Solder bonding member, semiconductor device, solder bonding method and method for producing semiconductor device

Abstract

The present invention provides a solder bonding member (4) for bonding a first object (2) and a second object (3) to each other, the solder bonding member (4) containing Sn as a main component, while containing not less than 3% by mass but less than 4% by mass of Ag, not less than 0.5% by mass but less than 1.0% by mass of Cu, not less than 2.5% by mass but less than 4% by mass of Bi and not less than 0.5% by mass but less than 3% by mass of Sb. This solder bonding member (4) has: a main phase (12) which contains Sn, Ag and Cu and has a melting point that is not less than 210°C but less than 220°C; an Sn-Bi alloy phase (10) which covers at least a part of the main phase (12) and has a melting point that is not less than 135°C but less than 145°C; and an Sn-Bi-Sb alloy phase (11) which covers at least a part of the Sn-Bi alloy phase (10) and has a melting point that is not less than 170°C but less than 180°C.

Description

Soldered joint member, semiconductor device, soldering method, and method for manufacturing semiconductor device

[0001] The present disclosure relates to a soldered joint member, a semiconductor device, a soldering method, and a method for manufacturing a semiconductor device.

[0002] In recent years, there has been an increasing demand for reliability in semiconductor devices that include semiconductor elements and circuit boards. In semiconductor devices, the joint (joint) between the semiconductor element and the circuit board in particular is required to have improved reliability because the difference in thermal expansion coefficient between the two is large and defects are likely to occur.

[0003] On the other hand, in order to reduce the environmental impact, the use of lead-free solder, which does not contain lead (Pb), a substance subject to environmental regulations, is being promoted for joining such joints. A typical conventional lead-free solder is known to have a composition of Sn-3Ag-0.5Cu (wt%) (Sn-3Ag-0.5Cu solder).

[0004] The melting point of Sn-3Ag-0.5Cu solder is 220°C. In order to melt this lead-free solder and increase its fluidity (to wet and spread it over the joined surface), the heating temperature must be raised to approximately 250°C, 30°C higher than the melting point. During the subsequent cooling, thermal contraction can cause the joined components to warp or accumulate high residual stress. Therefore, during joint reliability evaluations after cooling (heat cycle tests, power cycle tests), stress is released, making the solder joint prone to cracking early.

[0005] In order to reduce such residual stress after soldering, Bi, In, etc., which have the effect of lowering the melting point, are added to the Sn-3Ag-0.5Cu solder.

[0006] For example, Patent Document 1 (JP 2002-120085 A) discloses a lead-free solder alloy having a melting temperature lower than 215°C and consisting essentially of 76 to 96% tin, 0.2 to 2.5% copper, 2.5 to 4.5% silver, and more than 0 to 12% indium. It is stated that this makes it possible to provide a lead-free solder having a moderate melting temperature range (175 to 210°C) useful for mainstream electronics manufacturing, and providing high strength and high fatigue resistance.

[0007] Furthermore, Patent Document 2 (JP 2018-149558 A) discloses a lead-free solder alloy containing 1% by mass to 4% by mass of Ag, 0.1% by mass to 1% by mass of Cu, 1.5% by mass to 5% by mass of Sb, 1% by mass to 6% by mass of In, and the balance being Sn. Also disclosed is a lead-free solder alloy that further contains 1% by mass to 5.5% by mass of Bi in addition to the above composition.

[0008] Incidentally, Patent Document 2 discloses specific reflow conditions (temperature profile) as follows: preheating from 170°C to 190°C for 110 seconds, a peak temperature of 245°C, a time at 200°C or higher for 65 seconds, a time at 220°C or higher for 45 seconds, and a cooling rate from the peak temperature to 200°C of 3 to 8°C / second.

[0009] JP 2002-120085 A JP 2018-149558 A

[0010] In Patent Documents 1 and 2, no attention is paid to the structure (configuration) of the joint after soldering, which causes problems in actual use.

