Electronic devices

Abstract

To provide an electronic device that can easily and accurately diagnose solder lifespan. [Solution] The electronic device comprises a substrate 30, electronic components soldered to the substrate 30, and a spring member 50 soldered to the substrate 30. The spring member 50 has a mounting portion 51 soldered to the substrate 30, a fixing portion 52 mechanically fixed to the substrate 30 at a position different from the mounting portion 51, and an elastic portion 53 provided between the mounting portion 51 and the fixing portion 52. The elastic portion 53 is held in a deformed state between the mounting portion 51 and the fixing portion 52 so as to apply a reaction force due to deformation to the solder 80 that joins the mounting portion 51 and the substrate 30.

Description

Technical Field

[0001] The disclosure in this specification relates to an electronic device.

Background Art

[0002] Patent Document 1 discloses an electronic device capable of diagnosing deterioration of a soldering portion of a circuit component mounted on a printed circuit board. The description of the prior art document is incorporated herein by reference as an explanation of the technical elements in this specification.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, dummy components are mounted on a printed circuit board, and the degree of deterioration of the soldering portion of the circuit component is diagnosed by setting the stress applied to the soldering portion of the dummy component to be more severe than the stress applied to the soldering portion of the circuit component. However, even if cracks occur in the soldering portion of the dummy component and the solder breaks, it is difficult to visually confirm, and since it conducts by contact, it cannot be accurately diagnosed by an electrical inspection. Therefore, a cross-sectional inspection is required for accurate diagnosis. From the above viewpoints, or from other viewpoints not mentioned, further improvements are required for the electronic device.

[0005] One object of the present disclosure is to provide an electronic device capable of easily and accurately diagnosing the solder life.

Means for Solving the Problems

[0006] An electronic device according to one aspect of the disclosure is a substrate (30), Electronic components (40) soldered to the circuit board, A spring member (50) soldered to the circuit board, Equipped with, The spring member has a mounting portion (51) soldered to the substrate, a fixing portion (52) mechanically fixed to the substrate at a position different from the mounting portion, and an elastic portion (53) provided between the mounting portion and the fixing portion. The elastic part is held in a deformed state between the mounting part and the fixed part so as to apply a reaction force due to deformation to the solder (80) that joins the mounting part and the substrate.

[0007] According to the disclosed electronic device, a reaction force due to the deformation of the elastic part is applied to the solder that joins the spring member to the substrate. As a result, the solder joining the spring member to the substrate is more prone to degradation than the solder joining the electronic component to the substrate. When the solder joining the spring member to the substrate breaks due to degradation, the elastic part displaces to relieve the deformation, and the mounting part separates from the substrate. By confirming the breakage through visual or electrical inspection, the lifespan of the solder joining the electronic component to the substrate can be diagnosed. Therefore, the lifespan of the solder joining the electronic component to the substrate can be diagnosed simply and accurately.

[0008] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims are illustrative in their correspondence with the embodiments described later and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view showing an electronic device according to the first embodiment. [Figure 2] This is a side view from the X1 direction in Figure 1. [Figure 3] This is a plan view showing the configuration of an electronic device, excluding the enclosure. [Figure 4]This is an enlarged view of region IV in Figure 3. [Figure 5] This diagram shows the positional relationship of the spring member before and after screw fastening. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 4, showing the state before fastening. [Figure 7] This diagram shows the fastened state. [Figure 8] This diagram shows the state of a broken solder joint. [Figure 9] This is a plan view showing the area around the spring member in the electronic device according to the second embodiment. [Figure 10] This is a diagram showing the equivalent circuit diagram in Figure 9. [Figure 11] This is a plan view showing an electronic device according to the third embodiment. [Figure 12] This is a cross-sectional view showing the periphery of a spring member in an electronic device according to the fourth embodiment. [Figure 13] This is an enlarged plan view of the area around the spring member in the electronic device according to the fifth embodiment. [Figure 14] Figure 13 is a cross-sectional view along the line XIV-XIV, showing the state before fastening. [Figure 15] This diagram shows the fastened state. [Figure 16] This diagram shows the state of a broken solder joint. [Modes for carrying out the invention]

[0010] Several embodiments will be described below with reference to the drawings. In each embodiment, the same reference numerals are used for corresponding components, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier can be applied to the other parts of that configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations from multiple embodiments can be partially combined even if not explicitly stated, as long as there are no particular problems with the combination.

