Thermocompression bonding and reflow soldering packaging method, flip-chip bonding structure and chip structure

Abstract

The invention discloses a thermocompression bonding and reflow soldering packaging method, a flip-chip bonding structure and a chip structure, and relates to the technical field of chips. Comprising the following steps: preparing a plurality of welding spots on one side of a substrate to obtain a first welding plate; preparing a plurality of gold bumps on one side of the chip to obtain a second welding plate; the side, with the solder, of the first welding plate is welded to the side, with the gold bumps, of the second welding plate, and a packaged chip is obtained; wherein the welding pressure is 20-25g per gold bump. By directly welding the side, with the solder, of the first welding plate and the side, with the gold bumps, of the second welding plate, the step of flattening the gold bumps in traditional flip reflow soldering is omitted, preparation of the first welding plate and preparation of the second welding plate can be conducted at the same time, flip bonding between a chip and a substrate is achieved on the same production line, and the production efficiency is improved. And electrical signal interconnection is realized. The gold bump leveling process link is reduced, the complexity of the process flow is reduced, the yield is improved, the manufacturing cost is reduced, and the production and manufacturing efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of chip technology, and in particular to a packaging method of thermal compression bonding and reflow soldering, a flip-chip bonding structure and a chip structure. Background Art

[0002] With the rapid development of 5G and artificial intelligence, the demand for computing power has exploded, which has put forward higher requirements for the packaging of integrated circuit chips, optical chips, etc., especially for the packaging interconnection density and packaging volume. In the advanced packaging technology of semiconductor integrated circuit chips, flip chip packaging technology is usually required to realize the electrical signal interconnection between chips and chips, and between chips and substrates. Flip chip bonding is mainly divided into thermocompression bonding, thermosonic bonding and mass reflow.

[0003] The traditional gold wire bonding packaging method usually prepares gold bumps on the chip first, then uses a pressing plate to flatten the gold bumps for later use through a hot press bonding process, and then reflow soldering and flip-chip bonding with a substrate with solder to complete the flip-chip process.

[0004] However, the traditional gold wire bonding packaging method has problems such as complex process, long production line, and difficulty in achieving packaging on a single production line. Summary of the invention

[0005] The present application provides a packaging method of thermocompression bonding and reflow soldering, a flip-chip bonding structure and a chip structure to solve the problems of complex existing processes, long production lines, and difficulty in implementing packaging on one production line.

[0006] In a first aspect, the present application provides a packaging method of thermal compression bonding and reflow soldering, comprising the following steps:

[0007] Preparing a plurality of welding spots on one side of the substrate to obtain a first welding plate;

[0008] A plurality of gold bumps are prepared on one side of the chip to obtain a second welding plate;

[0009] Soldering the side of the first welding plate with solder to the side of the second welding plate with gold bumps to obtain a packaged chip;

[0010] The welding pressure is 20-25 g per gold bump.

[0011] The present application omits the step of flattening the gold bumps in the traditional flip-chip reflow soldering by directly soldering the side of the first soldering plate with solder to the side of the second soldering plate with gold bumps, so that the preparation of the first soldering plate and the preparation of the second soldering plate can be carried out simultaneously, and the production rhythm is consistent, and the flip-chip bonding between the chip and the substrate is realized on the same production line to achieve electrical signal interconnection. The gold bump flattening process is reduced, the complexity of the process flow is reduced, the yield is improved, the manufacturing cost is reduced, and the production efficiency is improved. At the same time, in order to ensure that the gold bumps of the second soldering plate and the solder of the first soldering plate can be in flat contact with the solder during welding, the welding pressure is controlled at 20 to 25 g per gold bump, which can increase the contact area of ​​the welding and improve the firmness of the welding.

[0012] It should be noted that when the side of the first welding plate with solder is welded to the side of the second welding plate with gold bumps, the positions of the first welding plate and the second welding plate need to be aligned to ensure that each gold bump corresponds to each solder point one by one, the number of gold bumps is consistent with the number of welding points, and the position of each gold bump also corresponds to the welding point to ensure the quality of welding. The accuracy of alignment can be improved by pre-making alignment marks on the first welding plate or the second welding plate with the help of high-definition imaging equipment.