[0011] Specifically, Sn, the main component of solder, forms an intermetallic compound at the joining surface. Near the interface between the intermetallic compound and its surroundings, other additive elements are locally concentrated relative to the main component Sn, forming a phase with a melting point different from the melting point of the solder alone before use. For example, if the other additive element is Bi, a Sn-Bi eutectic phase (melting point 140°C) is formed. Therefore, during solidification and shrinkage after solder joining, the main phase solidifies first, followed by a phase with a lower melting point (e.g., a Sn-Bi phase). This misalignment in solidification timing can lead to shrinkage cavities (crevice-like gaps that occur during the solidification process) and stress due to thermal contraction, potentially damaging the semiconductor element being joined.

[0012] Furthermore, if warping or unevenness occurs in the joined member (semiconductor element or substrate) after soldering, the electrical characteristics of the semiconductor element will vary for each solder joint, causing problems in electrical design. Furthermore, if unevenness occurs in the semiconductor element, stress will be applied to the semiconductor element during the subsequent wire bonding process (electrical wiring), which may cause the semiconductor element to crack or lead to wire bond failure.

[0013] In Patent Documents 1 and 2, the addition of In has the effect of lowering the melting point of the solder. However, since In is a metal that oxidizes easily, if the solder contains a large amount of In, voids may occur due to oxidation of In during initial joining. For this reason, in practice, the amount of In added must be less than the amount described in the above documents.

[0014] An object of the present disclosure is to provide a solder that can suppress the occurrence of defects attributable to joints formed using the solder.

[0015] The solder joint member of the present embodiment is a solder joint member for joining a first object and a second object, and contains Sn as a main component, 3% by mass or more and less than 4% by mass of Ag, 0.5% by mass or more and less than 1.0% by mass of Cu, 2.5% by mass or more and less than 4% by mass of Bi, and 0.5% by mass or more and less than 3% by mass of Sb, and has a main phase containing Sn, Ag, and Cu and having a melting point of 210°C or more and less than 220°C, a Sn—Bi alloy phase coating at least a portion of the main phase and having a melting point of 135°C or more and less than 145°C, and a Sn—Bi—Sb alloy phase coating at least a portion of the Sn—Bi alloy phase and having a melting point of 170°C or more and less than 180°C.

[0016] According to the present disclosure, it is possible to suppress the occurrence of defects caused by joints formed using solder.

[0017] The solder joint member of the present disclosure has two phases near the joint interface with the object (joined object) that have a melting point lower than that of the main phase inside, which alleviates stress generated during thermal contraction (solidification contraction) and suppresses the occurrence of defects caused by the stress, thereby providing a highly reliable joint (and a semiconductor device having the same).

[0018] Furthermore, by having the above two phases, the stress generated after bonding is also alleviated, and therefore a bonded portion (and a semiconductor device having the same) that can maintain high reliability even after bonding is provided.

[0019] FIG. 2 is a flowchart showing a manufacturing procedure for a semiconductor device (semiconductor element bonded body). FIG. 3 is a schematic cross-sectional view showing a first step in FIG. 1. FIG. 4 is a schematic cross-sectional view showing a second step in FIG. 1. FIG. 5 is a schematic cross-sectional view showing a third step in FIG. 1. FIG. 6 is a schematic cross-sectional view showing a fourth step in FIG. 1. FIG. 7 is a schematic cross-sectional view showing a fifth step in FIG. 1. FIG. 8 is a schematic cross-sectional view of a joint interface portion after the fifth step in FIG. 1. FIG. 9 is a DSC measurement result of a solder joint member of Example 1. FIG. 10 is a DSC measurement result of a solder joint member of Comparative Example 1. FIG. 11 is a cross-sectional observation result of a solder joint member of Example 1. FIG. 12 is a cross-sectional observation result of a solder joint member of Comparative Example 1. FIG. 13 is a schematic cross-sectional view of a solder joint member of embodiment 1.

