Electronic device member and electronic device

Abstract

To provide an electronic device member that can ensure high bonding reliability of a solder layer.SOLUTION: An electronic device member 100 includes a first substrate 2, at least one protruding portion 6 protruding from the first substrate 2, and a solder layer 12, and the at least one protruding portion 6 has at least one side surface 61, a tip surface 62, and at least one connection portion 64 between the side surface 61 and the tip surface 62, and the solder layer 12 is in contact with the tip surface 62. In the connection portion 64, the at least one side surface 61 and the tip surface 62 form an obtuse angle θ1.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an electronic device member and an electronic device including the same. [Background technology]

[0002] There is known an electronic device in which an element is disposed between two substrates. Patent Document 1 describes an infrared sensor in which a plurality of bolometer films are disposed between two substrates. The two substrates are connected by a sidewall, and an enclosed space is formed between the two substrates and the sidewall. A plurality of pillar-shaped electrical connection members are disposed in the enclosed space to electrically connect the two substrates. The thickness of the sidewall and the electrical connection members is constant in the height direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 171488 Summary of the Invention [Problem to be solved by the invention]

[0004] In some cases, the electrical connection members and side walls are joined to one of the substrates by a solder layer. If the solder layer has insufficient bonding reliability, it will affect the functions of the side walls and the electrical connection members. For this reason, the solder layer is required to have high bonding reliability.

[0005] An object of the present invention is to provide an electronic device member which can easily ensure high bonding reliability of a solder layer. [Means for solving the problem]

[0006] The electronic device member of the present invention comprises a first substrate, at least one protruding portion protruding from the first substrate, and a solder layer, the at least one protruding portion having at least one side surface, a tip surface, and a connection portion between the at least one side surface and the tip surface, the solder layer being in contact with the tip surface, and the connection portion being such that the at least one side surface and the tip surface form an obtuse angle. Effect of the Invention

[0007] According to the present invention, it is possible to provide an electronic device member in which high bonding reliability of the solder layer can be easily ensured. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic plan view of an infrared sensor according to a first embodiment. [Diagram 2] 2 is a schematic partial cross-sectional view of the infrared sensor taken along line 2-2 in FIG. 1. [Diagram 3] 3(a) is a schematic plan view showing the positional relationship between the electrical connection member on the first substrate side, the side wall, thermistor element, and lead wire in part A of FIG. 1, and FIG. 3(b) is a schematic plan view showing the positional relationship between the electrical connection member on the second substrate side, the side wall, and thermistor element in part A of FIG. 1. [Figure 4] FIG. 2 is a schematic cross-sectional view of a first substrate and a second substrate before bonding. [Diagram 5] FIG. 4 is a schematic cross-sectional view of the first substrate and the second substrate after bonding. [Figure 6] FIG. 4 is a schematic cross-sectional view of an electrical connection member of a comparative example. [Figure 7] 2A to 2C are schematic diagrams illustrating a method for forming an electrical connection member according to the first embodiment. [Figure 8] FIG. 6 is a schematic cross-sectional view of an electrical connection member according to a second embodiment. [Figure 9] FIG. 11 is a schematic cross-sectional view of an electrical connection member according to a third embodiment. [Figure 10] 10A to 10C are schematic diagrams illustrating a method for forming an electrical connection member according to a third embodiment. [Figure 11]FIG. 11 is a schematic cross-sectional view of an electrical connection member according to a modified example of the third embodiment. [Figure 12] 13A to 13C are schematic diagrams illustrating a method for forming an electrical connection member according to a modified example of the third embodiment. [Figure 13] FIG. 11 is a schematic plan view of an electronic device member according to a fourth embodiment. [Figure 14] FIG. 13 is a schematic plan view of an electronic device member according to a modified example of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, some embodiments of the electronic device member of the present invention and the electronic device having the electronic device member will be described with reference to the drawings. The drawings are schematic diagrams for illustrating the present invention, and shapes and dimensions may not be consistent between drawings. In the following description and drawings, the X direction and the Y direction are parallel to the main surface 21 of the first substrate 2 and the main surface 31 of the second substrate 3. The main surfaces 21 and 31 are the surfaces of the first substrate 2 and the second substrate 3 facing each other. The X direction and the Y direction are perpendicular to each other. The Z direction is a direction perpendicular to the X direction and the Y direction, and is a direction perpendicular to the main surfaces 21 and 31 of the first substrate 2 and the second substrate 3, or a direction in which the first substrate 2 and the second substrate 3 are stacked.

