Solder and packaging structure

Abstract

The invention discloses a solder and a packaging structure. The solder comprises: a base material; the repairing capsule is mixed in the base material and internally comprises a repairing material; the microneedle is mixed in the base material, the microneedle is a shape memory alloy, and the microneedle deforms to puncture at least part of the repair capsule, so that the repair material flows out of the punctured repair capsule and fills the space defect of the base material; or / and the melting point of the repairing material is less than the phase transition temperature of the shape memory alloy. The self-repairing of the solder can be realized through the matching of the repairing capsule and the microneedle, so that the solder has longer service life and higher reliability.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a solder and packaging structure. Background Technology

[0002] As a core component of systems such as new energy vehicles and photovoltaic inverters, power modules require their internal solder layers to withstand temperature shocks, power cycling, and real-world complex operating conditions. Due to temperature cycling, the solder layers in the packaging structure are repeatedly subjected to mechanical and / or thermal stresses. These mechanical and / or thermal stresses can cause microcracks in the solder layers, and as the number of temperature cycles increases, these cracks continue to propagate, eventually leading to delamination or voids in the solder layers. This increases the module's thermal resistance and conduction resistance, ultimately causing product failure. Summary of the Invention

[0003] In view of the above problems, the purpose of this application is to provide a self-healing solder and packaging structure with longer life and higher reliability.

[0004] According to one aspect of this application, a solder is provided, comprising: a base material; a repair capsule mixed in the base material, the capsule containing a repair material; and microneedles mixed in the base material, the microneedles being a shape memory alloy, wherein the microneedles deform to puncture at least a portion of the repair capsule, causing the repair material to flow out of the punctured repair capsule and fill spatial defects in the base material; and / or the melting point of the repair material is less than the phase transition temperature of the shape memory alloy.

[0005] Optionally, the conditions under which the microneedle deforms include: the base material generating the spatial defect; or / and the solder operating temperature reaching the phase transformation temperature of the shape memory alloy.

[0006] Optionally, the phase transformation temperature of the shape memory alloy is less than the maximum operating temperature of the solder.

[0007] Optionally, the melting point of the repair material is less than 100°C, and the phase transformation temperature of the shape memory alloy is 102°C to 108°C.

[0008] Optionally, the microneedles account for 5% to 15% of the solder, and the repair capsules account for 3% to 8% of the solder.

[0009] Optionally, the shape memory alloy includes a nickel-titanium alloy.

[0010] Optionally, the microneedle further includes a surface coating that at least covers the sidewalls of the microneedle, the coating being made of a material including nickel.

[0011] Optionally, the diameter of the microneedle is 7μm~9μm, the length is 75μm~85μm, and the thickness of the coating is 250nm~350nm.

[0012] Optionally, the repair material includes at least one of indium, tin, and bismuth.

[0013] Optionally, the repair material includes: Bi x In y Sn z Or Bi x In y Sn z -Sb, where 25≤x≤35, 45≤y≤55, 20≤z≤30, and x+y+z=100, wherein the atomic percentage of antimony does not exceed 1%.

[0014] Optionally, the repair capsule further includes a capsule shell encapsulating the repair material, the capsule shell having a thickness of 1.8μm to 2.2μm and being made of polyurea formaldehyde.

[0015] Optionally, the base material includes lead-containing solder, lead-free solder, or sintered metal material.

[0016] According to a second aspect of this application, a packaging structure is provided, wherein the packaging structure includes: a semiconductor chip; a substrate for carrying the semiconductor chip; wherein the semiconductor chip and the substrate are soldered together by solder as described in any one of the preceding claims.

[0017] According to a third aspect of this application, a packaging structure is provided, wherein the packaging structure includes: a semiconductor chip; a substrate for supporting the semiconductor chip; and a base plate for supporting the substrate; wherein the substrate and the base plate are soldered together by solder as described in any one of the preceding claims.

