Method, device and computer equipment for predicting alloying life of solder joint

Abstract

The present application relates to a method, device and computer equipment for predicting the alloying life of a solder joint. The solder joint includes a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer including the first metal and the second metal; the method includes: obtaining the flux of the first metal in the solder pad, the solder layer and the interface metal compound layer; obtaining the net flux of the first metal in the interface metal compound layer and the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer; establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer; predicting the alloying life of the solder joint based on the growth model of the interface metal compound layer. The use of this method can improve the prediction readiness and reduce time and economic costs.

Description

Technical Field

[0001] The present application relates to the field of microelectronic packaging, and in particular to a method and device for predicting the alloying life of a solder joint, and a computer device. Background Art

[0002] With the development of microelectronic packaging technology, the prediction of solder joint alloying life has become an important indicator for evaluating the reliability of package interconnection. As the size of solder joints continues to shrink, the reliability of devices and even the entire system is severely tested due to factors such as micro size and high current density effects. Improving the package I / O density is considered to be an important way to improve the integration of high-performance microelectronic devices. Taking lead-free micro solder joints as an example, the diameter of lead-free micro solder joints can reach less than 30um, and the intercept can be reduced to 20um, with ultra-high package I / O density. However, lead-free micro solder joints are more likely to alloy into a Cu-Sn intermetallic compound layer (IMC), which reduces the alloying life of solder joint interconnections, thereby posing a hidden danger to the reliability of devices and even the entire system.

[0003] Based on the existing technology, the prediction method of the alloying degree of the IMC layer is mainly applicable to the traditional large-volume interconnect solder joint structure, and it is unable to quantify the problem of complete alloying of the bump caused by the reduction of the solder joint size and the mutual transformation between different types of IMC layers. Summary of the invention

[0004] Based on this, it is necessary to provide a method, device and computer equipment for predicting the alloying life of welds, which can improve prediction readiness and reduce time and economic costs, in response to the above technical problems.

[0005] In a first aspect, the present application provides a method for predicting the alloying life of a solder joint, wherein the solder joint comprises a solder pad of a first metal and a solder layer of a second metal, wherein the solder pad and the solder layer are alloyed to generate an interface metal compound layer comprising the first metal and the second metal; the method comprises:

[0006] Obtaining the flux of the first metal in the pad, the solder layer, and the interface metal compound layer;

[0007] Obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0008] Establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0009] The alloying life of the solder joint is predicted based on the growth model of the interface metal compound layer.

[0010] In one embodiment, the solder pad includes a first solder pad and a second solder pad, and the solder layer is located between the first solder pad and the second solder pad; the interface metal compound layer is located between the first solder pad and the solder layer and between the second solder pad and the solder layer, and the interface metal compound layer includes a first interface metal compound layer and a second interface metal compound layer, and the first interface metal compound layer and the second interface metal compound layer are both reaction products of the first metal and the second metal.

[0011] It can be seen that the interface metal compound layer includes the first interface metal compound layer and the second interface metal compound layer, rather than a single metal compound layer, which makes the obtained growth model more reasonable, and thus the prediction of the alloying life is more accurate, which is of great significance for supporting the reliability design of microelectronic devices.

[0012] In one embodiment, the first pad includes a cathode pad, and the second pad includes an anode pad; the first metal includes copper, and the second metal includes tin; and obtaining the net flux of the first metal in the interface metal compound layer and the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer includes: establishing the following relationship between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the first pad and the solder layer and the flux of the first metal in the first pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer:

[0013]

[0014]

[0015] Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, represents the thermal diffusion flux of copper from the first pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the second interface metal compound layer to the second metal layer caused by the atomic concentration gradient, is the copper electromigration flux in the first interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second interface metal compound layer caused by electron wind.

[0016] The net electromigration flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula:

[0017]

[0018] Among them, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, D Cu / ε represents the thermal diffusion coefficient of the copper atoms in the first interface metal compound layer, is the effective charge number of the copper atoms in the first interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density.

[0019] The net electromigration flux of the first metal in the first pad in the second interface metal compound layer is obtained based on the following formula:

[0020]

[0021] Among them, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer, D Cu / η represents the thermal diffusion coefficient of the copper atoms in the second interface metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density.

[0022] The net heat diffusion flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula:

[0023]

[0024] Among them, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer.

[0025] The net heat diffusion flux of the first metal in the first pad in the second interface metal compound layer is obtained based on the following formula:

[0026]

[0027] Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn is the concentration of copper atoms dissolved in Sn solder, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer.

[0028] The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the second pad and the solder layer and the flux of the first metal in the second pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer:

[0029]

[0030]

[0031] Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, ε represents the thickness of the first interface metal compound layer, η represents the thickness of the second interface metal compound layer, represents the thermal diffusion flux of copper from the second pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the second interface metal compound layer to the second metal layer caused by the atomic concentration gradient, is the copper electromigration flux in the first interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second metal layer caused by electron wind force;

[0032] The net electromigration flux of the first metal in the second pad in the first interface metal compound layer is obtained based on the following formula:

[0033]

[0034] Among them, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, C Cu / ηrepresents the concentration of the copper atoms in the second interface metal compound layer; D Cu / ε represents the thermal diffusion coefficient of the copper atoms in the first interface metal compound layer, D Cu / η represents the thermal diffusion coefficient of the copper atoms in the second interface metal compound layer; is the effective charge number of the copper atoms in the first interfacial metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer; ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density;

[0035] The net electromigration flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula:

[0036]

[0037] Among them, C Cu / Sn represents the concentration of the copper atoms dissolved in the second metal layer, D Cu / Sn represents the thermal diffusion coefficient of the copper atoms in the second metal layer, is the effective charge number of the copper atom in the second metal layer; Sn is the resistivity of the second metal layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density;

[0038] The net heat diffusion flux of the first metal in the second pad in the first interface metal compound layer is obtained based on the following formula:

[0039]

[0040] Among them, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer;

[0041] The net heat diffusion flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula:

[0042]

[0043] Among them, C Cu / εrepresents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn is the concentration of copper atoms dissolved in tin solder, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer.

[0044] In one embodiment, the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer includes: obtaining the relationship between the net flux of the first metal in the first interface metal compound layer between the first pad and the solder layer and the growth rate of the first interface metal compound layer between the first pad and the solder layer based on the following formula:

[0045]

[0046] in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density;

[0047] The relationship between the net flux of the first metal in the second interface metal compound layer between the first pad and the solder layer and the growth rate of the second interface metal compound layer between the first pad and the solder layer is obtained based on the following formula:

[0048]

[0049] in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, D Cu / Sn is the thermal diffusion coefficient of copper atoms in the solder layer, represents the effective charge number of copper atoms in the solder layer, C Cu / Sn represents the concentration of the copper atoms dissolved in the second metal layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density;

[0050] The relationship between the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer and the growth rate of the first interface metal compound layer between the second pad and the solder layer is obtained based on the following formula:

[0051]

[0052] in, In the formula, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density;

[0053] The relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer is obtained based on the following formula:

[0054]

[0055] in, In the formula, C Cu / Sn is the concentration of copper atoms dissolved in Sn solder, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer, D Cu / Sn is the thermal diffusion coefficient of copper atoms in the solder layer, represents the effective charge number of copper atoms in the second interface metal compound layer, represents the effective charge number of copper atoms in the solder layer, ρ η is the resistivity of the second interface metal compound layer, ρ Sn is the resistivity of the solder layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density.

[0056] In one embodiment, the growth model of the interface metal compound layer is established based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer, including: obtaining the change of the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer with time under temperature stress based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer, and the formula for the change of the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer with time under temperature stress is:

[0057]

[0058] Among them, ε0 is the initial thickness of the first interface metal compound layer, and η0 is the initial thickness of the second interface metal compound layer. It can be seen that this method can obtain the thickness growth relationship of the Cu3Sn layer and the Cu6Sn5 layer under a single temperature stress when the Sn solder is not completely exhausted, thereby making the growth model more reasonable and the alloying life prediction more accurate.

