Welding method and device

Abstract

The invention discloses a welding method and device. The method comprises the steps that the gravity center position of a first to-be-welded structure is obtained, wherein the first to-be-welded structure comprises a first bonding pad and a plurality of components arranged on the first bonding pad; under the condition that the gravity center of the first to-be-welded structure deviates from the center of the first bonding pad, first position information and volume information of a balancing weight needing to be arranged on the first bonding pad when the gravity center of the first to-be-welded structure coincides with the center are calculated according to the densities and volumes corresponding to the multiple components; a target tool is arranged on the first to-be-welded structure, the volume of a target balancing weight on the target tool is determined according to the volume information, and the orthographic projection of the position of the target balancing weight on the target tool on the first to-be-welded structure coincides with the first position information; and welding the first to-be-welded structure and the second to-be-welded structure. According to the embodiment of the invention, the problem of welding layer inclination caused by structure gravity center shift of the to-be-welded part can be solved, and the reliability of a welded semiconductor product is ensured.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor packaging technology, and in particular, relates to a welding method and device. Background Art

[0002] As power modules develop towards high power and large size, higher requirements are also put forward for the reliability of the solder layer. The flatness and thickness of the solder layer have a great influence on the reliability of the solder layer. When the product is subjected to temperature changes, resulting in thermal expansion and contraction, or when the product is subjected to mechanical external force impact, the thinner solder layer will produce greater strain than the relatively thicker solder layer, and face a higher risk of failure. In the packaging structure, the chip layout, circuit distribution, and component distribution on the pads of the parts to be welded are becoming more and more complex, and it is difficult to form a symmetrical distribution, resulting in uneven weight distribution of the parts to be welded, the center of gravity is offset, and uneven pressure on the solder layer is caused, causing the solder layer to tilt, resulting in an uneven solder layer, that is, the solder layer on one side becomes thinner.

[0003] At present, the tilting of the solder layer is usually suppressed by designing corresponding jigs and fixtures to apply uniform pressure to the workpiece to be welded. However, if the uniform pressure is applied to the workpiece as a whole, if the center of gravity of the workpiece is seriously offset, the jig will be lifted up and tilted together with the workpiece to be welded, so that the final result is still a tilted solder layer. In addition, if the weight of the jig is too large, the solder layer may overflow, which will make it impossible to effectively solve the problem of solder layer flatness, affecting the overall reliability of the semiconductor product formed by welding the workpiece to be welded. Summary of the invention

[0004] The embodiments of the present application provide a welding method and device, which can solve the problem of welding layer tilt caused by the center of gravity offset of the welded structure, and ensure the overall reliability of the semiconductor product constructed by welding.

[0005] In a first aspect, an embodiment of the present application provides a welding method, the method comprising:

[0006] Obtaining a center of gravity position of a first structure to be welded, wherein the first structure to be welded includes a first welding pad and a plurality of components disposed on the first welding pad;

[0007] In the case where the center of gravity of the first structure to be welded deviates from the center of the first welding pad, calculating first position information and volume information of a counterweight block that needs to be set on the first welding pad when the center of gravity of the first structure to be welded coincides with the center according to the density and volume corresponding to each of the plurality of components;

[0008] Based on the first position information and volume information, a target tool is set on the first structure to be welded, the volume of a target counterweight on the target tool is determined according to the volume information, and the orthographic projection of the position of the target counterweight on the target tool on the first structure to be welded coincides with the first position information;

[0009] The first structure to be welded and the second structure to be welded are welded.

[0010] In a second aspect, an embodiment of the present application provides a welding device, the device comprising:

[0011] An acquisition module, used for acquiring a center of gravity position of a first structure to be welded, wherein the first structure to be welded includes a first welding pad and a plurality of components arranged on the first welding pad;

[0012] a calculation module, configured to calculate, when the center of gravity of the first structure to be welded deviates from the center of the first welding pad, first position information and volume information of a counterweight block that needs to be set on the first welding pad when the center of gravity of the first structure to be welded coincides with the center, according to the densities and volumes corresponding to the plurality of components;

[0013] a setting module, configured to set a target tooling on the first structure to be welded based on the first position information and the volume information, wherein the volume of a target counterweight on the target tooling is determined according to the volume information, and an orthographic projection of the position of the target counterweight on the target tooling on the first structure to be welded coincides with the first position information;

[0014] The welding module is used to weld the first structure to be welded and the second structure to be welded.

[0015] The welding method and device of the embodiment of the present application obtain the center of gravity position of the structure to be welded including the welding pad and several components thereon, and when there is a deviation between the center of gravity of the structure to be welded and the center of the welding pad, determine the information of the counterweight block that needs to be set on the welding pad when the center of gravity coincides with the center according to the information of several components; further, based on the counterweight block information, a target tooling including the counterweight block is set on the structure to be welded, so that the original center of gravity offset of the structure to be welded before the target tooling is set is offset; thereby, when welding the structure to be welded, the center of gravity above the welding layer is adjusted to the horizontal center, which can solve the problem of welding layer tilting and ensure that the flatness of the welding layer is effectively controlled. Moreover, since there is no need to require the tooling to be heavy, there is no risk of overflow, so as to ensure the overall reliability of the semiconductor product constructed by welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1A is a front view of an exemplary packaging structure provided in an embodiment of the present application;

[0018] Figure 1B is a top view of an exemplary packaging structure provided in an embodiment of the present application;

[0019] Figure 2 It is a schematic diagram of a welding method provided in an embodiment of the present application;