[0010] In the following embodiments, an infrared sensor 1 will be described as an example of an electronic device. The infrared sensor 1 is mainly used as an imaging element of an infrared camera. The infrared camera can be used as a night vision scope or night vision goggles in a dark place, and can also be used to measure the temperature of a person or object. In the present invention, the detection target is not limited to infrared rays. The electronic device of the present invention can be applied to an electromagnetic wave sensor that detects, for example, terahertz waves or electromagnetic waves including the near-infrared region. In addition, as described later, the present invention can be applied to various electronic devices other than electromagnetic wave sensors.

[0011] (First embodiment) FIG. 1 is a schematic plan view of the infrared sensor 1, and FIG. 2 is a schematic partial cross-sectional view of the infrared sensor 1 taken along line 2-2 in FIG. 1. In FIG. 2, only one electrical connection member 6 is shown for convenience. FIG. 3(a) is a schematic plan view showing the positional relationship between the electrical connection member 6 on the first substrate 2 side, the side wall 4, a plurality of thermistor elements 7, and a plurality of lead wires 10 in part A in FIG. 1. FIG. 3(b) is a schematic plan view showing the positional relationship between the electrical connection member 6 on the second substrate 3 side, the side wall 4, and a plurality of thermistor elements 7 in part A in FIG. 1. As shown in FIG. 2, the infrared sensor 1 has the first substrate 2 and the second substrate 3 arranged opposite each other, and a side wall 4 connecting the first substrate 2 and the second substrate 3. The first substrate 2 and the second substrate 3 are mainly formed of silicon substrates, and an insulating film covering the lead wires 10, the circuit section 9, and the like is formed on the silicon substrate. In FIG. 2, the insulating layer is shown as being integrated with the first substrate 2 and the second substrate 3. The first substrate 2, the second substrate 3, and the side wall 4 form a sealed internal space 5. The internal space 5 is provided with a plurality of thermistor elements 7 functioning as sensing units of the infrared sensor 1. The plurality of thermistor elements 7 are arranged in a rectangular region 8 as shown in FIG. 1, and form a two-dimensional lattice array consisting of a plurality of rows extending in the X direction and a plurality of columns extending in the Y direction as shown in FIG. 3. The internal space 5 is under negative pressure or vacuum. This prevents or suppresses gas convection in the internal space 5, and reduces the thermal effect on the thermistor elements 7.

[0012] The first substrate 2 supports a plurality of thermistor elements 7. The second substrate 3 is provided with a circuit section 9 consisting of an ROIC (Readout IC) or the like. The first substrate 2 and the second substrate 3 are connected by a plurality of electrical connection members 6. The electrical connection members 6 are conductors in the shape of a truncated cone. The electrical connection members 6 are disposed in the internal space 5. The electrical connection members 6 are connected to lead wires 10 arranged in an array, and the lead wires 10 are connected to the thermistor elements 7. Thus, the thermistor elements 7 are electrically connected to the circuit section 9 via the electrical connection members 6 and the lead wires 10. At least one pad (not shown) for inputting and outputting with the outside is formed on the outer side of the side wall 4 of the second substrate 3.

