WO2020136979A1 - Solder joint - Google Patents

Solder joint Download PDF

Info

Publication number
WO2020136979A1
WO2020136979A1 PCT/JP2019/031255 JP2019031255W WO2020136979A1 WO 2020136979 A1 WO2020136979 A1 WO 2020136979A1 JP 2019031255 W JP2019031255 W JP 2019031255W WO 2020136979 A1 WO2020136979 A1 WO 2020136979A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
alloy layer
content
boundary
mol
Prior art date
Application number
PCT/JP2019/031255
Other languages
French (fr)
Japanese (ja)
Inventor
英治 日野
広信 澤渡
Original Assignee
Ｊｘ金属株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ｊｘ金属株式会社 filed Critical Ｊｘ金属株式会社
Priority to JP2020502503A priority Critical patent/JPWO2020136979A1/en
Priority to CN201980003606.1A priority patent/CN111630646A/en
Publication of WO2020136979A1 publication Critical patent/WO2020136979A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
    • B23K35/24—Selection of soldering or welding materials proper
    • B23K35/26—Selection of soldering or welding materials proper with the principal constituent melting at less than 400 degrees C
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C12/00—Alloys based on antimony or bismuth

Definitions

  • the present invention relates to solder joints.
  • solder alloys Due to environmental considerations, the use of lead-free solder alloys is recommended.
  • the temperature range of the solder alloy suitable for use as solder changes depending on the composition thereof.
  • Power devices are used in a wide range of fields such as hybrid vehicles and power transmission and transformation as elements for power conversion.
  • Si chip devices could be used, but in fields where high breakdown voltage, large current applications, and high speed operation are required, SiC, GaN, etc., which have a larger bandgap than Si, have been receiving attention in recent years.
  • the operating temperature of conventional power modules was up to 170°C, but next-generation SiC, GaN, etc. may reach temperatures of 200°C or higher. Along with this, heat resistance and heat dissipation are required for each material used for a module mounting these chips.
  • Sn-3.0Ag-0.5Cu solder (Ag: 3.0% by mass, Cu: 0.5% by mass, balance Sn) is used as the joint having such characteristics.
  • a joint is preferred.
  • heat resistance is required to be higher than that of a joint made of Sn-3.0Ag-0.5Cu solder having a melting point of around 220°C.
  • a joint portion made of Pb solder Pb-5Sn, which is not preferable from the viewpoint of environmental regulations, can handle the operating temperature of the next-generation type module.
  • Pb-5Sn solder has a sufficient function as a bonding material for next-generation power modules, it is lead-containing and should not be used from the viewpoint of future environmental regulations. Further, the Ag fine powder paste can give sufficient bonding strength and heat resistance to the bonding portion depending on the conditions, but it has a problem of material cost.
  • an object of the present invention is to provide a solder joint having excellent durability in a high temperature range.
  • the present invention includes the following (1).
  • (1) It is a joint part where the UBM and the solder alloy are joined, and in order from the UBM side, Ni layer continuous from the UBM side, NiSn alloy layer, (Cu, Ni, Pd) ⁇ Sn alloy layer, A BiSn alloy layer, A joint comprising a Bi layer continuous to the solder alloy side.
  • solder joint having excellent durability in a high temperature range can be obtained.
  • FIG. 1 is an EPMA composite map image after the reflow process of the joint portion of the first embodiment.
  • FIG. 2 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion in Example 1.
  • FIG. 3 is an EPMA composite map image after the reflow process of the joint portion of Comparative Example 1.
  • FIG. 4 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion of Comparative Example 1.
  • FIG. 5 is an STM image after the reflow processing of the joint portion in Example 1.
  • FIG. 6 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (55) in FIG.
  • FIG. 7 is an STM image after the reflow process of the joint portion of Comparative Example 1.
  • FIG. 8 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (75) in FIG. 7 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there.
  • the joint portion according to the present invention is a joint portion in which a UBM and a solder alloy are joined, and in order from the UBM side, a Ni layer continuous from the UBM side, a NiSn alloy layer, and a (Cu, Ni, Pd) ⁇ Sn alloy layer. , BiSn alloy layer and a Bi layer continuous to the solder alloy side.
  • the UBM (Under Bump Metal) is a metal layer that is interposed to form a solder bump on an electrode (for example, an Al electrode) on a chip (for example, a Si chip).
  • a Ni layer or a Ni alloy layer is usually formed, and a Pd layer and/or an Au layer or the like is formed thereon.
  • the UBM includes, for example, a Ni layer formed on an Al electrode on a Si chip, a Pd layer formed thereon, and an Au layer formed thereon.
  • the metal layer can be mentioned.
  • solder alloy may be a lead-free solder alloy, for example, the Bi—Cu—Sn alloy having the composition disclosed in the examples.
  • the joint portion of the present invention is a joint portion in which the UBM and the solder alloy are joined, the UBM loses the constitution of the original metal layer due to the joining, and only the Ni layer, which was the main layer of the UBM, can be detected. Remains as.
  • the Ni layer derived from this UBM is continuous all the way to the joint, and in the vicinity of the joint, the Ni layer is continuous from the UBM side.
  • the UBM side the side on which the UBM existed on both sides of the joining is referred to as the UBM side in this specification.
  • a Ni layer continuous from the UBM side may be simply referred to as a Ni layer.
  • This Ni layer is a layer continuous from the UBM side, but in order to clarify the structure of the joint, it is described as one of the layers constituting the joint in this specification.
  • solder alloy side of joint Since the joint portion of the present invention is a joint portion in which the UBM and the solder alloy are joined, the solder alloy side of the joint portion is continuous with the solder alloy.
  • the solder alloy is an alloy whose main component is Bi, and the solder alloy side of the joint is a Bi layer continuous to the solder alloy side.
  • the solder alloy has a phase different from that of the original solder alloy due to the joining, and of both sides of the joining, the side where this solder alloy exists is referred to as the solder alloy side in this specification.
  • the Bi layer continuous to the solder alloy side may be simply referred to as a Bi layer.
  • the Bi layer is a layer continuous to the solder alloy side, but is described as one of the layers forming the joint in this specification in order to clarify the constitution of the joint.
  • the NiSn alloy layer contains Ni, Sn, and P.
  • the Ni content at the boundary with the Ni layer is larger than the Ni content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer.
  • the Sn content at the boundary with the Ni layer is smaller than the Sn content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer.
  • the Sn content at the boundary with the Ni layer is 0.4 mol% or less, preferably 0.35 mol% or less.
  • the P content at the boundary with the Ni layer is larger than the P content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer.
  • the P content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is 0.5 mol% or less, preferably 0.3 mol% or less.
  • the Ni content at each distance from the boundary with the Ni layer is in the range of 21 mol% to 83 mol%, preferably in the range of 22 mol% to 80 mol%. That the Ni content at each distance from the boundary with the Ni layer is within the above range means that one or more measurement points are provided according to the distance from the boundary with the Ni layer, and the Ni content at each measurement point. It means that all of them are within the above range or can be estimated as such. Being able to make such an estimation means being able to make such an estimation, for example, by extrapolation from measurement values at adjacent measurement points.
  • the number of measurement points is not particularly limited, but from the viewpoint of practical measurement operation, for example, about 1 to 20 or about 1 to 5 measurement points can be provided. In the following description, the description “at each distance” is used in the same meaning as described above.
  • the Sn content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 48 mol%, preferably 0.25 mol% to 45 mol%. In range. That the Sn content at each distance from the boundary with the Ni layer is within the above range has the same meaning as described above for the Ni content.
  • the P content at each distance from the boundary with the Ni layer is in the range of 0.1 mol% to 10 mol%, preferably 0.2 mol% to 9 mol%. In range. That the P content at each distance from the boundary with the Ni layer is in the above range has the same meaning as described above for the Ni content.
  • the Bi content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is 2 mol% or less, preferably 1 mol% or less.
  • the Bi content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 2 mol%, preferably 0.3 mol% to 1.5 mol%. It is in the range of mol %. That the Bi content at each distance from the boundary with the Ni layer is within the above range has the same meaning as described above for the Ni content.
  • the NiSn alloy layer has a significantly reduced Bi content, that is, Bi intrusion is efficiently prevented.
  • the NiSn alloy layer has a thickness of, for example, 0.03 to 0.1 [ ⁇ m], preferably 0.04 to 0.1 [ ⁇ m], and preferably 0.05 to 0.1 [. ⁇ m], preferably in the range of 0.06 to 0.1 [ ⁇ m].
  • the Cu content at the boundary with the Ni layer is smaller than the Cu content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer.
  • the Cu content at the boundary with the Ni layer is 4 mol% or less, preferably 3 mol% or less.
  • the NiSn alloy layer further contains Pd.
  • the Pd content at the boundary with the Ni layer is smaller than the Pd content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer.
  • the Pd content at the boundary with the Ni layer is 3 mol% or less, preferably 2 mol% or less.
  • the Ni layer is a UBM derived layer as described above.
  • the Ni layer has a Ni content of 83 mol% or more, preferably 85 mol% or more, at each distance within 0.2 [ ⁇ m] from the boundary with the NiSn alloy layer.
  • the Ni layer may contain an elemental component derived from UBM.
  • the Ni layer may contain P, for example.
  • the Ni layer is such that the Bi content at each distance within 0.2 [ ⁇ m] from the boundary with the NiSn alloy layer is 0.2 mol% or less, preferably 0.1 mol% or less. is there.
  • the Bi content at each distance from the boundary with the NiSn alloy layer is the above or less means that the Ni content at each distance from the boundary with the Ni layer in the NiSn alloy layer has the same meaning as described above. is there.
  • the Ni content in the Ni layer is extremely reduced, that is, the invasion of Bi is effectively prevented.
  • the (Cu, Ni, Pd) ⁇ Sn alloy layer is a layer of Sn alloy in which Cu, Ni, and Pd are in solid solution. It is considered that this (Cu, Ni, Pd) ⁇ Sn alloy layer is formed from the constituent elements of UBM and the solder alloy. In a preferred embodiment, the (Cu, Ni, Pd) ⁇ Sn alloy layer contains Cu, Ni, Pd, and Sn.
  • the Cu content at each distance from the boundary with the NiSn alloy layer is in the range of 10 mol% to 22 mol%, preferably 12 mol% to It is in the range of 20 mol %.
  • the Ni content at each distance from the boundary with the NiSn alloy layer is in the range of 13 mol% to 21 mol%, preferably 14 mol% to It is in the range of 20 mol %.
  • the Pd content at each distance from the boundary with the NiSn alloy layer is in the range of 5 mol% to 19 mol%, preferably 6 mol% to It is in the range of 18 mol %.
  • the Sn content at each distance from the boundary with the NiSn alloy layer is in the range of 44 mol% to 55 mol%, preferably 45 mol% to It is in the range of 54 mol %.
  • the (Cu, Ni, Pd) ⁇ Sn alloy layer further contains Bi.
  • the Bi content at the boundary with the NiSn alloy layer is 2 mol% or less, preferably 1 mol% or less.
  • the Bi content in the (Cu, Ni, Pd) ⁇ Sn alloy layer when the Bi content is measured according to the distance from the boundary with the NiSn alloy layer, the Bi content is 0.1 mol% to There is a distance in the range of 24 mol%, preferably in the range of 0.2 mol% to 23 mol%, or in the range of 1 mol% to 24 mol%, or in the range of 2 mol% to 23 mol%.
  • the (Cu, Ni, Pd) ⁇ Sn alloy layer has a peak of Bi content, and the peak is located away from the boundary with the NiSn alloy layer,
  • the NiSn alloy layer prevents Bi from entering from the Bi layer side. That is, in a preferred embodiment, the peak of Bi content present in the (Cu, Ni, Pd) ⁇ Sn alloy layer, and the peak of Bi content located away from the boundary with the NiSn alloy layer,
  • the Bi content is in the above range and is larger than the Bi content at the boundary with the NiSn alloy layer.
  • the Bi content at the boundary with the BiSn alloy layer is 0.5 mol% or less, preferably 0.4 mol% or less.
  • the BiSn alloy layer contains Bi and Sn.
  • the Bi content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is 0.5 mol% or less, preferably 0.4 mol% or less.
  • the Sn content at the boundary with the Bi layer is 2 mol% or less, preferably 1 mol% or less.
  • the BiSn alloy layer further contains Cu, Ni and Pd.
  • the Cu content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is larger than the Cu content at the boundary with the Bi layer.
  • the Cu content at the boundary with the Bi layer is 0.5 mol% or less, preferably 0.3 mol% or less.
  • the Ni content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is larger than the Ni content at the boundary with the Bi layer.
  • the Ni content at the boundary with the Bi layer is 1 mol% or less, preferably 0.5 mol% or less.
  • the Pd content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is larger than the Pd content at the boundary with the Bi layer.
  • the Pd content at the boundary with the Bi layer is 0.6 mol% or less, preferably 0.3 mol% or less.
  • the Bi layer is a Bi layer continuous to the solder alloy side as described above, and contains Bi derived from the solder alloy as a main component.
  • the Bi layer has a Bi content of 97 mol% or more, preferably 98 mol% or more, at each distance within 0.2 [ ⁇ m] from the boundary with the BiSn alloy layer.
  • the Bi layer may contain an elemental component derived from the solder alloy.
  • phase liberated from the (Cu, Ni, Pd) ⁇ Sn alloy layer in the Bi layer there is no (Cu, Ni, Pd) ⁇ Sn alloy phase liberated from the (Cu, Ni, Pd) ⁇ Sn alloy layer in the Bi layer.
  • the phase of the (Cu, Ni, Pd) ⁇ Sn alloy released from the (Cu, Ni, Pd) ⁇ Sn alloy layer is specifically described as the phase in the image of the comparative example in Examples described later. This is the phase.
  • such phases are preferably absent, at least in the field of view under observation.
  • the concentration (mol %) of each element can be measured by the means disclosed in the examples described later, and specifically, it can be measured using STM (manufactured by JEOL, device name: JEM-2100F). You can The element concentration in the present invention means each element concentration when the total of Ni, Sn, Bi, Cu, Pd and P is set to 100 mol %.
  • the joint part according to the present invention can have a joint strength (shear strength) after being kept at a high temperature of 250° C. for 1000 hours, for example, 40 MPa or more, preferably 42 MPa or more. That is, it has excellent durability in a high temperature range.
  • This bonding strength can be measured by the procedure described later in the examples.
  • the reason why the joint of the present invention has excellent durability in a high temperature range is unknown, but from the comparison with Comparative Examples in Examples described later, the joint of the present invention has the above-mentioned layer structure. According to the present invention, it is possible to prevent the invasion of Bi from the Bi layer side to the Ni layer side by providing a predetermined NiSn alloy layer, thereby providing excellent characteristics. Have insight.