[0020] Figure 3 It is a flow chart of a method for calculating first position information and volume information of a counterweight block that needs to be set on a first welding pad when the center of gravity of a first structure to be welded coincides with the center provided by an embodiment of the present application;

[0021] Figure 4A is a front view of a main structure of a semiconductor device welded together when the number of counterweight blocks provided in an embodiment of the present application is one;

[0022] Figure 4B is a top view of a main structure of a semiconductor device welded together when the number of counterweight blocks provided in an embodiment of the present application is one;

[0023] Figure 4C The embodiment of this application provides Figure 4B Section A main section view;

[0024] Figure 5 It is a flow chart of another method for calculating first position information and volume information of a counterweight block that needs to be set on a first welding pad when the center of gravity of a first structure to be welded coincides with the center provided by an embodiment of the present application;

[0025] Fig. 6A is a front view of a main structure of a semiconductor device welded together when the number of counterweight blocks provided in an embodiment of the present application is at least two;

[0026] Figure 6B is a top view of a main structure of a semiconductor device welded together when the number of counterweight blocks provided in an embodiment of the present application is at least two;

[0027] Figure 6C The embodiment of this application provides Figure 6B Section B main section view;

[0028] Figure 7 It is a structural schematic diagram of a welding device provided in an embodiment of the present application;

[0029] Figure 8 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0031] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0032] In recent years, with the transformation and upgrading of the domestic economic structure, the strong development of emerging industries such as the Internet of Things, new energy, new materials, energy conservation and environmental protection, and a new generation of communication networks has greatly increased the requirements for power semiconductor products. Integrating two or more modules to achieve higher current and high power requirements is currently a major direction for improving the performance of power modules. However, this approach poses a higher challenge to the reliability of power modules and also puts forward higher requirements for the welding process.

[0033] Therefore, as power modules develop towards high power and large size, higher requirements are also put forward for the reliability of the solder layer. The flatness and thickness of the solder layer have a great influence on the reliability of the solder layer. When the product is subjected to temperature changes, resulting in thermal expansion and contraction, or when the product is subjected to mechanical external force impact, the thinner solder layer will produce greater strain than the relatively thicker solder layer, and face a higher risk of failure. In the packaging structure, the chip layout, circuit distribution, and component distribution on the pads of the parts to be welded are becoming more and more complex, and it is difficult to form a symmetrical distribution, resulting in uneven weight distribution of the parts to be welded, the center of gravity is offset, and uneven pressure on the solder layer is caused, causing the solder layer to tilt, resulting in an uneven solder layer, that is, the solder layer on one side becomes thinner.

[0034] refer to Figure 1A and Figure 1B , are the front view and top view of an exemplary packaging structure. Figure 1AAs shown, the lower layer of the weld layer 140 formed by the solder used in the welding process is the lower layer of the welded part 110, and the upper layer of the weld layer 140 is the upper layer of the welded part 120 and a plurality of components 130 distributed on the upper layer of the welded part 120. Among them, the lower layer of the welded part 110 is the welded part below the weld layer 140 among the welded parts, and can be the lower metal bottom plate; the upper layer of the welded part 120 is the eccentric welded part located above the weld layer 140 among the welded parts; the components 130 include but are not limited to electronic devices such as chips, capacitors, and resistors.

[0035] More specifically, Figure 1B As shown, the components 130 are asymmetrically distributed on the upper layer to be welded 120, resulting in uneven weight distribution of the upper layer to be welded 120 as a whole. Then, based on the pre-constructed xy coordinate system (the origin of the xy coordinate system is the center O of the upper layer to be welded 120, and the horizontal plane corresponding to the xy coordinate system is the surface of the upper layer to be welded 120 away from the welding layer 140), the center of gravity M of the upper layer to be welded 120 as a whole is determined. It can be seen that the center of gravity M deviates from the center O, that is, the center of gravity is offset. As a result, uneven pressure is applied to the welding layer 140, causing the welding layer 140 to tilt.

[0036] At present, the tilting of the solder layer is usually suppressed by designing corresponding jigs and fixtures to apply uniform pressure to the workpiece to be welded. However, if the uniform pressure is applied to the workpiece as a whole, if the center of gravity of the workpiece is seriously offset, the jig will be lifted up and tilted together with the workpiece to be welded, so that the final result is still a tilted solder layer. In addition, if the weight of the jig is too large, the solder layer may overflow, which will make it impossible to effectively solve the problem of solder layer flatness, affecting the overall reliability of the semiconductor product formed by welding the workpiece to be welded.

[0037] In order to solve the problems of the related art, an embodiment of the present application provides a welding method and a welding device.

[0038] The welding method provided in the embodiment of the present application is described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0039] Figure 2 FIG. 2 is a schematic diagram showing a flow chart of a welding method according to an embodiment of the present application. Figure 2 As shown, the welding method may specifically include the following steps:

[0040] S201, obtaining a center of gravity position of a first structure to be welded, where the first structure to be welded includes a first welding pad and a plurality of components disposed on the first welding pad;

[0041] S202, when there is a deviation between the center of gravity of the first structure to be welded and the center of the first welding pad, calculating first position information and volume information of a counterweight block that needs to be set on the first welding pad when the center of gravity of the first structure to be welded coincides with the center according to the densities and volumes corresponding to the plurality of components;

[0042] S203, based on the first position information and the volume information, setting a target tooling on the first structure to be welded, the volume of a target counterweight on the target tooling is determined according to the volume information, and the orthographic projection of the position of the target counterweight on the target tooling on the first structure to be welded coincides with the first position information;

[0043] S204, welding the first structure to be welded and the second structure to be welded.

