Lead bonding method and device based on 3D printing, electronic device and storage medium

Abstract

The present application relates to a kind of based on 3D printing wire bonding method and device, electronic equipment and storage medium.The method comprises: the parameter of wire bonding interconnection structure is determined;According to the parameter of wire bonding interconnection structure, the printing path parameter of 3D printing operation is determined;According to the printing path parameter, printing is executed, to form wire bonding interconnection structure.The present application solves the limitation of pad spacing in the prior art wire bonding technology on one hand, and on the other hand, it widens the selection of materials;There is also a significant improvement in the compatibility of method and process, and the process cost and process complexity are reduced.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit packaging, and more particularly to a 3D printing-based wire bonding method and apparatus, electronic device, and storage medium. Background Technology

[0002] With the development of integrated circuits, advanced packaging technologies are constantly evolving to adapt to the requirements and challenges of various new semiconductor processes and materials. The connections between the internal chip and external pins of a semiconductor package, as well as between chips, play a crucial role in establishing electrical connections between the chip and the external environment and ensuring smooth input / output between the chip and the outside world. This is a key aspect of the entire back-end packaging process. Wire bonding dominates the connection method due to its simple implementation, low cost, and applicability to various packaging forms; currently, over 90% of all package pins are connected using wire bonding.

[0003] Wire bonding forms an electrical connection by bonding the two ends of very fine metal wires to the chip and pins respectively. Based on the form of applied energy, wire bonding can be divided into thermo-press bonding, ultrasonic bonding, and thermo-ultrasonic bonding. Based on the type of wedge, it can be divided into wedge bonding and ball bonding. Currently, gold wire ball thermo-ultrasonic bonding is the most commonly used wire bonding method.

[0004] As integrated circuit dimensions continue to shrink and integration density increases exponentially, the size and spacing of bonding pads are also shrinking. Traditional wire bonding methods are becoming increasingly difficult to meet process requirements. At the same time, the high cost or complex processes of these traditional technologies have also greatly limited the packaging process. Summary of the Invention

[0005] To address the problems in existing technologies, this invention provides a wire bonding method based on 3D printing, comprising:

[0006] Determine the parameters of the wire bonding interconnect structure;

[0007] The printing path parameters for the 3D printing operation are determined based on the parameters of the wire-bonded interconnect structure.

[0008] Printing is performed according to the print path parameters to form a wire-bonded interconnect structure.

[0009] Further, determining the printing path parameters for the 3D printing operation based on the parameters of the wire-bonded interconnect structure includes:

[0010] The material parameters for the 3D printing operation are determined based on the parameters of the wire-bonded interconnect structure.

[0011] The 3D printing operation was simulated based on the parameters of the wire-bonded interconnect structure and the material parameters.

[0012] The printing path parameters for the 3D printing operation are determined based on the simulation results.

[0013] Furthermore, the material parameters include one or more of the following: the type of material, the composition of the material, the morphology of the material, and the rheological properties of the material.

[0014] Furthermore, the types of materials include metallic materials or polymeric materials, wherein the metallic materials include one or more of gold, silver, copper, aluminum, and nickel, and the polymeric materials include one or more of polymethyl methacrylate, polydimethylsiloxane, polyimide, epoxy resin, and acrylic resin.

[0015] Furthermore, before performing printing according to the printing path parameters, the method further includes: measuring and compensating the height of the chip surface where the wire bonding interconnect structure is located, and positioning the chip surface.

[0016] Furthermore, the wire bonding interconnect structure includes: interplanar bonding interconnect structure, step bonding interconnect structure, cross-trench bonding interconnect structure, or cross-line bonding interconnect structure.

[0017] Furthermore, the parameters of the wire bonding interconnect structure include structural parameters and performance parameters, wherein the structural parameters include one or more of shape, length and width, and the performance parameters include one or more of strength, conduction current and voltage.

[0018] Secondly, the present invention provides a wire bonding device based on 3D printing, comprising:

[0019] A wire bonding interconnect structure parameter determination unit is used to determine the parameters of the wire bonding interconnect structure;

[0020] The printing path parameter determination unit is used to determine the printing path parameters of the 3D printing operation based on the parameters of the wire bonding interconnect structure.

[0021] A printing operation execution unit is used to perform printing according to the printing path parameters, thereby forming a wire bonding interconnect structure.

[0022] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any of the 3D printing-based wire bonding methods in the first aspect.

[0023] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the 3D printing-based wire bonding methods in the first aspect.