  • the present invention includes the following (1) and the following. (1) It is a joint part where the UBM and the solder alloy are joined, and in order from the UBM side, Ni layer continuous from the UBM side, NiSn alloy layer, (Cu, Ni, Pd) ⁇ Sn alloy layer, A BiSn alloy layer, A joint comprising a Bi layer continuous to the solder alloy side.
  • the NiSn alloy layer contains Ni, Sn, and P, In the NiSn alloy layer, the Ni content at the boundary with the Ni layer is larger than the Ni content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer, In the NiSn alloy layer, the Sn content at the boundary with the Ni layer is smaller than the Sn content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer, In the NiSn alloy layer, the Sn content at the boundary with the Ni layer is 0.4 mol% or less, In the NiSn alloy layer, the P content at the boundary with the Ni layer is larger than the P content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer, In the NiSn alloy layer, the P content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is 0.5 mol% or less, the joint according to (1).
  • the NiSn alloy layer contains Ni, Sn, and P, In the NiSn alloy layer, the Ni content at each distance from the boundary with the Ni layer is in the range of 21 mol% to 83 mol%, In the NiSn alloy layer, the Sn content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 48 mol%, In the NiSn alloy layer, the joint portion according to any one of (1) to (2), wherein the P content at each distance from the boundary with the Ni layer is in the range of 0.1 mol% to 10 mol %.
  • the Cu content at the boundary with the Ni layer is smaller than the Cu content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer, The joint portion according to any one of (2) to (6), wherein in the NiSn alloy layer, the Cu content at the boundary with the Ni layer is 4 mol% or less.
  • the NiSn alloy layer further contains Pd, In the NiSn alloy layer, the Pd content at the boundary with the Ni layer is smaller than the Pd content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer, In the NiSn alloy layer, the joint portion according to any one of (2) to (7), wherein the Pd content at the boundary with the Ni layer is 3 mol% or less.
  • the Ni layer has a Bi content of 0.2 mol% or less at each distance within 0.2 [ ⁇ m] from the boundary with the NiSn alloy layer, and the bonding according to any one of (1) to (8) above. Department.
  • the (Cu, Ni, Pd) ⁇ Sn alloy layer contains Cu, Ni, Pd, and Sn, In the (Cu, Ni, Pd) ⁇ Sn alloy layer, the Cu content at each distance from the boundary with the NiSn alloy layer is in the range of 10 mol% to 22 mol %, In the (Cu, Ni, Pd) ⁇ Sn alloy layer, the Ni content at each distance from the boundary with the NiSn alloy layer is in the range of 13 mol% to 21 mol %, In the (Cu, Ni, Pd) ⁇ Sn alloy layer, the Pd content at each distance from the boundary with the NiSn alloy layer is in the range of 5 mol% to 19 mol %, In the (Cu, Ni, Pd) ⁇ Sn alloy layer, the Sn content at each distance from the Cu
  • the (Cu, Ni, Pd) ⁇ Sn alloy layer further contains Bi, In the (Cu, Ni, Pd) ⁇ Sn alloy layer, the Bi content at the boundary with the NiSn alloy layer is 2 mol% or less, In the (Cu, Ni, Pd) ⁇ Sn alloy layer, when the Bi content is measured according to the distance from the boundary with the NiSn alloy layer, the Bi content is in the range of 0.1 mol% to 24 mol %. There is a distance, The joint portion according to (10), wherein in the (Cu, Ni, Pd) ⁇ Sn alloy layer, the Bi content at the boundary with the BiSn alloy layer is 0.5 mol% or less.
  • the BiSn alloy layer contains Bi and Sn, In the BiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is 0.5 mol% or less, The joint portion according to any one of (1) to (11), wherein in the BiSn alloy layer, the Sn content at the boundary with the Bi layer is 2 mol% or less.
  • the BiSn alloy layer further contains Cu, Ni and Pd, In the BiSn alloy layer, the Cu content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is larger than the Cu content at the boundary with the Bi layer, In the BiSn alloy layer, the Cu content at the boundary with the Bi layer is 0.5 mol% or less, In the BiSn alloy layer, the Ni content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is larger than the Ni content at the boundary with the Bi layer, In the BiSn alloy layer, the Ni content at the boundary with the Bi layer is 1 mol% or less, In the BiSn alloy layer, the Pd content at the boundary with the (Cu, Ni, Pd) ⁇ Sn alloy layer is larger than the Pd content at the boundary with the Bi layer, In the BiSn alloy layer, the joint portion according to (12), wherein the Pd content at the boundary with the Bi layer is 0.6 mol% or less.
  • the UBM is the joint part according to any one of (1) to (14), which is a UBM formed by sequentially stacking nickel, palladium, and gold on an electrode.
  • the invention of the present application includes an electronic component, a power device, a printed circuit board, an LED, a flexible circuit material, and a heat dissipation material having the above-mentioned joint portion.
  • Example 1 [Formation of UBM] An Al surface (thickness: 3 ⁇ m) was formed on one surface of the Si wafer by sputtering, and a polyimide film was further formed by coating, and then a land having an opening with a diameter of 300 ⁇ m was formed in the polyimide film by exposure and development. Further, a Ni layer (thickness 2.5 ⁇ m), a Pd layer (thickness 0.05 ⁇ m), and an Au layer (thickness 0.02 ⁇ m) are sequentially formed on the land portion by electroless plating to form a UBM (Under Bump Metal). ) Is provided. Since the reducing agent for hypophosphite ions is added to the electroless Ni plating solution, P is codeposited on the Ni layer.
  • solder powder The composition of the solder powder used in Example 1 by ICP analysis is shown in Table 1. The solder powder used was 300 ⁇ m ⁇ .
  • EPMA analysis, STM analysis After that, the sample was encapsulated with resin and the cross section was polished. The cleaned and smoothed sample surface was analyzed by EPMA (manufactured by JEOL, device name: JXA-8500F). Since the thickness of the solder joint portion after the reflow treatment is about 1 ⁇ m or less, the solder joint portion was measured by a highly accurate STM (manufactured by JEOL, device name: JEM-2100F). Although the image accuracy of the measurement by EPMA is inferior to that of STM, image processing was performed with the size of one pixel being 0.08 ⁇ m. For further quantification, the same sample was thinly processed and measured by STM.
  • FIG. 1 shows an image of a composite map created by measuring the cross section of the joint portion of Example 1 immediately after the reflow treatment by EPMA.
  • Example 1 [Share strength measurement] The joint portion of Example 1 was subjected to shear strength measurement as described below after being held at a temperature of 250° C. for 1000 hours in the atmosphere after the reflow treatment described above. The results are shown in Table 1.
  • the bonding strength was measured according to MIL STD-883G.
  • the tool attached to the load sensor descends to the board surface, the device detects the board surface and stops descending, and the tool rises to the set height from the detected board surface and pushes the joint with the tool The load was measured.
  • the results are summarized in Table 1.
  • Comparative Example 1 As Comparative Example 1, a solder powder having a composition different from that of Example 1 is used, reflow treatment is performed under conditions different from those of Example 1, and the other steps are similar to those of Example 1 to form a joint. Then, EPMA measurement, STM measurement, and shear strength measurement were performed on this joint. Table 1 shows the ICP analysis value of the composition of the solder powder of Comparative Example 1 and the shear strength measurement result.
  • the reflow processing conditions of Comparative Example 1 were as follows: The temperature was raised from room temperature to 150°C at a heating rate of 0.9°C/sec. Next, the temperature was raised from 150° C. to 290° C. at a heating rate of 4.5° C./sec. Then the temperature of 290° C. was maintained for 40 seconds. Next, it was cooled from 290° C. to room temperature at an initial temperature decreasing rate of 8° C./sec. These operations were performed in a nitrogen atmosphere.
  • Fig. 3 shows an image of a composite map created by measuring the cross section of the joint of Comparative Example 1 immediately after the reflow treatment by EPMA.
  • FIG. 5 shows an STM image of the cross section of the joint portion of Example 1 immediately after the reflow treatment.
  • FIG. 6 is a graph showing the numerical value of each element concentration (mol %) along the analysis line written in this STM image for the joint portion of Example 1. Regarding the element concentration (mol %), the total of 6 elements in the graph, that is, Ni, Sn, Bi, Cu, Pd, and P was 100%.
  • FIG. 7 shows an STM image of the cross section of the joint of Comparative Example 1 immediately after the reflow treatment.
  • FIG. 8 is a graph showing the numerical value of each element concentration (mol %) along the analysis line written in this STM image for the joint portion of Comparative Example 1.
  • FIG. 1 is an EPMA composite map image after the reflow process of the joint portion of the first embodiment.
  • a layer considered as a (Cu, Ni, Pd) ⁇ Sn layer (13) was observed, and a (Cu, Ni, Pd) ⁇ Sn layer was observed.
  • the (Cu, Ni, Pd) ⁇ Sn layer (13) has a relatively uniform thickness, and is separated from the (Cu, Ni, Pd) ⁇ Sn layer (13) in the Bi layer (14). No (Cu,Ni,Pd) ⁇ Sn phase was observed. In FIG. 1, no penetration of Bi into the Ni layer (11) is observed even in the image of the colored composite map.
  • the black region occupying the lower half or more of the image of FIG. 1 is the Al layer (3 ⁇ m) that is the base of the Ni layer (11) and the Si base material that is the base of the Al layer.
  • FIG. 2 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion in Example 1.
  • a layer that is considered to be a (Cu, Ni, Pd) ⁇ Sn layer (23) was observed, and a (Cu, Ni, Pd) ⁇ Sn layer was observed.
  • a NiSn alloy layer (having a thickness of about 0.2 ⁇ m) (22). No Bi intrusion is observed in the NiSn alloy layer (22) even in the image of the composite map that is colored.
  • the (Cu, Ni, Pd) ⁇ Sn layer (23) has an increased thickness as compared with FIG.
  • FIG. 3 is an EPMA composite map image after the reflow process of the joint portion of Comparative Example 1.
  • a layer that is considered to be a (Cu, Ni, Pd) ⁇ Sn layer (32) was observed, and a (Cu, Ni, Pd) ⁇ Sn layer was observed.
  • a layer (thickness: about 0.1 ⁇ m) which is also seen as a NiSn alloy layer (32′), but the NiSn(32′) alloy layer has a trace amount that cannot be observed in gray scale.
  • Bi intrusion (35) is observed in the image of the colorized composite map.
  • the (Cu, Ni, Pd) ⁇ Sn layer (32) has a non-uniform thickness, and is separated from this (Cu, Ni, Pd) ⁇ Sn layer (32) (Cu, Ni, Pd).
  • the ⁇ Sn phase (33) is observed in the Bi layer (34).
  • the penetration of Bi into the Ni layer (31) is not observed even in the image of the colorized composite map.
  • the black region occupying the lower half or more of the image of FIG. 3 is the Al layer (3 ⁇ m) that is the base of the Ni layer (31) and the Si base material that is the base of the Al layer.
  • FIG. 4 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion of Comparative Example 1.
  • the Ni layer is present as in FIG. 3, but in the image of the colorized composite map, the penetration of Bi is observed in almost the entire thickness of the Ni layer (about 1.8 ⁇ m in thickness).
  • the Ni layer (42) is a thin Ni layer (42), and the Ni layer (41) in which no intrusion of Bi is observed is very thin (about 0.4 ⁇ m thick).
  • FIG. 5 is an STM image after the reflow processing of the joint portion in Example 1.
  • a layer that is considered to be a (Cu, Ni, Pd) ⁇ Sn layer (53) is observed in the vicinity of the interface between the Ni layer (51) and the Bi layer (54).
  • An area (52) as if an elongated hole is formed in the vertical direction is observed.
  • this region (52) is a P-rich region having a relatively high P concentration. The thickness of this P-rich region was about 0.13 ⁇ m.
  • FIG. 6 is a graph prepared by performing analysis along the analysis line (55) and measuring the concentration of atoms at each analysis point.
  • FIG. 6 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (55) in FIG. 5 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there.
  • the left side of the graph is the Ni layer side
  • the right side of the graph is the Bi layer side.
  • the starting point of the horizontal axis is in the Ni layer. From 0.15 ⁇ m, the Ni concentration decreases, and near 0.22 ⁇ m, the Sn concentration begins to rise rapidly from the state where there is almost no Sn concentration. It is considered that the NiSn alloy layer starts from this position.
  • the P concentration at this position is relatively higher than before and after it, the P concentration decreases with increasing distance, and the P concentration almost disappears near 0.26 ⁇ m.
  • the Ni concentration decreases and the Sn concentration increases.
  • the NiSn alloy layer ends at the position where the P concentration disappears and a new (Cu, Ni, Pd) ⁇ Sn layer starts.
  • the Pd concentration is relatively higher than before and after it.
  • the Sn concentration is estimated to be 48 mol% and the Ni concentration is 21 mol%, and the value of ⁇ is 0.8.
  • the BiSn alloy layer Cu, Ni, and Pd are present in addition to Bi and Sn.
  • concentrations of Cu, Ni, and Pd in the BiSn alloy layer all decrease with an increase in the distance, and disappear in the vicinity of 0.56 ⁇ m. It is considered that the BiSn alloy layer ends and the Bi layer starts at the position where the Cu, Ni, and Pd concentrations disappear.
  • FIG. 7 is an STM image after the reflow process of the joint portion of Comparative Example 1.
  • a layer considered to be a (Cu, Ni, Pd) ⁇ Sn layer (73) is observed near the interface between the Ni layer (71) and the Bi layer (74).
  • the P-rich region (72) which seems to have an elongated hole in the up-and-down direction, is slightly uneven in shape as compared with FIG. 5, the analysis is performed along the observed analysis line (75).
  • FIG. 8 is a graph created by measuring the concentration of atoms at each analysis point.
  • FIG. 8 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (75) in FIG. 7 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there.
  • the left side of the graph is the Ni layer side
  • the right side of the graph is the Bi layer side.
  • Bi penetrates to the position corresponding to the boundary between the NiSn alloy layer and the (Cu, Ni, Pd) ⁇ Sn layer, and in the graph of FIG.
  • the graph of FIG. 6 it is observed that Bi penetrates through the position corresponding to the NiSn alloy layer to the position corresponding to the Ni layer in the graph of FIG.
  • the Sn concentration is estimated to be 18 mol% and the Ni concentration is estimated to be 23 mol%. It became 0.0.
  • the ⁇ of the (Cu, Ni, Pd) ⁇ Sn layer was estimated to be 0.7 to 1.2, and the average value was 0.85.
  • the present invention provides a solder joint portion having excellent durability in a high temperature range without containing lead added.
  • the present invention is an industrially useful invention.
  • Ni layer 12 NiSn alloy layer 13 (Cu, Ni, Pd) ⁇ Sn layer 14 Bi layer 21 Ni layer 22 NiSn alloy layer 23 (Cu, Ni, Pd) ⁇ Sn layer 24 Bi layer 31 Ni layer (no Bi penetration) 32 (Cu,Ni,Pd) ⁇ Sn layer 32′ NiSn alloy layer 33 Free (Cu,Ni,Pd) ⁇ Sn phase 34 Bi layer 35 Penetration Bi 41 Ni layer (no Bi penetration) 42 Ni layer (with Bi intrusion) 43' NiSn alloy phase (discontinuous) 43 (Cu, Ni, Pd) ⁇ Sn layer 44 Free (Cu, Ni, Pd) ⁇ Sn phase 45 Bi layer 46 Ni phase 51 Ni layer 52 P rich region 53 (Cu, Ni, Pd) ⁇ Sn layer 54 Bi layer 55 Analysis line 71 Ni layer 72 P rich region 73 (Cu, Ni, Pd) ⁇ Sn layer 74 Bi layer 75 Analysis line

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Mechanical Engineering (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)
  • Electroplating Methods And Accessories (AREA)

Abstract

A solder joint, which has excellent durability in a high-temperature range, is provided by means of a joint that bonds a UBM and a solder alloy and that contains, in order from the UBM side, a Ni layer connected from the UBM side, a NiSn alloy layer, a (Cu, Ni, Pd)αSn alloy layer, a BiSn alloy layer, and a Bi layer connected to the solder alloy side.