[0044] Thus, the center of gravity position of the structure to be welded including the welding pad and several components thereon is obtained, and when there is a deviation between the center of gravity of the structure to be welded and the center of the welding pad, the information of the counterweight block that needs to be set on the welding pad when the center of gravity coincides with the center is determined according to the information of several components; further, based on the counterweight block information, a target tooling including a counterweight block is set on the structure to be welded, so that the original center of gravity offset of the structure to be welded before the target tooling is set is offset; thereby, when welding the structure to be welded, the center of gravity above the welding layer is adjusted to the horizontal center, which can solve the problem of welding layer tilting and ensure that the flatness of the welding layer is effectively controlled. Moreover, since there is no need to require the tooling to be heavy, there is no risk of overflow, so as to ensure the overall reliability of the semiconductor product constructed by welding.

[0045] The specific implementation methods of the above steps are introduced below.

[0046] In some embodiments, in S201, the mass distribution of the first pad is uniform, the masses of the plurality of components are different, or the plurality of components are asymmetrically distributed on the first pad. Then, the center of gravity position of the first structure to be welded can be determined by obtaining the second position information of the center corresponding to each of the plurality of components, and then according to the second position information corresponding to each of the plurality of components, density and volume, and the moment balance principle.

[0047] In specific implementation, by establishing a coordinate system, the coordinates of the center points of each component can be obtained according to the positions of each component relative to the origin of the coordinate system, and the second position information of the centers corresponding to the components can be obtained. Specifically, the center of the first pad is determined as the origin of the coordinate system, and the first surface of the first pad is determined as the horizontal plane corresponding to the coordinate system, wherein the first surface is the surface of the first pad away from the solder layer preformed by the solder used in the welding process.

[0048] Furthermore, assuming that the second position information (x i ,yi ), ρ i represents the density of the ith component, V i represents the volume of the i-th component, then according to the moment balance principle, the total center of mass of several components can be calculated as:

[0049]

[0050] It can be understood that, since the mass distribution of the first pad is uniform, the total center of mass of the components obtained by the above calculation is the center of gravity of the first structure to be welded. It should be noted that if the first pad itself is eccentric, it can be regarded as a component and substituted into formulas (1) and (2); in addition, to simplify the calculation, the component welding layer that has little effect on the result can be ignored for the center of gravity calculation of this embodiment.

[0051] In some embodiments, in S102, the material of the counterweight block includes, but is not limited to, copper, aluminum, and other materials; the shape of the counterweight block includes, but is not limited to, a cylindrical, cubic, and other shapes that can be placed stably. This embodiment does not specifically limit this. In addition, it should be noted that in this embodiment, after the material is selected, the density of the counterweight block is a preset value, i.e., ρ 配 is known, therefore, when considering the mass of the counterweight, only its volume information needs to be considered.

[0052] As an optional embodiment, when the center of gravity of the first structure to be welded deviates from the center of the first welding pad and the number of the counterweight block is one, S102 can be performed by Figure 3 The method shown is implemented. Figure 3 As shown, the present embodiment provides a method for calculating first position information and volume information of a counterweight block that needs to be set on a first welding pad when the center of gravity of a first structure to be welded coincides with the center, which may specifically include the following steps: S301 to S304.

[0053] S301. Determine a minimum value of volume information of a counterweight according to size information of a first welding pad.

[0054] In specific implementation, it is assumed that the first position information (x a ,y a ), V a Represents the volume information of the counterweight, ρ 配 represents the density of the counterweight, then:

[0055]

[0056] Wherein, x represents the horizontal coordinate of the center of gravity of the first structure to be welded; y represents the vertical coordinate of the center of gravity of the first structure to be welded; n represents the number of components; x iIndicates the second position information of the i-th component (x i ,y i ) in the horizontal axis; y i Indicates the second position information of the i-th component (x i ,y i ) in the vertical coordinate; ρ i represents the density of the i-th component; V i Represents the volume of the i-th component; V a Represents the volume information of the counterweight; ρ 配 Indicates the density of the counterweight; x a Indicates the first position information of the counterweight (x a ,y a ) in the horizontal axis; y a Indicates the first position information of the counterweight (x a ,y a ) in the vertical axis.

[0057] It can be understood that (x, y) represents the center of gravity of the first structure to be welded. According to the coordinate system established in this embodiment, when x and y are 0, the center of gravity of the first structure to be welded coincides with the center.

[0058] It should also be understood that in the above formulas (3) and (4), there is V a 、x a ,y a To solve the equation, we can give one of the three unknowns, for example, we can give the volume of the counterweight, that is, V a Is known.

[0059] Specifically, the volume information V of the counterweight block a is related to the size information of the first pad. Then, according to the above formulas (3) and (4), we can get:

[0060]

[0061] It can be seen that when x a When the maximum value is taken, that is, x a =x max When V a has a minimum value; when x a →0, V a →+∞. Similarly, when y a When the maximum value is reached, y a =y max When V a has a minimum value; when y a →0, V a →+∞. That is, the minimum value of the volume information of the counterweight block can be determined according to the following formula:

[0062]

[0063] S302: Determine the maximum value of the volume information of the counterweight according to the load-bearing capacity of the solder layer preformed by the solder used in the welding process. For example, the mass information obtained according to the density and volume information of the counterweight does not exceed 30g.