[0011] (First Embodiment) First, the schematic configuration of the electronic device will be described.

[0012] <Electronic Device> FIG. 1 is a plan view showing an example of an electronic device according to the first embodiment. FIG. 2 is a side view seen from the X1 direction of FIG. 1. In FIG. 2, the substrate and electronic components housed in the housing are shown by broken lines. Also, the bottom wall and side wall of the case are shown by a dashed line. FIG. 3 is a plan view showing the configuration of the electronic device with the housing excluded (omitted). For convenience, in FIG. 3, only the lands to which the spring members are joined are shown as conductors of the substrate.

[0013] Hereinafter, the thickness direction of the substrate is shown as the Z direction. Also, one direction orthogonal to the Z direction is shown as the X direction, and the direction orthogonal to both the Z direction and the X direction is shown as the Y direction. Unless otherwise specified, the shape viewed in plan from the Z direction, in other words, the shape along the XY plane defined by the X direction and the Y direction, is defined as the planar shape. The plan view from the Z direction may be simply referred to as a plan view.

[0014] The electronic device 10 illustrated in FIGS. 1 to 3 includes a housing 20, a substrate 30, electronic components 40, spring members 50, connectors 60, and fastening members 70. The electronic device 10 may be, for example, an electronic control unit (ECU). ECU is an abbreviation for Electronic Control Unit. The electronic device 10 may be mounted on, for example, a moving body. The moving body may be, for example, a vehicle, an aircraft, a ship, a construction machine, an agricultural machine, or the like. The moving body may be a manned moving body or an unmanned moving body.

[0015] The housing 20 houses at least some of the other elements of the electronic device 10. The housing 20 protects the elements of the electronic device 10 that are arranged in the housing space inside the housing. The housing 20 is composed of multiple members. The housing 20 may consist of two or three or more members. The housing 20 may be formed using a resin material or a metal material. Part of the housing 20 may be formed using a resin material and other parts of the housing 20 may be formed using a metal material. The planar shape of the housing 20 is not particularly limited. The example housing 20 has a substantially rectangular planar shape.

[0016] The illustrated housing 20 is configured to be divisible into two parts in the Z direction. The housing 20 comprises two components, specifically a case 21 and a cover 22. By assembling the case 21 and the cover 22, a housing 20 with an enclosure space is formed. The case 21 is box-shaped with one side open. The case 21 has a bottom wall 211 and a side wall 212. The side wall 212 is connected to the outer peripheral edge of the bottom wall 211. The side wall 212 is annular. The shape of the cover 22 is not particularly limited. The cover 22 is provided to cover the opening of the case 21. The cover 22 may be, for example, substantially flat.

[0017] The case 21 has a support portion 213 that protrudes in the Z direction from the inner surface of the bottom wall 211. The support portion 213 is sometimes referred to as a base. The support portion 213 is the part of the case 21 that supports the substrate 30. The support portion 213 may also be connected to the side wall 212. One of the support portions 213 is provided in a position that overlaps with the spring member 50 in a plan view. The protruding tip surface (upper surface) of the support portion 213 is, for example, a flat surface that is substantially perpendicular to the Z direction.

[0018] The substrate 30 is sometimes referred to as a printed circuit board or wiring board. The substrate 30 has one side 30a and one side 30b. The side 30b is the side opposite to the one side 30a in the thickness direction (Z direction). The side 30b is the side facing the bottom wall 211 in the Z direction. The planar shape of the substrate 30 is not particularly limited. The example substrate 30 has a substantially rectangular planar shape. The substrate 30 is fixed to the case 21 while placed on the support portion 213. The substrate 30 comprises an insulating substrate 31 and a conductor 32.

[0019] The insulating substrate 31 is a substrate that supports (holds) the conductor 32. The insulating substrate 31 is formed using an electrically insulating material such as resin. As the insulating substrate 31, for example, one containing only resin, or one combining resin with glass cloth, nonwoven fabric, etc., can be used.