[0020] Hereinafter, embodiments of the present disclosure will be described. In the drawings, dimensional relationships such as length, width, thickness, and depth have been appropriately changed for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

[0021] Embodiment 1 <Solder Joint Member> The solder joint member 4 of this embodiment is a member that joins a first object 2 (e.g., a substrate) and a second object 3 (e.g., a semiconductor element) (see FIG. 6 ). Note that, unlike the solder sheet 1 described below, the solder joint member 4 is a member made of solder (solder alloy) that has been melted by a heating process and then solidified, and exists in a state joined to both of the members to be joined (the first object and the second object).

[0022] The solder joint member 4 of this embodiment contains Sn as the main component, 3% by mass or more but less than 4% by mass of Ag, 0.5% by mass or more but less than 1.0% by mass of Cu, 2.5% by mass or more but less than 4% by mass of Bi, and 0.5% by mass or more but less than 3% by mass of Sb.

[0023] Furthermore, the solder joint member 4 of this embodiment has: a main phase 12 (high melting point phase) containing Sn, Ag, and Cu and having a melting point of 210°C or more and less than 220°C; a Sn—Bi alloy phase 10 (low melting point phase) covering at least a part of the main phase 12 and having a melting point of 135°C or more and less than 145°C; and a Sn—Bi—Sb alloy phase 11 (mid melting point phase) covering at least a part of the Sn—Bi alloy phase 10 and having a melting point of 170°C or more and less than 180°C (see FIGS. 7 and 12 ).

[0024] As described above, the solder joint member 4 of this embodiment has a multi-phase structure, and has a plurality of separate phases with different melting points.

[0025] In the solder joint member 4, the Sn-Bi-Sb alloy phase 11 (medium melting point phase), the Sn-Bi alloy phase 10 (low melting point phase), and the main phase 12 (high melting point phase) are basically present in this order from the side of the joined member (first object 2 or second object 3).

[0026] The solder joint member 4 of this embodiment contains Sn as a main component. Here, the "main component" refers to the component that is contained in the largest amount among the components contained in the solder joint member 4. The content of Sn in the solder joint member 4 is preferably 60 mass % or more, more preferably 70 mass % or more, and even more preferably 80 mass % or more.

[0027] In the solder joint member 4 of this embodiment, the Ag content is 3 mass % or more and less than 4 mass %, and the Cu content is 0.5 mass % or more and less than 1.0 mass %. It has been confirmed that the effects of the present disclosure can be obtained when the Ag and Cu contents are within these ranges.

[0028] The addition of Ag or Cu has the effect of lowering the melting point, with the melting point of the Sn-Ag-Cu eutectic being 220°C, compared to the melting point of Sn alone, which is 232°C. The addition of Ag also provides a high-strengthening effect through the fine dispersion strengthening of Ag-Sn compounds. The addition of Cu has the effect of preventing Sn from forming coarse interface compounds at the bonding interface. In the absence of Cu, the compound reaction at the bonding interface progresses, Sn disappears, and Bi tends to concentrate, so it is preferable to keep the amount of Cu added within the above range.

[0029] The solder joint member 4 may contain elements other than those mentioned above, for example, In, which has a melting point lowering effect, may be contained as another additive element in an amount of 0.1 mass % or more but less than 1 mass %. Even in this case, the same effect as above can be obtained without significantly affecting the bondability.

[0030] Second Embodiment <Semiconductor Device> A semiconductor device according to the present embodiment includes a substrate 2 and a semiconductor element 3. The substrate 2 and the semiconductor element 3 are joined via the solder joint member 4 described in the first embodiment. This provides a highly reliable semiconductor device.

[0031] Third Embodiment <Soldering Method> The soldering method of the present embodiment is a soldering method for joining a first object 2 (e.g., a substrate) and a second object 3 (e.g., a semiconductor element) (see FIGS. 1 to 6).