[0024] This invention solves the limitations of existing wire bonding technology on pad spacing and broadens the range of materials available. It also significantly improves the compatibility of methods and processes, and reduces process costs and complexity. Attached Figure Description

[0025] Figure 1 A flowchart illustrating the wire bonding method based on 3D printing provided in an embodiment of the present invention;

[0026] Figures 2 to 7 A schematic diagram of a 3D-printed wire bonding structure provided in an embodiment of the present invention;

[0027] Figure 8 A flowchart for determining the printing path parameters of a 3D printing operation based on the parameters of a wire-bonded interconnect structure, provided in an embodiment of the present invention;

[0028] Figure 9 A schematic diagram of the 3D-printed wire bonding device provided in an embodiment of the present invention;

[0029] Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0030] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Traditional wire bonding technology currently only accommodates pad spacing limits of 37 to 40 μm, and has limited material selection and low process compatibility. Specifically, the existing technical problems include: (1) the current wire bonding technology is limited by pad spacing; (2) the current wire bonding technology is limited by bonding materials; and (3) the current wire bonding technology is complex and costly. Table 1 below shows relevant information about traditional wire bonding processes.

[0032] Bonding process Bonding pressure Bonding temperature ultrasound Lead material solder pad material hot-pressed type high 300-500 none Au A1、Au Ultrasonic Low 25 have Au, A1 A1、Au Thermo-ultrasonic Low 100-150 have Au A1、Au

[0033] Figure 1 A flowchart illustrating a 3D-printed wire bonding method provided in an embodiment of the present invention. (Refer to...) Figure 1 The method includes the following steps:

[0034] Step S101: Determine the parameters of the wire bonding interconnect structure;

[0035] Step S103: Determine the printing path parameters for the 3D printing operation based on the parameters of the wire bonding interconnect structure;

[0036] Step S105: Perform printing according to the printing parameters to form a wire bond interconnect structure.

[0037] The steps of the method will be described below through specific embodiments.

[0038] In one embodiment, in step S101, the parameters of the wire bonding interconnect structure can be determined. In this invention, the wire bonding structure is a structure in which the two ends of very fine metal leads are bonded to the chip and pin respectively to form an electrical connection. This invention can be applied to various different wire bonding interconnect structures, including but not limited to ladder bonding interconnect structures. Figure 2 As shown), cross-trench bonding interconnect structure ( Figure 3 As shown), cross-line bonding interconnect structure ( Figure 4 (as shown), Figure 5 The ladder bonding path is shown. Figure 6 This shows the shape when the lead reaches its highest point. Figure 7 The diagram shows the state at the end of wire bonding.

[0039] In addition, the parameters of the lead interconnect structure may include structural parameters and performance parameters. Structural parameters may include shape, length, width, etc., while performance parameters may include various mechanical properties (e.g., tensile strength, fatigue strength, etc.), electrical properties (e.g., resistance, current or voltage), heat resistance, corrosion resistance, moisture resistance, etc., and are not limited to these.

[0040] As a carrier connecting chips and pins, wire bonding interconnect structures typically require good electrical properties (e.g., strong conductivity, resistance to Kirkendall effect, etc.). Therefore, electrical parameters can be selected as parameters for wire bonding interconnect structures.

[0041] Furthermore, the parameters of the various interconnect structures mentioned above can be added or removed according to actual needs. For example, for chips operating under specific conditions, different interconnect structure parameters can be added. For instance, for chips operating in high-temperature environments, high-temperature resistance parameters can be added as parameters for the wire bonding interconnect structure; for chips operating in low-temperature environments, low-temperature resistance parameters can be added as parameters for the wire bonding interconnect structure. As another example, for chips operating in both high-temperature and humid environments, both high-temperature resistance and humidity resistance parameters can be added as parameters for the wire bonding interconnect structure; and for chips operating in both low-temperature and humid environments, both low-temperature resistance and humidity resistance parameters can be added as parameters for the wire bonding interconnect structure.

[0042] For example, for a chip that operates under certain stress, voltage, and current, the strength, current, and voltage parameters can be selected as parameters for the wire bonding interconnect structure.

[0043] Based on the parameters of the wire bonding interconnect structure determined in step S101, the printing path parameters for the 3D printing operation can be determined in step S103.

[0044] In this invention, the printing path parameters may include printing speed and printing path. For example, the printing path is a forward kinematic bonding path calculated based on Bell's knot.