Description

はんだ接合部Solder joint
　本発明は、はんだ接合部に関する。 The present invention relates to solder joints.
　環境面の配慮から、鉛を含有しないはんだ合金の使用が推奨されている。はんだ合金は、その組成に応じてはんだとしての使用に適した温度域が変わってくる。 Due to environmental considerations, the use of lead-free solder alloys is recommended. The temperature range of the solder alloy suitable for use as solder changes depending on the composition thereof.
　パワーデバイスは、電力変換用の素子として、ハイブリッド自動車、送変電など幅広い分野で使用されている。従来はＳｉチップのデバイスで対応できたが、高耐圧、大電流用途、高速動作が求められる分野では、Ｓｉよりもバンドギャップが大きいＳｉＣ、ＧａＮ等が近年注目を浴びている。 　Power devices are used in a wide range of fields such as hybrid vehicles and power transmission and transformation as elements for power conversion. Conventionally, Si chip devices could be used, but in fields where high breakdown voltage, large current applications, and high speed operation are required, SiC, GaN, etc., which have a larger bandgap than Si, have been receiving attention in recent years.
　従来のパワーモジュールでは動作温度が１７０℃程度までであったのが、次世代型のＳｉＣ、ＧａＮ等では２００℃あるいはそれ以上の温度域となる可能性があるとされる。これに伴い、これらチップを搭載したモジュールに使用される各材料には耐熱性、放熱性が求められている。 The operating temperature of conventional power modules was up to 170°C, but next-generation SiC, GaN, etc. may reach temperatures of 200°C or higher. Along with this, heat resistance and heat dissipation are required for each material used for a module mounting these chips.
　このような特性を備えた接合部としては、Ｐｂフリーの観点からは例えばＳｎ－３．０Ａｇ－０．５Ｃｕはんだ（Ａｇ：３．０質量％、Ｃｕ：０．５質量％、残部Ｓｎ）による接合部が好ましいとされる。しかし、次世代型モジュールでは動作温度が２００℃を超える可能性があるので、融点が２２０℃付近であるＳｎ－３．０Ａｇ－０．５Ｃｕはんだによる接合部よりも、さらに耐熱性が求められる。具体的にはラジエターの冷却およびエンジン回りの温度の許容性から、好ましくは２５０℃以上の高温に耐える接合部が求められる。あるいは、環境規制の観点から好ましくないＰｂはんだ（Ｐｂ－５Ｓｎ）による接合部であれば次世代型モジュールの動作温度には対応しうるとされる。 From the viewpoint of Pb-free, for example, Sn-3.0Ag-0.5Cu solder (Ag: 3.0% by mass, Cu: 0.5% by mass, balance Sn) is used as the joint having such characteristics. A joint is preferred. However, since the operating temperature of the next-generation type module may exceed 200° C., heat resistance is required to be higher than that of a joint made of Sn-3.0Ag-0.5Cu solder having a melting point of around 220°C. Specifically, from the viewpoint of the cooling of the radiator and the tolerance of the temperature around the engine, it is desirable to have a joint that can withstand a high temperature of 250° C. or higher. Alternatively, it is said that a joint portion made of Pb solder (Pb-5Sn), which is not preferable from the viewpoint of environmental regulations, can handle the operating temperature of the next-generation type module.
　また、近年次世代型モジュールの接合部として注目されているのが金属微粉ペーストによる接合部である。金属粉のサイズが小さいので、表面エネルギーが高く、その金属の融点よりもはるかに低い温度で焼結が始まる。そして、はんだとは異なり、いったん焼結すれば、その金属の融点近くまで昇温しないと再溶融しない。このような特性を生かし、Ａｇ微粉ペーストによる接合部の開発が進んでいる（特許文献１）。 Also, in recent years, attention has been paid to the joints of next-generation modules as to the joints made of fine metal powder paste. Due to the small size of the metal powder, the surface energy is high and sintering begins at temperatures well below the melting point of the metal. Then, unlike solder, once sintered, it will not remelt unless the temperature is raised to near the melting point of the metal. Taking advantage of such characteristics, development of a joint portion using Ag fine powder paste is in progress (Patent Document 1).
　Ｐｂ－５Ｓｎはんだは次世代型パワーモジュールの接合材料としての機能は十分であるが、有鉛であり、将来的な環境規制の観点からも使用しないことが望ましい。また、Ａｇ微粉ペーストは条件によっては十分な接合強度、耐熱性を接合部に付与することが可能であるが、材料価格の問題点を抱える。 Although Pb-5Sn solder has a sufficient function as a bonding material for next-generation power modules, it is lead-containing and should not be used from the viewpoint of future environmental regulations. Further, the Ag fine powder paste can give sufficient bonding strength and heat resistance to the bonding portion depending on the conditions, but it has a problem of material cost.
国際公開第２０１１／１５５０５５号International Publication No. 2011/155055
　次世代型パワーモジュールの接合材料に求められる高温域、例えば２５０℃を超える温度域においても、優れた耐久性を有するはんだ接合部が、求められていた。 There was a demand for solder joints with excellent durability even in the high temperature range required for joining materials for next-generation power modules, for example, in the temperature range exceeding 250°C.
　したがって、本発明の目的は、高温域において優れた耐久性を有する、はんだ接合部を提供することにある。 Therefore, an object of the present invention is to provide a solder joint having excellent durability in a high temperature range.
　高温域において優れた特性を有するはんだ接合部の研究開発の多くが、はんだ合金の融点に着目して行われてきた。しかし、本発明者はさらに鋭意研究開発を行ったところ、はんだ接合部の高温特性は、むしろはんだ接合によって形成された接合部の構造に依存することを見いだし、その構造を特定して、本発明に到達した。 Much of the research and development of solder joints that have excellent properties at high temperatures has focused on the melting point of the solder alloy. However, as a result of further research and development, the present inventor found that the high temperature characteristics of the solder joint depended rather on the structure of the joint formed by the solder joint, and the structure was specified to identify the present invention. Reached
　したがって、本発明は以下の（１）を含む。
　（１）
　ＵＢＭとはんだ合金を接合した接合部であって、ＵＢＭ側から順に、
　ＵＢＭ側から連続するＮｉ層と、
　ＮｉＳｎ合金層と、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層と、
　ＢｉＳｎ合金層と、
　はんだ合金側へと連続するＢｉ層を含んでなる、接合部。 Therefore, the present invention includes the following (1).
(1)
It is a joint part where the UBM and the solder alloy are joined, and in order from the UBM side,
Ni layer continuous from the UBM side,
NiSn alloy layer,
(Cu, Ni, Pd) αSn alloy layer,
A BiSn alloy layer,
A joint comprising a Bi layer continuous to the solder alloy side.
　本発明によれば、高温域において優れた耐久性を有する、はんだ接合部を得ることができる。 According to the present invention, a solder joint having excellent durability in a high temperature range can be obtained.
図１は、実施例１の接合部のリフロー処理後のＥＰＭＡ複合マップ画像である。FIG. 1 is an EPMA composite map image after the reflow process of the joint portion of the first embodiment. 図２は、実施例１の接合部のリフロー処理後に、２５０℃の温度で１０００時間保持した後のＥＰＭＡ複合マップ画像である。FIG. 2 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion in Example 1. 図３は、比較例１の接合部のリフロー処理後のＥＰＭＡ複合マップ画像である。FIG. 3 is an EPMA composite map image after the reflow process of the joint portion of Comparative Example 1. 図４は、比較例１の接合部のリフロー処理後に、２５０℃の温度で１０００時間保持した後のＥＰＭＡ複合マップ画像である。FIG. 4 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion of Comparative Example 1. 図５は、実施例１の接合部のリフロー処理後のＳＴＭ画像である。FIG. 5 is an STM image after the reflow processing of the joint portion in Example 1. 図６は、図５の分析ライン（５５）に沿って分析して得られた原子の濃度（モル％）を縦軸とし、分析ラインの分析の開始点からの距離を横軸としたグラフである。FIG. 6 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (55) in FIG. 5 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there. 図７は、比較例１の接合部のリフロー処理後のＳＴＭ画像である。FIG. 7 is an STM image after the reflow process of the joint portion of Comparative Example 1. 図８は、図７の分析ライン（７５）に沿って分析して得られた原子の濃度（モル％）を縦軸とし、分析ラインの分析の開始点からの距離を横軸としたグラフである。FIG. 8 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (75) in FIG. 7 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there.
　以下に本発明を実施の態様をあげて詳細に説明する。本発明は以下にあげる具体的な実施の態様に限定されるものではない。 The present invention will be described in detail below with reference to embodiments. The present invention is not limited to the specific embodiments described below.
［ＵＢＭとはんだ合金を接合した接合部］
　本発明による接合部は、ＵＢＭとはんだ合金を接合した接合部であって、ＵＢＭ側から順に、ＵＢＭ側から連続するＮｉ層と、ＮｉＳｎ合金層と、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層と、ＢｉＳｎ合金層と、はんだ合金側へと連続するＢｉ層を含んでなる。 [Joint part where UBM and solder alloy are joined]
The joint portion according to the present invention is a joint portion in which a UBM and a solder alloy are joined, and in order from the UBM side, a Ni layer continuous from the UBM side, a NiSn alloy layer, and a (Cu, Ni, Pd)αSn alloy layer. , BiSn alloy layer and a Bi layer continuous to the solder alloy side.
　このような層構造によって、高温域において優れた耐久性を有する、はんだ接合部を得ることができる。 With such a layer structure, it is possible to obtain a solder joint having excellent durability in a high temperature range.
［ＵＢＭ］
　ＵＢＭ（Ｕｎｄｅｒ　Ｂｕｍｐ　Ｍｅｔａｌ）とは、チップ（例えばＳｉチップ）の上の電極（例えばＡｌ電極）に、はんだバンプを形成するために介在させる金属層である。ＵＢＭとしては、通常は、Ｎｉ層又はＮｉ合金層を形成して、その上にＰｄ層及び／又はＡｕ層などが形成されている。本発明の好適な実施の態様において、ＵＢＭとして、例えば、Ｓｉチップ上のＡｌ電極上に形成された、Ｎｉ層、その上に形成されたＰｄ層、その上に形成されたＡｕ層からなる、金属層をあげることができる。 [UBM]
The UBM (Under Bump Metal) is a metal layer that is interposed to form a solder bump on an electrode (for example, an Al electrode) on a chip (for example, a Si chip). As the UBM, a Ni layer or a Ni alloy layer is usually formed, and a Pd layer and/or an Au layer or the like is formed thereon. In a preferred embodiment of the present invention, the UBM includes, for example, a Ni layer formed on an Al electrode on a Si chip, a Pd layer formed thereon, and an Au layer formed thereon. The metal layer can be mentioned.
［はんだ合金］
　好適な実施の態様において、はんだ合金として、無鉛はんだ合金をあげることができ、例えば実施例に開示された組成のＢｉ－Ｃｕ－Ｓｎ合金をあげることができる。 [Solder alloy]
In a preferred embodiment, the solder alloy may be a lead-free solder alloy, for example, the Bi—Cu—Sn alloy having the composition disclosed in the examples.
［接合部のＵＢＭ側］
　本発明の接合部は、ＵＢＭとはんだ合金を接合した接合部であるから、接合によってＵＢＭは元の金属層の構成を失っており、ＵＢＭの主たる層であったＮｉ層だけが検出可能な層として残っている。このＵＢＭに由来するＮｉ層が接合部までずっと連続しており、接合部付近において、上記のＵＢＭ側から連続するＮｉ層となっている。ＵＢＭは接合によって元の構成を失っているが、接合の両側のうち、このＵＢＭが存在した側を、本明細書において、ＵＢＭ側と呼ぶ。本明細書において、ＵＢＭ側から連続するＮｉ層を、単にＮｉ層と呼ぶことがある。このＮｉ層は、ＵＢＭ側から連続している層ではあるが、接合部の構成を明確にするために、本明細書では、接合部を構成する層のひとつとして、記載している。 [UBM side of joint]
Since the joint portion of the present invention is a joint portion in which the UBM and the solder alloy are joined, the UBM loses the constitution of the original metal layer due to the joining, and only the Ni layer, which was the main layer of the UBM, can be detected. Remains as. The Ni layer derived from this UBM is continuous all the way to the joint, and in the vicinity of the joint, the Ni layer is continuous from the UBM side. Although the UBM loses its original configuration due to the joining, the side on which the UBM existed on both sides of the joining is referred to as the UBM side in this specification. In this specification, a Ni layer continuous from the UBM side may be simply referred to as a Ni layer. This Ni layer is a layer continuous from the UBM side, but in order to clarify the structure of the joint, it is described as one of the layers constituting the joint in this specification.
［接合部のはんだ合金側］
　本発明の接合部は、ＵＢＭとはんだ合金を接合した接合部であるから、接合部のはんだ合金側は、はんだ合金へと連続している。好適な実施の態様において、はんだ合金は、主成分をＢｉとする合金であって、接合部のはんだ合金側は、はんだ合金側へ連続するＢｉ層となっている。はんだ合金は接合によって元のはんだ合金とは異なった相を有するものとなっているが、接合の両側のうち、このはんだ合金が存在する側を、本明細書においてはんだ合金側と呼ぶ。本明細書において、はんだ合金側へ連続するＢｉ層を、単にＢｉ層と呼ぶことがある。このＢｉ層は、はんだ合金側へ連続している層ではあるが、接合部の構成を明確にするために、本明細書では、接合部を構成する層のひとつとして、記載している。 [Solder alloy side of joint]
Since the joint portion of the present invention is a joint portion in which the UBM and the solder alloy are joined, the solder alloy side of the joint portion is continuous with the solder alloy. In a preferred embodiment, the solder alloy is an alloy whose main component is Bi, and the solder alloy side of the joint is a Bi layer continuous to the solder alloy side. The solder alloy has a phase different from that of the original solder alloy due to the joining, and of both sides of the joining, the side where this solder alloy exists is referred to as the solder alloy side in this specification. In this specification, the Bi layer continuous to the solder alloy side may be simply referred to as a Bi layer. The Bi layer is a layer continuous to the solder alloy side, but is described as one of the layers forming the joint in this specification in order to clarify the constitution of the joint.
［ＮｉＳｎ合金層］
　好適な実施の態様において、ＮｉＳｎ合金層は、Ｎｉ、Ｓｎ、及びＰを含有する。好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＮｉ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＮｉ含有量よりも大きい。好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＳｎ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＳｎ含有量よりも小さい。 [NiSn alloy layer]
In a preferred embodiment, the NiSn alloy layer contains Ni, Sn, and P. In a preferred embodiment, in the NiSn alloy layer, the Ni content at the boundary with the Ni layer is larger than the Ni content at the boundary with the (Cu, Ni, Pd)αSn alloy layer. In a preferred embodiment, in the NiSn alloy layer, the Sn content at the boundary with the Ni layer is smaller than the Sn content at the boundary with the (Cu, Ni, Pd)αSn alloy layer.
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＳｎ含有量は、０．４モル％以下であり、好ましくは０．３５モル％以下である。 In a preferred embodiment, in the NiSn alloy layer, the Sn content at the boundary with the Ni layer is 0.4 mol% or less, preferably 0.35 mol% or less.
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰ含有量よりも大きい。 In a preferred embodiment, in the NiSn alloy layer, the P content at the boundary with the Ni layer is larger than the P content at the boundary with the (Cu, Ni, Pd)αSn alloy layer.