[0032] The solder joining method of this embodiment includes a heating step of heating a solder sheet 1, which contains Sn as the main component, 3% by mass or more but less than 4% by mass of Ag, 0.5% by mass or more but less than 1.0% by mass of Cu, 2.5% by mass or more but less than 4% by mass of Bi, and 0.5% by mass or more but less than 3% by mass of Sb, while sandwiched between a first object 2 and a second object 3.

[0033] Through the heating step, the solder sheet 1 becomes the solder joining member 4, and the first object 2 and the second object 3 are joined together. Note that steps other than the heating step will be described later in the examples.

[0034] In the heating step, the heating temperature (maximum temperature reached) is preferably 220° C. or higher and lower than 230° C., and the heating time (the time during which the temperature is maintained at 220° C. or higher and lower than 230° C.) is preferably 10 minutes or longer and shorter than 20 minutes. In this case, the solder joint member of this embodiment can be more reliably formed, and the effects of the solder joint member described above can be obtained.

[0035] Furthermore, in this disclosure, the oxygen concentration in the solder sheet 1 is also important. Bi is easily oxidized, and unless Bi is added and stored in a vacuum desiccator or the like, the solder wettability is poor and good bonding cannot be achieved. The oxygen concentration contained in the solder sheet 1 is preferably greater than 0 ppm and less than 500 ppm, in which case the same effect as above can be more reliably obtained.

[0036] Fourth Embodiment <Method for Manufacturing a Semiconductor Device> A method for manufacturing a semiconductor device according to the present embodiment is a method for manufacturing a semiconductor device including a substrate and a semiconductor element. The method for manufacturing a semiconductor device according to the present embodiment includes a step of bonding a substrate (substrate wiring such as a copper plate) and a semiconductor element using the solder bonding method according to the third embodiment. This provides a highly reliable semiconductor device.

[0037] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0038] Example 1 Hereinafter, with reference to the flowchart shown in FIG. 1, an example of the procedure for producing a semiconductor element bonded body (a bonded body of a semiconductor element and a substrate) in the method for manufacturing a semiconductor device of this embodiment will be described.

[0039] First, in the first step (S1), the solder sheet 1 is cut to a predetermined size (see FIG. 2).

[0040] Specifically, first, as a representative example of the solder composition, each element was added and melted to obtain the composition shown below: Sn-3.5Ag-0.7Cu-3.3Bi-2.0Sb (the numbers indicate mass %; Sn is the remainder of the composition ratio of the other elements), and a bulk body was produced.

[0041] Next, a rolled solder sheet 1 was produced by a rolling process at 100° C. or less so that the thickness would be 100 μm, and then cut into a size of 5 mm×5 mm, the same as the size of the semiconductor element described below.

[0042] In addition, the solder sheet 1 can be manufactured not only by rolling, but also by melting a bulk body and sequentially pouring the molten solder through thin slits. Furthermore, when the element combination is as many as five elements, as described above, the composition of the bulk body may become non-uniform due to temperature variations in the melting furnace. In this case, a Sn-Ag-Cu bulk body may be first manufactured, and then re-melted and the remaining Bi and Sb may be added in predetermined amounts to adjust the solder composition. Alternatively, the solder may be first formed into solder balls, which may then be uniformly distributed on a flat plate and compression-molded to produce a sheet.

[0043] Next, in the second step (S2), the solder sheet 1 was placed on the substrate 2 (copper plate) (see FIG. 3).

[0044] A tough-pitch copper plate (thickness: 1 mm, size: 10 mm x 10 mm) was used as the substrate 2. The outermost surface of the substrate 2 was made of pure copper and was not plated.

[0045] To prevent oxidation, a predetermined amount of rust inhibitor with a decomposition temperature of 100°C or less, which does not affect the bonding properties, may be applied to the outermost surface of the CuMo alloy plate. Furthermore, to prevent the solder sheet 1 from shifting from its initial position when it is placed, an organic agent that thermally decomposes at a high temperature of 100°C or higher may be used as a tackifier. The viscosity of the tackifier is preferably 200 Pa·s or higher. Alternatively, a resist film may be applied to areas other than the joining portion of the Cu plate to prevent the solder sheet 1 from shifting.