[0018] According to the solder and encapsulation structure provided in this application, repair capsules and microneedles are mixed into the base material. During temperature cycling, the microneedles deform under heat and puncture the repair capsules, allowing the liquefied or molten repair material inside to flow out. When spatial defects such as cracks appear in the solder, the flowing-out repair material fills these defects due to capillary action, achieving self-healing of the solder. Simultaneously, the combined effect of crack stress and temperature-induced microneedle deformation increases the success rate of puncturing the repair capsules, facilitating crack filling and reinforcement in the early stages of crack initiation, further improving the solder's lifespan and reliability. Attached Figure Description

[0019] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0020] Figure 1 A schematic structural diagram of the solder according to an embodiment of this application is shown;

[0021] Figure 2 This diagram illustrates the solder self-healing process according to an embodiment of this application.

[0022] Figure 3 A schematic structural diagram of the packaging structure of an embodiment of this application is shown. Detailed Implementation

[0023] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0024] Furthermore, certain terms are used in this specification and claims to refer to specific components. Those skilled in the art will understand that manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function.

[0025] It should be understood that in the following description, when a component or circuit is said to be "connected to" another component or "connected" between two nodes, it can be directly coupled or connected to the other component or there can be intermediate components. The connection between components can be physical, logical, or a combination thereof. Conversely, when a component is said to be "directly coupled to" or "directly connected to" another component, it means that there are no intermediate components between them.

[0026] Furthermore, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0027] This application provides a solder. This solder can be used for structural support and connection as well as heat transfer. For example, it can be applied to packaging structures and used as a welding layer between a semiconductor chip and a substrate or between a substrate and a base plate, or it can be used with circuit boards, power modules, etc. to achieve structural integrity.

[0028] The solder provided in this application includes a base material and repair capsules and microneedles mixed in the base material. The microneedles are made of shape memory alloy and can puncture at least part of the repair capsules under certain conditions. The repair material in the repair capsules melts when heated and flows out of the repair capsules to fill spatial defects in the base material, thereby achieving self-healing of the solder.

[0029] It should be noted that, in this embodiment, the term "spatial defect" refers to cracks, fractures, tears, cavities, breaks, separations, pores, deformations, defects, or similar defects in the crystal or lattice structure of the solder. Spatial defects may be minute or coarse, and regardless of whether they are visible to the naked eye, they may affect or impair at least one physical and mechanical property of the solder (e.g., conductivity, permeability, strength, etc.).

[0030] Figure 1 The following is a schematic structural diagram of the solder according to an embodiment of this application. Figure 1 The solder provided in this application will be further described.

[0031] refer to Figure 1 The solder 120 disclosed in this application includes: base material 121, repair capsule 122, and microneedles 123.

[0032] The base material 121 is the main component of the solder 120. The metal in the base material 121 should have a high melting point, for example, higher than the subsequent process temperature of the solder and the highest operating temperature in the application scenario, to prevent the base material 121 from failing.

[0033] It should be understood that the maximum operating temperature of the solder in the application scenario should be greater than or equal to the maximum value between the maximum impact temperature and the maximum cycle temperature, that is, greater than or equal to the highest temperature in the temperature impact range and the highest temperature in the temperature cycle range.

[0034] Taking the solder used for welding semiconductor chips, especially power semiconductor chips, as an example, the temperature shock range is usually -40℃ to 125℃, and the temperature cycling range is usually -65℃ to 150℃.

[0035] In some embodiments, the base material 121 may be lead-containing solder, lead-free solder, or nano-metal sintered material. The nano-metal sintered material may further include nano-silver sintered material or nano-copper sintered material.

[0036] Repair capsule 122 is mixed in base material 121. Repair capsule 122 includes a capsule shell 122b and repair material 122a enclosed by the capsule shell 122b. The capsule shell 122b can be punctured by microneedles 123 under certain conditions, allowing the internal repair material 122a to flow out after melting upon heating. The capsule shell 122b serves to isolate and protect the repair material 122a, preventing it from directly contacting and reacting with the base material 121, or preventing it from flowing out before the capsule shell 122b is punctured.

[0037] Microneedles 123 are also mixed in base material 121. Microneedles 123 are made of shape memory alloy, which can deform under certain conditions.

[0038] Among them, microneedles 123 have at least one of the following characteristics, or both:

[0039] i) Deformation occurs, puncturing at least part of the repair capsule, causing the repair material 122a to flow out of the punctured repair capsule 122 and fill the space defects of the base material 121;

[0040] ii) The melting point of the repair material is less than the phase transition temperature of the shape memory alloy.