[0064] S303: Determine any value within the interval corresponding to the maximum value and the minimum value as the volume information of the counterweight.

[0065] S304, calculating the first position information of the counterweight according to the second position information, density and volume corresponding to the plurality of components, the volume information of the counterweight and the moment balance principle.

[0066] Specifically, based on the above formulas (3) and (4), the first position information of the counterweight block can be calculated as:

[0067]

[0068] It should be noted that we can also give x a or a To solve for the other two values. Therefore, when the coordinate (x a ,y a ) Place a density of ρ 配 And the volume is V a The counterweight block can make the center of gravity of the first structure to be welded coincide with the center.

[0069] Further, in some embodiments, in S103, based on the first position information and the volume information, a target tooling is set on the first structure to be welded, the volume of the target counterweight on the target tooling is determined according to the volume information, and the orthographic projection of the position of the target counterweight on the target tooling on the first structure to be welded coincides with the first position information. The target tooling includes a tooling body and a target counterweight set on the tooling body, and the mass distribution of the tooling body is uniform.

[0070] Thus, in S104, the first structure to be welded is welded to the second structure to be welded. Specifically, solder can be used to connect the first structure to be welded through reflow soldering to form a subunit, and the subunit is connected to the second structure to be welded through reflow soldering to form the main structure of the semiconductor. In other words, the first part to be welded and the components are welded together through reflow soldering to form a subunit, and the subunit is then welded together with the second part to be welded through reflow soldering, wherein the subunit is the solder layer when the first part to be welded with the components is welded to the second part to be welded.

[0071] In specific implementation, the reflow soldering method can achieve mechanical and electrical connection between the pins or solder ends of electronic components pre-mounted on the pads and the pads of the printed circuit board by heating and melting the solder paste pre-coated on the pads. In this way, based on the effect of hot air flow on the solder joints, the flux undergoes a physical reaction under a certain high-temperature air flow to achieve SMD welding.

[0072] In specific implementation, solder paste is coated on the first pad by screen printing or syringe dispensing, or a solder sheet is placed, and components such as chips, capacitors, resistors, etc. are adhered accordingly. After the reflow soldering process, an eccentric module with several components of different volumes, uneven positions, and different densities distributed on the surface is obtained, and the component welding is completed.

[0073] refer to Figure 4A and Figure 4B , when the number of counterweight blocks is one, the main structure of the semiconductor formed by welding is shown in the front view and the top view, Figure 4C Shows Figure 4B Section A main section view. Figure 4A , Figure 4B and Figure 4C As shown, the main structure of the semiconductor obtained by welding the first structure to be welded 420 and the second structure to be welded 410 includes a welding layer 440 formed by the solder used in the welding process, wherein the first structure to be welded 420 includes a first welding pad and a plurality of components 430 arranged on the first welding pad; after the target tooling 470 is arranged on the first structure to be welded 420, the center of gravity N corresponding to the entire first structure to be welded 420 coincides with the center O. Specifically, the target tooling 470 includes a tooling body and a target counterweight 460 arranged on the tooling body, and the mass distribution of the tooling body is uniform.

[0074] In addition, in some embodiments, a bearing assembly for bearing the target counterweight is provided on the tooling body, and the orthographic projection of the position of the bearing assembly on the target tooling on the first structure to be welded coincides with the first position information. Specifically, the bearing assembly may be, for example but not limited to, a groove structure, and the weight of the bearing assembly is negligible. In this way, based on the bearing assembly, the target counterweight may not be placed in the exact center of the tooling body, that is, the target tooling is an eccentric tooling.

[0075] Therefore, it is only necessary to process a target tooling including a load-bearing component and a target counterweight block to be set on the first structure to be welded, so that the center of gravity above the weld layer can be adjusted to the horizontal center (i.e. coincide with the center), so that the weight above the weld layer is evenly distributed, the flatness of the weld layer is improved, and the operation is simple and easy to implement.

[0076] In another embodiment, before welding the first structure to be welded and the second structure to be welded, the first structure to be welded provided with the target tooling can be placed in the receiving cavity of the limiting tooling, wherein the size of the receiving cavity of the limiting tooling matches the size of the first structure to be welded. Figure 4A , Figure 4B and Figure 4C As shown, 450 is a limiting tool. Alternatively, the limiting tool 450 can be a hollowed-out thin-walled block designed according to the size information of the first structure to be welded and the size information of the target tool.

[0077] In this way, first place the limiting fixture. Since the solder is in a flowing state when it melts, the eccentric module (the first pad and components of the first structure to be welded) is prone to displacement, and at the same time causes the target fixture above it to be offset or tilted. Therefore, the limiting fixture can play a limiting constraint role to prevent the eccentric module from deviating from the target fixture, and keep the target fixture in a vertical state to ensure that the contact surface with the eccentric module is level and maintain the center of gravity. Then, put the target fixture along the hollowed-out position of the limiting fixture until it contacts the first structure to be welded. In this way, under the constraint of the limiting fixture, the target fixture is maintained in a relatively high level state, which can keep the eccentric module flat. Finally, load the target counterweight block in the target fixture so that the eccentric module, the target fixture and the target counterweight block are maintained horizontally and in the center of gravity as a whole, so that the welding layer below the eccentric module is maintained in a flat state.

[0078] In addition, it should be understood that after the target tooling is processed, x a ,y a When the distribution of several components of the first structure to be welded changes, that is, when the center of gravity (x′, y′) changes, for a target tooling including only a single counterweight, it is impossible to adjust the center of gravity to coincide with the center again by only adjusting the volume information of the counterweight. To this end, by adopting a target tooling including multiple (i.e., at least two) counterweights, the degree of freedom of the counterweight is greater than the degree of freedom of the center of gravity, so that the center of gravity of the first structure to be welded as a whole can be adjusted.