[0046] The solder sheet 1 may be slightly curved during cutting or handling. This is because the solder sheet 1 is completely melted by heating, so there is no effect from the initial shape of the solder sheet 1. However, since a semiconductor element will be placed on the solder sheet 1 in the next process, if the solder sheet 1 is curved so much that it is not possible to place the semiconductor element on it, it may be corrected to be parallel on another flat plate.

[0047] Next, in the third step (S3), the semiconductor element 3 was placed on the solder sheet 1 (see FIG. 4). The semiconductor element 3 was made of Si, had a thickness of 100 μm, and was 5 mm × 5 mm in size. A Ni film was formed on the surface to be joined to allow the solder to wet. The aforementioned tack material may also be applied between the semiconductor element 3 and the solder sheet 1 to fix the mounting position.

[0048] Next, in the fourth step, the stack of the components obtained in the above steps was placed on a hot plate 6 in a heating furnace 5 (see FIG. 5). Then, formic acid, a typical organic acid capable of reducing oxide films, was sealed in the heating furnace 5, and the solder sheet 1 was melted by heating at 180°C for 5 minutes and then at 230°C for 10 minutes to form a solder joint member 4.

[0049] Next, in a fifth step (S5), the sample (semiconductor element bonded assembly) on which the solder bonding member 4 was formed was placed on a cooling plate 7 and cooled (see FIG. 6).

[0050] At this time, if the semiconductor element warps or swells (causing unevenness) due to thermal contraction of the solder, this will cause variations in the electrical characteristics of the semiconductor element 3. Therefore, in the cooling step, the sample was gradually cooled over 360 seconds to 130°C (to reduce the temperature by 100°C from 230°C to 130°C), at which point it was possible to remove the sample.

[0051] This type of cooling (slow cooling) step is not performed in general solder manufacturing processes because it would increase the tact time (work time) for soldering. However, taking into consideration the effects of the semiconductor element 3 described above, the above-described slow cooling step was performed to reduce stress as much as possible.

[0052] A semiconductor element bonded body was obtained through the above steps. Fig. 7 is a schematic cross-sectional view showing a bonding interface 8 (a portion of the solder bonding member 4 and substrate 2 side, including the bonding interface between them) of the semiconductor element bonded body obtained after step 5 (see Fig. 6). As shown in Fig. 7, the bonding interface 8 contains, in order from the substrate 2 side, an interface compound 9 (a compound containing components of the substrate 2 and the solder sheet 1), a Sn—Bi alloy phase 10 (a low-melting point phase), a Sn—Bi—Sb alloy phase 11 (a medium-melting point phase), and a main phase 12.

[0053] The configuration of each phase in the entire solder joint member 4 including the substrate 2 side and the semiconductor element 3 side is as shown in FIG.

[0054] <Evaluation> The semiconductor element 3 was removed from the obtained sample (semiconductor element bonded body), and a portion of the solder bonding member 4 was scraped off from the semiconductor element 3 side, leaving only the bonding interface 8 on the substrate (Cu plate) 2 side. Note that the sample was previously washed with ethanol, since processing oil, polishing dust, moisture, etc. were mixed in during the preparation, and the sample was left to stand at room temperature for 24 hours after washing.

[0055] Differential scanning calorimetry (DSC) was performed on the joint interface 8 of the solder joint member 4. A pan containing the sample was made of platinum (Pt). DSC measurement (instrument) is a method (instrument) for measuring changes in the state of a sample, and the melting point of the solder joint member 4 at the joint interface 8 can be confirmed by DSC measurement. The temperature rise rate during DSC measurement was 2°C / min.

[0056] The DSC measurement results of the sample are shown in Figure 8. In Figure 8, the horizontal axis represents the heating temperature in the DSC measurement, and the vertical axis represents the heat flow of the solder joint member 4. Note that, since an endothermic reaction occurs when the material changes from solid to liquid, the heat flow takes a negative value. The vertical axis is logarithmic, and the heat flow is measured in mW. The values ​​shown in Figure 8 are relative values ​​(relative to the Pt pan).