[0013] It should be noted that gold bumps will form gold shoulders during the forming process. When the first welding plate and the second welding plate are welded, the gold shoulders need to be flattened to maximize the contact area between the gold bumps and the pads with solder in the first welding plate to achieve high-quality electrical signal interconnection. If the welding pressure is lower than 20g / gold bump, the gold shoulders of the gold bumps cannot be completely flattened, affecting the firmness of the welding. If the welding pressure is higher than 25g / gold bump, the gold bumps will be crushed, the ball height will be too small, and it will not be able to play a good mechanical support role. At the same time, it also makes the subsequent bottom filling process difficult to operate and the yield rate is low.

[0014] In some embodiments, the soldering temperature is 217°C to 240°C. When the soldering temperature is within this range, insufficient melting of the solder can be reduced, resulting in shrinkage of the solder joint, rough surface, cold solder joints, and poor mechanical strength. The solder fluidity is reduced, resulting in defects such as bridging and short circuits; and / or,

[0015] The welding time is 15 to 25 seconds. Within this range, the solder can be fully melted, reducing the occurrence of cold solder joints and bridging, and forming a good connection between the solder joint and the pad.

[0016] The distribution density of the gold bumps on the second welding plate is 30 to 88 / μm 2The more gold bumps there are per unit area, the better the welding firmness between the first welding plate and the second welding plate. However, the higher the welding density of the gold bumps, the higher the requirements for the forming process of the gold bumps. Considering the welding firmness and cost comprehensively, the distribution density of the gold bumps on the second welding plate is within this range, which can improve the welding firmness, improve the welding quality, and reduce the cost at the same time.

[0017] In some embodiments, the number of the gold bumps on the second welding plate is 220 to 660. When the number of the gold bumps on the second welding plate is within this range, good welding points can be formed to achieve good electrical interconnection performance.

[0018] In some embodiments, the diameter of the gold bump on the second welding plate is 40 to 100 μm. The diameter of the gold bump on the second welding plate is within this range, which can ensure a firm bond between the gold bump and the pad, high reliability, good electrical performance, and high interconnection density and high packaging integration.

[0019] In some embodiments, the height of the gold bump on the second welding plate is H, 15μm≤H1≤50μm. When the height of the gold bump on the second welding plate is within this range, the interconnection density can be made higher while ensuring the feasibility of the bottom filling process.

[0020] In some embodiments, the spacing between adjacent gold bumps on the second welding plate is 10-100 μm. The spacing between adjacent gold bumps on the second welding plate within this range can play a role in electrical signal interconnection and mechanical support, while achieving high-density solder joint interconnection.

[0021] In some embodiments, the melting point of the solder at the solder joint on the first welding plate is 217°C to 240°C, which can form a good bonding solder joint with stable electrical properties, reduce the risk of damage to the chip microstructure, and reduce the probability of the weld breaking when subjected to external force, thereby improving the strength and stability of the welding structure.

[0022] In a second aspect, the present application provides a flip-chip bonding structure, including a packaged chip made by the packaging method of the first aspect using thermocompression bonding and reflow soldering.

[0023] In a third aspect, the present application provides a chip structure, including the flip-chip bonding structure of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a process flow chart of the prior art packaging method of thermal compression bonding and reflow soldering in this application.

[0026] Figure 2 The process flow chart of the packaging method of thermal compression bonding and reflow soldering according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0028] Reflow

[0029] Reflow soldering is a soldering technology that achieves mechanical and electrical connections between surface mounted components and printed circuit board pads by remelting the paste solder pre-distributed to the printed circuit board pads. The core of reflow soldering is the heat conduction process, which efficiently transfers heat to the circuit board and components to melt the solder paste and form reliable solder joints after cooling. It is widely used in consumer electronics, industrial control and automotive electronics, and has the advantages of high efficiency, reliability and strong adaptability. In the reflow process, accurately controlling the heating rate and peak temperature of each temperature zone to ensure that the solder paste is fully melted and forms good solder joints is the key to improving product quality. As a key technology in electronic manufacturing, reflow soldering achieves reliable connection between electronic components and PCB boards by accurately controlling the heating and cooling process. It not only improves production efficiency, but also ensures the welding quality of the product.