[0059] In one embodiment, the establishing of the growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer includes: based on the relationship between the net flux of the first metal in the first interface metal compound layer between the first pad and the solder layer and the growth rate of the first interface metal compound layer between the first pad and the solder layer and the relationship between the net flux of the first metal in the second interface metal compound layer between the first pad and the solder layer and the growth rate of the second interface metal compound layer between the first pad and the solder layer, obtaining the formula for the change of the thickness of the first interface metal compound layer between the first pad and the solder over time and the change of the thickness of the second interface metal compound layer between the first pad and the solder over time under temperature stress coupled current stress:

[0060]

[0061] Wherein, C1 is an integral constant related to the initial thickness of the first interface metal compound layer between the first pad and the solder layer, and C2 is an integral constant related to the initial thickness of the second interface metal compound layer between the first pad and the solder layer;

[0062] Based on the relationship between the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer and the growth rate of the first interface metal compound layer between the second pad and the solder layer, and the relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer, a formula for the change with time of the thickness of the first interface metal compound layer between the second pad and the solder and the change with time of the thickness of the second interface metal compound layer between the second pad and the solder under temperature stress coupled current stress is obtained:

[0063]

[0064] Wherein, C'1 and C'2 are integral constants related to the initial thickness of the first interface metal compound layer between the second pad and the solder layer, and C'1 and C'2 are integral constants related to the initial thickness of the second interface metal compound layer between the second pad and the solder layer.

[0065] In one embodiment, the predicting the alloying life of the solder joint based on the growth model of the interface metal compound layer includes: predicting the alloying life of the solder joint when the second metal solder layer is exhausted based on the growth model of the interface metal compound layer, including: predicting the alloying life of the solder joint when the material layer is exhausted based on the initial thickness of the solder layer, the initial thickness of the first interface metal compound layer and the initial thickness of the second interface metal compound layer, the growth thickness of the first interface metal compound layer and the growth thickness of the second interface metal compound layer.

[0066] In one embodiment, the predicting the alloying life of the solder joint based on the growth model of the interface metal compound layer includes: predicting the alloying life of the solder joint when the second interface metal compound layer is completely transformed into the first interface metal compound layer based on the growth model of the interface metal compound layer, including: predicting the alloying life of the solder joint when the second interface metal compound layer is completely transformed into the first interface metal compound layer under temperature stress based on the following formula:

[0067]

[0068] Wherein, 0.68 is the conversion ratio of the thickness of the first interface metal compound layer and the second interface metal compound layer. Here, ε0 represents the initial thickness of the first interface metal compound layer when the solder is completely consumed, and η0 represents the initial thickness of the second interface metal compound layer when the solder is completely consumed.

[0069] The alloying life of the solder joint when the second interface metal compound layer is completely transformed into the first interface metal compound layer under temperature stress coupled current stress is predicted based on the following formula:

[0070] η=η0-0.68×(Δε Anode +Δε Cathode )

[0071] Among them, Δε Cathode is the growth thickness of the first interface metal compound layer between the first pad and the solder layer when the solder is completely consumed, Δε Anode is the growth thickness of the first interface metal compound layer between the second pad and the solder layer when the solder is completely consumed.

[0072] It can be seen that this method can solve the problem of mutual transformation between different types of IMC layers, thereby being able to more accurately predict the alloying life of the above-mentioned solder joints.

[0073] In a second aspect, the present application also provides a device for predicting the alloying life of a solder joint. The device comprises:

[0074] The solder joint comprises a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer comprising the first metal and the second metal; the device comprises:

[0075] An acquisition module, used for acquiring the flux of the first metal in the pad, the solder layer and the interface metal compound layer;

[0076] A first processing module, used for obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0077] A second processing module is used to establish a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0078] The third processing module is used to predict the alloying life of the solder joint based on the growth model of the interface metal compound layer.

[0079] In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program, wherein the solder joint mentioned in the following steps includes a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer including the first metal and the second metal:

[0080] Obtaining the flux of the first metal in the pad, the solder layer, and the interface metal compound layer;

[0081] Obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0082] Establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0083] The alloying life of the solder joint is predicted based on the growth model of the interface metal compound layer.

[0084] In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented, wherein the solder joint mentioned in the following steps includes a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer including the first metal and the second metal:

[0085] Obtaining the flux of the first metal in the pad, the solder layer, and the interface metal compound layer;

[0086] Obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0087] Establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0088] The alloying life of the solder joint is predicted based on the growth model of the interface metal compound layer.

[0089] In a fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented, wherein the solder joint mentioned in the following steps includes a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer including the first metal and the second metal:

[0090] Obtaining the flux of the first metal in the pad, the solder layer, and the interface metal compound layer;

[0091] Obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0092] Establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0093] The alloying life of the solder joint is predicted based on the growth model of the interface metal compound layer.

[0094] The alloying life prediction method, device, computer equipment, storage medium and computer program product of the solder joint obtain the net flux of the first metal and the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer according to the flux of the first metal, and then obtain the growth model of the net flux of the first metal and the interface metal compound layer according to the growth rate, and predict the alloying life of the solder joint based on the growth model. It can be seen that the above-mentioned growth model is gradually obtained based on the flux of the first metal, so that the prediction of the alloying life is more reasonable, thereby improving the prediction readiness, thereby reducing or avoiding the time and economic costs generated by a large number of life and failure analysis tests, and has huge economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] Figure 1 A schematic diagram of a process for predicting alloying life of a solder joint in one embodiment;

[0096] Figure 2 is a schematic structural diagram of a welding point in an embodiment;

[0097] Figure 3 is a schematic structural diagram of another welding point in an embodiment;

[0098] Figure 4 A schematic diagram of the structure of copper flux in a solder joint under the temperature and current stress coupling conditions in one embodiment;

[0099] Figure 5 A schematic diagram of a scenario comparing an experimental result and a predicted result of the growth thickness of an interface metal compound layer in an embodiment;

[0100] Figure 6 A schematic diagram of a scenario comparing an experimental result and a predicted result of the growth thickness of an interface metal compound layer in another embodiment;

[0101] Figure 7 A schematic diagram of the structure of another welding point of an embodiment;

[0102] Figure 8 A schematic diagram of a scenario for predicting alloying life of a solder joint in an embodiment;

[0103] Fig. 9 A device for predicting the alloying life of a solder joint in an embodiment;

[0104] Fig.10 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0105] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0106] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0107] Hereinafter, although terms such as "first", "second", etc. may be used to describe various components, these components are not necessarily limited to the above terms. The above terms are only used to distinguish one component from another. It will also be understood that expressions used in the singular include plural expressions unless the expression in the singular has an obviously different meaning in the context.

[0108] A method for predicting the degree of alloying of solder joints is based on the numerical calculation of different atomic migration fluxes between solder joint interfaces, and simulates and calculates the atomic migration fluxes of copper pads, tin solder and interfaces between different IMCs under temperature and current stress conditions. The atomic flux obtained by theoretical calculation is combined with the mass density relationship of the conversion reaction between different structures, and converted into the change of interface position, which is then used to characterize the functional relationship of the IMC layer thickness changing with time.

[0109] Another method for predicting the degree of alloying of solder joints is based on the mass transport conservation principle of copper atoms. It simulates and calculates the net flux of copper atoms in copper pads, tin solder and Cu6Sn5 layer structures under temperature and current stress conditions. The theoretically calculated copper atom migration flux is converted into the thickness change of the Cu6Sn5 layer, which is then used to characterize the functional relationship between the thickness of the Cu6Sn5 layer and time.