[0057] From the results shown in Fig. 8, three main heat flow peaks (inverse peaks) were observed. These three peaks correspond to a phase having a melting point of 135°C or higher and lower than 145°C (low-melting-point phase: Sn-Bi alloy phase 10), a phase having a melting point of 170°C or higher and lower than 180°C (intermediate-melting-point phase: Sn-Bi-Sb alloy phase 11), and a phase having a melting point of 210°C or higher and lower than 220°C (main phase 12).

[0058] From these results, it can be confirmed that in this example, multiple phases are formed due to the interfacial reaction during bonding, as shown in the bonding interface portion 8 (part of the substrate side of the solder bonding member 4) after the fifth step shown in FIG.

[0059] Next, the bond strength of the sample (semiconductor element bonded body) was measured by a die shear test. The result was a bond strength of 48 MPa. This value is equal to or greater than the target value of 40 MPa. Note that, since the peel strength of a similar bonded body obtained using general-purpose Sn-3Ag-0.5Cu solder was 40 MPa, a bond strength higher than this was set as the target value. The reason for the high bond strength is presumed to be that the addition of Bi and Sb to the solder partially activates the solid solution strengthening mechanism.

[0060] The amount of warpage (maximum distance from the substrate) of the semiconductor element in the sample (semiconductor element bonded assembly) was also measured. As a result, the amount of warpage for the entire semiconductor element was 10 μm or less, which cleared the target of 30 μm or less. On the other hand, when using general-purpose Sn-3Ag-0.5Cu solder, the amount of warpage was 40 μm, which did not clear the target.

[0061] Comparative Example 1 In order to consider the effect of adding Sb, a sample (semiconductor element bonded body) was prepared in the same manner as in Example 1, except that the solder sheet 1 did not contain Sb (the solder sheet 1 had a composition of Sn-3.5Ag-0.7Cu-3.3Bi), and the same evaluation was performed.

[0062] Figure 9 shows the DSC measurement results for Comparative Example 1. As shown in Figure 9, no mid-melting point phase was observed in Comparative Example 1, and the low-melting point phase was outside the range of "135°C or more and less than 145°C" in Example 1. This is thought to be because the added Sb has the effect of increasing the melting points of the low-melting point phase and the mid-melting point phase. Note that, as in Example 1, a peak corresponding to a phase having a melting point of 210°C or more and less than 220°C was observed for the main phase 12. This is thought to be more pronounced due to the concentration of Sb at the bonding interface.

[0063] To clarify the above mechanism, elemental mapping was performed on the solder joint member 4 of the sample of Example 1, which was produced using the Sb-containing solder sheet 1 (Sn-3.5Ag-0.7Cu-3.3Bi-2.0Sb). As a result, as shown in Figure 10, Sb and Bi were concentrated particularly at the joint interface, indicating that this was a low-melting point phase and a medium-melting point phase.

[0064] Furthermore, as shown in the SEM photograph of Figure 11, in the sample of Comparative Example 1 produced using solder sheet 1 (Sn-3.5Ag-0.7Cu-3.3Bi) without added Sb, shrinkage cavities due to solidification shrinkage were confirmed on the interface compound 9. This is thought to be because, without the addition of Sb, the main phase 12 solidifies, and then the low-melting-point phase solidifies all at once, causing shrinkage cavities to form. In other words, the addition of Sb is thought to have the effect of suppressing solidification shrinkage cracking of the low-melting-point phase due to phase separation formed at the joint interface during the slow cooling process for suppressing residual stress in the joint in the present disclosure.

[0065] (Example 2) The amounts of Bi and Sb added were changed as shown in Table 1. For the bonded samples obtained in the same manner as in Example 1 except for the above, the presence or absence of solidification cracks was visually confirmed using SEM photographs. The confirmation results are shown in Table 1. In Table 1, "OK" indicates that there was no solidification cracking, and "NG" indicates that there was solidification cracking.