[0013] FIG. 4 is a schematic cross-sectional view of the first substrate 2 and the second substrate 3 before bonding. The side wall 4 is fixed to the first substrate 2 in advance. The side wall 4 is a protruding portion protruding from the first substrate 2 in the Z direction. The side wall 4 is made of, for example, Ni, and is produced by plating. The side wall 4 is a rectangular frame portion (see FIG. 1) with rounded corners in a plan view from the Z direction, and has a continuous frame shape in any cross section perpendicular to the Z direction. In other words, the side wall 4 is a continuous closed wall body, and surrounds the region 8 in which the multiple thermistor elements 7 are arranged. The side wall 4 has two side surfaces (an inner side surface 41 and an outer side surface 42), a frame-shaped tip surface 43, and a frame-shaped base surface 44 connected to the first substrate 2, and the tip surface 43 and the base surface 44 are approximately planar. A frame-shaped solder layer 11 is provided on the tip surface 43. The solder layer 11 is provided on the tip surface 43 before the first substrate 2 and the second substrate 3 are joined. The solder layer 11 is made of AuSn, but the material of the solder layer 11 is not limited. The electrical connection member 6 will be described in detail below.

[0014] FIG. 5 is a schematic cross-sectional view of the first substrate 2 and the second substrate 3 after bonding. FIG. 5 is an enlarged view of part B in FIG. 2, and shows the electrical connection member 6 and the solder layer 12 in more detail. Since the electrical connection members 6 have substantially the same configuration, one electrical connection member 6 will be described here. The electrical connection member 6 is a protruding portion protruding from the first substrate 2 in the Z direction. The electrical connection member 6 is made of, for example, Ni, and is produced by plating. By producing the electrical connection member 6 and the side wall 4 from the same material, the plating process is simplified. The electrical connection member 6 may extend in an oblique direction (i.e., in a direction inclined from the Z direction) with respect to the main surface 21 of the first substrate 2. The electrical connection member 6 has one curved side surface 61, a tip surface 62 connected to the side surface 61, and a base surface 63 connected to the side surface 61, and the tip surface 62 and the base surface 63 are approximately planar. The base surface 63 is located on the opposite side to the tip surface 62 with respect to the direction in which the electrical connection member 6, which is the protruding portion, protrudes (Z direction in this embodiment). As shown in FIG. 4, before the first substrate 2 and the second substrate 3 are joined, a solder layer 12 is provided on the tip surface 62. The solder layer 12 is made of AuSn, but the material of the solder layer 12 is not limited. The first substrate 2 is provided with an underlayer 22 for connection with the electrical connection member 6, and the lead wire 10 and the electrical connection member 6 are electrically connected via the underlayer 22. The second substrate 3 is provided with a pad portion 32 for connection with the electrical connection member 6. The base surface 63 is in contact with the underlayer 22, and the solder layer 12 is in contact with the pad portion 32. Note that the pad portion 32 is not shown in FIGS. 2 and 4.

[0015] The first substrate 2, the side wall 4, the plurality of electrical connection members 6, the solder layer 11 provided on the side wall 4, and the solder layer 12 provided on each of the plurality of electrical connection members 6 constitute an electronic device member 100 (see FIG. 4) in an electronic device (infrared sensor 1 in this embodiment). The electronic device member 100 can be manufactured by joining the electronic device member 100 to the second substrate 3. The procedure for joining the electronic device member 100 to the second substrate 3 is as follows. First, the first substrate 2 is disposed above the second substrate 3 as shown in FIG. 4. Next, the solder layers 11 and 12 are heated while the solder layers 12 on the tip surfaces 62 of the plurality of electrical connection members 6 and the solder layer 11 on the tip surface 43 of the side wall 4 are pressed downward against the second substrate 3. The solder layers 11 and 12 melt or soften by heating. Part of the melted or softened solder layers 11, 12 is pressed to wrap around the side surface 61 of the electrical connection member 6 and the side surface (inner side surface 41 and outer side surface 42) of the side wall 4. As shown in FIG. 5, the solder layer 12 of the electrical connection member 6 contacts the tip surface 62 and the side surface 61 of the electrical connection member 6, and the electrical connection member 6 is firmly joined to the second substrate 3. Similarly, although not shown, the solder layer 11 of the side wall 4 contacts the tip surface 43 and the side surface (inner side surface 41 and outer side surface 42) of the side wall 4, and the side wall 4 is firmly joined to the second substrate 3. In this way, the first substrate 2 is joined to the second substrate 3 via the protruding portion (the side wall 4 and the plurality of electrical connection members 6) and the solder layers 11, 12, and an electronic device (infrared sensor 1) is formed.