[0110] However, the calculation of the atomic migration flux between interfaces in the first method mentioned above needs to be based on a large number of interface thermal diffusion and electromigration parameters. At present, the research on interface parameters needs to be deepened, and the acquisition of relevant parameters and the accuracy of parameters cannot be guaranteed. In addition, this method does not involve the prediction of the process of complete alloying of solder joints into IMC layers or mutual transformation between IMC layers as the size of lead-free solder joints is reduced, so the alloying life prediction of solder joints cannot be achieved.

[0111] The second method mentioned above simplifies the IMC layer in the lead-free solder joint and only considers the growth effect of the Cu6Sn5 metal compound in the lead-free solder joint. Therefore, it fails to quantitatively characterize the thickness growth relationship of the Cu3Sn layer with temperature and current stress. In addition, this method does not involve the prediction of the process of the solder joint being completely alloyed into the IMC layer or the mutual transformation between the IMC layers as the size of the lead-free solder joint is reduced, so it cannot achieve the alloying life prediction of the lead-free solder joint.

[0112] See also Figure 1 , Figure 1 FIG. 1 is a flow diagram of a method for predicting alloying life of a solder joint in an embodiment. The solder joint mentioned in the above process includes a solder pad of a first metal and a solder layer of a second metal. The solder pad and the solder layer are alloyed to generate an interface metal compound layer including the first metal and the second metal. Figure 2 , Figure 2 FIG. 1 is a schematic diagram of the structure of a solder joint in an embodiment. The schematic diagram of the structure of the solder joint includes the solder pad 201 of the first metal and the solder layer 202 of the second metal, combined with Figure 2 The schematic diagram of the solder joint structure is shown in FIG. Figure 1 The process diagram includes the following steps:

[0113] Step 101, obtaining the flux of the first metal in the pad, the solder layer and the interface metal compound layer.

[0114] Among them, the pad 201 includes a first pad and a second pad, and the solder layer 202 is located between the above-mentioned first pad and the above-mentioned second pad; the above-mentioned interface metal compound layer is located between the above-mentioned first pad and the solder layer and between the above-mentioned second pad and the above-mentioned solder layer, and the above-mentioned interface metal compound layer includes a first interface metal compound layer and a second interface metal compound layer, and the above-mentioned first interface metal compound layer and the above-mentioned second interface metal compound layer both include a first metal and a second metal; the above-mentioned first pad includes a cathode pad, and the above-mentioned second pad includes an anode pad; the above-mentioned first metal includes copper, and the above-mentioned second metal includes tin.

[0115] Here we take copper as the first metal and tin as the second metal as an example for detailed description. Figure 3 , Figure 3The schematic diagram of the structure of another solder joint in an embodiment includes a first solder pad 301, a solder layer 302, a first interface metal compound layer 303, and a second interface metal compound layer 304. The first solder pad 301 may include a copper solder pad, the solder layer 302 may include a tin layer, the first interface metal compound layer 303 may include a Cu3Sn layer, and the second interface metal compound layer 304 may include a Cu6Sn5 layer. The flux of the copper Cu in the first solder pad 301, the solder layer 302, the first interface metal compound layer 303, and the second interface metal compound layer 304 is obtained, and the flux of Cu includes the thermal diffusion flux of Cu, the electromigration flux of Cu, and the dissolution flux of Cu atoms.

[0116] Specifically, combined Figure 2 and Figure 3 , see Figure 4 , Figure 4 FIG. 1 is a schematic diagram of the structure of Cu flux in a solder joint under the temperature and current stress coupling conditions in one embodiment.

[0117] Figure 4 Middle J chem represents the Cu thermal diffusion flux caused by the atomic concentration gradient, which is always from the structure with high copper atomic concentration to the structure with low concentration; the flux J em represents the Cu electromigration flux caused by the electron wind, and its direction is consistent with the electron flow direction; while the flux J diss It represents the dissolution flux of copper atoms. The atomic migration under the action of the electric field will lead to the unsaturated concentration of copper atoms, thus forming the dissolution flux.

[0118] in, Figure 4 In and The Cu electromigration fluxes in the first pad 301, the first interface metal compound layer 303, the second interface metal compound layer 304 and the tin solder layer 302 are respectively. Under current stress, the directional migration of copper atoms is the key factor that causes the difference in the IMC layer between the cathode and the anode of the solder joint. Among them, the first pad 301 structure has good anti-electromigration ability, so the The flux can be ignored in the calculation, and the Cu electromigration flux in the first interface metal compound layer 303, the second interface metal compound layer 304, and the solder layer 302 is recorded as (That is, Representing the above or ), and calculated according to the Huntington model:

[0119]

[0120] In the formula, C Cu / Bulk and DCu / Bulk represent the concentration and diffusion coefficient of copper atoms in the migration body tissue respectively. is the effective charge number of the copper atom in the migration body. (For example, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, represents the effective charge number of copper atoms in the second metal solder layer), e is the unit charge, and ρ Bulk is the resistivity of the migration body, j is the average current density, k is the Boltzmann constant, and T is the Kelvin temperature of the solder joint.

[0121] Figure 4 In and They are the copper atom dissolution flux from the first pad 301 to the first interface metal compound layer 303, from the first interface metal compound layer 303 to the second interface metal compound layer 304, and from the second interface metal compound layer 304 to the solder layer 302. When the temperature and current conditions are constant, the copper atom dissolution flux is only related to the solubility of Cu, but the solubility of copper atoms in solid tissues is usually low, so the resulting dissolution flux can be ignored in the calculation.

[0122] Step 202, obtaining the net flux of the first metal in the interface metal compound layer and the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer.

[0123] Specifically, based on the numerical analysis of the Cu flux in step 201 and in combination with the mass transport conservation principle of copper atoms, a relationship between the net flux of copper atoms and the thickness of the first interface metal compound 303 layer and the second interface metal compound 304 is established.

[0124] For the cathode:

[0125]

[0126]

[0127] For the anode:

[0128]

[0129]

[0130] In the formula, C Cu / ε and C Cu / ηrepresents the concentration of copper atoms in the Cu3Sn 303 (ε phase) and Cu6Sn5 304 (η phase) layers, respectively, and ε and η represent the thickness of the first interface metal compound layer 303 and the second interface metal compound layer 304, respectively; in formulas (2) to (5), and The difference is the net thermal diffusion flux of copper atoms in the first interface metal compound layer 303, which is equivalent to the diffusion process of copper atoms in the first interface metal compound layer 303 caused by the atomic concentration difference between the first pad 301 and the second interface metal compound layer 304. and The difference is the net thermal diffusion flux of copper atoms in the second interface metal compound layer 304, which is equivalent to the diffusion process of copper atoms in the second interface metal compound layer 304 caused by the atomic concentration difference between the second interface metal compound layer 304 and the Sn solder.

[0131] The net heat diffusion flux of copper atoms in the first interface metal compound layer 303 is obtained based on the following formula:

[0132]

[0133] The net heat diffusion flux of copper atoms in the second interface metal compound 304 layer is obtained based on the following formula:

[0134]

[0135] Among them, C Cu is the concentration of copper atoms in the first pad 301, C Cu / Sn is the concentration of Cu atoms dissolved in the solder layer 302. Cu / ε and D Cu / η are the thermal diffusion coefficients of copper atoms in the first interface metal compound layer 303 and the second interface metal compound layer 304, respectively.