[0030] Thermal Compression Bonding

[0031] Thermocompression bonding is an advanced chip bonding process, mainly used in advanced packaging technology. Especially in applications that require high precision and high reliability, such as solder ball-based flip chip bonding packaging. It can well make up for the shortcomings of reflow soldering bonding and provide more precise control capabilities. The core of thermocompression bonding is to achieve direct metal bonding between the chip and the substrate through the combined action of heat and pressure. It has been widely used in solder ball-based flip chip bonding packaging. Its principle is similar to that of traditional diffusion welding, and the main influencing parameters include temperature, pressure and time. During the thermocompression bonding process, both the chip and the substrate are in a vacuum adsorption state to ensure their flatness. After alignment, the bonding is completed through precision mechanical control. The system monitors the temperature, pressure and displacement in real time during the whole process. When the chip contacts the substrate, the system quickly raises the temperature to above the melting point of the solder ball, and quickly cools down and solidifies during the cooling stage.

[0032] With the rapid development of 5G and artificial intelligence, the demand for computing power has exploded, which has put forward higher requirements for the packaging of integrated circuit chips, optical chips, etc., especially for the packaging interconnection density and packaging volume. In the advanced packaging technology of semiconductor integrated circuit chips, flip chip packaging technology is usually required to realize the electrical signal interconnection between chips and chips, and between chips and substrates. Flip chip bonding is mainly divided into thermocompression bonding, thermosonic bonding and mass reflow.

[0033] like Figure 1 As shown in the figure, the traditional gold wire bonding packaging method usually prepares gold bumps on the chip first, then uses a pressing plate to flatten the gold bumps for standby use through a hot press bonding process, and then reflows the gold bumps with the substrate with solder to complete the flip-chip process. However, the traditional gold wire bonding packaging method requires the consistency of the gold bumps after flattening to be controlled at 2μm. The addition of steps makes the entire process complicated, the production line is long, and it is difficult to achieve packaging on a single production line. The defect rate increases, the manufacturing cost increases, and the efficiency is reduced.

[0034] Therefore, it is necessary to propose a new packaging structure and preparation method to overcome the traditional packaging defects, optimize the traditional packaging structure and method, and overcome unfavorable factors to meet the high-speed, high-density, and low-power packaging requirements of electronic components for high-speed computing and artificial intelligence.

[0035] In view of this, the present application provides a packaging method of thermal compression bonding and reflow soldering, a flip-chip bonding structure and a chip structure to solve the problems of complex existing processes, long production lines, and difficulty in implementing packaging on one production line.

[0036] First, as Figure 2 As shown, the present application provides a packaging method of thermal compression bonding and reflow soldering, comprising the following steps:

[0037] Preparing a plurality of welding spots on one side of the substrate to obtain a first welding plate;

[0038] A plurality of gold bumps are prepared on one side of the chip to obtain a second welding plate;

[0039] Soldering the side of the first welding plate with solder to the side of the second welding plate with gold bumps to obtain a packaged chip;

[0040] The welding pressure is 20-25 g per gold bump.

[0041] The present application omits the step of flattening the gold bumps in the traditional flip-chip reflow soldering by directly soldering the side of the first soldering plate with solder to the side of the second soldering plate with gold bumps, so that the preparation of the first soldering plate and the preparation of the second soldering plate can be carried out simultaneously, and the production rhythm is consistent, and the flip-chip bonding between the chip and the substrate is realized on the same production line to achieve electrical signal interconnection. The gold bump flattening process is reduced, the complexity of the process flow is reduced, the yield is improved, the manufacturing cost is reduced, and the production efficiency is improved. At the same time, in order to ensure that the gold bumps of the second soldering plate and the solder of the first soldering plate can be in flat contact with the solder during welding, the welding pressure is controlled at 20 to 25 g per gold bump, which can increase the contact area of ​​the welding and improve the firmness of the welding. The welding pressure includes but is not limited to 20g / gold bump, 20.5g / gold bump, 21g / gold bump, 21.5g / gold bump, 22g / gold bump, 22.5g / gold bump, 23g / gold bump, 23.5g / gold bump, 24g / gold bump, 24.5g / gold bump or 25g / gold bump.