[0079] In some embodiments, when the center of gravity of the first structure to be welded deviates from the center of the first welding pad, and the number of the counterweight blocks is at least two, S102 may be performed by: Figure 5 The method shown is implemented. Figure 5 As shown, another method for calculating the first position information and volume information of the counterweight block that needs to be set on the first welding pad when the center of gravity of the first structure to be welded coincides with the center provided in this embodiment can specifically include the following steps: S501 to S505.

[0080] S501, determining first position information corresponding to at least two counterweight blocks according to the number of counterweight blocks;

[0081] S502, determining a minimum value of a volume of at least one candidate counterweight block among at least two counterweight blocks according to the size information of the first welding pad;

[0082] S503, determining the maximum value of the sum of the volumes of at least two counterweights according to the load-bearing capacity of the solder layer preformed by the solder used in the welding process;

[0083] S504, determining any value within the interval corresponding to the maximum value and the minimum value as volume information of at least one candidate counterweight;

[0084] S505. Calculate the volume information of non-alternative counterweights based on the second position information, density and volume corresponding to a number of components, the first position information corresponding to at least two counterweights, the volume information of at least one alternative counterweight, and the principle of moment balance. The non-alternative counterweight is a counterweight other than at least one alternative counterweight among the at least two counterweights.

[0085] Specifically, the volume information of the non-alternative counterweight block can be calculated according to the following formula:

[0086]

[0087] Wherein, x represents the horizontal coordinate of the center of gravity of the first structure to be welded; y represents the vertical coordinate of the center of gravity of the first structure to be welded; n represents the number of components; x i Indicates the second position information of the i-th component (x i ,y i ) in the horizontal axis; y i Indicates the second position information of the i-th component (x i ,y i ) in the vertical coordinate; ρ i represents the density of the ith component; V i represents the volume of the i-th component; ρ 配 Indicates the density of the counterweight; V b Indicates the volume information of the optional counterweight; x b Indicates the first position information of the alternative counterweight block (x b ,y b ) in the horizontal axis; y b Indicates the first position information of the alternative counterweight block (x b ,y b ) in the vertical axis; V c Indicates the volume information of non-optional counterweight blocks; x c Indicates the first position information of the non-alternative counterweight block (x c ,y c ) in the horizontal axis; y cIndicates the first position information of the non-alternative counterweight block (x c ,y c ) in the vertical axis.

[0088] It should be noted that the number of counterweights can be set according to actual needs, such as but not limited to two counterweights, three counterweights, or four counterweights. In this way, placing counterweights at two positions, three positions, or multiple positions can achieve adjustment of different centers of gravity by adjusting the volume information of the counterweights.

[0089] Take setting four counterweights as an example, refer to Fig. 6A and Figure 6B , when the number of counterweight blocks is at least two (for example, four), a front view and a top view of the main structure of the semiconductor formed by welding, Figure 6C Shows Figure 6B Section B main section view. Fig. 6A , Figure 6B and Figure 6C As shown, the main structure of the semiconductor obtained by welding the first structure to be welded 620 and the second structure to be welded 610 includes a welding layer 640 formed by the solder used in the welding process, wherein the first structure to be welded 620 includes a first welding pad and a plurality of components 630 arranged on the first welding pad; after the target tooling 670 is set on the first structure to be welded 620, the center of gravity Q corresponding to the entire first structure to be welded 620 coincides with the center O. Specifically, the target tooling 670 includes a tooling body and a plurality of target counterweights 660 arranged on the tooling body, and the mass distribution of the tooling body is uniform. In addition, before welding the first structure to be welded 620 and the second structure to be welded 610, the first structure to be welded 620 provided with the target tooling 670 can be placed in the accommodating cavity of the limiting tooling 650, wherein the size of the accommodating cavity of the limiting tooling 650 matches the size of the first structure to be welded 620.

[0090] Next, take the setting of four counterweight blocks as an example. Assume that the coordinates of the center points of the four counterweight blocks are (X b ,y b )、(x c ,y c )、(x d ,y d )、(x e ,y e ), the volumes are V b 、V c 、V d 、V e , the density is ρ 配 , then let

[0091]

[0092] Since the four counterweights are distributed at the four corners, the coordinates of their center points are (X b ,y b )、(x c ,y c )、(x d ,y d )、(x e ,y e ), that is, the first position information is known. Therefore, in the two formulas (12) and (13), V b 、V c 、V d 、V e To solve the equation, we can arbitrarily set two of the four unknowns. For example, let V b 、V c For a known, specific, V b 、V c The value range of can be determined according to the above formulas (12) and (13), then:

[0093]

[0094] When (ρ 配 y c +V d ρ 配 y d +V e ρ 配 y e )=0, and x b =x max When V b has a minimum value; when x b →0, V b →+∞. Similarly, y b =y max When V b has a minimum value; when x b →0, V b →+∞. Therefore, In addition, the maximum value of the volume information needs to take into account the solder layer's bearing capacity, which is generally not more than 30g. c The value range is similar to V b The same, and (V b +V c +V d +V e ) is less than 30g.