[0136] By solving formulas (2) to (7) together, the mathematical relationship between the thickness growth rate of the first interface metal compound layer 303 and the second interface metal compound layer 304 at the positive and negative electrodes of the lead-free solder joint and the net Cu flux can be obtained, as shown below:

[0137] For the cathode:

[0138]

[0139] For the anode:

[0140]

[0141]

[0142] in:

[0143]

[0144] In the formula, and Respectively represent the effective charge number of copper atoms in the first interface metal compound layer 303 and the second interface metal compound layer 304. ε and ρ η are the resistivities of the first interface metal compound layer 303 and the second interface metal compound layer 304 in the IMC layer, respectively.

[0145] Step 203: establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer.

[0146] (1) IMC layer growth model under single temperature stress:

[0147] When there is no current stress, the electromigration flux of copper atoms in the lead-free solder joint structure does not exist. Based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer, the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer under temperature stress are obtained over time. Therefore, N in formulas (8) to (11) is ε =N η =N' ε =N' η = 0. By integrating and solving formulas (8), (9), (10), and (11), the functional relationship between the thickness of the first interface metal compound layer 303 and the thickness of the second interface metal compound layer 304 under a single temperature stress as a function of time is obtained. Figure 3 , the first interface metal compound layer 303 and the second interface metal compound layer 304 are respectively arranged on the opposite side surfaces of the solder layer 302. Under a single temperature stress condition, the first interface metal compound layer 303 and the second interface metal compound layer 304 respectively arranged on the opposite side surfaces of the solder layer 302 change in the same manner. The following formula is the relationship between the thickness of the first interface metal compound layer 303 and the second interface metal compound layer 304 on one of the two opposite side surfaces of the solder layer 302 and time, and the relationship on the other side is the same.

[0148]

[0149] Wherein, ε0 and η0 are the initial thicknesses of the first interface metal compound layer 303 (Cu3Sn layer) and the second interface metal compound layer 304 (Cu6Sn5 layer), respectively. Under temperature stress, there is no obvious polarity difference in the growth of the IMC layer at both ends of the lead-free solder joint, so formula (13) can be used to characterize the thickness growth model of the first interface metal compound layer 303 and the second interface metal compound layer 304 under single temperature stress when the solder layer 302 is not completely exhausted.

[0150] (2) IMC layer growth model when temperature, current and stress are coupled:

[0151] When temperature and current stress are coupled, N ε ≠N η ≠N' ε ≠N' η ≠0, based on the relationship between the net flux of the first metal in the first interface metal compound layer between the first pad and the solder layer and the growth rate of the first interface metal compound layer between the first pad and the solder layer, and the relationship between the net flux of the first metal in the second interface metal compound layer between the first pad and the solder layer and the growth rate of the second interface metal compound layer between the first pad and the solder layer, the change of the thickness of the first interface metal compound layer between the first pad and the solder over time under temperature stress and current stress and the change of the thickness of the second interface metal compound layer between the first pad and the solder over time are obtained, and based on the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer The relationship between the net flux of the first metal and the growth rate of the first interface metal compound layer between the second pad and the solder layer and the relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer are obtained to obtain the change of the thickness of the first interface metal compound layer between the second pad and the solder with time and the change of the thickness of the second interface metal compound layer between the second pad and the solder with time under temperature stress and current stress; specifically, by integrating and solving formulas (8), (9), (10) and (11), the functional relationship between the thickness of the first interface metal compound layer 303 and the second interface metal compound layer 304 and the stress time can be obtained:

[0152] For the cathode:

[0153]

[0154] For the anode:

[0155]

[0156] Wherein, C1, C2, C'1 and C'2 are integral constants related to the initial thickness of the IMC layer, respectively. Therefore, formulas (14) and (15) respectively quantitatively characterize the thickness growth model of the first interface metal compound layer 303 and the second interface metal compound layer 304 of the positive and negative electrodes of the solder joint with temperature, current stress and time when the solder layer 302 is not completely exhausted under the coupling of temperature and current stress.

[0157] In order to verify the accuracy of the above growth model, the reported experimental data are compared with the thickness growth prediction results of the Cu6Sn5 layer and the Cu3Sn layer under temperature and current stress in the case of the present invention. Please refer to Table 1, which shows some material parameters required for numerical calculation of a prediction method:

[0158] Table 1. Some material parameters required for numerical calculation of prediction method

[0159]

[0160] C Cu , C Cu / η and C Cu / ε They are 0.84×10 23 , 0.31×10 23 and 0.52×10 23 at. / cm 3 , c Sn About 0.11×10 21 at. / cm 3 Substitute the necessary parameters into formula (13) and compare with the published literature data.

[0161] The above growth model is verified based on some material parameters in Table 1. Figure 5 , Figure 5 FIG. 1 is a schematic diagram of a scenario comparing an experimental result and a predicted result of the growth thickness of an interface metal compound layer in an embodiment, Figure 5 It can be seen that at 155℃( Figure 5 (a) in Figure), 180℃( Figure 5 (b) in the figure shows that under single temperature conditions, the experimental results and predicted results of the growth of Cu3Sn layer and Cu6Sn5 layer in the Cu / Sn / Cu lead-free solder joint structure show good consistency in the thickness of the Cu3Sn layer and Cu6Sn5 layer with the extension of temperature stress action time.

[0162] See also Figure 6 , Figure 6FIG. 1 is a schematic diagram of a scenario comparing an experimental result of the growth thickness of an interface metal compound layer with a predicted result in an embodiment. Figure 6 It can be seen that at a temperature of 155°C and a current density of 0.53×10 4 A / cm 2 Under the condition, the anode end of the Cu / Sn / Cu lead-free solder joint structure ( Figure 6 (a) in the figure) and the cathode end ( Figure 6 The comparison results of the growth thickness verification of the Cu6Sn5 layer and the Cu3Sn layer in (b) show that under the coupling of temperature and current stress for 40 hours, the predicted maximum deviation of the anode Cu6Sn5 layer is about 1.3um, and the maximum deviation of the Cu6Sn5 layer is only 1.1um. It can also be concluded that the growth trend of the Cu6Sn5 layer and the Cu3Sn layer at the positive and negative electrodes of the solder joint is in good agreement with the model results.

[0163] Therefore, combined with Figure 5 and Figure 6 The comparison results show that, no matter under single temperature stress conditions or temperature and current coupled stress conditions, the prediction method of the present application document can accurately calculate the growth model of the thickness of the Cu6Sn5 layer and Cu3Sn layer in the lead-free solder under different temperature and current stresses with stress time, and then can accurately predict the alloying life of the above solder joints based on the above growth model.

[0164] Step 203: predicting the alloying life of the solder joint based on the growth model of the interface metal compound layer.

[0165] (1) Alloying life when tin solder is exhausted:

[0166] Predicting the alloying life of the solder joint when the solder layer is exhausted based on the growth model of the interface metal compound layer includes:

[0167] Based on the initial thickness of the solder layer, the initial thickness of the first interface metal compound layer and the initial thickness of the second interface metal compound layer, the growth thickness of the first interface metal compound layer and the growth thickness of the second interface metal compound layer, the alloying life of the solder joint when the material layer is exhausted is predicted; specifically, as the temperature and current stress time increase, the IMC layer will continue to grow in the lead-free solder joint according to the relationship of formulas (13) to (15). When the solder layer 302 is completely consumed, that is, the solder layer 302 is completely transformed into the first interface metal compound layer Cu3Sn 303 and the second interface metal compound layer Cu6Sn5 304. Based on the initial thickness of the solder layer 302, the initial thickness of the first interface metal compound layer 303 and the initial thickness of the second interface metal compound layer 304, the growth thickness of the first interface metal compound layer 303 and the second interface metal compound layer 304 can be used to determine whether the solder is completely exhausted and transformed at the current moment. The judgment criterion can be determined based on the thickness transformation relationship of the solder layer 302, the second interface metal compound layer 304 and the first interface metal compound layer 303, as shown below:

[0168] a. Consuming 1um solder layer can be converted into about 2.14um first interface metal compound layer;

[0169] b. Consuming 1um solder layer can convert into about 1.4um second interface metal compound layer.