[0045] In this invention, the 3D printing operation is mainly completed by a precision motion platform and a print head. The print head on the precision motion platform prints out the required structure according to the shape of the designed wire interconnect structure, thereby obtaining the wire interconnect structure.

[0046] Various printing path parameters can be set, such as parameters related to the precision motion platform, parameters related to the print head (e.g., a precision five-axis motion platform or a multi-degree-of-freedom precision manipulator), and parameters related to material output (e.g., precision pneumatic control output or precision screw propulsion).

[0047] For example, when a wider linewidth is required based on the structural parameters (e.g., line width) of the wire bond interconnect structure determined above, a higher printhead printing speed can be set as the print path parameter for the printing operation. Conversely, when a narrower linewidth is required based on the structural parameters (e.g., line width) of the wire bond interconnect structure determined above, a lower printhead printing speed can be set as the print path parameter for the printing operation.

[0048] Based on the printing path parameters of the printing operation determined in step S103 above, printing is performed in step S105 to form a wire bonding interconnect structure.

[0049] For example, if parameters related to the precision motion platform, the print head, and the material output are determined through step S103, these printing path parameters can be imported into the 3D printing device. By inputting the execution command, the 3D printing device will begin to perform the printing operation according to the above parameters, thereby obtaining the wire bonding interconnect structure.

[0050] Through the above steps S101, S103 and S105, a wire bonding interconnect structure is obtained by performing 3D printing, and the pad spacing of the wire bonding interconnect structure is at the submicron level.

[0051] To further improve the efficiency and accuracy of printing operations, more suitable printing path parameters can be obtained through simulation. In this invention, the printing path parameters may include printing speed and printing path.

[0052] In another embodiment of this disclosure, such as Figure 8 As shown, determining the printing path parameters of the 3D printing operation based on the parameters of the wire bond interconnect structure can include the following steps: Step S201: Determine the material parameters of the 3D printing operation based on the parameters of the wire bond interconnect structure; Step S203: Simulate the 3D printing operation based on the parameters of the wire bond interconnect structure and the material parameters; Step S205: Determine the printing path parameters of the 3D printing operation based on the simulation results.

[0053] As mentioned above, the parameters of the wire bonding interconnect structure can include structural parameters and performance parameters. The structural parameters can include shape, length, width, etc., and the performance parameters include various mechanical properties, electrical properties, heat resistance, corrosion resistance, moisture resistance, etc., and are not limited to these.

[0054] In step S201, the material parameters can be determined based on these parameters. For example, when a certain strength and a certain resistance are required, the material parameters corresponding to meeting these requirements can be determined. When a certain corrosion resistance and a certain resistance are required, the material parameters corresponding to meeting these requirements can be determined. In other words, the material parameters can be determined based on the structural and performance parameters required for the wire bonding interconnect structure. These material parameters include the material type, material composition, material morphology, and rheological properties of the material.

[0055] For example, you can choose a single metallic gold as the material type, a material composition of 100 wt% gold, and a material form of solid powder as the material parameters; or you can choose a combination of metallic gold and silver, a material composition of 80 wt% gold and 20 wt% silver, and a material form of solid powder as the material parameters.

[0056] This invention can use one or more of gold, silver, copper, aluminum, and nickel, and is not limited to these materials; it can also use other metals, ceramics, polymers, and other materials. This invention can also use various combinations of different materials, such as gold-silver combinations, gold-copper combinations, etc., and is not limited to these combinations.

[0057] In addition to wire bonding via metals as described above, wire bonding can also be achieved through optical interconnects and optoelectronic interconnects in this invention. In this case, the materials can be polymers, including but not limited to polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyimide (PI), epoxy resin, and acrylic resin.

[0058] Besides the lack of limitations on the type and composition of materials, the form of the materials can also vary. For example, metal powder or "ink" gel can be selected. In this invention, "ink" can refer to a gel-like object with a certain viscosity obtained by mixing raw materials with a certain solvent, or it can be printed using micro / nano metal powders or filaments in conjunction with a heated extrusion printhead. Furthermore, in this invention, the rheological parameters of the materials can be determined. In this paper, the rheological parameters of the materials include viscosity and thixotropy.

[0059] In step S203, the 3D printing operation can be simulated based on the determined material parameters (e.g., material type, material composition, material morphology, material rheological properties, etc.) and the parameters of the lead interconnect structure (e.g., structural parameters, performance parameters).

[0060] Different material parameters and lead interconnect structure parameters will result in different printing parameter paths (e.g., printing speed or printing path).