[0016] FIG. 6 is a partial enlarged view of the electrical connection member 106 and the solder layer 12 of the comparative example. The configuration and the effect of the electrical connection member 6 of this embodiment will be described in more detail with reference to FIGS. 5 and 6. In this embodiment, the electrical connection member 6 has a truncated cone shape with a central axis parallel to the Z direction and a tip surface 62 smaller than a base surface 63 as a whole. The electrical connection member 6 has a circular shape in any cross section perpendicular to the Z direction, and the width of the electrical connection member 6 decreases monotonically from the base surface 63 to the tip surface 62. The width of the electrical connection member 6 refers to the minimum value of the distance between two intersections where a straight line passing through the center of gravity of the electrical connection member 6 intersects with a side surface 61 of the electrical connection member 6 in a cross section perpendicular to the Z direction. In the electrical connection member 6 of this embodiment, since any cross section perpendicular to the Z direction is a circle, the width is synonymous with the diameter, but the electrical connection member 6 may have a cross-sectional shape other than a circle (for example, an ellipse, a polygon), in which case the width is defined as above.

[0017] As shown in FIG. 5, in this embodiment, at a connection 64 between the side surface 61 and the tip surface 62 of the electrical connection member 6, the side surface 61 and the tip surface 62 form an obtuse angle θ1, i.e., an angle exceeding 90 degrees. The angle between the side surface 61 and the tip surface 62 is defined in any cross section (FIG. 5 is an example of this cross section) that passes through the center line of the electrical connection member 6 and is parallel to the Z direction. The electrical connection member 106 of the comparative example is a cylinder whose central axis is parallel to the Z direction. At a connection 64 between the side surface 61 and the tip surface 62 of the electrical connection member 106, the side surface 61 and the tip surface 62 form a right angle θ0. In this embodiment, when the solder layer 12 is heated and pressed, the solder layer 12 tends to creep up along the side surface 61 of the electrical connection member 6 toward the first board 2. This is because the solder layer 12 that overflows to the radially outer side of the electrical connection member 6 tends to rise along the side surface 61. In contrast, in the comparative example, compared to this embodiment, the solder layer 12 is less likely to creep up along the side surface 61 of the electrical connection member 106, and the area of ​​the portion of the side surface 61 covered by the solder layer 12 is also smaller. As a result, in this embodiment, the bonding reliability of the electrical connection member 6 with the second substrate 3 is improved compared to the comparative example, and the reliability of the electrical connection between the first substrate 2 and the second substrate 3 is also improved.

[0018] A connection portion 64 between the side surface 61 and the tip surface 62 of the electrical connection member 6 is a starting point from which the solder layer 12 creeps up along the side surface 61 of the electrical connection member 6. Therefore, by making an obtuse angle θ1 between the side surface 61 and the tip surface 62 at the connection portion 64, it is possible to effectively encourage the occurrence of creeping up of the solder layer 12. Note that the connection portion 64 is not necessarily edge-shaped, and may exist on a curve in FIG. 5. In this case, it is sufficient that the angle formed by the tangent to the curve at the connection portion 64 and the tip surface 62 is the obtuse angle θ1.