[0095] Select V arbitrarily in the above range b , V c After that, we can get:

[0096]

[0097]

[0098] It can be obtained that when (x b ,y b )、(x c ,y c )、(x d ,y d ) and (x e ,y e ) Set the given value V for each of the four positions b , V c And the calculated value V d , V e The corresponding volume information and density is ρ 配 When there are four counterweights, the center of gravity can be adjusted to coincide with the center.

[0099] In this way, when the type, quantity, distribution and other factors of the components of the eccentric module change, causing its center of gravity to change, the volume V of the four counterweight blocks can be simply adjusted. b , V c , V d , V e , so that the center of gravity can quickly re-coincide with the center, which can be applied to various eccentric conditions without adjusting the setting position of the counterweight block, that is, there is no need to redesign the entire target tooling, only the original target tooling needs to be adjusted, which is simple and flexible.

[0100] In addition, during the reflow process, bubbles emitted by the volatilization of the solder flux in the solder layer will squeeze the eccentric module above and cause it to tilt, while the target tooling and the target counterweight block on it can suppress the bubble squeezing force through their own gravity, reduce the tilt caused by the bubbles, and obtain a smoother solder layer. On the other hand, since this embodiment uses the target tooling method to solve the tilt of the solder layer, there is no need to use a heavy weight block to forcibly flatten the solder layer, thus avoiding the occurrence of tin overflow, and the matching tooling and fixture do not need to be too precise.

[0101] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0102] Based on the same technical concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides a welding device 700.

[0103] like Figure 7 As shown, the welding device 700 may include:

[0104] An acquisition module 701 is used to acquire a center of gravity position of a first structure to be welded, where the first structure to be welded includes a first welding pad and a plurality of components disposed on the first welding pad;

[0105] A calculation module 702 is used to calculate first position information and volume information of a counterweight block that needs to be set on the first pad when the center of gravity of the first structure to be welded coincides with the center according to the density and volume corresponding to the plurality of components when there is a deviation between the center of gravity of the first structure to be welded and the center of the first pad;

[0106] A setting module 703 is used to set a target tooling on the first structure to be welded based on the first position information and the volume information, the volume of the target counterweight on the target tooling is determined according to the volume information, and the orthographic projection of the position of the target counterweight on the target tooling on the first structure to be welded coincides with the first position information;

[0107] The welding module 704 is used to weld the first structure to be welded and the second structure to be welded.

[0108] In some embodiments, the mass distribution of the first pad is uniform, the masses of the plurality of components are different, or the plurality of components are asymmetrically distributed on the first pad.

[0109] In some embodiments, the acquisition module 701 is specifically used to obtain the second position information of the center corresponding to each of the plurality of components; and determine the center of gravity position of the first structure to be welded according to the second position information, density and volume corresponding to each of the plurality of components and the principle of moment balance.

[0110] In some embodiments, there is one counterweight block, and the calculation module 702 is specifically used to determine the minimum value of the volume information of the counterweight block based on the size information of the first solder pad; determine the maximum value of the volume information of the counterweight block based on the bearing capacity of the solder layer preformed by the solder used in the welding process; determine any value within the interval corresponding to the maximum value and the minimum value as the volume information of the counterweight block; calculate the first position information of the counterweight block based on the second position information, density and volume corresponding to each of a number of components, the volume information of the counterweight block, and the principle of torque balance.

[0111] In some embodiments, the calculation module 702 is specifically configured to calculate the first position information of the counterweight according to the following formula:

[0112]

[0113]

[0114] Wherein, x represents the horizontal coordinate of the center of gravity of the first structure to be welded; y represents the vertical coordinate of the center of gravity of the first structure to be welded; n represents the number of components; x i Indicates the second position information of the i-th component (x i ,y i ) in the horizontal axis; y i Indicates the second position information of the i-th component (x i ,y i ) in the vertical coordinate; ρ i represents the density of the i-th component; V i Represents the volume of the i-th component; V a Represents the volume information of the counterweight; ρ 配 Indicates the density of the counterweight; x a Indicates the first position information of the counterweight (x a ,y a ) in the horizontal axis; y a Indicates the first position information of the counterweight (x a ,y a ) in the vertical axis.

[0115] In some embodiments, the calculation module 702 is specifically configured to determine the minimum value of the volume information of the counterweight according to the following formula:

[0116]

[0117] In some embodiments, the number of counterweight blocks is at least two, and the calculation module 702 is further specifically used to determine the first position information corresponding to each of the at least two counterweight blocks according to the number of counterweight blocks; determine the minimum value of the volume of at least one alternative counterweight block among the at least two counterweight blocks according to the size information of the first solder pad; determine the maximum value of the sum of the volumes of the at least two counterweight blocks according to the bearing capacity of the solder layer preformed by the solder used in the welding process; determine any value within the interval corresponding to the maximum value and the minimum value as the volume information of at least one alternative counterweight block; calculate the volume information of a non-alternative counterweight block according to the second position information, density and volume corresponding to each of a number of components, the first position information corresponding to each of the at least two counterweight blocks, the volume information of at least one alternative counterweight block and the principle of torque balance, where the non-alternative counterweight block is a counterweight block other than at least one alternative counterweight block among the at least two counterweight blocks.