[0020] The conductor 32 is arranged on an insulating substrate 31. The conductor 32, together with the electronic component 40, constitutes a circuit. The conductor 32 is formed using a metallic material with good conductivity, such as Cu. The conductor 32 includes at least wiring. The wiring may be referred to as a conductor pattern, wiring pattern, etc. The wiring is formed, for example, by patterning metal foil. Part of the wiring is a land to which the electronic component 40 is electrically connected. A land is the portion of the wiring that is exposed from the solder resist. In addition to wiring, the conductor 32 may also include via conductors. Via conductors are formed by placing a conductor, such as plating, in through holes (vias) formed in the insulating layer that constitutes the substrate. Via conductors electrically connect wiring arranged in different layers. The conductor 32 may also include conductors that do not provide wiring functionality.

[0021] The wiring includes at least surface wiring arranged on the surface layer on one side 30a of the insulating substrate 31. The wiring may also include surface wiring arranged on the surface layer on the back side 30b, or inner layer wiring arranged inside the insulating substrate 31. The substrate 30 may be a single-sided substrate, a double-sided substrate, or a multilayer substrate with three or more layers. The exemplary conductor 32 includes a land 33 as part of the wiring arranged on the surface layer on one side 30a. The land 33 is a conductor that does not provide wiring functionality and is provided for soldering the spring member 50 to the substrate 30.

[0022] The electronic components 40 are mounted on the substrate 30. The electronic components 40, together with the conductors 32 of the substrate 30, form a circuit. The electronic device 10 comprises a plurality of electronic components 40. The electronic components 40 are electrically connected to lands (wirings) on the substrate 30 (not shown). The electronic components 40 include at least surface-mount electronic components soldered to the lands. The electronic components 40 include at least electronic components arranged on one side 30a. The electronic components 40 may also include electronic components arranged on the back side 30b.

[0023] The connector 60 is mounted on the circuit board 30. The connector 60 electrically connects the circuit, which includes the circuit board 30 and the electronic components 40, to an external device. The connector 60 includes an external connection terminal (not shown) that electrically connects the conductor 32 of the circuit board 30 to the external device. Part of the connector 60 is housed within the housing 20, and the other part is exposed to the outside of the housing 20. The connector 60 is exposed to the outside through an opening 2121 in the housing 20. As illustrated, the opening 2121 may be defined by a notch and cover 22 provided in the case 21.

[0024] The spring member 50 is mounted on the substrate 30. The spring member 50 is a component used to diagnose the lifespan (remaining lifespan) of the solder used to join the electronic component 40 to the substrate 30. The spring member 50 is soldered to the substrate 30. The spring member 50 is arranged on one surface 30a. Details of the spring member 50 will be described later.

[0025] <Spring component> Figure 4 is an enlarged view of area IV shown by the dashed line in Figure 3. Figure 4 shows the spring member soldered to the substrate and fixed by the fastening member. In Figure 4, the head of the fastening member is omitted and the column portion is shown with a dashed line to show the through hole of the spring member. The outer contour of the washer is shown with a solid line. For convenience, the solder is omitted. Figure 5 is a diagram showing the positional relationship of the spring member before and after screw fastening. Figure 6 is a cross-sectional view along the line VI-VI in Figure 4. Figure 6 shows the state before fastening. That is, it shows the state before the spring member is soldered to the substrate and fixed by the fastening member. Figure 7 shows the state after fastening. Figure 7 shows the spring member soldered to the substrate and fixed by the fastening member. Figure 7 corresponds to Figure 4. Figure 8 shows the state when the solder has broken.

[0026] The spring member 50 is soldered to the substrate 30. The spring member 50 is fixed to the substrate 30 at a location separate from the solder joint. The spring member 50 applies a deformation reaction force to the solder joining the spring member 50 to the substrate 30 such that the stress application conditions are more severe than those of the solder joining the electronic component 40 to the substrate 30. It is formed using a material that can be soldered to the substrate 30. The spring member 50 is formed using a metallic material such as copper. The spring member 50 has at least a mounting portion 51, a fixing portion 52, and an elastic portion 53. The spring member 50 may further have a contact portion 54.