　好適な実施の態様において、ＮｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰ含有量は、０．５モル％以下、好ましくは０．３モル％以下である。 In a preferred embodiment, in the NiSn alloy layer, the P content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 0.5 mol% or less, preferably 0.3 mol% or less.
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＮｉ含有量が２１モル％～８３モル％の範囲、好ましくは２２モル％～８０モル％の範囲にある。Ｎｉ層との境界からの各距離におけるＮｉ含有量が上記範囲にあるとは、Ｎｉ層との境界からの距離に応じて１箇所以上の測定点を設けて、それぞれの測定点においてＮｉ含有量を測定しても、いずれも上記範囲内となっていること、あるいはそのように見積もることができることを意味する。そのように見積もることができるとは、例えば、近接する測定点での測定値からの外挿によってそのように見積もることができることをいう。測定点の数には、特に制限はないが、現実的な測定操作の観点からは、例えば１～２０個程度、あるいは１～５個程度の測定点を設けることができる。以下の記載において、「各距離において」との記載は、上述と同様の意味で使用される。 In a preferred embodiment, in the NiSn alloy layer, the Ni content at each distance from the boundary with the Ni layer is in the range of 21 mol% to 83 mol%, preferably in the range of 22 mol% to 80 mol%. That the Ni content at each distance from the boundary with the Ni layer is within the above range means that one or more measurement points are provided according to the distance from the boundary with the Ni layer, and the Ni content at each measurement point. It means that all of them are within the above range or can be estimated as such. Being able to make such an estimation means being able to make such an estimation, for example, by extrapolation from measurement values at adjacent measurement points. The number of measurement points is not particularly limited, but from the viewpoint of practical measurement operation, for example, about 1 to 20 or about 1 to 5 measurement points can be provided. In the following description, the description “at each distance” is used in the same meaning as described above.
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＳｎ含有量が０．２モル％～４８モル％の範囲、好ましくは０．２５モル％～４５モル％の範囲にある。Ｎｉ層との境界からの各距離におけるＳｎ含有量が上記範囲にあるとは、Ｎｉ含有量について上述したものと同様の意味である。 In a preferred embodiment, in the NiSn alloy layer, the Sn content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 48 mol%, preferably 0.25 mol% to 45 mol%. In range. That the Sn content at each distance from the boundary with the Ni layer is within the above range has the same meaning as described above for the Ni content.
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＰ含有量が０．１モル％～１０モル％の範囲、好ましくは０．２モル％～９モル％の範囲にある。Ｎｉ層との境界からの各距離におけるＰ含有量が上記範囲にあるとは、Ｎｉ含有量について上述したものと同様の意味である。 In a preferred embodiment, in the NiSn alloy layer, the P content at each distance from the boundary with the Ni layer is in the range of 0.1 mol% to 10 mol%, preferably 0.2 mol% to 9 mol%. In range. That the P content at each distance from the boundary with the Ni layer is in the above range has the same meaning as described above for the Ni content.
　好適な実施の態様において、ＮｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＢｉ含有量が、２モル％以下、好ましくは１モル％以下である。 In a preferred embodiment, in the NiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 2 mol% or less, preferably 1 mol% or less.
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＢｉ含有量が、０．２モル％～２モル％の範囲、好ましくは０．３モル％～１．５モル％の範囲にある。Ｎｉ層との境界からの各距離におけるＢｉ含有量が上記範囲にあるとは、Ｎｉ含有量について上述したものと同様の意味である。このように、好適な実施の態様において、ＮｉＳｎ合金層において、Ｂｉの含有量が極めて低減されており、つまり、Ｂｉの侵入が効率的に阻止されている。 In a preferred embodiment, in the NiSn alloy layer, the Bi content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 2 mol%, preferably 0.3 mol% to 1.5 mol%. It is in the range of mol %. That the Bi content at each distance from the boundary with the Ni layer is within the above range has the same meaning as described above for the Ni content. As described above, in the preferred embodiment, the NiSn alloy layer has a significantly reduced Bi content, that is, Bi intrusion is efficiently prevented.
　好適な実施の態様において、ＮｉＳｎ合金層の厚みが、例えば、０．０３～０．１［μｍ］、好ましくは０．０４～０．１［μｍ］、好ましくは０．０５～０．１［μｍ］、好ましくは０．０６～０．１［μｍ］の範囲にある。 In a preferred embodiment, the NiSn alloy layer has a thickness of, for example, 0.03 to 0.1 [μm], preferably 0.04 to 0.1 [μm], and preferably 0.05 to 0.1 [. μm], preferably in the range of 0.06 to 0.1 [μm].
　好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＣｕ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＣｕ含有量よりも小さい。好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＣｕ含有量は、４モル％以下、好ましくは３モル％以下である。 In a preferred embodiment, in the NiSn alloy layer, the Cu content at the boundary with the Ni layer is smaller than the Cu content at the boundary with the (Cu, Ni, Pd)αSn alloy layer. In a preferred embodiment, in the NiSn alloy layer, the Cu content at the boundary with the Ni layer is 4 mol% or less, preferably 3 mol% or less.
　好適な実施の態様において、ＮｉＳｎ合金層は、さらに、Ｐｄを含有する。好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰｄ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰｄ含有量よりも小さい。好適な実施の態様において、ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰｄ含有量は、３モル％以下、好ましくは２モル％以下である。 In a preferred embodiment, the NiSn alloy layer further contains Pd. In a preferred embodiment, in the NiSn alloy layer, the Pd content at the boundary with the Ni layer is smaller than the Pd content at the boundary with the (Cu, Ni, Pd)αSn alloy layer. In a preferred embodiment, in the NiSn alloy layer, the Pd content at the boundary with the Ni layer is 3 mol% or less, preferably 2 mol% or less.
［Ｎｉ層］
　好適な実施の態様において、Ｎｉ層は、上述のようにＵＢＭに由来する層である。好適な実施の態様において、Ｎｉ層は、ＮｉＳｎ合金層との境界から０．２［μｍ］以内の各距離におけるＮｉ含有量が８３モル％以上、好ましくは８５モル％以上である。好適な実施の態様において、Ｎｉ層は、ＵＢＭに由来する元素成分を含んでいてもよい。好適な実施の態様において、Ｎｉ層は、例えばＰを含んでいてもよい。 [Ni layer]
In a preferred embodiment, the Ni layer is a UBM derived layer as described above. In a preferred embodiment, the Ni layer has a Ni content of 83 mol% or more, preferably 85 mol% or more, at each distance within 0.2 [μm] from the boundary with the NiSn alloy layer. In a preferred embodiment, the Ni layer may contain an elemental component derived from UBM. In a preferred embodiment, the Ni layer may contain P, for example.
　好適な実施の態様において、Ｎｉ層は、ＮｉＳｎ合金層との境界から０．２［μｍ］以内の各距離におけるＢｉ含有量が、０．２モル％以下、好ましくは０．１モル％以下である。ＮｉＳｎ合金層との境界からの各距離におけるＢｉ含有量が上記以下であるとは、ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＮｉ含有量について、上述したものと同様の意味である。このように、好適な実施の態様において、Ｎｉ層において、Ｂｉの含有量が極めて低減されており、つまり、Ｂｉの侵入が効率的に阻止されている。 In a preferred embodiment, the Ni layer is such that the Bi content at each distance within 0.2 [μm] from the boundary with the NiSn alloy layer is 0.2 mol% or less, preferably 0.1 mol% or less. is there. The Bi content at each distance from the boundary with the NiSn alloy layer is the above or less means that the Ni content at each distance from the boundary with the Ni layer in the NiSn alloy layer has the same meaning as described above. is there. Thus, in the preferred embodiment, the Ni content in the Ni layer is extremely reduced, that is, the invasion of Bi is effectively prevented.
［（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層］
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、Ｃｕ、Ｎｉ、Ｐｄが固溶しているＳｎ合金の層である。この（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、ＵＢＭとはんだ合金の成分元素から、形成されると考えられる。好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、Ｃｕ、Ｎｉ、Ｐｄ、及びＳｎを含有する。 [(Cu, Ni, Pd) αSn alloy layer]
The (Cu, Ni, Pd)αSn alloy layer is a layer of Sn alloy in which Cu, Ni, and Pd are in solid solution. It is considered that this (Cu, Ni, Pd)αSn alloy layer is formed from the constituent elements of UBM and the solder alloy. In a preferred embodiment, the (Cu, Ni, Pd)αSn alloy layer contains Cu, Ni, Pd, and Sn.
　好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＣｕ含有量が１０モル％～２２モル％の範囲、好ましくは１２モル％～２０モル％の範囲にある。 In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, the Cu content at each distance from the boundary with the NiSn alloy layer is in the range of 10 mol% to 22 mol%, preferably 12 mol% to It is in the range of 20 mol %.
　好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＮｉ含有量が１３モル％～２１モル％の範囲、好ましくは１４モル％～２０モル％の範囲にある。 In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, the Ni content at each distance from the boundary with the NiSn alloy layer is in the range of 13 mol% to 21 mol%, preferably 14 mol% to It is in the range of 20 mol %.
　好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＰｄ含有量が５モル％～１９モル％の範囲、好ましくは６モル％～１８モル％の範囲にある。 In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, the Pd content at each distance from the boundary with the NiSn alloy layer is in the range of 5 mol% to 19 mol%, preferably 6 mol% to It is in the range of 18 mol %.
　好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＳｎ含有量が４４モル％～５５モル％の範囲、好ましくは４５モル％～５４モル％の範囲にある。 In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, the Sn content at each distance from the boundary with the NiSn alloy layer is in the range of 44 mol% to 55 mol%, preferably 45 mol% to It is in the range of 54 mol %.
　好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、さらに、Ｂｉを含有する。好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界におけるＢｉ含有量が、２モル％以下、好ましくは１モル％以下である。好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの距離に応じてＢｉ含有量を測定した場合に、Ｂｉ含有量が０．１モル％～２４モル％の範囲、好ましくは０．２モル％～２３モル％の範囲、あるいは１モル％～２４モル％の範囲、あるいは２モル％～２３モル％の範囲にある距離が存在する。すなわち、好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層には、Ｂｉ含有量のピークが存在していて、そのピークはＮｉＳｎ合金層との境界から離れて位置しており、このことは、ＮｉＳｎ合金層が、Ｂｉ層側からのＢｉの侵入を防いでいることを意味すると、本発明者は考えている。すなわち、好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層に存在するＢｉ含有量のピークであって、ＮｉＳｎ合金層との境界から離れて位置するＢｉ含有量のピークとは、上記範囲のＢｉ含有量であって、ＮｉＳｎ合金層との境界におけるＢｉ含有量よりも大きなＢｉ含有量となっている。 In a preferred embodiment, the (Cu, Ni, Pd)αSn alloy layer further contains Bi. In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, the Bi content at the boundary with the NiSn alloy layer is 2 mol% or less, preferably 1 mol% or less. In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, when the Bi content is measured according to the distance from the boundary with the NiSn alloy layer, the Bi content is 0.1 mol% to There is a distance in the range of 24 mol%, preferably in the range of 0.2 mol% to 23 mol%, or in the range of 1 mol% to 24 mol%, or in the range of 2 mol% to 23 mol%. That is, in a preferred embodiment, the (Cu, Ni, Pd)αSn alloy layer has a peak of Bi content, and the peak is located away from the boundary with the NiSn alloy layer, The present inventor believes that this means that the NiSn alloy layer prevents Bi from entering from the Bi layer side. That is, in a preferred embodiment, the peak of Bi content present in the (Cu, Ni, Pd)αSn alloy layer, and the peak of Bi content located away from the boundary with the NiSn alloy layer, The Bi content is in the above range and is larger than the Bi content at the boundary with the NiSn alloy layer.
　好適な実施の態様において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＢｉＳｎ合金層との境界におけるＢｉ含有量が、０．５モル％以下、好ましくは０．４モル％以下である。 In a preferred embodiment, in the (Cu, Ni, Pd)αSn alloy layer, the Bi content at the boundary with the BiSn alloy layer is 0.5 mol% or less, preferably 0.4 mol% or less.
［ＢｉＳｎ合金層］
　好適な実施の態様において、ＢｉＳｎ合金層は、Ｂｉ及びＳｎを含有する。好適な実施の態様において、ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＢｉ含有量が、０．５モル％以下、好ましくは０．４モル％以下である。好適な実施の態様において、ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＳｎ含有量が、２モル％以下、好ましくは１モル％以下である。 [BiSn alloy layer]
In a preferred embodiment, the BiSn alloy layer contains Bi and Sn. In a preferred embodiment, in the BiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 0.5 mol% or less, preferably 0.4 mol% or less. In a preferred embodiment, in the BiSn alloy layer, the Sn content at the boundary with the Bi layer is 2 mol% or less, preferably 1 mol% or less.
　好適な実施の態様において、ＢｉＳｎ合金層は、さらに、Ｃｕ、Ｎｉ、Ｐｄを含有する。 In a preferred embodiment, the BiSn alloy layer further contains Cu, Ni and Pd.
　好適な実施の態様において、ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＣｕ含有量は、Ｂｉ層との境界におけるＣｕ含有量よりも大きい。好適な実施の態様において、ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＣｕ含有量は、０．５モル％以下、好ましくは０．３モル％以下である。 In a preferred embodiment, in the BiSn alloy layer, the Cu content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Cu content at the boundary with the Bi layer. In a preferred embodiment, in the BiSn alloy layer, the Cu content at the boundary with the Bi layer is 0.5 mol% or less, preferably 0.3 mol% or less.
　好適な実施の態様において、ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＮｉ含有量は、Ｂｉ層との境界におけるＮｉ含有量よりも大きい。好適な実施の態様において、ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＮｉ含有量は、１モル％以下、好ましくは０．５モル％以下である。 In a preferred embodiment, in the BiSn alloy layer, the Ni content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Ni content at the boundary with the Bi layer. In a preferred embodiment, in the BiSn alloy layer, the Ni content at the boundary with the Bi layer is 1 mol% or less, preferably 0.5 mol% or less.