[0061] For example, the printing speed corresponding to material parameters of copper type, composition of 100wt% copper, and form of "ink" gel is different from the printing speed corresponding to material parameters of copper type, composition of 100wt% copper, and form of solid powder, because the bonding between "printed layers" is different when printing gel and printing solid powder.

[0062] For example, the printing paths corresponding to the parameters of interconnect structures with the same length and width but different shapes are different.

[0063] In other words, different material parameters and lead interconnect structure parameters will result in different printing speeds and printing paths. Therefore, different material parameters and lead interconnect structure parameters can be used as inputs for simulation.

[0064] In step S205, the printing path parameters of the 3D printing operation can be determined based on the simulation results. In this invention, the printing path parameters may include printing speed and printing path. Therefore, based on the simulation results of step S203 above, the printing speed and printing path of the 3D printing operation can be determined.

[0065] When the simulation results are good, for example, when the simulated printing efficiency and printing accuracy are good, the printing speed and printing path corresponding to the simulation results can be determined as the actual printing speed and printing path.

[0066] When the simulation results are unsatisfactory, for example, when the simulated printing efficiency is poor (e.g., printing time is long), the printing speed can be set higher (adjusting the pressure of the feed material).

[0067] When the simulation results are unsatisfactory, for example, when the simulated printing accuracy is poor (e.g., the printed line width does not meet the requirements), the printing speed can be set to be slower (e.g., by adjusting the feeding pressure to reduce the output speed).

[0068] Therefore, the printing path parameters of the 3D printing operation can be determined based on the simulation results.

[0069] Through the above steps S201, S203 and S205, more suitable printing path parameters are obtained through simulation, which further improves the efficiency and accuracy of printing operations.

[0070] According to any of the above embodiments, in order to further improve the accuracy of the printing operation, the height of the chip surface where the wire bonding interconnect structure is located can be measured and compensated, and the chip surface can be positioned before printing is performed according to the printing path parameters.

[0071] Height compensation values ​​can be obtained by scanning a chip with a high-precision height sensor. Specifically, this involves: acquiring height data of corresponding positions by relative movement of the height sensor within the processing area; and calculating the required compensation in the height direction for each position by comparing the obtained height data with preset locking height data. The height sensor mentioned above can be a white light height sensor, a laser sensor, a force sensor (contact sensor), etc., and this invention is not limited to these.

[0072] Visual positioning systems can be used to achieve visual positioning of processing points. Specifically, this involves using a vertical industrial camera to capture processing points of specific shapes. Before the equipment begins processing, the vertical camera needs to be calibrated with the print head, height sensor, and other components. Therefore, once the corresponding processing point is captured, the relative position between the processing point and the relevant processing head can be calculated in the background.

[0073] By utilizing height compensation and visual positioning, the path of the printing operation can be calculated more accurately, thereby further improving the precision of the printing operation.

[0074] Optionally, the obtained wire-bonded interconnect structure sample can be processed after the printing operation is completed.

[0075] For example, to further improve the crystallinity of a sample or to further eliminate internal stress, sintering can be used to process the sample. Examples of methods include laser in-situ sintering, infrared in-situ sintering, induction in-situ sintering, photonic in-situ sintering, or thermal sintering.

[0076] In addition, other heat treatment methods can be used, including vacuum annealing, reduction annealing, and forced-air drying.

[0077] It should be noted that the above-mentioned processes are not mandatory, but can be selected or not depending on actual needs. For example, when the mechanical parameters (e.g., stress) of the lead interconnect structure are required to be low, that is, when it is not necessary to reduce the internal stress level, no processing is required; while when it is necessary to keep the internal stress low, processing can be performed to eliminate the internal stress.

[0078] As can be seen from the above-disclosed embodiments, the present invention solves the limitation on pad spacing in existing wire bonding technology, realizing wire bonding structures with pad spacing from submicron to micron. On the other hand, 3D printing can use a wide variety of materials and forms, including metals, ceramics, polymers, solid forms, and gel "ink" forms, thereby broadening the selection of materials and the compatibility of methods. Compared with existing wire bonding technology, it reduces the limitations of various conditions such as pressure and temperature, improves the ease of operation, and thus reduces process costs and process complexity.

[0079] Figure 9 This is a schematic diagram of a 3D-printed wire bonding device provided in an embodiment of the present invention. (Refer to...) Figure 9 The device 300 includes:

[0080] The wire bonding interconnect structure parameter determination unit 301 is used to determine the parameters of the wire bonding interconnect structure;

[0081] The printing path parameter determination unit 303 is used to determine the printing path parameters of the 3D printing operation based on the parameters of the wire bonding interconnect structure.

