the bonding wire; If the wire arc height is not less than the length of the lead mouth head, the minimum distance of the welding head is calculated according to the diameter of the lead mouth and the diameter of the bonding wire.

5. The method for calibrating the distance between adjacent bonding points based on the ultrasonic cold pressure bonding process according to claim 4, characterized in that: In the S31, the corresponding lead mouth model is selected according to the wedge model, and the length of the lead mouth head and the diameter of the lead mouth are collected according to the lead mouth model.

6. The method of claim 1, wherein: The value of the design bonding wire angle is in the range of -90° to 90°.

7. An electronic device, comprising a processor and a memory connected to the processor in communication, and configured to store executable instructions of the processor, characterized in that: The processor is configured to execute the method in any one of claims 1-6.

8. A server, characterized by: The device comprises at least one processor, and a memory connected with the processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the processor to enable the at least one processor to execute the method in any one of claims 1-6.

9. A computer readable storage medium storing a computer program, characterized in that: The computer program is executed by the processor to implement the method in any one of claims 1-6.

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