　好適な実施の態様において、ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰｄ含有量は、Ｂｉ層との境界におけるＰｄ含有量よりも大きい。好適な実施の態様において、ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＰｄ含有量は、０．６モル％以下、好ましくは０．３モル％以下である。 In a preferred embodiment, in the BiSn alloy layer, the Pd content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Pd content at the boundary with the Bi layer. In a preferred embodiment, in the BiSn alloy layer, the Pd content at the boundary with the Bi layer is 0.6 mol% or less, preferably 0.3 mol% or less.
［Ｂｉ層］
　好適な実施の態様において、Ｂｉ層は、上述のようにはんだ合金側へ連続するＢｉ層であり、はんだ合金に由来するＢｉを主成分としている。好適な実施の態様において、Ｂｉ層は、ＢｉＳｎ合金層との境界から０．２［μｍ］以内の各距離におけるＢｉ含有量が９７モル％以上、好ましくは９８モル％以上である。好適な実施の態様において、Ｂｉ層は、はんだ合金に由来する元素成分を含んでいてもよい。 [Bi layer]
In a preferred embodiment, the Bi layer is a Bi layer continuous to the solder alloy side as described above, and contains Bi derived from the solder alloy as a main component. In a preferred embodiment, the Bi layer has a Bi content of 97 mol% or more, preferably 98 mol% or more, at each distance within 0.2 [μm] from the boundary with the BiSn alloy layer. In a preferred embodiment, the Bi layer may contain an elemental component derived from the solder alloy.
　好適な実施の態様において、Ｂｉ層中に、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層から遊離した（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金の相を有さない。（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層から遊離した（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金の相とは、具体的には、後述する実施例における比較例の画像中の相として説明しているような相をいう。好適な実施の態様において、このような相が、少なくとも観察している視野中には存在していないことが好ましい。このように存在しないことを確認する作業は困難ではあるが、例えば、接合部付近の画像について、合計で１００［μｍ2］以上の視野について観察しても、Ｂｉ層中に、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層から遊離した（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金の相を有さない場合には、Ｂｉ層中に、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層から遊離した（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金の相を有さないとの条件を満たすものと扱うことができる。 In a preferred embodiment, there is no (Cu, Ni, Pd)αSn alloy phase liberated from the (Cu, Ni, Pd)αSn alloy layer in the Bi layer. The phase of the (Cu, Ni, Pd)αSn alloy released from the (Cu, Ni, Pd)αSn alloy layer is specifically described as the phase in the image of the comparative example in Examples described later. This is the phase. In a preferred embodiment, such phases are preferably absent, at least in the field of view under observation. Although it is difficult to confirm that there is no such existence, for example, even when the image near the junction is observed in a visual field of 100 [μm 2 ] or more in total, (Cu, Ni , Pd) αSn alloy layer freed from the (Cu, Ni, Pd) αSn alloy phase, the (Cu, Ni, Pd) αSn alloy layer released into the Bi layer (Cu, Ni , Pd) αSn alloy having no phase can be treated as satisfying the condition.
［元素濃度］
　各元素の濃度（モル％）は、後述する実施例に開示した手段で測定することができ、例えば、具体的にはＳＴＭ（ＪＥＯＬ製、装置名：ＪＥＭ－２１００Ｆ）を使用して測定することができる。本発明における元素濃度は、Ｎｉ、Ｓｎ、Ｂｉ、Ｃｕ、Ｐｄ、Ｐの合計を、１００モル％となるようにした場合の、各元素濃度をいう。 [Element concentration]
The concentration (mol %) of each element can be measured by the means disclosed in the examples described later, and specifically, it can be measured using STM (manufactured by JEOL, device name: JEM-2100F). You can The element concentration in the present invention means each element concentration when the total of Ni, Sn, Bi, Cu, Pd and P is set to 100 mol %.
［接合強度（シェア強度）］
　好適な実施の態様において、本発明による接合部は、２５０℃、１０００時間の高温保持後の接合強度（シェア強度）が、例えば４０ＭＰａ以上、好ましくは４２ＭＰａ以上とすることができる。すなわち、高温域において優れた耐久性を有するものとなっている。この接合強度は、実施例において後述する手順によって、測定することができる。本発明の接合部が、高温域において優れた耐久性を有するものとなっている理由は不明であるが、後述する実施例における比較例との対比から、本発明に接合部が上記の層構造をとることによって、特に所定のＮｉＳｎ合金層を備えることによって、Ｂｉ層側からＮｉ層側へのＢｉの侵入を防ぐことができ、それによって優れた特性を備えるに至ったのではないかと本発明者は洞察している。 [Joint strength (shear strength)]
In a preferred embodiment, the joint part according to the present invention can have a joint strength (shear strength) after being kept at a high temperature of 250° C. for 1000 hours, for example, 40 MPa or more, preferably 42 MPa or more. That is, it has excellent durability in a high temperature range. This bonding strength can be measured by the procedure described later in the examples. The reason why the joint of the present invention has excellent durability in a high temperature range is unknown, but from the comparison with Comparative Examples in Examples described later, the joint of the present invention has the above-mentioned layer structure. According to the present invention, it is possible to prevent the invasion of Bi from the Bi layer side to the Ni layer side by providing a predetermined NiSn alloy layer, thereby providing excellent characteristics. Have insight.
［好適な実施の態様］
　好適な実施の態様において、本願発明は、次の（１）以下を含む。
　（１）
　ＵＢＭとはんだ合金を接合した接合部であって、ＵＢＭ側から順に、
　ＵＢＭ側から連続するＮｉ層と、
　ＮｉＳｎ合金層と、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層と、
　ＢｉＳｎ合金層と、
　はんだ合金側へと連続するＢｉ層を含んでなる、接合部。
　（２）
　ＮｉＳｎ合金層は、Ｎｉ、Ｓｎ、及びＰを含有し、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＮｉ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＮｉ含有量よりも大きく、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＳｎ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＳｎ含有量よりも小さく、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＳｎ含有量は、０．４モル％以下であり、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰ含有量よりも大きく、
　ＮｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰ含有量は、０．５モル％以下である、（１）に記載の接合部。
　（３）
　ＮｉＳｎ合金層は、Ｎｉ、Ｓｎ、及びＰを含有し、
　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＮｉ含有量が２１モル％～８３モル％の範囲にあり、
　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＳｎ含有量が０．２モル％～４８モル％の範囲にあり、
　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＰ含有量が０．１モル％～１０モル％の範囲にある、（１）～（２）のいずれかに記載の接合部。
　（４）
　ＮｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＢｉ含有量が、２モル％以下である、（１）～（３）のいずれかに記載の接合部。
　（５）
　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＢｉ含有量が、０．２モル％～２モル％の範囲にある、（１）～（４）のいずれかに記載の接合部。
　（６）
　ＮｉＳｎ合金層の厚みが、０．０５～０．１［μｍ］の範囲にある、（１）～（５）のいずれかに記載の接合部。
　（７）
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＣｕ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＣｕ含有量よりも小さく、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＣｕ含有量は、４モル％以下である、（２）～（６）のいずれかに記載の接合部。
　（８）
　ＮｉＳｎ合金層は、さらに、Ｐｄを含有し、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰｄ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰｄ含有量よりも小さく、
　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰｄ含有量は、３モル％以下である、（２）～（７）のいずれかに記載の接合部。
　（９）
　Ｎｉ層は、ＮｉＳｎ合金層との境界から０．２［μｍ］以内の各距離におけるＢｉ含有量が、０．２モル％以下である、（１）～（８）のいずれかに記載の接合部。
　（１０）
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、Ｃｕ、Ｎｉ、Ｐｄ、及びＳｎを含有し、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＣｕ含有量が１０モル％～２２モル％の範囲にあり、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＮｉ含有量が１３モル％～２１モル％の範囲にあり、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＰｄ含有量が５モル％～１９モル％の範囲にあり、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＳｎ含有量が４４モル％～５５モル％の範囲にある、（１）～（９）のいずれかに記載の接合部。
　（１１）
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、さらに、Ｂｉを含有し、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界におけるＢｉ含有量が、２モル％以下であり、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの距離に応じてＢｉ含有量を測定した場合に、Ｂｉ含有量が０．１モル％～２４モル％の範囲にある距離が存在し、
　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＢｉＳｎ合金層との境界におけるＢｉ含有量が、０．５モル％以下である、（１０）に記載の接合部。
　（１２）
　ＢｉＳｎ合金層は、Ｂｉ及びＳｎを含有し、
　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＢｉ含有量が、０．５モル％以下であり、
　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＳｎ含有量が、２モル％以下である、（１）～（１１）のいずれかに記載の接合部。
　（１３）
　ＢｉＳｎ合金層は、さらに、Ｃｕ、Ｎｉ、Ｐｄを含有し、
　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＣｕ含有量は、Ｂｉ層との境界におけるＣｕ含有量よりも大きく、
　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＣｕ含有量は、０．５モル％以下であり、
　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＮｉ含有量は、Ｂｉ層との境界におけるＮｉ含有量よりも大きく、
　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＮｉ含有量は、１モル％以下であり、
　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰｄ含有量は、Ｂｉ層との境界におけるＰｄ含有量よりも大きく、
　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＰｄ含有量は、０．６モル％以下である、（１２）に記載の接合部。
　（１４）
　Ｂｉ層中に、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層から遊離した（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金の相を有さない、（１）～（１３）のいずれかに記載の接合部。
　（１５）
　ＵＢＭは、電極上に、ニッケル、パラジウム、及び金が、順に積層されて形成されたＵＢＭである、（１）～（１４）のいずれかに記載の接合部。
　（１６）
　２５０℃、１０００時間の高温保持後の接合強度が４０ＭＰａ以上である、（１）～（１５）のいずれかに記載の接合部。
　（１７）
　（１）～（１６）のいずれかに記載の接合部を有する、電子部品。
　（１８）
　（１）～（１６）のいずれかに記載の接合部を有する、パワーデバイス。
　（１９）
　（１）～（１６）のいずれかに記載の接合部を有する、プリント回路板。 [Preferred Embodiment]
In a preferred embodiment, the present invention includes the following (1) and the following.
(1)
It is a joint part where the UBM and the solder alloy are joined, and in order from the UBM side,
Ni layer continuous from the UBM side,
NiSn alloy layer,
(Cu, Ni, Pd) αSn alloy layer,
A BiSn alloy layer,
A joint comprising a Bi layer continuous to the solder alloy side.
(2)
The NiSn alloy layer contains Ni, Sn, and P,
In the NiSn alloy layer, the Ni content at the boundary with the Ni layer is larger than the Ni content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
In the NiSn alloy layer, the Sn content at the boundary with the Ni layer is smaller than the Sn content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
In the NiSn alloy layer, the Sn content at the boundary with the Ni layer is 0.4 mol% or less,
In the NiSn alloy layer, the P content at the boundary with the Ni layer is larger than the P content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
In the NiSn alloy layer, the P content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 0.5 mol% or less, the joint according to (1).
(3)
The NiSn alloy layer contains Ni, Sn, and P,
In the NiSn alloy layer, the Ni content at each distance from the boundary with the Ni layer is in the range of 21 mol% to 83 mol%,
In the NiSn alloy layer, the Sn content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 48 mol%,
In the NiSn alloy layer, the joint portion according to any one of (1) to (2), wherein the P content at each distance from the boundary with the Ni layer is in the range of 0.1 mol% to 10 mol %.
(4)
The joint portion according to any one of (1) to (3), wherein in the NiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 2 mol% or less.
(5)
In the NiSn alloy layer, the joint portion according to any one of (1) to (4), wherein the Bi content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 2 mol %.
(6)
The joint part according to any one of (1) to (5), wherein the thickness of the NiSn alloy layer is in the range of 0.05 to 0.1 [μm].
(7)
In the NiSn alloy layer, the Cu content at the boundary with the Ni layer is smaller than the Cu content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
The joint portion according to any one of (2) to (6), wherein in the NiSn alloy layer, the Cu content at the boundary with the Ni layer is 4 mol% or less.
(8)
The NiSn alloy layer further contains Pd,
In the NiSn alloy layer, the Pd content at the boundary with the Ni layer is smaller than the Pd content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
In the NiSn alloy layer, the joint portion according to any one of (2) to (7), wherein the Pd content at the boundary with the Ni layer is 3 mol% or less.
(9)
The Ni layer has a Bi content of 0.2 mol% or less at each distance within 0.2 [μm] from the boundary with the NiSn alloy layer, and the bonding according to any one of (1) to (8) above. Department.
(10)
The (Cu, Ni, Pd)αSn alloy layer contains Cu, Ni, Pd, and Sn,
In the (Cu, Ni, Pd) αSn alloy layer, the Cu content at each distance from the boundary with the NiSn alloy layer is in the range of 10 mol% to 22 mol %,
In the (Cu, Ni, Pd)αSn alloy layer, the Ni content at each distance from the boundary with the NiSn alloy layer is in the range of 13 mol% to 21 mol %,
In the (Cu, Ni, Pd)αSn alloy layer, the Pd content at each distance from the boundary with the NiSn alloy layer is in the range of 5 mol% to 19 mol %,
In the (Cu, Ni, Pd)αSn alloy layer, the Sn content at each distance from the boundary with the NiSn alloy layer is in the range of 44 mol% to 55 mol%, and the Sn content is in the range of (1) to (9). The junction described.
(11)
The (Cu, Ni, Pd)αSn alloy layer further contains Bi,
In the (Cu, Ni, Pd) αSn alloy layer, the Bi content at the boundary with the NiSn alloy layer is 2 mol% or less,
In the (Cu, Ni, Pd)αSn alloy layer, when the Bi content is measured according to the distance from the boundary with the NiSn alloy layer, the Bi content is in the range of 0.1 mol% to 24 mol %. There is a distance,
The joint portion according to (10), wherein in the (Cu, Ni, Pd) αSn alloy layer, the Bi content at the boundary with the BiSn alloy layer is 0.5 mol% or less.
(12)
The BiSn alloy layer contains Bi and Sn,
In the BiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 0.5 mol% or less,