[0170] The standard relationship is mainly determined based on the molar mass, density and conversion ratio of the solder layer 302 , the first interface metal compound layer 303 and the second interface metal compound layer 304 .

[0171] (2) Alloying life when Cu6Sn5 304 is completely converted into the first interface metal compound layer 303 (Cu3Sn layer):

[0172] After the solder layer 302 is completely consumed, the structure of the solder joint organization changes. The schematic diagram of the copper atomic flux is as follows: Figure 7 As shown, Figure 7 The schematic diagram of the structure of another solder joint of an embodiment includes a first solder pad 301, a first interface metal compound layer 303 and a second interface metal compound layer 304. The second interface metal compound layer 304 will be transformed into Cu3Sn in the alloying stage, and the thickness of the second interface metal compound layer 304 decreases with stress time. The specific transformation relationship is as follows:

[0173] 9Cu+Cu6Sn5→5Cu3Sn (16)

[0174] Specifically, after the solder layer 302 is completely consumed, the net flux of copper atoms in the first interface metal compound layer 303 does not change. Therefore, the growth of the thickness of the first interface metal compound layer 303 can still be performed with reference to formulas (13) to (15). Since the net flux of copper atoms in the second interface metal compound layer 304 changes, the thickness of the second interface metal compound layer 304 can be determined by referring to the conversion relationship of formula (16) in combination with the molar mass, density, etc. of the second interface metal compound layer 304 and the first interface metal compound layer 303.

[0175] The alloying life of the solder joint when the second interface metal compound layer 304 is completely transformed into the first interface metal compound layer 303 is predicted based on the growth model of the interface metal compound layer, including:

[0176] The alloying life of the above solder joint when the second interface metal compound layer 304 is completely transformed into the first interface metal compound layer 303 under temperature stress is predicted based on the following formula:

[0177]

[0178] Wherein, 0.68 is the conversion ratio of the thickness of the first interface metal compound layer 303 and the second interface metal compound layer 304. Here, ε0 and η0 respectively represent the thickness of the first interface metal compound layer 303 on one side after the solder layer 302 is fully alloyed and the initial thickness of the second interface metal compound layer 304. Figure 7 After the solder layer 302 is fully alloyed, Figure 3 The second interface metal compound layer 304 on the two opposite sides of the solder layer 302 is integrated into one, and there is only one second interface metal compound layer 304 , but the first interface metal compound layer 303 is still provided with one layer on each of the two opposite sides of the solder layer 302 .

[0179] The alloying life of the above solder joint when the second interface metal compound layer 304 is completely transformed into the first interface metal compound layer 303 under temperature coupled current stress is predicted based on the following formula:

[0180] η=η0-0.68×(Δε Anode +Δε Cathode ) (18)

[0181] Among them, Δε Cathode and Δε Anodeare the growth thickness of the cathode and anode first interface metal compound layers 303, respectively, which can be represented by the ε parameter in formulas (14) and (15) respectively. Based on the conversion relationship of formulas (17) and (18), the alloying life when the second interface metal compound layer 304 in the lead-free solder joint is completely converted into the first interface metal compound layer 303 can be determined.

[0182] because Figure 5 and Figure 6 The accuracy of the above growth model has been verified. The alloying life prediction will be carried out based on the above growth model and through a specific solder joint structure.

[0183] Specifically, a Cu / Sn / Cu lead-free solder joint structure is selected, and the thickness of the tin solder layer 302 in its initial state is 13um, the total thickness of the Cu6Sn5 layer and the Cu3Sn layer are 8um and 4um respectively, and are evenly distributed at both ends of the solder joint. The alloying life is predicted based on the above lead-free solder joint structure.

[0184] See also Figure 8 , Figure 8 FIG. 1 is a schematic diagram of a scenario for predicting the alloying life of a solder joint in an embodiment. Figure 8 It can be seen that Figure 8 Figures (a), (b), (c), and (d) are respectively 155℃ high temperature, 155℃ high temperature coupling current density 1.0×10 5 A / cm 2 , 180℃ high temperature and 180℃ high temperature coupling current density 1.0×10 5 A / cm 2 Under the condition of stress time, the relationship between the thickness of Cu6Sn5 layer, Cu3Sn layer and total IMC layer and stress time is analyzed. The growth curve of IMC layer in this relationship is divided into three stages: in stage I, when the tin solder is not completely consumed, the thickness of Cu6Sn5 layer and Cu3Sn layer keeps growing with the stress; in stage II, when the tin solder is completely consumed and the Cu6Sn5 layer is transformed into the Cu3Sn layer, the thickness of Cu6Sn5 layer decreases with stress time, and the thickness of Cu3Sn layer continues to increase with stress time; in stage III, the Cu6Sn5 layer is completely transformed into the Cu3Sn layer, and the thickness of IMC layer in the solder joint basically no longer changes. Figure 8 The relationship between the thickness of the Cu6Sn5 layer, the Cu3Sn layer and the total IMC layer and the stress time is obtained, and the alloying life of the above lead-free solder joint is shown in Table 2 below. Table 2 is the prediction result of the alloying life of a solder joint.

[0185] Table 2, alloying life prediction results of solder joints

[0186]

[0187] It can be seen from the above process that by numerically quantifying the copper atomic flux under temperature and current stress, the net flux of copper atoms in the Cu3Sn layer and the Cu6Sn5 layer are obtained respectively, and based on the proportional relationship of the copper atomic concentration in different IMC layers, a growth model that can be used to characterize the IMC layer at different alloying stages is formed, thereby realizing the alloying life prediction of lead-free solder joints, making the prediction of the above alloying life more reasonable, thereby improving the above prediction readiness, reducing or avoiding the time and economic costs generated by a large number of life and failure analysis tests, and having huge economic and social benefits.

[0188] This application document has strong general applicability, and performs full life cycle stage prediction using the examples of consumption of the covered solder layer 302, complete conversion of the solder into the second interface metal compound layer 304 and the first interface metal compound layer 303, and complete conversion of the second interface metal compound layer 304 into the first interface metal compound layer 303, which is of great significance for supporting the reliability design of high-performance microelectronic devices.

[0189] It should be understood that, although the steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indications of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0190] Based on the same inventive concept, the embodiment of the present application also provides a device for predicting the alloying life of a solder joint for implementing the above-mentioned method for predicting the alloying life of a solder joint. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in the embodiment of the device for predicting the alloying life of one or more solder joints provided below can refer to the limitations of the method for predicting the alloying life of a solder joint above, and will not be repeated here.

[0191] In one embodiment, Fig. 9 As shown, Fig. 9 In one embodiment, a device 900 for predicting the alloying life of a solder joint is provided. The device comprises: an acquisition module 901, a first processing module 902, a second processing module 903 and a third processing module 904, wherein:

[0192] An acquisition module 901 is used to acquire the flux of the first metal in the pad 201, the solder layer 202 and the interface metal compound layer;

[0193] A first processing module 902 is used to obtain a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0194] A second processing module 903 is used to establish a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0195] The third processing module 904 is used to predict the alloying life of the solder joint based on the growth model of the interface metal compound layer.

[0196] Each module in the above-mentioned device for predicting the alloying life of a solder joint can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each of the above modules.

[0197] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Fig.10 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store flux, net flux, growth rate, growth model and related calculation methods. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for predicting the alloying life of a solder joint is implemented. The above-mentioned solder joint includes a solder pad of a first metal and a solder layer of a second metal, and the above-mentioned solder pad and the above-mentioned solder layer are alloyed to generate an interface metal compound layer including the first metal and the second metal; the above-mentioned method includes:

[0198] Obtaining the flux of the first metal in the pad, the solder layer and the interface metal compound layer;

[0199] Obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer;

[0200] Establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer;

[0201] The alloying life of the solder joint is predicted based on the growth model of the interface metal compound layer.