[0042] It should be noted that when the side of the first welding plate with solder is welded to the side of the second welding plate with gold bumps, the positions of the first welding plate and the second welding plate need to be aligned to ensure that each gold bump corresponds to each solder point one by one, the number of gold bumps is consistent with the number of welding points, and the position of each gold bump also corresponds to the welding point to ensure the quality of welding. The accuracy of alignment can be improved by pre-making alignment marks on the first welding plate or the second welding plate with the help of high-definition imaging equipment.

[0043] It should be noted that gold bumps will form gold shoulders during the forming process. When the first welding plate and the second welding plate are welded, the gold shoulders need to be flattened to maximize the contact area between the gold bumps and the pads with solder in the first welding plate to achieve high-quality electrical signal interconnection. If the welding pressure is lower than 20g / gold bump, the gold shoulders of the gold bumps cannot be completely flattened, affecting the firmness of the welding. If the welding pressure is higher than 25g / gold bump, the gold bumps will be crushed, the ball height will be too small, and it will not be able to play a good mechanical support role. At the same time, it also makes the subsequent bottom filling process difficult to operate and the yield rate is low.

[0044] It should be noted that the gold bump is formed on the pad by thermosonic bonding of gold wire. The purity of the gold wire is 99.99%, and it can be doped with 0.001‰ Be or 0.001‰ Cu. The doping of Be and Cu can improve the hardness and tensile strength of the gold wire, and can also reduce the material cost. The diameter of the gold wire can be 15 to 100μm, which is convenient for the formation of the gold bump.

[0045] It should be noted that the material of the first welding plate can be aluminum oxide, aluminum nitride, or silicon, the material corresponding to the solder joint area of ​​the solder joint is copper or gold, and the solder material of the solder joint can be tin-lead solder, tin-silver solder, tin-copper solder, tin-bismuth solder, tin-zinc solder, or tin-indium solder.

[0046] In combination with the first aspect, in some embodiments provided in the present application, the welding temperature is 217°C to 240°C. Within this range, the welding temperature can reduce the insufficient melting of the solder, resulting in the shrinkage of the solder joints, the rough surface, the occurrence of cold solder joints and poor mechanical strength. Reduce the excessive fluidity of the solder, the occurrence of defects such as bridging and short circuits. The welding temperature includes but is not limited to 217°C, 220°C, 223°C, 225°C, 228°C, 230°C, 232°C, 235°C, 237°C or 240°C.

[0047] In combination with the first aspect, in some embodiments provided in the present application, the welding time is 15 to 25 seconds. Within this range, the solder can be fully melted, the occurrence of cold solder joints and bridging phenomena can be reduced, and a good connection can be formed between the solder joint and the pad. The welding time includes but is not limited to 15 seconds, 1 second, 17 seconds, 18 seconds, 19 seconds, 20 seconds, 21 seconds, 22 seconds, 23 seconds, 24 seconds or 25 seconds.

[0048] In combination with the first aspect, in some embodiments provided in the present application, the distribution density of the gold bumps on the second welding plate is 30 to 88 per μm. 2 The number of gold bumps per unit area is better, and the firmness of the welding between the first welding plate and the second welding plate is better. However, the higher the welding density of the gold bumps is, the higher the requirements for the forming process of the gold bumps are. Considering the welding firmness and cost, the distribution density of the gold bumps on the second welding plate is within this range, which can improve the firmness of welding, improve the quality of welding, and reduce costs. The distribution density of the gold bumps includes but is not limited to 30 / μm 2 , 35 / μm 2 , 40 / μm 2 , 45 / μm 2 , 50 / μm 2 , 55 / μm 2 , 60 / μm 2 , 65 / μm 2 , 70 / μm 2 , 75 / μm 2 , 80 / μm 2 , 85 / μm 2 or 88 / μm 2 .

[0049] In combination with the first aspect, in some embodiments provided in the present application, the number of the gold bumps on the second welding plate is 220 to 660. Within this range, a good welding point can be formed to achieve good electrical interconnection performance. The number of the gold bumps includes but is not limited to 220, 250, 300, 350, 400, 450, 500, 550 or 600.

[0050] In combination with the first aspect, in some embodiments provided in the present application, the diameter of the gold bump on the second welding plate is 40 to 100 μm. Within this range, the gold bump can be firmly bonded to the pad, with high reliability and good electrical performance, while also having high interconnection density and high packaging integration. The diameter of the gold bump includes but is not limited to 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm or 100 μm.