The joint portion according to any one of (1) to (11), wherein in the BiSn alloy layer, the Sn content at the boundary with the Bi layer is 2 mol% or less.
(13)
The BiSn alloy layer further contains Cu, Ni and Pd,
In the BiSn alloy layer, the Cu content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Cu content at the boundary with the Bi layer,
In the BiSn alloy layer, the Cu content at the boundary with the Bi layer is 0.5 mol% or less,
In the BiSn alloy layer, the Ni content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Ni content at the boundary with the Bi layer,
In the BiSn alloy layer, the Ni content at the boundary with the Bi layer is 1 mol% or less,
In the BiSn alloy layer, the Pd content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Pd content at the boundary with the Bi layer,
In the BiSn alloy layer, the joint portion according to (12), wherein the Pd content at the boundary with the Bi layer is 0.6 mol% or less.
(14)
The joint according to any one of (1) to (13), wherein the Bi layer does not have a phase of the (Cu, Ni, Pd)αSn alloy released from the (Cu, Ni, Pd)αSn alloy layer.
(15)
The UBM is the joint part according to any one of (1) to (14), which is a UBM formed by sequentially stacking nickel, palladium, and gold on an electrode.
(16)
The joint according to any one of (1) to (15), which has a joint strength of 40 MPa or more after being kept at a high temperature of 250° C. for 1000 hours.
(17)
An electronic component having the joint according to any one of (1) to (16).
(18)
A power device having the junction according to any one of (1) to (16).
(19)
A printed circuit board having the joint according to any one of (1) to (16).
　好適な実施の態様において、本願発明は、上記接合部を有する電子部品、パワーデバイス、プリント回路板、ＬＥＤ、フレキシブル回路材、放熱材を含む。 In a preferred embodiment, the invention of the present application includes an electronic component, a power device, a printed circuit board, an LED, a flexible circuit material, and a heat dissipation material having the above-mentioned joint portion.
　以下に実施例をあげて、本発明を詳細に説明する。本発明は、以下に例示する実施例に限定されるものではない。 The present invention will be described in detail below with reference to examples. The present invention is not limited to the examples illustrated below.
［実施例１］
［ＵＢＭの形成］
　Ｓｉウエハの片面にスパッタリングにより、Ａｌ面（厚さ３μｍ）を作製し、更に塗布によりポリイミド膜を形成その後露光現像によりポリイミド膜に３００μｍ直径の開口部のランドを形成した。
　さらに無電解めっきによりランド部の上に、Ｎｉ層（厚さ２．５μｍ）、Ｐｄ層（厚さ０．０５μｍ）、Ａｕ層（厚さ０．０２μｍ）を順次形成してＵＢＭ（Ｕｎｄｅｒ　Ｂｕｍｐ　Ｍｅｔａｌ）を設けた。なお、無電解Ｎｉめっき液には次亜リン酸イオンの還元剤が添加されているため、Ｎｉ層にＰが共析するものとなる。 [Example 1]
[Formation of UBM]
An Al surface (thickness: 3 μm) was formed on one surface of the Si wafer by sputtering, and a polyimide film was further formed by coating, and then a land having an opening with a diameter of 300 μm was formed in the polyimide film by exposure and development.
Further, a Ni layer (thickness 2.5 μm), a Pd layer (thickness 0.05 μm), and an Au layer (thickness 0.02 μm) are sequentially formed on the land portion by electroless plating to form a UBM (Under Bump Metal). ) Is provided. Since the reducing agent for hypophosphite ions is added to the electroless Ni plating solution, P is codeposited on the Ni layer.
［はんだ粉］
　実施例１において使用したはんだ粉のＩＣＰ分析による組成を表１に示す。はんだ粉は、３００μｍΦであるものを使用した。 [Solder powder]
The composition of the solder powder used in Example 1 by ICP analysis is shown in Table 1. The solder powder used was 300 μmΦ.
［リフロー処理］
　ＵＢＭの上にフラックスを塗布し、さらにその上に３００μｍΦのはんだ粉を搭載し、リフロー処理を行って、加熱接合させた。リフロー処理の条件は、以下とした：
　室温から１１０℃まで１．４℃／秒の昇温速度で昇温した。次に、１１０℃から１４０℃まで０．７℃／秒の昇温速度で昇温した。１４０℃から２００℃まで０．８℃／秒の昇温速度で昇温した。次に２００℃から２９０℃まで４．５℃／秒の昇温速度で昇温した。次に、２９０℃の温度を４０秒間維持した。次に、２９０℃から室温まで初期７℃／秒の降温速度で冷却した。これらの操作は窒素雰囲気中で行った。 [Reflow process]
Flux was applied onto the UBM, solder powder of 300 μmΦ was further mounted on the UBM, reflow treatment was performed, and heat bonding was performed. The conditions for the reflow process were as follows:
The temperature was raised from room temperature to 110° C. at a heating rate of 1.4° C./sec. Next, the temperature was raised from 110° C. to 140° C. at a heating rate of 0.7° C./sec. The temperature was raised from 140°C to 200°C at a heating rate of 0.8°C/sec. Next, the temperature was raised from 200° C. to 290° C. at a heating rate of 4.5° C./sec. Then the temperature of 290° C. was maintained for 40 seconds. Next, it was cooled from 290° C. to room temperature at an initial cooling rate of 7° C./sec. These operations were performed in a nitrogen atmosphere.
［ＥＰＭＡ分析、ＳＴＭ分析］
　その後そのサンプルを樹脂封入し、断面を研磨した。清浄および平滑化されたサンプル表面をＥＰＭＡ（ＪＥＯＬ製、装置名：ＪＸＡ－８５００Ｆ）で分析した。リフロー処理後のはんだ接合部はその厚みがおよそ１μｍ以下であるので、精度の高いＳＴＭ（ＪＥＯＬ製、装置名：ＪＥＭ－２１００Ｆ）で測定した。ＥＰＭＡによる測定は画像精度がＳＴＭに比べ劣るが、１ピクセルの大きさが０．０８μｍである画像処理を行った。更に定量化を図るために、同じサンプルを薄く加工しＳＴＭで測定した。 [EPMA analysis, STM analysis]
After that, the sample was encapsulated with resin and the cross section was polished. The cleaned and smoothed sample surface was analyzed by EPMA (manufactured by JEOL, device name: JXA-8500F). Since the thickness of the solder joint portion after the reflow treatment is about 1 μm or less, the solder joint portion was measured by a highly accurate STM (manufactured by JEOL, device name: JEM-2100F). Although the image accuracy of the measurement by EPMA is inferior to that of STM, image processing was performed with the size of one pixel being 0.08 μm. For further quantification, the same sample was thinly processed and measured by STM.
　実施例１の接合部について、リフロー処理の直後の接合部断面をＥＰＭＡによって測定して作成した複合マップの画像を、図１として示す。 FIG. 1 shows an image of a composite map created by measuring the cross section of the joint portion of Example 1 immediately after the reflow treatment by EPMA.
　実施例１の接合部について、リフロー処理の後に、２５０℃の温度で１０００時間保持した後の接合部の断面について、同様に、ＥＰＭＡによって測定して複合マップを作成した。この複合マップの画像を図２として示す。 Regarding the joint of Example 1, after the reflow treatment, the cross section of the joint after being held at a temperature of 250° C. for 1000 hours was similarly measured by EPMA to create a composite map. An image of this composite map is shown as FIG.
［シェア強度測定］
　実施例１の接合部について、上述したリフロー処理の後に、大気雰囲気下で２５０℃の温度で１０００時間保持した後に、シェア強度測定を次のように行った。この結果を表１に示す。
　接合強度は、ＭＩＬ　ＳＴＤ－８８３Ｇに準じて測定した。荷重センサに取り付けられたツールが基板面まで下降し、装置が基板面を検出し下降を停止し、検出した基板面から設定された高さまでツールが上昇し、ツールで接合部を押して破壊時の荷重を計測した。これらの結果をまとめて表１に示す。
　＜測定条件＞
　装置：ｄａｇｅ社製　ｄａｇｅ　ｓｅｒｉｅｓ　４０００
　方法：ダイシェアテスト
　テストスピード：１００μｍ／秒
　テスト高さ：２０．０μｍ
　ツール移動量：０．９ｍｍ [Share strength measurement]
The joint portion of Example 1 was subjected to shear strength measurement as described below after being held at a temperature of 250° C. for 1000 hours in the atmosphere after the reflow treatment described above. The results are shown in Table 1.
The bonding strength was measured according to MIL STD-883G. The tool attached to the load sensor descends to the board surface, the device detects the board surface and stops descending, and the tool rises to the set height from the detected board surface and pushes the joint with the tool The load was measured. The results are summarized in Table 1.
<Measurement conditions>
Device: dage series 4000 manufactured by dage
Method: Die shear test Test speed: 100 μm/sec Test height: 20.0 μm
Tool movement amount: 0.9mm
［比較例１］
　比較例１として、実施例１とは組成が異なるはんだ粉を使用して、実施例１とは異なる条件のリフロー処理を行って、その他については実施例１と同様の手順によって、接合部を形成して、この接合部に対してＥＰＭＡ測定、ＳＴＭ測定、及びシェア強度測定を行った。比較例１のはんだ粉の組成のＩＣＰ分析値とシェア強度測定結果を、表１に示す。比較例１のリフロー処理条件は、以下とした：
　室温から１５０℃まで０．９℃／秒の昇温速度で昇温した。次に、１５０℃から２９０℃まで４．５℃／秒の昇温速度で昇温した。次に、２９０℃の温度を４０秒間維持した。次に、２９０℃から室温まで初期８℃／秒の降温速度で冷却した。これらの操作は窒素雰囲気中で行った。 [Comparative Example 1]
As Comparative Example 1, a solder powder having a composition different from that of Example 1 is used, reflow treatment is performed under conditions different from those of Example 1, and the other steps are similar to those of Example 1 to form a joint. Then, EPMA measurement, STM measurement, and shear strength measurement were performed on this joint. Table 1 shows the ICP analysis value of the composition of the solder powder of Comparative Example 1 and the shear strength measurement result. The reflow processing conditions of Comparative Example 1 were as follows:
The temperature was raised from room temperature to 150°C at a heating rate of 0.9°C/sec. Next, the temperature was raised from 150° C. to 290° C. at a heating rate of 4.5° C./sec. Then the temperature of 290° C. was maintained for 40 seconds. Next, it was cooled from 290° C. to room temperature at an initial temperature decreasing rate of 8° C./sec. These operations were performed in a nitrogen atmosphere.
　比較例１の接合部について、リフロー処理の直後の接合部断面をＥＰＭＡによって測定して作成した複合マップの画像を、図３として示す。 Fig. 3 shows an image of a composite map created by measuring the cross section of the joint of Comparative Example 1 immediately after the reflow treatment by EPMA.
　比較例１の接合部について、リフロー処理の後に、２５０℃の温度で１０００時間保持した後の接合部の断面について、同様に、ＥＰＭＡによって測定して複合マップを作成した。この複合マップの画像を図４として示す。 Regarding the joint of Comparative Example 1, after the reflow treatment, the cross section of the joint after being held at a temperature of 250° C. for 1000 hours was similarly measured by EPMA to create a composite map. An image of this composite map is shown as FIG.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
［ＳＴＭ画像とライン分析］
　実施例１の接合部について、リフロー処理の直後の接合部断面のＳＴＭ像を、図５として示す。実施例１の接合部について、このＳＴＭ像に記入された分析ラインに沿って、各元素濃度（モル％）を数値化したグラフを、図６として示す。元素濃度（モル％）は、グラフ中の６元素、すなわち、Ｎｉ、Ｓｎ、Ｂｉ、Ｃｕ、Ｐｄ、Ｐの合計を、１００％とした。 [STM image and line analysis]
FIG. 5 shows an STM image of the cross section of the joint portion of Example 1 immediately after the reflow treatment. FIG. 6 is a graph showing the numerical value of each element concentration (mol %) along the analysis line written in this STM image for the joint portion of Example 1. Regarding the element concentration (mol %), the total of 6 elements in the graph, that is, Ni, Sn, Bi, Cu, Pd, and P was 100%.
　比較例１の接合部について、リフロー処理の直後の接合部断面のＳＴＭ像を、図７として示す。比較例１の接合部について、このＳＴＭ像に記入された分析ラインに沿って、各元素濃度（モル％）を数値化したグラフを、図８として示す。 FIG. 7 shows an STM image of the cross section of the joint of Comparative Example 1 immediately after the reflow treatment. FIG. 8 is a graph showing the numerical value of each element concentration (mol %) along the analysis line written in this STM image for the joint portion of Comparative Example 1.
［評価］
　図１は、実施例１の接合部のリフロー処理後のＥＰＭＡ複合マップ画像である。
　図１には、Ｎｉ層（１１）とＢｉ層（１４）の界面近傍に、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（１３）と見られる層が観察され、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（１３）の直下には、ＮｉＳｎ合金層（厚さ約０．１μｍ）（１２）が存在する。このＮｉＳｎ合金層（１２）には、カラー化した複合マップの画像によっても、Ｂｉの侵入は全く観察されない。また、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（１３）には比較的に厚さが揃っており、Ｂｉ層（１４）中に（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（１３）から遊離してしまった（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ相は、全く観察されない。図１においては、Ｎｉ層（１１）中へのＢｉの侵入は、カラー化した複合マップの画像においても全く観察されない。なお、図１の画像の下半分以上を占める黒い領域は、Ｎｉ層（１１）の下地となっているＡｌ層（３μｍ）とさらにその下地となっているＳｉ基材である。 [Evaluation]
FIG. 1 is an EPMA composite map image after the reflow process of the joint portion of the first embodiment.
In FIG. 1, in the vicinity of the interface between the Ni layer (11) and the Bi layer (14), a layer considered as a (Cu, Ni, Pd)αSn layer (13) was observed, and a (Cu, Ni, Pd)αSn layer was observed. Immediately below (13) is a NiSn alloy layer (thickness of about 0.1 μm) (12). Bi intrusion is not observed in the NiSn alloy layer (12) at all even in the image of the composite map colored. Further, the (Cu, Ni, Pd)αSn layer (13) has a relatively uniform thickness, and is separated from the (Cu, Ni, Pd)αSn layer (13) in the Bi layer (14). No (Cu,Ni,Pd)αSn phase was observed. In FIG. 1, no penetration of Bi into the Ni layer (11) is observed even in the image of the colored composite map. The black region occupying the lower half or more of the image of FIG. 1 is the Al layer (3 μm) that is the base of the Ni layer (11) and the Si base material that is the base of the Al layer.
　図２は、実施例１の接合部のリフロー処理後に、２５０℃の温度で１０００時間保持した後のＥＰＭＡ複合マップ画像である。
　図２には、Ｎｉ層（２１）とＢｉ層（２４）の界面近傍に、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（２３）と見られる層が観察され、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（２３）の直下には、ＮｉＳｎ合金層（厚さ約０．２μｍ）（２２）が存在する。このＮｉＳｎ合金層（２２）には、カラー化した複合マップの画像によっても、Ｂｉの侵入は全く観察されない。また、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（２３）は、図１と比較して厚みを増しているが、その全体は依然としてＮｉＳｎ合金層（２２）との密着を維持している。Ｂｉ層（２４）中には、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（２３）から遊離してしまった（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ相は、全く観察されない。また、Ｂｉ層（２４）中には、Ｎｉ層に由来すると見られるＮｉ相は、カラー化した複合マップの画像においても全く観察されない。図２においては、Ｎｉ層（２１）中へのＢｉの侵入は、カラー化した複合マップの画像においても全く観察されない。 FIG. 2 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion in Example 1.