[0082] The printing operation execution unit 305 is used to perform printing according to the printing path parameters, thereby forming a wire bonding interconnect structure.

[0083] As can be seen from the above, each unit 301 to 305 of the device 300 can respectively execute each step in the 3D printing-based wire bonding method described with reference to the above embodiments, and its details will not be described here.

[0084] On the other hand, the present invention provides an electronic device. For example... Figure 10 As shown, the electronic device 400 includes a processor 401, a memory 402, a communication interface 403, and a communication bus 404.

[0085] The processor 401, memory 402, and communication interface 403 communicate with each other through the communication bus 404.

[0086] The processor 401 is used to call the computer program in the memory 402. When the processor 401 executes the computer program, it implements the various steps in the wire bonding method based on 3D printing provided in the embodiments of the present invention as described above.

[0087] Furthermore, when the computer program in the aforementioned memory can be implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several computer programs to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0088] On the other hand, the present invention provides a non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, implements the various steps of the 3D printing-based wire bonding method provided in the embodiments of the present invention as described above.

[0089] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0090] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wire bonding method based on 3D printing, characterized in that, include: Determine the parameters of the wire bonding interconnect structure; The printing path parameters for the 3D printing operation are determined based on the parameters of the wire-bonded interconnect structure. Printing is performed according to the stated print path parameters, thereby forming a wire-bonded interconnect structure. The step of determining the printing path parameters for the 3D printing operation based on the parameters of the wire-bonded interconnect structure includes: The material parameters for the 3D printing operation are determined based on the parameters of the wire-bonded interconnect structure. The 3D printing operation was simulated based on the parameters of the wire-bonded interconnect structure and the material parameters. The printing path parameters of the 3D printing operation are determined based on the simulation results. The material parameters include one or more of the following: material type, material composition, material morphology, and material rheological properties. The print path parameters include print speed and print path; The parameters of the wire bonding interconnect structure include structural parameters and performance parameters, wherein the structural parameters include one or more of shape, length and width, and the performance parameters include one or more of strength, conduction current and voltage. The wire bonding interconnect structure includes: interplanar bonding interconnect structure, stepped bonding interconnect structure, cross-trench bonding interconnect structure, or cross-line bonding interconnect structure.

2. The wire bonding method based on 3D printing according to claim 1, characterized in that, The materials include metallic materials or polymeric materials. The metallic materials include one or more of gold, silver, copper, aluminum, and nickel. The polymeric materials include one or more of polymethyl methacrylate, polydimethylsiloxane, polyimide, epoxy resin, and acrylic resin.

3. The wire bonding method based on 3D printing according to any one of claims 1 to 2, characterized in that, Before performing printing according to the printing path parameters, the method further includes: measuring and compensating the height of the chip surface where the wire bonding interconnect structure is located, and positioning the chip surface.

4. A wire bonding device based on 3D printing, characterized in that, include: A wire bonding interconnect structure parameter determination unit is used to determine the parameters of the wire bonding interconnect structure; The printing path parameter determination unit is used to determine the printing path parameters of the 3D printing operation based on the parameters of the wire bonding interconnect structure. The printing operation execution unit is used to perform printing according to the printing path parameters, thereby forming a wire-bonded interconnect structure. The step of determining the printing path parameters for the 3D printing operation based on the parameters of the wire-bonded interconnect structure includes: The material parameters for the 3D printing operation are determined based on the parameters of the wire-bonded interconnect structure. The 3D printing operation was simulated based on the parameters of the wire-bonded interconnect structure and the material parameters. The printing path parameters of the 3D printing operation are determined based on the simulation results. The material parameters include one or more of the following: material type, material composition, material morphology, and material rheological properties. The print path parameters include print speed and print path; The parameters of the wire bonding interconnect structure include structural parameters and performance parameters, wherein the structural parameters include one or more of shape, length and width, and the performance parameters include one or more of strength, conduction current and voltage. The wire bonding interconnect structure includes: interplanar bonding interconnect structure, stepped bonding interconnect structure, cross-trench bonding interconnect structure, or cross-line bonding interconnect structure.

5. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any one of the 3D printing-based wire bonding methods as claimed in claims 1-3.

6. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the wire bonding method based on 3D printing as described in any one of claims 1-3.

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