[0051] In combination with the first aspect, in some embodiments provided in the present application, the height of the gold bump on the second welding plate is H, 15μm≤H1≤50μm, and the height of the gold bump on the second welding plate is within this range, which can make the interconnection density higher and ensure the feasibility of the bottom filling process. The height of the gold bump includes but is not limited to 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm.

[0052] In combination with the first aspect, in some embodiments provided in the present application, the spacing between adjacent gold bumps on the second welding plate is 10 to 100 μm. The spacing between adjacent gold bumps on the second welding plate within this range can play a role in electrical signal interconnection and mechanical support, while achieving high-density solder joint interconnection. The spacing between adjacent gold bumps includes but is not limited to 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm or 100 μm.

[0053] In combination with the first aspect, in some embodiments provided in the present application, the melting point of the solder of the solder joint on the first soldering plate is 217°C to 240°C, which can form a good bonding solder joint, stable electrical performance, reduce the risk of damage to the chip microstructure, and reduce the probability of the weld seam breaking when subjected to external force, thereby improving the strength and stability of the soldering structure. The melting point of the solder includes but is not limited to 217°C, 220°C, 225°C, 230°C, 232°C, 235°C, 237°C or 240°C.

[0054] In a second aspect, the present application provides a flip-chip bonding structure, including a packaged chip made by the packaging method of the first aspect of the thermocompression bonding and reflow soldering. The flip-chip bonding structure has all the technical solutions of the packaging method of the thermocompression bonding and reflow soldering, and thus has all the beneficial effects of the packaging method of the thermocompression bonding and reflow soldering, which will not be described in detail in this application.

[0055] In a third aspect, the present application provides a chip structure, including the flip-chip bonding structure of the second aspect. The chip structure has all the technical solutions of the packaging method of the thermal compression bonding and reflow soldering, and thus has all the beneficial effects of the packaging method of the thermal compression bonding and reflow soldering, which will not be described in detail in this application.

[0056] The technical solution provided in this application is described in detail below in conjunction with embodiments.

[0057] Example 1

[0058] Embodiment 1 of the present application provides a packaging method of thermal compression bonding and reflow soldering, comprising the following steps:

[0059] Preparing a plurality of welding spots on one side of the substrate to obtain a first welding plate;

[0060] A plurality of gold bumps are prepared on one side of the chip to obtain a second welding plate;

[0061] Soldering the side of the first welding plate with solder to the side of the second welding plate with gold bumps to obtain a packaged chip;

[0062] Among them: the welding pressure is 25g / gold bump;

[0063] The welding temperature is 217°C and the welding time is 15s;

[0064] The distribution density of the gold bumps on the second welding plate is 88 / μm 2 , the number of gold bumps is 880;

[0065] The diameter of the gold bumps on the second welding plate is 40 μm, the height is 15 μm, and the spacing between adjacent gold bumps is 60 μm;

[0066] The melting point of the solder at the solder joint on the first soldering plate is 217°C.

[0067] Example 2

[0068] Embodiment 2 of the present application provides a packaging method of thermal compression bonding and reflow soldering and a processing method thereof.

[0069] Preparing a plurality of welding spots on one side of the substrate to obtain a first welding plate;

[0070] A plurality of gold bumps are prepared on one side of the chip to obtain a second welding plate;

[0071] Soldering the side of the first welding plate with solder to the side of the second welding plate with gold bumps to obtain a packaged chip;

[0072] Among them: the welding pressure is 20g / gold bump;

[0073] The welding temperature is 240°C and the welding time is 25s;

[0074] The distribution density of the gold bumps on the second soldering plate is 30 / μm 2 , the number of gold bumps is 220;

[0075] The diameter of the gold bumps on the second welding plate is 100 μm, the height is 50 μm, and the spacing between adjacent gold bumps is 100 μm;

[0076] The melting point of the solder of the solder joint on the first soldering plate is 240°C.

[0077] Example 3

[0078] Embodiment 3 of the present application provides a packaging method of thermal compression bonding and reflow soldering and a processing method thereof.