[0019] As described above, the width W1 of the tip surface 62 of the electrical connection member 6 is smaller than the width W2 of the base surface 63. This makes it difficult for the molten or softened solder layer 12 to spread in the radial direction of the electrical connection member 6 on the second substrate 3 side. As shown in FIG. 3(b), a plurality of electrical connection members 6 are densely arranged on the second substrate 3. By reducing the width W1 (diameter) of the tip surface 62 of the electrical connection member 6, the distance between the electrical connection members 6 increases, reducing the possibility that the solder layer 12 will come into contact with the adjacent electrical connection member 6 and cause a short circuit.

[0020] As described above, the electrical connection member 6 is a truncated cone as a whole, and the side surface 61 of the electrical connection member 6 forms a constant angle (gradient) with the tip surface 62 at any position in the Z direction. That is, the side surface 61 and the tip surface 62 of the electrical connection member 6 form an obtuse angle θ1. By making the side surface 61 as a whole, not just at the connection portion 64, form an obtuse angle θ1 with the tip surface 62, the creeping up of the solder layer 12 continues to progress, and a wider range of the side surface 61 can be covered with the solder layer 12. As a result, the joining reliability is further improved. The shape of the electrical connection member 6 is not limited to a truncated cone, and the same effect can be obtained as long as the width of the electrical connection member 6 decreases monotonically from the base surface 63 to the tip surface 62.

[0021] The range of the side surface 61 that forms an obtuse angle θ1 with the tip surface 62 (hereinafter referred to as a first region 65) is not limited to the entire side surface 61, but may be a range that starts at the connection portion 64 and ends at any position between the connection portion 64 and the base surface 63. In this embodiment, the first region 65 coincides with the entire region of the side surface 61. The first region 65 forms a constant angle (gradient) with respect to the tip surface 62, but the angle (gradient) may vary depending on the position in the Z direction.

[0022] The side wall 4 is similar to the electrical connection member 6, and the description of the electrical connection member 6 is generally applied to the side wall 4. FIG. 5 can be regarded as a cross-sectional view of any plane perpendicular to the center line of the frame-shaped portion of the side wall 4 and parallel to the Z direction. Since the side wall 4 has two side surfaces (an inner side surface 41 and an outer side surface 42), it is preferable that the side surfaces 41, 42 and the tip surface 43 form an obtuse angle θ1 at a connection portion 45 (see FIG. 4) between each of the side surfaces 41, 42 and the tip surface 43. However, only one of the side surfaces may form an obtuse angle θ1 with the tip surface 43 at a connection portion 45 with the tip surface 43. Although not shown, for example, one side surface and the tip surface 43 may form an obtuse angle θ1, and the other side surface and the tip surface 43 may form a right angle. In other words, in the case of the side wall 4, it is sufficient that at least one side surface and the tip surface 43 form an obtuse angle θ1 at a connection portion 45 with the tip surface 43. Similarly, it is sufficient that at least one side surface has a first region that forms an obtuse angle θ1 with the tip surface 43. If a leak occurs at the joint of the side wall 4, the negative pressure or vacuum state of the internal space 5 cannot be maintained, and the thermal effect on the thermistor element 7 due to gas convection in the internal space 5 becomes large. In this embodiment, the sealing performance of the joint of the side wall 4 is improved, making it easier to ensure the performance of the infrared sensor 1.

[0023] FIG. 7 conceptually illustrates a method for producing the electrical connection member 6. FIG. 7 is upside down compared to FIGS. 2, 4, and 5. First, as shown in FIG. 7(a), a resist layer 13 is formed on the first substrate 2, and a truncated cone-shaped cavity 14 is formed in the resist layer 13. The cavity 14 is formed by exposing and developing the resist layer 13. During exposure, the focal position is moved in the Z direction while increasing and decreasing the diameter of the light beam, so that a truncated cone-shaped region can be exposed. Although not shown, an electrode layer for plating is formed on the underlayer 22 before forming the resist layer 13. Next, as shown in FIG. 7(b), the electrical connection member 6 and the solder layer 12 are formed in the cavity 14 of the resist layer 13 by a plating process. Thereafter, the resist layer 13 and unnecessary electrode film are removed, so that the electrical connection member 6 can be formed on the first substrate 2. The sidewall 4 can also be formed in the same manner as the electrical connection member 6.