[0202] In one embodiment, the above-mentioned solder pad includes a first solder pad and a second solder pad, and the above-mentioned solder layer is located between the above-mentioned first solder pad and the above-mentioned second solder pad; the above-mentioned interface metal compound layer is located between the above-mentioned first solder pad and the solder layer and between the above-mentioned second solder pad and the above-mentioned solder layer, and the above-mentioned interface metal compound layer includes a first interface metal compound layer and a second interface metal compound layer, and the above-mentioned first interface metal compound layer and the above-mentioned second interface metal compound layer both include a first metal and a second metal.

[0203] It can be seen that the above-mentioned interface metal compound layer includes the above-mentioned first interface metal compound layer and the above-mentioned second interface metal compound layer, rather than a single metal compound layer, which makes the obtained above-mentioned growth model more reasonable, and thus the prediction of the above-mentioned alloying life is more accurate, which is of great significance for supporting the reliability design of high-performance devices.

[0204] In one embodiment, the first pad includes a cathode pad, the second pad includes an anode pad; the first metal includes copper 301, and the second metal includes tin 302; the net flux of the first metal in the interface metal compound layer and the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer include:

[0205] The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the first pad and the solder layer and the flux of the first metal in the first pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer:

[0206]

[0207]

[0208] in,

[0209] In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, represents the thermal diffusion flux of Cu from the first pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of Cu from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of Cu from the second interface metal compound layer to the second metal due to the atomic concentration gradient, is the Cu electromigration flux in the first interface metal compound layer, is the Cu electromigration flux in the second interface metal compound layer, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer, D Cu / ε represents the diffusion coefficient of the copper atoms in the first interface metal compound layer, D Cu / η represents the diffusion coefficient of the copper atoms in the second interface metal compound layer, is the effective charge number of the copper atoms in the first interfacial metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer, e is the unit charge, and ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, j is the average current density, k is the Boltzmann constant, and T is the Kelvin temperature of the solder joint.

[0210] The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the second pad and the solder layer and the flux of the first metal in the second pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer:

[0211]

[0212]

[0213] in,

[0214] In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, ε represents the thickness of the first interface metal compound layer, η represents the thickness of the second interface metal compound layer, represents the thermal diffusion flux of Cu from the first pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of Cu from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of Cu from the second interface metal compound layer to the second metal layer due to the atomic concentration gradient, is the Cu electromigration flux in the first interface metal compound layer, is the Cu electromigration flux in the second interface metal compound layer, is the Cu electromigration flux in the second metal layer, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer, C Cu / Sn represents the concentration of the copper atoms in the second metal layer, D Cu / ε represents the diffusion coefficient of the copper atoms in the first interface metal compound layer, D Cu / η represents the diffusion coefficient of the copper atoms in the second interface metal compound layer, D Cu / Sn represents the diffusion coefficient of the copper atoms in the second metal layer, is the effective charge number of the copper atoms in the first interfacial metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer, is the effective charge number of the copper atom in the second metal layer, e is the unit charge, and ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, ρ Sn is the resistivity of the second metal layer, j is the average current density, k is the Boltzmann constant, and T is the Kelvin temperature of the solder joint.

[0215] The net heat diffusion flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula:

[0216]

[0217] Among them, C Cu is the concentration of copper atoms in the Cu pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer.

[0218] The net heat diffusion flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula:

[0219]

[0220] Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn is the concentration of copper atoms dissolved in tin solder, D Cu / η is the thermal diffusion coefficient of copper atoms in the above-mentioned second interface metal compound layer.

[0221] By solving the above formulas, the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer is obtained.

[0222] In one embodiment, the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer includes: obtaining the relationship between the net flux of the first metal in the first interface metal compound layer between the first pad and the solder layer and the growth rate of the first interface metal compound layer between the first pad and the solder layer based on the following formula:

[0223]

[0224] in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, C Cu is the concentration of copper atoms in the Cu pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer; and the relationship between the net flux of the first metal in the second interface metal compound layer between the first pad and the solder layer and the growth rate of the second interface metal compound layer between the first pad and the solder layer is obtained based on the following formula:

[0225]

[0226] in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, C Cu / Sn is the concentration of copper atoms dissolved in tin solder, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer;

[0227] The relationship between the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer and the growth rate of the first interface metal compound layer between the second pad and the solder layer is obtained based on the following formula:

[0228]

[0229] in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, C Cu / Sn is the concentration of copper atoms dissolved in tin solder, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; and the relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer is obtained based on the following formula:

[0230]

[0231] in, In the formula, C Cu / Sn is the concentration of copper atoms dissolved in tin solder, D Cu / Sn is the thermal diffusion coefficient of copper atoms in the above solder layer, represents the effective charge number of copper atoms in the above solder layer, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ηis the resistivity of the second interface metal compound layer, ρ Sn is the resistivity of the solder layer.

[0232] In one embodiment, the growth model of the interface metal compound layer is established based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer, including: obtaining the change of the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer over time under temperature stress based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer, and the formula for the change of the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer over time under the temperature stress is:

[0233]

[0234] Wherein, ε0 is the initial thickness of the first interface metal compound layer, and η0 is the initial thickness of the second interface metal compound layer. It can be seen that this method can obtain the thickness growth relationship between the first interface metal compound layer 303 and the second interface metal compound layer 304 under a single temperature stress when the solder layer 302 is not completely consumed, thereby making the above growth model more reasonable and the above alloying life prediction more accurate.

[0235] In one embodiment, the above-mentioned establishment of the growth model of the interface metal compound layer based on the relationship between the net flux of the above-mentioned first metal and the growth rate of the above-mentioned interface metal compound layer includes: based on the relationship between the net flux of the above-mentioned first metal in the above-mentioned first interface metal compound layer between the above-mentioned first pad and the above-mentioned solder layer and the growth rate of the above-mentioned first interface metal compound layer between the above-mentioned first pad and the above-mentioned solder layer and the relationship between the net flux of the above-mentioned first metal in the above-mentioned second interface metal compound layer between the above-mentioned first pad and the above-mentioned solder layer and the growth rate of the above-mentioned second interface metal compound layer between the above-mentioned first pad and the above-mentioned solder layer, obtaining the formula for the change of the thickness of the first interface metal compound layer between the above-mentioned first pad and the above-mentioned solder with time and the change of the thickness of the above-mentioned second interface metal compound layer between the above-mentioned first pad and the above-mentioned solder with time under temperature stress coupled current stress:

[0236]

[0237] Wherein, C1 is an integral constant related to the initial thickness of the first interface metal compound layer between the first pad and the solder layer, and C2 is an integral constant related to the initial thickness of the second interface metal compound layer between the first pad and the solder layer;

[0238] Based on the relationship between the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer and the growth rate of the first interface metal compound layer between the second pad and the solder layer, and the relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer, the formulas for the change of the thickness of the first interface metal compound layer between the second pad and the solder over time and the change of the thickness of the second interface metal compound layer between the second pad and the solder over time under temperature stress coupled current stress are obtained:

[0239]

[0240] Wherein, C'1 and C'2 are integral constants related to the initial thickness of the first interface metal compound layer between the second pad and the solder layer, and C'1 is an integral constant related to the initial thickness of the second interface metal compound layer between the second pad and the solder layer;

[0241] In one of the embodiments, the above-mentioned prediction of the alloying life of the above-mentioned solder joint based on the growth model of the above-mentioned interface metal compound layer includes: predicting the alloying life of the above-mentioned solder joint when the above-mentioned solder layer is exhausted based on the growth model of the above-mentioned interface metal compound layer, including: predicting the alloying life of the above-mentioned solder joint when the material layer is exhausted based on the initial thickness of the above-mentioned solder layer, the initial thickness of the above-mentioned first interface metal compound layer and the initial thickness of the above-mentioned second interface metal compound layer, the growth thickness of the above-mentioned first interface metal compound layer and the growth thickness of the above-mentioned second interface metal compound layer.