In FIG. 2, in the vicinity of the interface between the Ni layer (21) and the Bi layer (24), a layer that is considered to be a (Cu, Ni, Pd)αSn layer (23) was observed, and a (Cu, Ni, Pd)αSn layer was observed. Immediately below (23) is a NiSn alloy layer (having a thickness of about 0.2 μm) (22). No Bi intrusion is observed in the NiSn alloy layer (22) even in the image of the composite map that is colored. Further, the (Cu, Ni, Pd)αSn layer (23) has an increased thickness as compared with FIG. 1, but the whole thereof still maintains the close contact with the NiSn alloy layer (22). In the Bi layer (24), the (Cu,Ni,Pd)αSn phase released from the (Cu,Ni,Pd)αSn layer (23) is not observed at all. Further, in the Bi layer (24), the Ni phase that is considered to be derived from the Ni layer is not observed at all even in the image of the colorized composite map. In FIG. 2, no penetration of Bi into the Ni layer (21) is observed even in the image of the colorized composite map.
　図３は、比較例１の接合部のリフロー処理後のＥＰＭＡ複合マップ画像である。
　図３には、Ｎｉ層（３１）とＢｉ層（３４）の界面近傍に、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（３２）と見られる層が観察され、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（３２）の直下には、ＮｉＳｎ合金層（３２’）とも見られる層（厚さ約０．１μｍ）が存在するが、そのＮｉＳｎ（３２’）合金層にはグレースケールでは観察できない程度の微量のＢｉの侵入（３５）が、カラー化した複合マップの画像において観察される。また、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（３２）には厚さの不均一があり、この（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（３２）から遊離してしまった（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ相（３３）が、Ｂｉ層（３４）中に観察される。図３においては、Ｎｉ層（３１）中へのＢｉの侵入は、カラー化した複合マップの画像においても観察されない。なお、図３の画像の下半分以上を占める黒い領域は、Ｎｉ層（３１）の下地となっているＡｌ層（３μｍ）とさらにその下地となっているＳｉ基材である。 FIG. 3 is an EPMA composite map image after the reflow process of the joint portion of Comparative Example 1.
In FIG. 3, in the vicinity of the interface between the Ni layer (31) and the Bi layer (34), a layer that is considered to be a (Cu, Ni, Pd)αSn layer (32) was observed, and a (Cu, Ni, Pd)αSn layer was observed. Immediately below (32), there is a layer (thickness: about 0.1 μm) which is also seen as a NiSn alloy layer (32′), but the NiSn(32′) alloy layer has a trace amount that cannot be observed in gray scale. Bi intrusion (35) is observed in the image of the colorized composite map. Further, the (Cu, Ni, Pd)αSn layer (32) has a non-uniform thickness, and is separated from this (Cu, Ni, Pd)αSn layer (32) (Cu, Ni, Pd). The αSn phase (33) is observed in the Bi layer (34). In FIG. 3, the penetration of Bi into the Ni layer (31) is not observed even in the image of the colorized composite map. The black region occupying the lower half or more of the image of FIG. 3 is the Al layer (3 μm) that is the base of the Ni layer (31) and the Si base material that is the base of the Al layer.
　図４は、比較例１の接合部のリフロー処理後に、２５０℃の温度で１０００時間保持した後のＥＰＭＡ複合マップ画像である。
　図４には、図３と同様にＮｉ層が存在しているが、カラー化した複合マップの画像ではＮｉ層はその厚みのほぼ全体（厚さ約１．８μｍ）がＢｉの侵入が観察されるＮｉ層（４２）となっており、Ｂｉの侵入が観察されないＮｉ層（４１）はごく薄く（厚さ約０．４μｍ）存在するだけとなっている。Ｎｉ層（４２）とＢｉ層（４５）の界面近傍には、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（４３）と見られる層が観察され、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（４３）の直下には、ＮｉＳｎ合金層とも見られる層は、カラー化した複合マップの画像においても観察されないが、ＮｉＳｎ合金相（４３’）の塊が不連続に観察される。（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（４３）の形状は、ひどく乱れてしまっており、遊離してしまった（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ相（４４）が、Ｂｉ層（４５）中に多く観察される。さらに、Ｎｉ層に由来すると見られるＮｉ相（４６）が、Ｂｉ層（４５）中に多く観察される。 FIG. 4 is an EPMA composite map image after holding for 1000 hours at a temperature of 250° C. after the reflow treatment of the joint portion of Comparative Example 1.
In FIG. 4, the Ni layer is present as in FIG. 3, but in the image of the colorized composite map, the penetration of Bi is observed in almost the entire thickness of the Ni layer (about 1.8 μm in thickness). The Ni layer (42) is a thin Ni layer (42), and the Ni layer (41) in which no intrusion of Bi is observed is very thin (about 0.4 μm thick). In the vicinity of the interface between the Ni layer (42) and the Bi layer (45), a layer considered to be the (Cu, Ni, Pd)αSn layer (43) was observed, and the layer of the (Cu, Ni, Pd)αSn layer (43) was observed. Immediately below, a layer that is also seen as a NiSn alloy layer is not observed in the image of the colorized composite map, but a lump of the NiSn alloy phase (43′) is discontinuously observed. The shape of the (Cu, Ni, Pd)αSn layer (43) is severely disordered, and the released (Cu, Ni, Pd)αSn phase (44) is mostly present in the Bi layer (45). To be observed. Furthermore, a large amount of Ni phase (46), which seems to be derived from the Ni layer, is observed in the Bi layer (45).
　図５は、実施例１の接合部のリフロー処理後のＳＴＭ画像である。
　図５において、Ｎｉ層（５１）とＢｉ層（５４）の界面近傍に、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（５３）と見られる層が観察される。上下方向に細長い孔が空いているかのような領域（５２）が観察される。後述のように、この領域（５２）はＰ濃度が比較的に大きいＰリッチ領域である。このＰリッチ領域の厚みは約０．１３μｍであった。分析ライン（５５）に沿って、分析を行って、各分析点における原子の濃度を測定して作成したグラフが、図６である。 FIG. 5 is an STM image after the reflow processing of the joint portion in Example 1.
In FIG. 5, in the vicinity of the interface between the Ni layer (51) and the Bi layer (54), a layer that is considered to be a (Cu, Ni, Pd)αSn layer (53) is observed. An area (52) as if an elongated hole is formed in the vertical direction is observed. As will be described later, this region (52) is a P-rich region having a relatively high P concentration. The thickness of this P-rich region was about 0.13 μm. FIG. 6 is a graph prepared by performing analysis along the analysis line (55) and measuring the concentration of atoms at each analysis point.
　図６は、図５の分析ライン（５５）に沿って分析して得られた原子の濃度（モル％）を縦軸とし、分析ラインの分析の開始点からの距離を横軸としたグラフである。グラフの左側はＮｉ層側であり、グラフの右側はＢｉ層側である。横軸の開始点はＮｉ層中にある。０．１５μｍからとＮｉ濃度は減少してゆき、０．２２μｍ付近でＳｎ濃度がほぼ存在しない状態から急激に上昇し始める。この位置からＮｉＳｎ合金層が始まっていると考えられる。同時にこの位置ではＰ濃度がその前後よりも比較的に大きくなっており、距離の増大に伴ってＰ濃度は減少して、０．２６μｍ付近でＰ濃度がほぼ消失する。このＰ濃度の減少と並行して、Ｎｉ濃度は減少し、Ｓｎ濃度が上昇している。Ｐ濃度が消失する位置でＮｉＳｎ合金層が終わっており、新たに（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層が始まっていると考えられる。この（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層の開始位置では、Ｐｄ濃度がその前後よりも比較的に大きくなっている。ＮｉＳｎ合金層と（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層の境界では、Ｓｎ濃度が４８モル％、Ｎｉ濃度が２１モル％と見積もられ、αの値が０．８となる。この（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層の開始位置から距離が増大すると、Ｂｉ含有量が比較的に高い領域が０．３０μｍ付近で一時的に生じているが、その前後にはＢｉはほとんど含まれていない。その後、距離が増大する間、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層が続く。この間のαは０．８～０．９と見積もられ、平均値が０．８３であった。その後、距離が増大すると、０．４８μｍ付近でＢｉ濃度がほぼ存在しない状態から急激に上昇し始める。このＢｉ濃度が上昇開始する位置で（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層が終了して、ＢｉＳｎ合金層が開始している。ＢｉＳｎ合金層には、ＢｉとＳｎに加えて、Ｃｕ，Ｎｉ，Ｐｄが存在している。ＢｉＳｎ合金層中のＣｕ，Ｎｉ，Ｐｄの濃度は、いずれも距離の増大とともに減少して、０．５６μｍ付近でいずれも消失する。このＣｕ，Ｎｉ，Ｐｄの濃度が消失する位置で、ＢｉＳｎ合金層が終わっており、Ｂｉ層が始まっていると考えられる。 FIG. 6 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (55) in FIG. 5 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there. The left side of the graph is the Ni layer side, and the right side of the graph is the Bi layer side. The starting point of the horizontal axis is in the Ni layer. From 0.15 μm, the Ni concentration decreases, and near 0.22 μm, the Sn concentration begins to rise rapidly from the state where there is almost no Sn concentration. It is considered that the NiSn alloy layer starts from this position. At the same time, the P concentration at this position is relatively higher than before and after it, the P concentration decreases with increasing distance, and the P concentration almost disappears near 0.26 μm. Concurrently with the decrease in P concentration, the Ni concentration decreases and the Sn concentration increases. It is considered that the NiSn alloy layer ends at the position where the P concentration disappears and a new (Cu, Ni, Pd)αSn layer starts. At the starting position of this (Cu, Ni, Pd)αSn layer, the Pd concentration is relatively higher than before and after it. At the boundary between the NiSn alloy layer and the (Cu, Ni, Pd)αSn layer, the Sn concentration is estimated to be 48 mol% and the Ni concentration is 21 mol%, and the value of α is 0.8. When the distance from the starting position of the (Cu, Ni, Pd)αSn layer increases, a region having a relatively high Bi content temporarily occurs near 0.30 μm, but Bi is almost included before and after the region. It is not. The (Cu,Ni,Pd)αSn layer then follows while the distance increases. During this period, α was estimated to be 0.8 to 0.9, and the average value was 0.83. After that, when the distance increases, the Bi concentration starts to rise sharply in the vicinity of 0.48 μm from the state where there is almost no Bi concentration. The (Cu, Ni, Pd)αSn layer ends at the position where the Bi concentration starts to rise, and the BiSn alloy layer starts. In the BiSn alloy layer, Cu, Ni, and Pd are present in addition to Bi and Sn. The concentrations of Cu, Ni, and Pd in the BiSn alloy layer all decrease with an increase in the distance, and disappear in the vicinity of 0.56 μm. It is considered that the BiSn alloy layer ends and the Bi layer starts at the position where the Cu, Ni, and Pd concentrations disappear.
　図７は、比較例１の接合部のリフロー処理後のＳＴＭ画像である。
　図７において、Ｎｉ層（７１）とＢｉ層（７４）の界面近傍に、（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層（７３）と見られる層が観察される。上下方向に細長い孔が空いているかのようなＰリッチ領域（７２）が、図５よりはやや形状が乱れて不均一であるが、観察される分析ライン（７５）に沿って、分析を行って、各分析点における原子の濃度を測定して作成したグラフが、図８である。 FIG. 7 is an STM image after the reflow process of the joint portion of Comparative Example 1.
In FIG. 7, a layer considered to be a (Cu, Ni, Pd)αSn layer (73) is observed near the interface between the Ni layer (71) and the Bi layer (74). Although the P-rich region (72), which seems to have an elongated hole in the up-and-down direction, is slightly uneven in shape as compared with FIG. 5, the analysis is performed along the observed analysis line (75). FIG. 8 is a graph created by measuring the concentration of atoms at each analysis point.
　図８は、図７の分析ライン（７５）に沿って分析して得られた原子の濃度（モル％）を縦軸とし、分析ラインの分析の開始点からの距離を横軸としたグラフである。グラフの左側はＮｉ層側であり、グラフの右側はＢｉ層側である。図６のグラフであれば、ＮｉＳｎ合金層と（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層の境界に相当する位置にまで、図８のグラフでは、Ｂｉが侵入していることが観察される。また、図６のグラフであれば、ＮｉＳｎ合金層に相当する位置を通過して、Ｎｉ層に相当する位置にまで、図８のグラフでは、Ｂｉが侵入していることが観察される。なお、Ｐ濃度が消失する位置、すなわちＮｉＳｎ合金層と（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層の境界では、Ｓｎ濃度が１８モル％、Ｎｉ濃度が２３モル％と見積もられ、αの値が２．０となった。（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層のαは０．７～１．２と見積もられ、平均値が０．８５であった。 FIG. 8 is a graph in which the vertical axis represents the concentration (mol %) of atoms obtained by analysis along the analysis line (75) in FIG. 7 and the horizontal axis represents the distance from the analysis starting point of the analysis line. is there. The left side of the graph is the Ni layer side, and the right side of the graph is the Bi layer side. In the graph of FIG. 6, it is observed that Bi penetrates to the position corresponding to the boundary between the NiSn alloy layer and the (Cu, Ni, Pd)αSn layer, and in the graph of FIG. Further, in the graph of FIG. 6, it is observed that Bi penetrates through the position corresponding to the NiSn alloy layer to the position corresponding to the Ni layer in the graph of FIG. At the position where the P concentration disappears, that is, at the boundary between the NiSn alloy layer and the (Cu, Ni, Pd)αSn layer, the Sn concentration is estimated to be 18 mol% and the Ni concentration is estimated to be 23 mol%. It became 0.0. The α of the (Cu, Ni, Pd)αSn layer was estimated to be 0.7 to 1.2, and the average value was 0.85.
　本発明は、鉛が添加されて含まれることなく、高温域において優れた耐久性を有する、はんだ接合部を提供する。本発明は産業上有用な発明である。 The present invention provides a solder joint portion having excellent durability in a high temperature range without containing lead added. The present invention is an industrially useful invention.
１１　Ｎｉ層
１２　ＮｉＳｎ合金層
１３　（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層
１４　Ｂｉ層
　
２１　Ｎｉ層
２２　ＮｉＳｎ合金層
２３　（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層
２４　Ｂｉ層
　
３１　Ｎｉ層（Ｂｉ侵入無し）
３２　（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層
３２’　ＮｉＳｎ合金層
３３　遊離（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ相
３４　Ｂｉ層
３５　侵入Ｂｉ
　
４１　Ｎｉ層（Ｂｉ侵入無し）
４２　Ｎｉ層（Ｂｉ侵入有り）
４３’　ＮｉＳｎ合金相（不連続）
４３　（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層
４４　遊離（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ相
４５　Ｂｉ層
４６　Ｎｉ相
　
５１　Ｎｉ層
５２　Ｐリッチ領域
５３　（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層
５４　Ｂｉ層
５５　分析ライン
　
７１　Ｎｉ層
７２　Ｐリッチ領域
７３　（Ｃｕ，Ｎｉ，Ｐｄ）αＳｎ層
７４　Ｂｉ層
７５　分析ライン 11 Ni layer 12 NiSn alloy layer 13 (Cu, Ni, Pd) αSn layer 14 Bi layer
21 Ni layer 22 NiSn alloy layer 23 (Cu, Ni, Pd) αSn layer 24 Bi layer
31 Ni layer (no Bi penetration)
32 (Cu,Ni,Pd)αSn layer 32′ NiSn alloy layer 33 Free (Cu,Ni,Pd)αSn phase 34 Bi layer 35 Penetration Bi