[0024] Second Embodiment FIG. 8 shows a cross-sectional view of a protruding portion according to the second embodiment. As described above, the protruding portion may be either the electrical connection member 6 or the side wall 4, but here, the protruding portion is assumed to be the electrical connection member 6. The side surface 61 of the electrical connection member 6 has a first region 65 extending from the connection portion 64 to a position between the connection portion 64 and the first substrate 2, and a second region 66 located between the base surface 63 and the first region 65. The second region 66 reaches the base surface 63, but it is sufficient that the second region 66 is located at least partially between the base surface 63 and the first region 65 on the side surface 61. As in the first embodiment, the first region 65 of the side surface 61 and the tip surface 62 form an obtuse angle θ1. Also, the second region 66 and the base surface 63 form an obtuse angle θ2. The width of the electrical connection member 6 increases monotonically from the tip surface 62 to the base surface 63 in the first region 65 , and increases monotonically from the base surface 63 to the tip surface 62 in the second region 66 .

[0025] The electrical connection member 6 has an intermediate portion 67 having a width W3 larger than both the width W1 of the tip surface 62 and the width W2 of the base surface 63. In this embodiment, the intermediate portion 67 has a side portion perpendicular to the tip surface 62 that has a predetermined length in the Z direction, but the length of this portion in the Z direction may be zero. In other words, the first region 65 and the second region 66 may be separated or in contact in the Z direction. The first region 65 forms a constant angle (gradient) with respect to the tip surface 62, and the second region 66 has a constant angle (gradient) with respect to the base surface 63, but the angle (gradient) may vary depending on the position in the Z direction.

[0026] If the solder layer 12 creeps up the side surface 61 to the base surface 63, the solder layer 12 may come into contact with the adjacent electrical connection member 6 and cause a short circuit. In particular, as shown in FIG. 3(a), the base surface 63 has a larger cross-sectional area than the tip surface 62, and therefore the distance between the base surface 63 and the adjacent electrical connection member 6 is smaller than the tip surface 62. For this reason, it is preferable to suppress the solder layer 12 from creeping up to the tip surface 62. Since the second region 66 forms an obtuse angle θ2 with the base surface 63 (in other words, since the second region 66 forms an acute angle with the tip surface 62), the solder layer 12 does not easily creep up the side surface 61, unlike the first region 65. According to this embodiment, it is possible to secure an area where the solder layer 12 covers the side surface 61, and it is possible to reduce the possibility that the solder layer 12 reaches the base surface 63. The electrical connection member 6 can be formed by a method similar to that of the first embodiment. During exposure, a cavity 14 having a shape corresponding to the electrical connection member 6 can be formed in the resist layer 13 by moving the focal position in the Z direction while increasing or decreasing the diameter of the light beam.

[0027] (Third embodiment) 9 shows a cross-sectional view of a protruding portion according to the third embodiment. As described above, the protruding portion may be either the electrical connection member 6 or the side wall 4, but here, the protruding portion is assumed to be the electrical connection member 6. The electrical connection member 6 has a discontinuous portion 68 whose width discontinuously increases from the tip surface 62 toward the base surface 63 on the side surface 61. In this embodiment, the discontinuous portion 68 has an annular strip portion 68A that protrudes in a direction intersecting the Z direction, preferably in a direction perpendicular to the Z direction. When the solder layer 12 reaches the strip portion 68A, the strip portion 68A suppresses the solder layer 12 from creeping up, and the possibility of the solder layer 12 creeping up further toward the base surface 63 can be reduced.