[0242] In one embodiment, the above-mentioned prediction of the alloying life of the above-mentioned solder joint based on the growth model of the above-mentioned interface metal compound layer includes: predicting the alloying life of the above-mentioned solder joint when the above-mentioned second interface metal compound layer is completely converted into the above-mentioned first interface metal compound layer based on the growth model of the above-mentioned interface metal compound layer, including: predicting the alloying life of the above-mentioned solder joint when the above-mentioned second interface metal compound layer is completely converted into the above-mentioned first interface metal compound layer under temperature stress based on the following formula:

[0243]

[0244] Wherein, 0.68 is the conversion ratio of the thickness of the first interface metal compound layer 303 and the second interface metal compound layer 304. Here, ε0 represents the initial thickness of the first interface metal compound layer when the tin solder is completely consumed, and η0 represents the initial thickness of the second interface metal compound layer when the solder is completely consumed.

[0245] The alloying life of the solder joint when the second interface metal compound layer is completely transformed into the first interface metal compound layer under temperature stress coupled current stress is predicted based on the following formula:

[0246] η=η0-0.68×(Δε Anode +Δε Cathode )

[0247] Among them, Δε Cathode is the growth thickness of the first interface metal compound layer of the cathode when the solder is completely consumed, Δε Anode It is the growth thickness of the above-mentioned first interface metal compound layer in the anode when the solder is completely consumed.

[0248] It can be seen that this method can solve the problem of mutual transformation between different types of IMC layers, thereby being able to more accurately predict the alloying life of the above-mentioned solder joints.

[0249] The alloying life prediction method, device, computer equipment, storage medium and computer program product of the above-mentioned solder joint obtain the net flux of the above-mentioned first metal and the relationship between the net flux of the above-mentioned first metal and the growth rate of the above-mentioned interface metal compound layer according to the flux of the above-mentioned first metal, and then obtain the growth model of the net flux of the above-mentioned first metal and the above-mentioned interface metal compound layer according to the above-mentioned growth rate, and predict the alloying life of the above-mentioned solder joint based on the above-mentioned growth model. It can be seen that the above-mentioned growth model is gradually obtained based on the flux of the above-mentioned first metal, so that the prediction of the above-mentioned alloying life is more reasonable, thereby being able to improve the above-mentioned prediction readiness, thereby reducing or avoiding a large amount of time and economic costs generated by life and failure analysis tests, and having huge economic and social benefits.

[0250] Those skilled in the art will understand that Fig.10 The structure shown is merely a block diagram of a portion of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0251] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0252] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0253] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0254] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the above-mentioned computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0255] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0256] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for predicting the alloying life of a solder joint, characterized in that: The solder joint comprises a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer comprising the first metal and the second metal; the method comprises: Obtaining the flux of the first metal in the pad, the solder layer, and the interface metal compound layer; Obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer; Establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer; Predicting the alloying life of the solder joint based on the growth model of the interface metal compound layer; The pad includes a first pad and a second pad, the solder layer is located between the first pad and the second pad, the interface metal compound layer is located between the first pad and the solder layer and between the second pad and the solder layer, the interface metal compound layer includes a first interface metal compound layer and a second interface metal compound layer, the first interface metal compound layer and the second interface metal compound layer are both reaction products of the first metal and the second metal, the first interface metal compound layer includes a Cu3Sn layer, and the second interface metal compound layer includes a Cu6Sn5 layer; The first pad includes a cathode pad, the second pad includes an anode pad, the first metal includes copper, the second metal includes tin, and the obtaining of the net flux of the first metal in the interface metal compound layer and the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer includes: The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the first pad and the solder layer and the flux of the first metal in the first pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, ε and η represent the thickness of the first interface metal compound layer and the second interface metal compound layer, respectively, represents the thermal diffusion flux of copper from the first pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the second interface metal compound layer to the second metal layer caused by the atomic concentration gradient, is the copper electromigration flux in the first interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second interface metal compound layer caused by electron wind force; The net electromigration flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, D Cu / ε represents the thermal diffusion coefficient of the copper atoms in the first interface metal compound layer, is the effective charge number of the copper atoms in the first interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net electromigration flux of the first metal in the first pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer, D Cu / η represents the thermal diffusion coefficient of the copper atoms in the second interface metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net heat diffusion flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer; The net heat diffusion flux of the first metal in the first pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn represents the concentration of copper atoms dissolved in the solder layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer; The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the second pad and the solder layer and the flux of the first metal in the second pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, ε represents the thickness of the first interface metal compound layer, η represents the thickness of the second interface metal compound layer, represents the thermal diffusion flux of copper from the second pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the second interface metal compound layer to the second metal layer caused by the atomic concentration gradient, is the copper electromigration flux in the first interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second interface metal compound layer caused by electron wind force, is the copper electromigration flux in the solder layer caused by electron wind force; The net electromigration flux of the first metal in the second pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer; D Cu / ε represents the thermal diffusion coefficient of the copper atoms in the first interface metal compound layer, D Cu / η represents the thermal diffusion coefficient of the copper atoms in the second interface metal compound layer; is the effective charge number of the copper atoms in the first interfacial metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer; ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net electromigration flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / Sn represents the concentration of the copper atoms dissolved in the solder layer, D Cu / Sn represents the thermal diffusion coefficient of the copper atoms in the solder layer, is the effective charge number of the copper atoms in the solder layer; Sn is the resistivity of the solder layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net heat diffusion flux of the first metal in the second pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer; The net heat diffusion flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn represents the concentration of copper atoms dissolved in the solder layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer.

2. The method according to claim 1, characterized in that The relationship between the net flux of the first metal in the interface metal compound layer and the growth rate of the interface metal compound layer includes: The relationship between the net flux of the first metal in the first interface metal compound layer between the first pad and the solder layer and the growth rate of the first interface metal compound layer between the first pad and the solder layer is obtained based on the following formula: in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The relationship between the net flux of the first metal in the second interface metal compound layer between the first pad and the solder layer and the growth rate of the second interface metal compound layer between the first pad and the solder layer is obtained based on the following formula: in, In the formula, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer, represents the effective charge number of copper atoms in the solder layer, C Cu / Sn represents the concentration of the copper atoms dissolved in the solder layer, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The relationship between the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer and the growth rate of the first interface metal compound layer between the second pad and the solder layer is obtained based on the following formula: in, In the formula, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the first interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer is obtained based on the following formula: in, In the formula, C Cu / Sn represents the concentration of copper atoms dissolved in the solder layer, D Cu / Sn is the thermal diffusion coefficient of copper atoms in the solder layer, represents the effective charge number of copper atoms in the solder layer, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer, represents the effective charge number of copper atoms in the second interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer, ρ Sn is the resistivity of the solder layer.

3. The method according to claim 2, characterized in that The step of establishing a growth model of the interface metal compound layer based on a relationship between the net flux of the first metal and the growth rate of the interface metal compound layer comprises: Based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer, the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer under temperature stress are obtained. The formula for the thickness of the first interface metal compound layer and the thickness of the second interface metal compound layer under temperature stress is: Wherein, ε0 is the initial thickness of the first interface metal compound layer, and η0 is the initial thickness of the second interface metal compound layer.