[0041] In these embodiments, the conditions for the microneedle 123 to deform include at least one of the following, or both:

[0042] i) Spatial defects were generated in the base material 121, and ii) The working temperature of the solder 120 reached the phase transformation temperature of the shape memory alloy.

[0043] In this embodiment, the melting point of the repair material 122a is less than the phase transition temperature of the shape memory alloy. When the temperature of the solder 120 reaches the phase transition temperature of the shape memory alloy, the microneedle 123 will deform and puncture at least part of the repair capsule 122. The repair material 122a inside the repair capsule 122 has melted and can flow out of the repair capsule 122 to fill the spatial defects of the base material 121, thereby realizing the self-healing function of the solder.

[0044] In some embodiments, the phase transition temperature of the shape memory alloy should be at least lower than the maximum operating temperature of the solder, which can ensure that when the microneedle 123 deforms and punctures part of the repair capsule 122, the solder is still within the safe operating area (SOA) and has not failed, so as to realize the self-healing function of the solder.

[0045] In some embodiments, such as power semiconductor chip applications, the temperature shock range of solder 120 is typically -40°C to 125°C, and the temperature cycling range is typically -65°C to 150°C. Therefore, the melting point of the repair material 122a must be less than the phase transition temperature of the shape memory alloy and less than 150°C. Preferably, the melting point of the repair material 122a must be less than the phase transition temperature of the shape memory alloy and less than 125°C.

[0046] Based on the actual optimal application scenario, the phase transformation temperature of the shape memory alloy can be selected from 102 to 108℃, and the melting point of the repair material 122a can be selected from less than 100℃. These conditions can help to screen the optimal shape memory alloy material and repair material 122a that meet the actual application scenario.

[0047] In some embodiments, to meet conductivity requirements and without increasing solder resistance, the conductivity of the repair material 122a should be greater than 7.5 × 10⁻⁶. 6 S / m.

[0048] Specifically, in some embodiments, the repair material 122a may be selected from at least one of indium, tin, and bismuth.

[0049] In a preferred embodiment, the repair material 122a comprises a bismuth indium tin alloy (Bi x In y Sn z ) or antimony-containing variants of bismuth-indium-tin alloys (Bi x In y Sn z The bismuth-indium-tin alloy has the following properties: 25≤x≤35, 45≤y≤55, 20≤z≤30, and x+y+z=100, with the atomic percentage of antimony not exceeding 1% (Sb≤1at.%). The melting point of the bismuth-indium-tin alloy is below 100℃, meeting the optimal requirements for practical applications.

[0050] In some embodiments, the capsule shell 122b is made of polyurea formaldehyde.

[0051] In a preferred embodiment, the capsule shell has a thickness of 1.8~2.2μm, which can both contain the internal repair material 122a without easy leakage and facilitate the microneedles 123 to be punctured under suitable conditions.

[0052] In some embodiments, by controlling the proportion of the repair capsule 122 in the solder 120 to 3% to 8%, excessive porosity in the base material 121 can be avoided. In a preferred embodiment, this proportion is 4% to 6%, for example, 4%, 4.5%, 5%, 5.5%, and 6%.

[0053] In some embodiments, the shape memory alloy can be a nickel-titanium shape memory alloy, for example, it can be Ni 55.5Ti 44.5 Alloy. This ensures that, in the working environment of solder 120, the shape memory alloy can undergo a phase transformation and further induce deformation during temperature cycling.

[0054] Furthermore, in a preferred embodiment, the diameter of the microneedle 123 is 7~9μm, preferably 7μm, 7.5μm, 8μm, 8.5μm, or 9μm; and the length is 75~85μm, preferably 75μm, 80μm, or 85μm.

[0055] In some embodiments, by controlling the proportion of microneedles 123 in solder 120 to 5% to 15%, it is possible to avoid the difficulty in forming effective support for the base material 121 when the proportion of microneedles 123 is too low, and it is also possible to avoid the reduction of fluidity of the base material 121 when the proportion of microneedles 123 is too high.

[0056] In a preferred embodiment, the percentage is 8-12%, for example, 8%, 9%, 10%, 11%, or 12%.