[0079] Preparing a plurality of welding spots on one side of the substrate to obtain a first welding plate;

[0080] A plurality of gold bumps are prepared on one side of the chip to obtain a second welding plate;

[0081] Soldering the side of the first welding plate with solder to the side of the second welding plate with gold bumps to obtain a packaged chip;

[0082] Among them: the welding pressure is 22.5g / gold bump;

[0083] The welding temperature is 225℃ and the welding time is 20s;

[0084] The distribution density of the gold bumps on the second welding plate is 60 / μm 2 , the number of gold bumps is 440;

[0085] The diameter of the gold bumps on the second welding plate is 70 μm, the height is 30 μm, and the spacing between adjacent gold bumps is 80 μm;

[0086] The melting point of the solder at the solder joint on the first soldering plate is 225°C.

[0087] Comparative Example 1

[0088] Comparative Example 1 of the present application provides a packaging method of thermal compression bonding and reflow soldering, which is similar to Example 2, except that the welding pressure is 18g per gold bump.

[0089] In Comparative Example 1, since the welding pressure is less than 22.5 g / gold bump, the gold shoulder of the gold bump is not completely flattened, the solder joint is not fully in contact, the bonding force is not strong, and the reliability is poor.

[0090] Comparative Example 2

[0091] Comparative Example 2 of the present application provides a packaging method of thermal compression bonding and reflow soldering, which is similar to Example 1, except that the welding pressure is 26.5 g per gold bump.

[0092] According to Comparative Document 2, since the welding pressure is greater than 25g / gold bump, the gold bump will be crushed, making the bottom filling process difficult to operate and the filling glue cannot fully flow into the gap, resulting in a low yield.

[0093] In summary, by directly welding the side of the first welding plate with solder to the side of the second welding plate with gold bumps, the step of flattening the gold bumps in the traditional flip-chip reflow soldering is omitted, so that the preparation of the first welding plate and the preparation of the second welding plate can be carried out simultaneously, and the production rhythm is consistent, and the flip-chip bonding between the chip and the substrate is realized on the same production line to achieve electrical signal interconnection. The gold bump flattening process link is reduced, the complexity of the process flow is reduced, the yield is improved, the manufacturing cost is reduced, and the production efficiency is improved. At the same time, in order to ensure that the gold bumps of the second welding plate and the solder of the first welding plate can be flatly contacted with the solder during welding, the welding pressure is controlled at 20-25g / gold bump, which can increase the contact area of ​​welding and improve the firmness of welding.

[0094] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0095] It should be noted that, in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is 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 the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically stipulated.

[0096] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A packaging method of thermocompression bonding and reflow soldering, characterized in that: The following steps are involved: Preparing a plurality of welding spots on one side of the substrate to obtain a first welding plate; A plurality of gold bumps are prepared on one side of the chip to obtain a second welding plate; Soldering the side of the first welding plate with solder to the side of the second welding plate with gold bumps to obtain a packaged chip; The welding pressure is 20-25 g per gold bump.

2. The packaging method of thermal compression bonding and reflow soldering according to claim 1, characterized in that: The welding temperature is 217℃~240℃; and / or, The welding time is 15 to 25 seconds.

3. The packaging method of thermocompression bonding and reflow soldering according to claim 1, characterized in that: The distribution density of the gold bumps on the second welding plate is 30 to 88 / μm 2 .

4. The packaging method of thermocompression bonding and reflow soldering according to claim 1, characterized in that: The number of the gold bumps on the second welding plate is 220 to 660.

5. The packaging method of thermocompression bonding and reflow soldering according to claim 1, characterized in that: The diameter of the gold bump on the second welding plate is 40 μm to 100 μm.

6. The packaging method of thermocompression bonding and reflow soldering according to claim 1, characterized in that: The height of the gold bump on the second welding plate is H, 15 μm≤H1≤50 μm.

7. The packaging method of thermocompression bonding and reflow soldering according to claim 1, characterized in that: The spacing between adjacent gold bumps on the second welding plate is 10 μm to 100 μm.

8. The packaging method of thermocompression bonding and reflow soldering according to claim 1, characterized in that: The melting point of the solder at the solder joint on the first soldering plate is 217°C to 240°C.

9. A flip-chip bonding structure, characterized in that: A packaged chip made by the packaging method of thermal compression bonding and reflow soldering as described in any one of claims 1 to 8.

10. A chip structure, characterized in that: Comprising the flip-chip bonding structure as claimed in claim 9.

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