[0028] FIG. 10 shows a method for forming the electrical connection member 6 of this embodiment. FIG. 10 shows the electrical connection member 6 upside down from FIG. 9. First, as shown in FIG. 10(a), a cavity 14A corresponding to the portion from the tip surface 62 of the electrical connection member 6 to the lower surface of the strip portion 68A is formed in the resist layer 13A. Although not shown, an electrode layer for plating is formed on the underlayer 22 before forming the resist layer 13. The cavity 14A can be formed by the same method as described in the first embodiment. Next, as shown in FIG. 10(b), a portion 6A from the tip surface 62 of the electrical connection member 6 to the strip portion 68A is formed by a plating process. At this time, the plating process is continued even after the cavity 14A of the resist layer 13A is completely filled with the metal constituting the electrical connection member 6. The metal constituting the electrical connection member 6 spreads radially outward from the cavity 14A above the cavity 14A, forming the strip portion 68A. Next, the resist layer 13A is completely removed once, and a resist layer 13B is formed again, and a cavity 14B corresponding to the portion 6B from the upper surface of the strip portion 68A to the base surface 63 of the electrical connection member 6 is formed above the strip portion 68A as shown in Fig. 10(c). The cavity 14B can be formed by the same method as described in the first embodiment. Next, as shown in Fig. 10(d), the cavity 14B is filled with the metal constituting the electrical connection member 6 by a plating process to form the portion 6B, and further the solder layer 12 is formed, and then the resist layer 13B and unnecessary electrode film are removed.

[0029] (Modification of the third embodiment) 11 shows a cross-sectional view of a protruding portion according to a modified example of the third embodiment. As described above, the protruding portion may be either the electrical connection member 6 or the side wall 4, but in this embodiment, the protruding portion is the electrical connection member 6. The discontinuous portion 68 has a step portion 68B. The width of the electrical connection member 6 is larger on the side of the base surface 63 than the step portion 68B compared to the side of the tip surface 62 than the step portion 68B, and the width of the electrical connection member 6 increases discontinuously from the tip surface 62 to the base surface 63. When the solder layer 12 reaches the step portion 68B, the step portion 68B suppresses the solder layer 12 from creeping up, and the possibility of the solder layer 12 creeping up further toward the base surface 63 can be reduced.

[0030] FIG. 12 shows a method for forming the electrical connection member 6 of the modified example. First, as shown in FIG. 12(a), a cavity 14C having a larger Z-direction dimension than the portion 6C from the tip surface 62 of the electrical connection member 6 to the step portion 68B is formed in the resist layer 13C. Although not shown, an electrode layer for plating is formed on the underlayer 22 before forming the resist layer 13C. Here, the cavity 14C including the portion above the step portion 68B of the electrical connection member 6 is formed, but the upper end of the cavity 14C may coincide with the step portion 68B. The cavity 14C can be formed by the same method as described in the first embodiment. Next, as shown in FIG. 12(b), the portion 6C is formed by a plating process. At this time, the plating process is once terminated before the cavity 14C of the resist layer 13 is completely filled with the metal constituting the electrical connection member 6. Next, the resist layer 13C is completely removed once, and a resist layer 13D is formed again, and a cavity 14D corresponding to the portion 6D of the electrical connection member 6 from the step portion 68B to the base surface 63 is formed above the step portion 68B, as shown in Fig. 12(c). The cavity 14D can be formed by the same method as described in the first embodiment. Next, as shown in Fig. 12(d), the cavity 14D is filled with the metal constituting the electrical connection member 6 by a plating process to form the portion 6D, and further the solder layer 12 is formed, and then the resist layer 13D and unnecessary electrode film are removed.