[0057] In some embodiments, the microneedle 123 further includes a surface coating. The surface coating is made of nickel and at least covers the sidewalls of the microneedle 123, i.e., the cylindrical surface of the needle body, and has a thickness of 250-350 nm. The surface coating design can absorb the phase transition stress of the microneedle 123, preventing excessive local stress during phase transitions that could lead to breakage of the base material 121.

[0058] In some embodiments, the microneedles 123 can be prepared by the following steps: vacuum melting; plastic processing; solution heat treatment; electroplating; and laser slitting.

[0059] Specifically, Ni 55.5 Ti 44.5Using microneedles with a diameter of 8 μm and a length of 80 μm as an example, the alloy was first melted in a vacuum environment. Isolating it from atmospheric pollution facilitates the production of high-purity, low-defect, and homogeneous alloy materials. The alloy material was then subjected to plastic forming. This plastic forming process can begin with hot forging to initially shape the billet; then hot rolling to shape it into a cylinder with a diameter of 1 mm; finally, hot drawing to stretch the cylindrical billet into a wire with a diameter of 8 μm. The solution heat treatment of the wire can include heating it to 500℃ and holding it for 20 minutes, followed by water quenching. The high temperature imparts a uniform austenitic structure (a high-temperature stable phase), and the rapid cooling via water quenching "freezes" the uniform austenitic structure after holding, providing a foundation for triggering the subsequent shape memory effect. After solution heat treatment, nickel is electroplated onto the surface of the shape memory alloy. Finally, the wire is laser-cut into microneedles with a length of 80 μm. It should be noted that at least one end of the cut microneedles is not covered by the nickel plating layer.

[0060] Figure 2 This diagram illustrates the solder self-healing process according to an embodiment of this application. Figure 2 In the example, solder 120 is used for soldering semiconductor chips, specifically for packaging structures. For clarity, in... Figure 2 Only one crack 10, a repair capsule 122, and a microneedle 123 are shown in the image.

[0061] Taking the requirement that the melting point of the repair material < the phase transformation temperature of the shape memory alloy < the maximum operating temperature of the solder as an example, refer to... Figure 2 When solder 120 is used as a bonding layer in a semiconductor package structure, cracks 10 are easily generated at the edges of solder 120 during temperature cycling due to the mismatch in the coefficient of thermal expansion. Furthermore, the cracks 10 and their propagation mostly occur in the low-temperature range. This low-temperature range can be, for example, the stage where the operating temperature of the package structure is maintained at the lower limit of the temperature range. This lower limit is, for example, -40°C during temperature shock and -65°C during temperature cycling.

[0062] When the operating temperature rises back to the melting point of the repair material 122a, the repair capsule 122 is filled with liquid or molten repair material 122a.

[0063] When the temperature continues to rise and reaches the phase transition temperature of microneedle 123, the phase transition of microneedle 123 induces deformation, causing microneedle 123 to elongate or bend.

[0064] exist Figure 2In this example, the elongation of the microneedle 123 is used. The elongation and deformation of the microneedle 123 punctures the capsule shell 122b, causing the repair material 122a, which is in a liquid or molten state inside, to flow out. Since the crack 10 is generally at the micrometer scale in its initial stage, the liquid or molten repair material 122a will fill the crack 10 very quickly under the action of capillary effect, thereby achieving self-repair of the solder 120, which is more conducive to extending the service life of the solder 120 and improving its reliability. At the same time, filling the crack 10 with the repair material 122a can also reduce the volume of electrical break caused by the crack, thereby restoring the electrical properties of the solder.

[0065] In this embodiment, when the microneedle 123 elongates and deforms, the external crack 10 will also generate stress. The stress can cause the capsule shell 122b to rupture, thereby causing the repair material 122a to flow out of the crack in the repair solder 120.

[0066] It is important to emphasize that in some embodiments, the stress from crack 10 alone can cause the repair capsule 122 to rupture. However, because the initial crack may be difficult to trigger the shape memory alloy phase transformation due to crack displacement and low local stress, the difficulty of rupturing the repair capsule 122 increases, leading to a delay in repair. In the solder provided in this application, the stress provided by the external crack 10 to the repair capsule 122b is used as an auxiliary force, combined with the stress and deformation generated by the microneedle 123 during the phase transformation, which can more effectively improve the puncture probability of the repair capsule 122.