[0027] The mounting portion 51 is the part of the spring member 50 that is soldered to the substrate 30. The mounting portion 51 is connected to the substrate 30 via solder 80. The mounting portion 51 remains soldered to the substrate 30 until a crack occurs in the solder 80, the crack propagates, and the mounting portion 51 breaks. The mounting portion 51 is soldered to the substrate 30 before the fixing portion 52 is fixed to the substrate 30.

[0028] The fixing portion 52 is the part of the spring member 50 that is fixed to the substrate 30 at a different position from the mounting portion 51. The fixing portion 52 is not soldered, but mechanically connected to the substrate 30, i.e., mechanically joined. The fixing portion 52 is fixed to the substrate 30 after the mounting portion 51 has been soldered. The fixing portion 52 is displaced as it is fixed to the substrate 30. The fixing portion 52 is fixed to the substrate 30 in such a way that it deforms the elastic portion 53 and generates a reaction force in the elastic portion 53 due to the deformation.

[0029] The elastic portion 53 is a part of the spring member 50 provided between the mounting portion 51 and the fixing portion 52. One end of the elastic portion 53 is connected to the mounting portion 51, and the other end is connected to the fixing portion 52. When the fixing portion 52 is fixed to the substrate 30 while the mounting portion 51 is soldered to the substrate 30, the elastic portion 53 deforms in conjunction with the fixing of the fixing portion 52. The elastic portion 53 applies a reaction force due to the deformation to the solder joint of the mounting portion 51, i.e., the solder 80. The elastic portion 53 is held in a deformed state between the mounting portion 51 and the fixing portion 52 so as to apply a reaction force due to the deformation to the solder 80. When a crack occurs in the solder 80 and the bonding strength of the solder 80 decreases to below the reaction force, the solder 80 breaks, i.e., the bond between the mounting portion 51 and the substrate 30 is released. Due to the breakage of the solder 80, the elastic portion 53 is displaced to eliminate its deformed state. As a result, the mounting section 51 moves away from the object to be joined.

[0030] The contact portion 54 is connected to the fixed portion 52 at a different position from the elastic portion 53. The contact portion 54 contacts the substrate 30 when the spring member 50 is placed on the substrate 30. Before the mounting portion 51 is soldered to the substrate 30, the spring member 50 contacts the substrate 30 at multiple locations, including the contact portion 54 and the mounting portion 51, and stands upright on the substrate 30.

[0031] The example spring member 50 is formed by press-forming a metal plate of a predetermined thickness. As shown in Figures 3 and 4, the spring member 50 has a substantially rectangular shape in plan view, with the X direction being the longitudinal direction and the Y direction being the short direction. The spring member 50 extends in the X direction in plan view. The elements of the spring member 50 are arranged in the X direction in the order of mounting portion 51, elastic portion 53, fixing portion 52, and contact portion 54.

[0032] The mounting portion 51 is provided at one end in the X direction. The mounting portion 51 is arranged on one surface 30a such that at least a portion of it overlaps with the land 33 in a plan view. In this arrangement, the mounting portion 51 is joined to the land 33 of the substrate 30 via solder 80, as shown in Figures 6 and 7. The thickness direction of the mounting portion 51 is substantially parallel to the Z direction. Note that "substantially" in this embodiment does not mean perfect agreement, but rather allows for variations of a certain degree, such as manufacturing tolerances.

[0033] The contact portion 54 is located at the end opposite to the mounting portion 51 in the X direction. The thickness direction of the contact portion 54 is approximately parallel to the Z direction. The contact portion 54 contacts one surface 30a when the mounting portion 51 is placed on the land 33. The spring member 50 contacts one surface 30a of the substrate 30 at both ends in the X direction and stands upright on the substrate 30. In the freestanding state before the fixing portion 52 is fixed to the substrate 30, the contact portion 54 extends from the fixing portion 52 along one surface 30a.