[0031] (Fourth embodiment) FIG. 13 shows a side wall 104 of an electronic device member according to the fourth embodiment. The side wall 104 has a plurality of divided protruding portions 105, which cooperate to form an interrupted frame shape in any cross section perpendicular to the Z direction. The fabricated side wall 104 has a plurality of openings 15. Such a side wall 104 can be used for an electronic device that needs to communicate with the outside, such as a gas sensor. In this embodiment, the side wall 104 can also have a configuration similar to that of the side wall 4 in each of the above-mentioned embodiments and modifications. Each protruding portion 105 has an inner side surface 41 and an outer side surface 42, as well as two side surfaces 47, 48 that form an opening 15, and at least one of these side surfaces 41, 42, 47, 48 and the tip surface 43 preferably forms an obtuse angle θ1 with the tip surface 43 at a connection portion 45 (see FIG. 4) between the side surface and the tip surface 43. Alternatively, it is preferable that the first region of at least one of these side surfaces 41, 42, 47, 48 and the tip surface 43 form an obtuse angle θ1.

[0032] FIG. 14 shows a side wall 204 of an electronic device member according to a modification of the fourth embodiment. Only one opening 15 is provided in the side wall 204. The side wall 204 is a single protruding portion. In this modification, the side wall 204 also has the inner side surface 41 and the outer side surface 42, as well as two side surfaces 47 and 48 that form the opening 15. At a connection portion 45 (see FIG. 4) between at least one of these side surfaces 41, 42, 47, and 48 and the tip surface 43, the side surface preferably forms an obtuse angle θ1 with the tip surface 43. Alternatively, it is preferable that a first region in at least one of these side surfaces 41, 42, 47, and 48 forms an obtuse angle θ1 with the tip surface 43. [Explanation of symbols]

[0033] 1. Infrared sensor (electronic device) 2 First Board 3 Second Board 4, 104, 204 Side wall (protruding part) 6 Electrical connection parts (protruding parts) 11, 12 Solder layers 41, 42, 47, 48, 61 Side 43, 62 Tip surface 44, 63 base 64 Connection 65 First Area 66 Second Area 67 Middle Section 68 Discontinuities 68A Belt 68B Step 100 Electronic device materials

Claims

1. A solder joint includes a first substrate, at least one protruding portion protruding from the first substrate, and a solder layer; the at least one protruding portion has at least one side surface, a tip surface, and a connection portion between the at least one side surface and the tip surface, the solder layer being in contact with the tip surface; The electronic device member, wherein the at least one side surface and the tip surface of the connection portion form an obtuse angle.

2. 2. The electronic device member according to claim 1, wherein the at least one side has a first region extending from the connection portion to between the connection portion and the first substrate, and the first region and the tip surface form an obtuse angle.

3. 2 . The electronic device member according to claim 1 , wherein the at least one protruding portion has a base surface located opposite the tip surface in a protruding direction of the at least one protruding portion, and a width of the tip surface is smaller than a width of the base surface.

4. 2. The electronic device member according to claim 1, wherein the at least one protrusion has a base surface located opposite the tip surface in a direction in which the at least one protrusion protrudes, and a width of the at least one protrusion monotonically decreases from the base surface to the tip surface.

5. 3. The electronic device member according to claim 2, wherein the at least one protrusion has a base surface located opposite the tip surface in a direction in which the at least one protrusion protrudes, the at least one side has a second region located between the base surface and the first region, and the second region and the base surface form an obtuse angle.

6. 2. The electronic device member according to claim 1, wherein the at least one protrusion has a base surface located opposite the tip surface in a direction in which the at least one protrusion protrudes, and an intermediate portion on the at least one side surface having a width greater than both a width of the tip surface and a width of the base surface.

7. 2. The electronic device member according to claim 1, wherein the at least one protrusion has a base surface located opposite the tip surface in a direction in which the at least one protrusion protrudes, and a discontinuous portion on the at least one side surface whose width discontinuously increases from the tip surface toward the base surface.

8. An electronic device member comprising: the electronic device member according to claim 1 ; and a second substrate; An electronic device in which the first substrate is joined to the second substrate via the at least one protruding portion and the solder layer.

Images