[0067] More specifically, taking the phase transition temperature of the microneedle as 105℃ as an example, due to the auxiliary effect of the crack, the microneedle may undergo a phase transition at 100℃, which is more conducive to filling and strengthening the crack 10 in the early stage of crack 10, thereby inhibiting its propagation earlier.

[0068] This application also provides a packaging structure. Figure 3 A schematic structural diagram of the package structure 100 according to an embodiment of this application is shown. The package structure 100 is used to package a semiconductor chip 110, which can be a diode such as a power diode, an MPS (merged pin Schottky) diode, a Schottky diode, a MOS gate diode, or a transistor device such as a MOSFET, a JFET (junction FET), an IGBT, a FinFET, a HEMT, a thyristor, or a combination thereof, particularly a power semiconductor chip, such as a Si MOSFET chip, a SiC MOSFET chip, a Si IGBT chip, etc.

[0069] Semiconductor chip 110 can be made of any semiconductor material suitable for manufacturing semiconductor chips. Examples of such materials include, but are not limited to, elemental semiconductor materials such as silicon (Si) or germanium (Ge), group IV compound semiconductor materials such as silicon carbide (SiC) or silicon germanium (SiGe), and binary, ternary, or quaternary III-V semiconductor materials such as gallium nitride (GaN), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium gallium phosphide (InGaPa), aluminum gallium nitride (AlGaN), aluminum indium nitride (AlInN), indium gallium nitride (InGaN), aluminum gallium indium nitride (AlGaInN), or indium gallium arsenide (InGaAsP).

[0070] It should be understood that, in some embodiments, the package structure 100 can also be used to package the peripheral circuitry of the semiconductor chip 110 or other integrated circuit chips. The package structure 100 also includes: solder 120, substrate 130, base plate 140 as described above, and packaging insulating material 150.

[0071] The solder 120 includes a first solder 120a for connecting the semiconductor chip 110 and the substrate 130 and / or a second solder 120b for connecting the substrate 130 and the base plate 140. In a preferred embodiment, the thickness of a single layer of solder 120 is 0.1 to 0.5 mm.

[0072] The substrate 130 is used to carry the semiconductor chip 110 and provide a conductive path. For example, it is a ceramic substrate, specifically a direct bonded copper (DBC) ceramic substrate or an active metal brazing (AMB) ceramic substrate. The substrate 130 is disposed between the semiconductor chip 110 and the base plate 140 to achieve electrical insulation between the two.

[0073] The base plate 140 is used to support the substrate 130 and provide a heat dissipation path. The base plate 140 is, for example, a copper base plate, a copper-clad base plate, or a heat sink.

[0074] Taking a ceramic substrate as an example, substrate 130 includes an upper metal layer 131, a ceramic layer 132, and a lower metal layer 133 stacked together. The ceramic layer 132 serves for insulation and thermal conductivity. The ceramic layer 132 can be made of ceramic materials such as alumina, aluminum nitride, zirconium-doped alumina, silicon nitride, or aluminum oxynitride. In a preferred embodiment, aluminum nitride ceramic, which has the highest thermal conductivity, is selected to improve heat dissipation performance. The upper metal layer 131 is electrically connected to the semiconductor chip 110 and is mainly used for current or signal transmission; the lower metal layer 133 is connected to the base plate 140 and is mainly used for heat dissipation.

[0075] In some embodiments, the upper metal layer 131 is etched to form multiple independent sub-metal layers. Figure 1 The example uses three sub-metal layers 131a, 131b, and 131c. Each sub-metal layer is connected within the package structure 100 to a corresponding semiconductor device 110, peripheral circuit, or other integrated circuit chip, and transmits current or signals to the outside of the package structure via external terminals.