[0034] The fixing portion 52 is connected to the contact portion 54. In the self-supporting state of the spring member 50, the fixing portion 52 has an inclination that moves away from the surface 30a as it moves away from the contact portion 54. The spring member 50 has an inclined portion that moves away from the surface 30a as it moves away from the contact portion 54, and the inclined portion includes the fixing portion 52.

[0035] The fixing portion 52 is fixed to the base plate 30 by fastening the fastening member 70. The fastening member 70 is a screw, bolt, etc. The fastening member 70 in this example is a screw. The screw has a head and a column portion connected to the head. The fixing portion 52 has a through hole 55 through which the fastening member 70 is inserted. The base plate 30 has a through hole 34. The case 21 has a screw hole 214 in the support portion 213. The screw, which is the fastening member 70, is inserted through the through hole 55 in the fixing portion 52 and the through hole 34 in the base plate 30 and screwed into the screw hole 214 in the support portion 213. In this way, the fixing portion 52 is fixed to the base plate 30. The fixing portion 52 is fixed between the base plate 30 and the head of the fastening member 70. The fixing portion 52 is displaced by being pushed by the fastening member 70 during the fastening process. The thickness direction of the fixing portion 52 is inclined with respect to the Z direction in the state before fixing, and is approximately parallel to the Z direction in the state after fixing.

[0036] The upper part of Figure 5 shows the spring member 50 with the mounting portion 51 soldered and the contact portion 54 in contact with the substrate 30. The spring member 50 shown in the upper part is a side view showing the state before the fixing portion 52 is fixed to the substrate 30. The lower part of Figure 5 is a plan view showing the state after the fixing portion 52 has been fixed to the substrate 30. Point A0 indicates the end position of the contact portion 54, that is, the boundary position between the contact portion 54 and the fixing portion 52. The fixing portion 52 rotates around point A0 as a pivot point and is fixed to the substrate 30. Points B1 and C1 are the ends of the portion that overlaps with the position of the fastening member 70 in the fixed state. The fastening member 70 initially contacts point C1. Points B2 and C2 are the positions of points B1 and C1 after the fixing portion 52 has been displaced. Points B3 and C3 indicate the ends of the fastening member 70 in the fixed state. In a plan view in the Z direction, points B3 and B1 coincide, and points C3 and C1 coincide. Point B2 is located between points B3 and C3. Point C2 coincides with point C4, which is located outside of point C3. By making the through hole 55 oval-shaped, the inclined fixing portion 52 can be fixed to the substrate 30 by the fastening member 70.

[0037] In a plan view, one end of the elastic portion 53 in the X direction is connected to the mounting portion 51, and the other end is connected to the fixing portion 52. The illustrated inclined portion includes a part of the elastic portion 53. In the self-supporting state of the spring member 50, the elastic portion 53 has an inclined portion that is continuous with the fixing portion 52, a portion whose thickness direction is substantially parallel to the Z direction, and an inclined portion that connects the substantially parallel portion and the mounting portion 51. The elastic portion 53 deforms in accordance with the displacement of the fixing portion 52 during the process in which the fixing portion 52 is fixed to the substrate 30. With the fixing portion 52 fixed to the substrate 30, the elastic portion 53 has a folded shape with a vertex portion that is separated from the substrate 30. When the solder 80 breaks, the elastic portion 53 is displaced in the direction that opens the fold, and as a result the mounting portion 51 is displaced upward. Therefore, the breakage of the solder 80 can be detected by visual inspection or by an imaging device.

[0038] As illustrated, a notch 56 may be provided in the spring member 50. The notch 56 is provided, for example, at the boundary between the fixed portion 52 and the elastic portion 53. The notch 56 is provided, for example, at both ends in the Y direction. The notch 56 is provided so as not to overlap with the washer 71. By providing the notch 56, the force that causes the elastic portion 53 to return to its position relative to the fixed portion 52 before it was fixed by the fastening member 70, that is, the force that causes it to deform downward in the fixed state, is weakened. As a result, the elastic portion 53 becomes more easily displaced in the opening direction, and consequently the mounting portion 51 becomes more easily displaced upward.