[0118] In some embodiments, the calculation module 702 is further specifically configured to calculate the volume information of the non-alternative counterweight according to the following formula:

[0119]

[0120]

[0121] Wherein, x represents the horizontal coordinate of the center of gravity of the first structure to be welded; y represents the vertical coordinate of the center of gravity of the first structure to be welded; n represents the number of components; x i Indicates the second position information of the i-th component (x i ,y i ) in the horizontal axis; y i Indicates the second position information of the i-th component (x i ,y i ) in the vertical coordinate; ρ i represents the density of the i-th component; V i represents the volume of the i-th component; ρ 配 Indicates the density of the counterweight; V b Indicates the volume information of the optional counterweight; x b Indicates the first position information of the candidate counterweight (x b ,y b ) in the horizontal axis; y b Indicates the first position information of the candidate counterweight (x b ,y b ) in the vertical axis; V c Indicates the volume information of non-optional counterweight blocks; x c Indicates the first position information of the non-alternative counterweight block (x c ,y c ) in the horizontal axis; y c Indicates the first position information of the non-alternative counterweight block (x c ,y c ) in the vertical axis.

[0122] In some embodiments, the target tooling includes a tooling body and a target counterweight block arranged on the tooling body. The mass distribution of the tooling body is uniform, and a bearing component for bearing the target counterweight block is arranged on the tooling body. The position of the bearing component on the target tooling coincides with the first position information in its orthographic projection on the first structure to be welded.

[0123] In some embodiments, the welding device 700 further includes a placement module ( Figure 7 (not shown) is used to place the first structure to be welded provided with the target tooling in the accommodating cavity of the limiting tooling, and the size of the accommodating cavity of the limiting tooling matches the size of the first structure to be welded.

[0124] It should be noted that, for the convenience of description, the above device is described in various modules according to their functions. Of course, when implementing this application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0125] The device of the above embodiment is used to implement the corresponding welding method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0126] Based on the same technical concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides an electronic device.

[0127] Figure 8 A more specific schematic diagram of the hardware structure of an electronic device provided by this embodiment is shown.

[0128] The electronic device 800 may include a processor 801 and a memory 802 storing computer program instructions.

[0129] Specifically, the processor 801 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0130] The memory 802 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 802 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 802 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 802 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 802 is a non-volatile solid-state memory.

[0131] In certain embodiments, the memory may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, typically, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of the present application.

[0132] The processor 801 implements any one of the welding methods in the above embodiments by reading and executing the computer program instructions stored in the memory 802 .

[0133] In some examples, the electronic device 800 may further include a communication interface 803 and a bus 810. Figure 8 As shown, the processor 801, the memory 802, and the communication interface 803 are connected via a bus 810 and communicate with each other.

[0134] The communication interface 803 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0135] Bus 810 includes hardware, software or both, and the parts of online data flow billing equipment are coupled to each other. For example, but not limitation, bus 810 may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-end bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 810 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the present application considers any suitable bus or interconnection.

[0136] Exemplarily, the electronic device 800 may be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA).

[0137] Based on the same technical concept, corresponding to any of the above-mentioned embodiments, the present application also provides a non-transitory computer-readable storage medium. The computer-readable storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any of the welding methods in the above-mentioned embodiments is implemented. Examples of computer-readable storage media include non-transitory computer-readable storage media, such as portable disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, etc.

[0138] Based on the same technical concept, corresponding to any of the above-mentioned embodiments, the present application also provides a computer program product, which includes computer program instructions. In some embodiments, the computer program instructions can be executed by one or more processors of a computer so that the computer and / or the processor execute the welding method. Corresponding to the execution subject corresponding to each step in each embodiment of the welding method, the processor that executes the corresponding step can belong to the corresponding execution subject.

[0139] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0140] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0141] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0142] The above reference is according to the method of the embodiment of the present application, the flow chart of the device (system) and the computer program product and / or the block diagram described various aspects of the present application.It should be understood that each square box in the flow chart and / or the block diagram and the combination of each square box in the flow chart and / or the block diagram can be realized by computer program instructions.These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the realization of the function / action specified in one or more square boxes of the flow chart and / or the block diagram.Such a processor can be but is not limited to a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit.It can also be understood that each square box in the block diagram and / or the flow chart and the combination of the square boxes in the block diagram and / or the flow chart can also be realized by the dedicated hardware that performs the specified function or action, or can be realized by the combination of dedicated hardware and computer instructions.

[0143] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A welding method, characterized in that: include: Obtaining a center of gravity position of a first structure to be welded, wherein the first structure to be welded includes a first welding pad and a plurality of components disposed on the first welding pad; In the case where the center of gravity of the first structure to be welded deviates from the center of the first welding pad, first position information and volume information of a counterweight block that needs to be set on the first welding pad when the center of gravity of the first structure to be welded coincides with the center are calculated according to the density and volume corresponding to each of the plurality of components; Based on the first position information and volume information, a target tooling is set on the first structure to be welded, the volume of a target counterweight on the target tooling is determined according to the volume information, and the orthographic projection of the position of the target counterweight on the target tooling on the first structure to be welded coincides with the first position information; The first structure to be welded and the second structure to be welded are welded.

2. The method according to claim 1, characterized in that The mass of the first pad is evenly distributed, the masses of the plurality of components are different, or the plurality of components are asymmetrically distributed on the first pad; The obtaining of the center of gravity position of the first structure to be welded comprises: Acquire second position information of centers corresponding to each of the plurality of components; The center of gravity position of the first structure to be welded is determined according to the second position information, density and volume corresponding to each of the plurality of components and the moment balance principle.