4. The method according to claim 3, characterized in that: The step of establishing a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer comprises: Based on the relationship between the net flux of the first metal in the first interface metal compound layer between the first pad and the solder layer and the growth rate of the first interface metal compound layer between the first pad and the solder layer, and the relationship between the net flux of the first metal in the second interface metal compound layer between the first pad and the solder layer and the growth rate of the second interface metal compound layer between the first pad and the solder layer, a formula for the change with time of the thickness of the first interface metal compound layer between the first pad and the solder and the change with time of the thickness of the second interface metal compound layer between the first pad and the solder under temperature stress coupled current stress is obtained: Wherein, C1 is an integral constant related to the initial thickness of the first interface metal compound layer between the first pad and the solder layer, and C2 is an integral constant related to the initial thickness of the second interface metal compound layer between the first pad and the solder layer; Based on the relationship between the net flux of the first metal in the first interface metal compound layer between the second pad and the solder layer and the growth rate of the first interface metal compound layer between the second pad and the solder layer, and the relationship between the net flux of the first metal in the second interface metal compound layer between the second pad and the solder layer and the growth rate of the second interface metal compound layer between the second pad and the solder layer, a formula for the change with time of the thickness of the first interface metal compound layer between the second pad and the solder and the change with time of the thickness of the second interface metal compound layer between the second pad and the solder under temperature stress coupled current stress is obtained: Wherein, C'1 and C'2 are integral constants related to the initial thickness of the first interface metal compound layer between the second pad and the solder layer, and C'1 and C'2 are integral constants related to the initial thickness of the second interface metal compound layer between the second pad and the solder layer.

5. The method according to claim 4, characterized in that The predicting of the alloying life of the solder joint based on the growth model of the interface metal compound layer comprises: predicting the alloying life of the solder joint when the second metal solder layer is exhausted based on the growth model of the interface metal compound layer, comprising: Based on the initial thickness of the second metal solder layer, the initial thickness of the first interface metal compound layer and the initial thickness of the second interface metal compound layer, the growth thickness of the first interface metal compound layer and the growth thickness of the second interface metal compound layer, the alloying life of the solder joint when the second metal solder layer is exhausted is predicted.

6. The method according to claim 5, characterized in that The predicting of the alloying life of the solder joint based on the growth model of the interface metal compound layer includes: predicting the alloying life of the solder joint when the second interface metal compound layer is completely transformed into the first interface metal compound layer based on the growth model of the interface metal compound layer, including: The alloying life of the solder joint under temperature stress when the second interface metal compound layer is completely transformed into the first interface metal compound layer is predicted based on the following formula: Wherein, 0.68 is the conversion ratio of the thickness of the first interface metal compound layer and the second interface metal compound layer, where ε0 represents the initial thickness of the first interface metal compound layer when the solder is completely exhausted, and η0 represents the initial thickness of the second interface metal compound layer when the solder is completely exhausted; The alloying life of the solder joint when the second interface metal compound layer is completely transformed into the first interface metal compound layer under temperature stress coupled current stress is predicted based on the following formula: η=η0-0.68×(δ Anode +No Cathode ) Among them, Δε Cathode is the growth thickness of the first interface metal compound layer between the first pad and the solder layer when the solder is completely consumed, Δε Anode is the growth thickness of the first interface metal compound layer between the second pad and the solder layer when the solder is completely consumed.

7. A device for predicting alloying life of a solder joint, characterized in that: The solder joint comprises a solder pad of a first metal and a solder layer of a second metal, and the solder pad and the solder layer are alloyed to generate an interface metal compound layer comprising the first metal and the second metal; the device comprises: An acquisition module, used for acquiring the flux of the first metal in the pad, the solder layer and the interface metal compound layer; A first processing module, used for obtaining a net flux of the first metal in the interface metal compound layer and a relationship between the net flux of the first metal and a growth rate of the interface metal compound layer; A second processing module is used to establish a growth model of the interface metal compound layer based on the relationship between the net flux of the first metal and the growth rate of the interface metal compound layer; A third processing module, configured to predict the alloying life of the solder joint based on a growth model of the interface metal compound layer; The pad includes a first pad and a second pad, the solder layer is located between the first pad and the second pad, the interface metal compound layer is located between the first pad and the solder layer and between the second pad and the solder layer, the interface metal compound layer includes a first interface metal compound layer and a second interface metal compound layer, the first interface metal compound layer and the second interface metal compound layer are both reaction products of the first metal and the second metal, the first interface metal compound layer includes a Cu3Sn layer, and the second interface metal compound layer includes a Cu6Sn5 layer; The first pad includes a cathode pad, the second pad includes an anode pad, the first metal includes copper, the second metal includes tin, and the first processing module is further configured to: The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the first pad and the solder layer and the flux of the first metal in the first pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, ε and η represent the thickness of the first interface metal compound layer and the second interface metal compound layer, respectively, represents the thermal diffusion flux of copper from the first pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the second interface metal compound layer to the second metal layer caused by the atomic concentration gradient, is the copper electromigration flux in the first interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second interface metal compound layer caused by electron wind force; The net electromigration flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, D Cu / ε represents the thermal diffusion coefficient of the copper atoms in the first interface metal compound layer, is the effective charge number of the copper atoms in the first interface metal compound layer, ρ ε is the resistivity of the first interface metal compound layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net electromigration flux of the first metal in the first pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer, D Cu / η represents the thermal diffusion coefficient of the copper atoms in the second interface metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net heat diffusion flux of the first metal in the first pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer; The net heat diffusion flux of the first metal in the first pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn represents the concentration of copper atoms dissolved in the solder layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer; The following relationship is established between the thickness change of the first interface metal compound layer and the second interface metal compound layer between the second pad and the solder layer and the flux of the first metal in the second pad, the first interface metal compound layer, the second interface metal compound layer and the solder layer: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer, ε represents the thickness of the first interface metal compound layer, η represents the thickness of the second interface metal compound layer, represents the thermal diffusion flux of copper from the second pad to the first interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the first interface metal compound layer to the second interface metal compound layer caused by the atomic concentration gradient, represents the thermal diffusion flux of copper from the second interface metal compound layer to the second metal layer caused by the atomic concentration gradient, is the copper electromigration flux in the first interface metal compound layer caused by electron wind force, is the copper electromigration flux in the second interface metal compound layer caused by electron wind force, is the copper electromigration flux in the solder layer caused by electron wind force; The net electromigration flux of the first metal in the second pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of the copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of the copper atoms in the second interface metal compound layer; D Cu / ε represents the thermal diffusion coefficient of the copper atoms in the first interface metal compound layer, D Cu / η represents the thermal diffusion coefficient of the copper atoms in the second interface metal compound layer; is the effective charge number of the copper atoms in the first interfacial metal compound layer, is the effective charge number of the copper atoms in the second interface metal compound layer; ε is the resistivity of the first interface metal compound layer, ρ η is the resistivity of the second interface metal compound layer; k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net electromigration flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / Sn represents the concentration of the copper atoms dissolved in the solder layer, D Cu / Sn represents the thermal diffusion coefficient of the copper atoms in the solder layer, is the effective charge number of the copper atoms in the solder layer; Sn is the resistivity of the solder layer, k is the Boltzmann constant, T is the Kelvin temperature of the solder joint, e is the unit charge, and j is the average current density; The net heat diffusion flux of the first metal in the second pad in the first interface metal compound layer is obtained based on the following formula: Among them, C Cu is the concentration of copper atoms in the copper pad, D Cu / ε is the thermal diffusion coefficient of copper atoms in the first interface metal compound layer, C Cu / η represents the concentration of copper atoms in the second interface metal compound layer; The net heat diffusion flux of the first metal in the second pad in the second interface metal compound layer is obtained based on the following formula: Among them, C Cu / ε represents the concentration of copper atoms in the first interface metal compound layer, C Cu / Sn represents the concentration of copper atoms dissolved in the solder layer, D Cu / η is the thermal diffusion coefficient of copper atoms in the second interface metal compound layer.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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