[0076] As an example, in Figure 1 The diagram shows only one semiconductor chip 110. This semiconductor chip 110 is fixed to the substrate 130 by being connected to a sub-metal layer 131b via a first solder 120a, and is electrically connected to sub-metal layers 131a and 131c via bonding wires 111 and 112. Taking a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) as an example, the sub-metal layer 131b can provide the drain voltage to the MOSFET, the sub-metal layer 131a can provide the gate voltage, and the sub-metal layer 131c can provide the source voltage. Taking an IGBT (Insulated-Gate Bipolar Transistor) as an example, the sub-metal layer 131b can provide the collector voltage, the sub-metal layer 131a can provide the gate voltage, and the sub-metal layer 131c can provide the emitter voltage. Of course, the semiconductor chip 110 can also be replaced with components in the peripheral circuit, such as NTC resistors (Negative Temperature Coefficient Thermistors) or capacitors, or other integrated circuit chips, which will not be listed here.

[0077] The lower metal layer 133 is connected to the base plate 140 via the second solder 120b to be fixed on the base plate 140.

[0078] The encapsulation insulating material 150, such as silicone gel / epoxy resin, is used to encapsulate and protect the semiconductor chip 110, bonding wires 111 and 112, and substrate 130.

[0079] In the packaging structure 100 provided in this application, the solder 120 provided in this application is used, so any of the above-mentioned beneficial effects can also be achieved.

[0080] Furthermore, it should be understood that the aforementioned base plate 140 is an optional structure. For example, when the substrate 130 is an IMS (insulating metal substrate), the insulating substrate of the IMS can replace the function of the base plate 140. That is to say, in some other embodiments of the packaging structure, it may include the semiconductor chip 110 as described above, the substrate 130 as described above, and a first solder 120a for soldering the semiconductor chip 110 and the substrate 130 together.

[0081] As described above, these embodiments of this application do not exhaustively cover all details, nor do they limit this application to specific embodiments. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to effectively utilize this application and its modifications. The scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A solder, wherein, include: Base material; Repair capsules, mixed in the base material, contain repair materials; as well as Microneedles, mixed in the base material, wherein the microneedles are shape memory alloys. Wherein, the microneedles deform and puncture at least a portion of the repair capsule, causing the repair material to flow out of the punctured repair capsule and fill the spatial defects of the base material; or / and The melting point of the repair material is less than the phase transition temperature of the shape memory alloy.

2. The solder according to claim 1, wherein, The conditions under which the microneedles deform include: The base material generates the spatial defects; or / and The working temperature of the solder reaches the phase transformation temperature of the shape memory alloy.

3. The solder according to claim 1, wherein, The phase transformation temperature of the shape memory alloy is less than the maximum operating temperature of the solder.

4. The solder according to any one of claims 1-3, wherein, The melting point of the repair material is less than 100℃, and the phase transformation temperature of the shape memory alloy is 102℃~108℃.

5. The solder according to any one of claims 1-3, wherein, The microneedles comprise 5% to 15% of the solder. The repair capsule accounts for 3% to 8% of the solder.

6. The solder according to any one of claims 1-3, wherein, The shape memory alloy includes nickel-titanium alloys.

7. The solder according to claim 6, wherein, The microneedle also includes a surface coating that at least covers the sidewalls of the microneedle, and the coating is made of nickel.

8. The solder according to claim 7, wherein, The microneedles have a diameter of 7μm to 9μm and a length of 75μm to 85μm, and the coating thickness is 250nm to 350nm.

9. The solder according to any one of claims 1-3, wherein, The repair material includes at least one of indium, tin, and bismuth.

10. The solder according to claim 9, wherein, The repair material includes: Bi x In y Sn z Or Bi x In y Sn z -Sb, Where 25≤x≤35, 45≤y≤55, 20≤z≤30, and x+y+z=100, The atomic percentage of antimony is no more than 1%.

11. The solder according to any one of claims 1-3, wherein, The repair capsule also includes a capsule shell that encapsulates the repair material. The thickness of the capsule shell is 1.8μm to 2.2μm, and the material includes polyurea formaldehyde.

12. The solder according to claim 1, wherein, The base material includes lead-containing solder, lead-free solder, or sintered metal materials.

13. A packaging structure, wherein, The packaging structure includes: Semiconductor chips; A substrate for supporting the semiconductor chip; The semiconductor chip and the substrate are connected by soldering as described in any one of claims 1-12.

14. A packaging structure, wherein, The packaging structure includes: Semiconductor chips; A substrate for supporting the semiconductor chip; The base plate is used to support the substrate; The substrate and the base plate are connected by soldering as described in any one of claims 1-12.

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