3. The method according to claim 1, characterized in that The number of the counterweight block is one; The calculating, based on the densities and volumes corresponding to the plurality of components, first position information and volume information of a counterweight block that needs to be set on the first pad when the center of gravity of the first structure to be welded coincides with the center, includes: Determining a minimum value of volume information of the counterweight block according to the size information of the first welding pad; Determining the maximum value of the volume information of the counterweight block according to the load-bearing capacity of the solder layer preformed by the solder used in the welding process; Determine any value within the interval corresponding to the maximum value and the minimum value as the volume information of the counterweight block; The first position information of the counterweight block is calculated according to the second position information, density and volume corresponding to each of the plurality of components, the volume information of the counterweight block and the moment balance principle.

4. The method according to claim 3, characterized in that The calculating the first position information of the counterweight block according to the second position information, density and volume corresponding to each of the plurality of components and the volume information of the counterweight block and the moment balance principle includes: The first position information of the counterweight is calculated according to the following formula: Wherein, x represents the horizontal coordinate of the center of gravity of the first structure to be welded; y represents the vertical coordinate of the center of gravity of the first structure to be welded; n represents the number of components; x i Indicates the second position information of the i-th component (x i ,y i ) in the horizontal axis; y i Indicates the second position information of the i-th component (x i ,y i ) in the vertical coordinate; ρ i represents the density of the i-th component; V i Represents the volume of the i-th component; V a Represents the volume information of the counterweight; ρ 配 Indicates the density of the counterweight; x a Indicates the first position information of the counterweight (x a ,y a ) in the horizontal axis; y a Indicates the first position information of the counterweight (x a ,y a ) in the vertical axis.

5. The method according to claim 4, characterized in that The step of determining the minimum value of the volume information of the counterweight block according to the size information of the first pad includes: The minimum value of the volume information of the counterweight block is determined according to the following formula:

6. The method according to claim 1, characterized in that The number of the counterweight blocks is at least two; The calculating, based on the densities and volumes corresponding to the plurality of components, first position information and volume information of a counterweight block that needs to be set on the first pad when the center of gravity of the first structure to be welded coincides with the center, includes: Determining first position information corresponding to at least two counterweight blocks according to the number of the counterweight blocks; Determining a minimum value of a volume of at least one candidate counterweight block among at least two counterweight blocks according to the size information of the first welding pad; Determine the maximum value of the sum of the volumes of at least two counterweights according to the load-bearing capacity of the solder layer preformed by the solder used in the welding process; Determine any value within the interval corresponding to the maximum value and the minimum value as the volume information of the at least one candidate counterweight block; According to the second position information, density and volume corresponding to each of the several components, the first position information corresponding to each of the at least two counterweights, the volume information of the at least one alternative counterweight and the principle of moment balance, the volume information of the non-alternative counterweight is calculated. The non-alternative counterweight is a counterweight among the at least two counterweights except for the at least one alternative counterweight.

7. The method according to claim 6, characterized in that The method of calculating the volume information of the non-alternative balancing weight according to the second position information, density and volume corresponding to each of the plurality of components, the first position information corresponding to each of the at least two balancing weights, the volume information of the at least one alternative balancing weight and the moment balance principle, wherein the non-alternative balancing weight is a balancing weight among the at least two balancing weights except the at least one alternative balancing weight, comprises: Calculate the volume information of non-optional counterweights according to the following formula: Wherein, x represents the horizontal coordinate of the center of gravity of the first structure to be welded; y represents the vertical coordinate of the center of gravity of the first structure to be welded; n represents the number of components; x i Indicates the second position information of the i-th component (x i ,y i ) in the horizontal axis; y i Indicates the second position information of the i-th component (x i ,y i ) in the vertical coordinate; ρ i represents the density of the ith component; V i represents the volume of the i-th component; ρ 配 Indicates the density of the counterweight; V b Indicates the volume information of the optional counterweight; x b Indicates the first position information of the alternative counterweight block (x b ,y b ) in the horizontal axis; y b Indicates the first position information of the alternative counterweight block (x b ,y b ) in the vertical axis; V c Indicates the volume information of non-optional counterweight blocks; x c Indicates the first position information of the non-alternative counterweight block (x c ,y c ) in the horizontal axis; y c Indicates the first position information of the non-alternative counterweight block (x c ,y c ) in the vertical axis.

8. The method according to any one of claims 1 to 7, characterized in that: The target tooling includes a tooling body and a target counterweight block arranged on the tooling body, the mass distribution of the tooling body is uniform, and a bearing component for bearing the target counterweight block is arranged on the tooling body, and the position of the bearing component on the target tooling has an orthographic projection on the first structure to be welded that coincides with the first position information.

9. The method according to any one of claims 1 to 7, characterized in that: Before welding the first structure to be welded and the second structure to be welded, the method further includes: The first structure to be welded provided with the target tooling is placed in the accommodating cavity of the limiting tooling, and the size of the accommodating cavity of the limiting tooling matches the size of the first structure to be welded.

10. A welding device, characterized in that: include: An acquisition module, used for acquiring a center of gravity position of a first structure to be welded, wherein the first structure to be welded includes a first welding pad and a plurality of components arranged on the first welding pad; a calculation module, configured to calculate, when the center of gravity of the first structure to be welded deviates from the center of the first welding pad, first position information and volume information of a counterweight block that needs to be set on the first welding pad when the center of gravity of the first structure to be welded coincides with the center, according to the densities and volumes corresponding to the plurality of components; a setting module, configured to set a target tooling on the first structure to be welded based on the first position information and the volume information, wherein the volume of a target counterweight on the target tooling is determined according to the volume information, and an orthographic projection of the position of the target counterweight on the target tooling on the first structure to be welded coincides with the first position information; The welding module is used to weld the first structure to be welded and the second structure to be welded.

Images