[0066]

[0067] The results shown in Table 1 show that when 2.5% by mass or more but less than 4% by mass of Bi and 0.5% by mass or more but less than 3% by mass of Sb were added, no solidification cracking occurred and good bonding was possible. Furthermore, in this case, the bond strength of the bonded sample was confirmed to be 40 MPa or more. This is thought to be because high bond strength was maintained due to the absence of solidification cracking (shrinkage cavities). The amount of warping of the semiconductor element was also good, being 10 μm or less.

[0068] When the Bi content was less than 2.5 mass%, sufficient solder wettability was not obtained, resulting in insufficient joint strength (less than 40 MPa).When the Bi content was 4 mass% or more, the proportion of the low-melting-point phase increased, causing solidification cracking and resulting in insufficient joint strength (less than 40 MPa).

[0069] When the Sb content was less than 0.5 mass %, the mid-melting point phase was not sufficiently effective, solidification cracking occurred, and the joint strength was insufficient (less than 40 MPa).When the Sb content was 3 mass % or more, the melting point of the main phase 12 also increased, and sufficient solder wettability was not obtained, resulting in insufficient joint strength (less than 40 MPa).

[0070] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0071] 1 solder sheet, 2 first object (substrate: copper plate), 3 second object (semiconductor element), 4 solder joint member, 5 heating furnace, 6 hot plate, 7 cooling plate, 8 joint interface, 9 interface compound, 10 Sn—Bi alloy phase (low melting point phase), 11 Sn—Bi—Sb alloy phase (intermediate melting point phase), 12 main phase.

Claims

1. A solder joint member for joining a first object and a second object, The alloy contains Sn as a main component, 3 mass% or more and less than 4 mass% of Ag, 0.5 mass% or more and less than 1.0 mass% of Cu, 2.5 mass% or more and less than 4 mass% of Bi, and 0.5 mass% or more and less than 3 mass% of Sb, A main phase containing Sn, Ag and Cu and having a melting point of 210° C. or more and less than 220° C.; a Sn—Bi—Sb alloy phase that covers at least a portion of the main phase and has a melting point of 170° C. or higher and lower than 180° C.; A solder joint member comprising: a Sn--Bi--Sb alloy phase that covers at least a portion of the Sn--Bi--Sb alloy phase and has a melting point of 135° C. or higher and lower than 145° C.

2. The solder joint member according to claim 1 , further comprising 0.1 mass % or more and less than 1 mass % In.

3. A solder joint member as described in claim 1 or 2, wherein the first object is a substrate and the second object is a semiconductor element.

4. A substrate and a semiconductor element are provided, A semiconductor device, wherein the substrate and the semiconductor element are joined via the solder joint member according to claim 1 .

5. A solder joining method for joining a first object and a second object, comprising the steps of: The method includes a heating step of heating a solder sheet containing Sn as a main component, 3 mass% or more and less than 4 mass% Ag, 0.5 mass% or more and less than 1.0 mass% Cu, 2.5 mass% or more and less than 4 mass% Bi, and 0.5 mass% or more and less than 3 mass% Sb, while the solder sheet is sandwiched between the first object and the second object; The soldering method, wherein in the heating step, the heating temperature is 220° C. or more and less than 230° C., and the heating time is 10 minutes or more and less than 20 minutes.

6. The soldering method according to claim 5 , wherein a total amount of oxygen contained in the solder sheet is greater than 0 ppm and less than 500 ppm.

7. A solder joining method as described in claim 5 or 6, wherein the first object is a substrate and the second object is a semiconductor element.

8. A method for manufacturing a semiconductor device including a substrate and a semiconductor element, comprising the steps of: A method for manufacturing a semiconductor device, comprising the step of bonding the substrate and the semiconductor element by using the solder bonding method according to claim 7.