41 Ni layer (no Bi penetration)
42 Ni layer (with Bi intrusion)
43' NiSn alloy phase (discontinuous)
43 (Cu, Ni, Pd) αSn layer 44 Free (Cu, Ni, Pd) αSn phase 45 Bi layer 46 Ni phase
51 Ni layer 52 P rich region 53 (Cu, Ni, Pd) αSn layer 54 Bi layer 55 Analysis line
71 Ni layer 72 P rich region 73 (Cu, Ni, Pd) αSn layer 74 Bi layer 75 Analysis line

Claims (19)

  1. 　ＵＢＭとはんだ合金を接合した接合部であって、ＵＢＭ側から順に、
    　ＵＢＭ側から連続するＮｉ層と、
    　ＮｉＳｎ合金層と、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層と、
    　ＢｉＳｎ合金層と、
    　はんだ合金側へと連続するＢｉ層を含んでなる、接合部。     It is a joint part where the UBM and the solder alloy are joined, and in order from the UBM side,
    Ni layer continuous from the UBM side,
    NiSn alloy layer,
    (Cu, Ni, Pd) αSn alloy layer,
    A BiSn alloy layer,
    A joint comprising a Bi layer continuous to the solder alloy side.
  2. 　ＮｉＳｎ合金層は、Ｎｉ、Ｓｎ、及びＰを含有し、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＮｉ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＮｉ含有量よりも大きく、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＳｎ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＳｎ含有量よりも小さく、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＳｎ含有量は、０．４モル％以下であり、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰ含有量よりも大きく、
    　ＮｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰ含有量は、０．５モル％以下である、請求項１に記載の接合部。     The NiSn alloy layer contains Ni, Sn, and P,
    In the NiSn alloy layer, the Ni content at the boundary with the Ni layer is larger than the Ni content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
    In the NiSn alloy layer, the Sn content at the boundary with the Ni layer is smaller than the Sn content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
    In the NiSn alloy layer, the Sn content at the boundary with the Ni layer is 0.4 mol% or less,
    In the NiSn alloy layer, the P content at the boundary with the Ni layer is larger than the P content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
    The joint portion according to claim 1, wherein in the NiSn alloy layer, the P content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 0.5 mol% or less.
  3. 　ＮｉＳｎ合金層は、Ｎｉ、Ｓｎ、及びＰを含有し、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＮｉ含有量が２１モル％～８３モル％の範囲にあり、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＳｎ含有量が０．２モル％～４８モル％の範囲にあり、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＰ含有量が０．１モル％～１０モル％の範囲にある、請求項１～２のいずれかに記載の接合部。     The NiSn alloy layer contains Ni, Sn, and P,
    In the NiSn alloy layer, the Ni content at each distance from the boundary with the Ni layer is in the range of 21 mol% to 83 mol%,
    In the NiSn alloy layer, the Sn content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 48 mol%,
    The joint portion according to any one of claims 1 and 2, wherein the Ni content in the NiSn alloy layer is in the range of 0.1 mol% to 10 mol% at each distance from the boundary with the Ni layer.
  4. 　ＮｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＢｉ含有量が、２モル％以下である、請求項１～３のいずれかに記載の接合部。 The joined portion according to any one of claims 1 to 3, wherein in the NiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 2 mol% or less.
  5. 　ＮｉＳｎ合金層において、Ｎｉ層との境界からの各距離におけるＢｉ含有量が、０．２モル％～２モル％の範囲にある、請求項１～４のいずれかに記載の接合部。 The joint portion according to any one of claims 1 to 4, wherein in the NiSn alloy layer, the Bi content at each distance from the boundary with the Ni layer is in the range of 0.2 mol% to 2 mol%.
  6. 　ＮｉＳｎ合金層の厚みが、０．０３～０．１［μｍ］の範囲にある、請求項１～５のいずれかに記載の接合部。 The joint portion according to any one of claims 1 to 5, wherein the thickness of the NiSn alloy layer is in the range of 0.03 to 0.1 [μm].
  7. 　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＣｕ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＣｕ含有量よりも小さく、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＣｕ含有量は、４モル％以下である、請求項２～６のいずれかに記載の接合部。     In the NiSn alloy layer, the Cu content at the boundary with the Ni layer is smaller than the Cu content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
    The joint portion according to any one of claims 2 to 6, wherein in the NiSn alloy layer, the Cu content at the boundary with the Ni layer is 4 mol% or less.
  8. 　ＮｉＳｎ合金層は、さらに、Ｐｄを含有し、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰｄ含有量は、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰｄ含有量よりも小さく、
    　ＮｉＳｎ合金層において、Ｎｉ層との境界におけるＰｄ含有量は、３モル％以下である、請求項２～７のいずれかに記載の接合部。     The NiSn alloy layer further contains Pd,
    In the NiSn alloy layer, the Pd content at the boundary with the Ni layer is smaller than the Pd content at the boundary with the (Cu, Ni, Pd)αSn alloy layer,
    The joint portion according to any one of claims 2 to 7, wherein in the NiSn alloy layer, the Pd content at the boundary with the Ni layer is 3 mol% or less.
  9. 　Ｎｉ層は、ＮｉＳｎ合金層との境界から０．２［μｍ］以内の各距離におけるＢｉ含有量が、０．２モル％以下である、請求項１～８のいずれかに記載の接合部。 The joint portion according to any one of claims 1 to 8, wherein the Ni layer has a Bi content of 0.2 mol% or less at each distance within 0.2 [μm] from the boundary with the NiSn alloy layer.
  10. 　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、Ｃｕ、Ｎｉ、Ｐｄ、及びＳｎを含有し、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＣｕ含有量が１０モル％～２２モル％の範囲にあり、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＮｉ含有量が１３モル％～２１モル％の範囲にあり、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＰｄ含有量が５モル％～１９モル％の範囲にあり、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの各距離におけるＳｎ含有量が４４モル％～５５モル％の範囲にある、請求項１～９のいずれかに記載の接合部。     The (Cu, Ni, Pd)αSn alloy layer contains Cu, Ni, Pd, and Sn,
    In the (Cu, Ni, Pd) αSn alloy layer, the Cu content at each distance from the boundary with the NiSn alloy layer is in the range of 10 mol% to 22 mol %,
    In the (Cu, Ni, Pd)αSn alloy layer, the Ni content at each distance from the boundary with the NiSn alloy layer is in the range of 13 mol% to 21 mol %,
    In the (Cu, Ni, Pd)αSn alloy layer, the Pd content at each distance from the boundary with the NiSn alloy layer is in the range of 5 mol% to 19 mol %,
    10. The (Cu, Ni, Pd)αSn alloy layer according to claim 1, wherein the Sn content at each distance from the boundary with the NiSn alloy layer is in the range of 44 mol% to 55 mol %. Joint.
  11. 　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層は、さらに、Ｂｉを含有し、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界におけるＢｉ含有量が、２モル％以下であり、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＮｉＳｎ合金層との境界からの距離に応じてＢｉ含有量を測定した場合に、Ｂｉ含有量が０．１モル％～２４モル％の範囲にある距離が存在し、
    　（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層において、ＢｉＳｎ合金層との境界におけるＢｉ含有量が、０．５モル％以下である、請求項１０に記載の接合部。     The (Cu, Ni, Pd)αSn alloy layer further contains Bi,
    In the (Cu, Ni, Pd) αSn alloy layer, the Bi content at the boundary with the NiSn alloy layer is 2 mol% or less,
    In the (Cu, Ni, Pd)αSn alloy layer, when the Bi content is measured according to the distance from the boundary with the NiSn alloy layer, the Bi content is in the range of 0.1 mol% to 24 mol%. There is a distance,
    The joint portion according to claim 10, wherein in the (Cu, Ni, Pd) αSn alloy layer, the Bi content at the boundary with the BiSn alloy layer is 0.5 mol% or less.
  12. 　ＢｉＳｎ合金層は、Ｂｉ及びＳｎを含有し、
    　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＢｉ含有量が、０．５モル％以下であり、
    　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＳｎ含有量が、２モル％以下である、請求項１～１１のいずれかに記載の接合部。     The BiSn alloy layer contains Bi and Sn,
    In the BiSn alloy layer, the Bi content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is 0.5 mol% or less,
    The joint portion according to any one of claims 1 to 11, wherein in the BiSn alloy layer, the Sn content at the boundary with the Bi layer is 2 mol% or less.
  13. 　ＢｉＳｎ合金層は、さらに、Ｃｕ、Ｎｉ、Ｐｄを含有し、
    　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＣｕ含有量は、Ｂｉ層との境界におけるＣｕ含有量よりも大きく、
    　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＣｕ含有量は、０．５モル％以下であり、
    　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＮｉ含有量は、Ｂｉ層との境界におけるＮｉ含有量よりも大きく、
    　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＮｉ含有量は、１モル％以下であり、
    　ＢｉＳｎ合金層において、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層との境界におけるＰｄ含有量は、Ｂｉ層との境界におけるＰｄ含有量よりも大きく、
    　ＢｉＳｎ合金層において、Ｂｉ層との境界におけるＰｄ含有量は、０．６モル％以下である、請求項１２に記載の接合部。     The BiSn alloy layer further contains Cu, Ni and Pd,
    In the BiSn alloy layer, the Cu content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Cu content at the boundary with the Bi layer,
    In the BiSn alloy layer, the Cu content at the boundary with the Bi layer is 0.5 mol% or less,
    In the BiSn alloy layer, the Ni content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Ni content at the boundary with the Bi layer,
    In the BiSn alloy layer, the Ni content at the boundary with the Bi layer is 1 mol% or less,
    In the BiSn alloy layer, the Pd content at the boundary with the (Cu, Ni, Pd)αSn alloy layer is larger than the Pd content at the boundary with the Bi layer,
    The joint part according to claim 12, wherein the Pd content at the boundary with the Bi layer in the BiSn alloy layer is 0.6 mol% or less.
  14. 　Ｂｉ層中に、（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金層から遊離した（Ｃｕ、Ｎｉ、Ｐｄ）αＳｎ合金の相を有さない、請求項１～１３のいずれかに記載の接合部。 The joint portion according to any one of claims 1 to 13, wherein the Bi layer does not have a phase of (Cu, Ni, Pd)αSn alloy released from the (Cu, Ni, Pd)αSn alloy layer.
  15. 　ＵＢＭは、電極上に、ニッケル、パラジウム、及び金が、順に積層されて形成されたＵＢＭである、請求項１～１４のいずれかに記載の接合部。 The joint part according to any one of claims 1 to 14, wherein the UBM is a UBM formed by sequentially stacking nickel, palladium, and gold on an electrode.
  16. 　２５０℃、１０００時間の高温保持後の接合強度が４０ＭＰａ以上である、請求項１～１５のいずれかに記載の接合部。 The joint according to any one of claims 1 to 15, which has a joint strength of 40 MPa or more after being kept at a high temperature of 250°C for 1000 hours.
  17. 　請求項１～１６のいずれかに記載の接合部を有する、電子部品。 An electronic component having the joint according to any one of claims 1 to 16.
  18. 　請求項１～１６のいずれかに記載の接合部を有する、パワーデバイス。 A power device having the joint according to any one of claims 1 to 16.
  19. 　請求項１～１６のいずれかに記載の接合部を有する、プリント回路板。 A printed circuit board having the joint according to any one of claims 1 to 16.
PCT/JP2019/031255 2018-12-28 2019-08-07 Solder joint WO2020136979A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2020502503A JPWO2020136979A1 (en) 2018-12-28 2019-08-07 Solder joint
CN201980003606.1A CN111630646A (en) 2018-12-28 2019-08-07 Solder joint

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018248474 2018-12-28
JP2018-248474 2018-12-28

Publications (1)

Publication Number Publication Date
WO2020136979A1 true WO2020136979A1 (en) 2020-07-02

Family

ID=71127139

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/031255 WO2020136979A1 (en) 2018-12-28 2019-08-07 Solder joint

Country Status (4)

Country Link
JP (1) JPWO2020136979A1 (en)
CN (1) CN111630646A (en)
TW (1) TWI717833B (en)
WO (1) WO2020136979A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011014705A (en) * 2009-07-01 2011-01-20 Hitachi Ltd Semiconductor device and method of manufacturing the same
JP2013093547A (en) * 2011-10-05 2013-05-16 Fujitsu Ltd Semiconductor device, electronic apparatus and semiconductor device manufacturing method
WO2014115798A1 (en) * 2013-01-28 2014-07-31 株式会社村田製作所 Solder bump formation method and solder bump
WO2014170994A1 (en) * 2013-04-18 2014-10-23 千住金属工業株式会社 Lead-free solder alloy
JP2015072996A (en) * 2013-10-02 2015-04-16 新光電気工業株式会社 Semiconductor device
US20170368644A1 (en) * 2016-06-23 2017-12-28 Purdue Research Foundation Transient liquid phase bonding process and assemblies formed thereby
JP2018047497A (en) * 2016-09-23 2018-03-29 住友金属鉱山株式会社 Bi-BASED SOLDER ALLOY AND METHOD FOR PRODUCING THE SAME, AND ELECTRONIC COMPONENT AND ELECTRONIC COMPONENT-MOUNTED SUBSTRATE COMPRISING THE SOLDER ALLOY

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6630251B1 (en) * 2002-09-23 2003-10-07 Delphi Technologies, Inc. Leach-resistant solder alloys for silver-based thick-film conductors
CN101076446A (en) * 2003-08-06 2007-11-21 密执安州立大学 Compound metallic substrate casting and solder composition and method
US7915741B2 (en) * 2009-02-24 2011-03-29 Unisem Advanced Technologies Sdn. Bhd. Solder bump UBM structure
TWI423358B (en) * 2011-08-04 2014-01-11 Nippon Steel & Sumikin Mat Co Solder balls and electronic components for semiconductor encapsulation

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011014705A (en) * 2009-07-01 2011-01-20 Hitachi Ltd Semiconductor device and method of manufacturing the same
JP2013093547A (en) * 2011-10-05 2013-05-16 Fujitsu Ltd Semiconductor device, electronic apparatus and semiconductor device manufacturing method
WO2014115798A1 (en) * 2013-01-28 2014-07-31 株式会社村田製作所 Solder bump formation method and solder bump
WO2014170994A1 (en) * 2013-04-18 2014-10-23 千住金属工業株式会社 Lead-free solder alloy
JP2015072996A (en) * 2013-10-02 2015-04-16 新光電気工業株式会社 Semiconductor device
US20170368644A1 (en) * 2016-06-23 2017-12-28 Purdue Research Foundation Transient liquid phase bonding process and assemblies formed thereby
JP2018047497A (en) * 2016-09-23 2018-03-29 住友金属鉱山株式会社 Bi-BASED SOLDER ALLOY AND METHOD FOR PRODUCING THE SAME, AND ELECTRONIC COMPONENT AND ELECTRONIC COMPONENT-MOUNTED SUBSTRATE COMPRISING THE SOLDER ALLOY

Also Published As

Publication number Publication date
TWI717833B (en) 2021-02-01
TW202039241A (en) 2020-11-01
CN111630646A (en) 2020-09-04
JPWO2020136979A1 (en) 2021-09-09

Similar Documents

Publication Publication Date Title
US20210167034A1 (en) Chip arrangements
TWI655052B (en) Lead-free, flawless solder alloy, its use, including solder joints, and methods of forming solder joints
KR101985646B1 (en) Low temperature high reliability tin alloy for soldering
TWI650426B (en) Advanced solder alloy and soldering method for electronic interconnection
US11229979B2 (en) High reliability lead-free solder alloys for harsh environment electronics applications
TWI655296B (en) Highly reliable lead-free solder alloy, its use and method of forming solder joints
US7829199B2 (en) Solder, and mounted components using the same
US10157877B2 (en) Semiconductor device and manufacturing method of semiconductor device
JP4722751B2 (en) Powder solder material and bonding material
JP3796181B2 (en) Electronic member having lead-free solder alloy, solder ball and solder bump
KR20140110926A (en) Bonding method, bond structure, and manufacturing method for same
JP5614507B2 (en) Sn-Cu lead-free solder alloy
JP6810915B2 (en) Solder material
JP6529632B1 (en) Semiconductor device using solder alloy, solder paste, molded solder, and solder alloy
WO2020136979A1 (en) Solder joint
JP2011251332A (en) HIGH-TEMPERATURE Pb-FREE SOLDER PASTE USING Al POWDER
Chen et al. Interfacial reactions of Ag and Ag-4Pd stud bumps with Sn-3Ag-0.5 Cu solder for flip chip packaging
JP6543890B2 (en) High temperature solder alloy
CN111132794B (en) Solder alloy
Hanim et al. Intermetallic evolution for isothermal aging up to 2000 hours on sn-4ag-0.5 cu and sn-37pb solders with ni/au layers
Noor et al. Bi Based Interconnect Systems and Applications
Li et al. Effects of surface finishes on the intermetallic growth and micro-structure evolution of the Sn3. 5Ag0. 7Cu lead-free solder joints
JP5744080B2 (en) Bonded body and semiconductor device
JP2005193294A (en) Lead-free solder
CN112951786A (en) Solder material, layer structure and forming method thereof, chip package and forming method thereof, chip arrangement and forming method thereof

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2020502503

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19904934

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19904934

Country of ref document: EP

Kind code of ref document: A1