[0039] <Summary of the First Embodiment> The electronic device 10 of this embodiment comprises a substrate 30, an electronic component 40, and a spring member 50. The electronic component 40 and the spring member 50 are solder-bonded to the substrate 30. The spring member 50 has a mounting portion 51 solder-bonded to the substrate 30, a fixing portion 52 mechanically fixed to the substrate 30 at a position different from the mounting portion 51, and an elastic portion 53 provided between the mounting portion 51 and the fixing portion 52. The elastic portion 53 is held in a deformed state between the mounting portion 51 and the fixing portion 52 so as to apply a reaction force due to deformation to the solder 80 that joins the mounting portion 51 and the substrate 30.

[0040] As described above, with the mounting portion 51 soldered to the substrate 30 and the fixing portion 52 fixed to the substrate 30, the elastic portion 53 is held in a deformed state between the mounting portion 51 and the fixing portion 52. Therefore, a reaction force due to the deformation of the elastic portion 53 can be applied to the solder 80. This makes the solder 80 subject to a more severe stress application environment than the solder used to bond the electronic component 40 to the substrate 30, making it more susceptible to degradation. Since the component being inspected itself applies stress to the solder 80, the fracture of the solder 80 can be inspected with a simple configuration.

[0041] Furthermore, if the solder 80 cracks due to deterioration and breaks as the cracks propagate, the elastic part 53 displaces to eliminate the deformation, and the mounting part 51 separates from the substrate 30 as a result of the displacement. The solder joint between the spring member 50 and the substrate 30 becomes open without becoming a loose contact. Therefore, the breakage of the solder 80 can be reliably detected by visual inspection or inspection using an imaging device. Consequently, the lifespan (remaining lifespan) of the solder connecting the electronic component 40 to the substrate 30 can be diagnosed based on the lifespan of the solder 80. As a result, the lifespan of the solder connecting the electronic component 40 to the substrate 30 can be diagnosed simply and accurately.

[0042] As illustrated, the electronic device 10 may include a fastening member 70 for fixing the spring member 50 to the substrate 30. The spring member 50 may be provided in the fixing part 52 and have a through hole 55 through which the fastening member 70 is inserted. The fixing part 52 may be fixed to the substrate 30 by fastening the fastening member 70 with the through hole 55 inserted. As described above, the fixing part 52 is displaced when the fastening member 70 is fastened, thereby deforming the elastic part 53. For example, when fixing the fastening member 70 to the housing 20 (support member), fastening can fix the substrate 30 to the housing 20 and fix the spring member 50 to the substrate 30. Therefore, the number of parts can be reduced and the manufacturing process can be simplified.

[0043] As illustrated, the spring member 50 may be connected to the fixing portion 52 at a position different from the elastic portion 53 and may have a contact portion 54 that contacts the substrate 30. Before the mounting portion 51 is soldered to the substrate 30, the spring member 50 may be configured to stand on its own on the substrate 30 by contacting the substrate 30 at multiple points, including the contact portion 54 and the mounting portion 51. Because the spring member 50 stands on its own, positioning becomes easier when soldering the mounting portion 51 and when fixing the fixing portion 52.

[0044] As illustrated, in a plan view of the substrate 30 in the thickness direction, the contact portion 54, the fixing portion 52, and the mounting portion 51 may be arranged in a predetermined direction. In the self-supporting state before the mounting portion 51 is soldered to the substrate 30, the contact portion 54 extends from the fixing portion 52 along the placement surface of the spring member 50 on the substrate 30, and the fixing portion 52 may have an inclination such that it moves away from the placement surface as it moves away from the contact portion 54. The Z direction corresponds to the thickness direction, and the X direction corresponds to the predetermined direction. With the above configuration, the self-supporting structure is stabilized. Therefore, the inclined fixing portion 52 can be stably fixed to the substrate 30. The displacement of the fixing portion 52 can generate deformation of the elastic portion 53.

[0045] <Variation> An example is shown in which the electronic device 10 includes a housing 20, but it is not limited to this. A configuration without a housing 20 is also possible. An example is shown in which the case 21 of the housing 20 also serves as a support member for the circuit board 30, but the support member is not limited to this.

[0046] (Second Embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, a configuration was shown in which solder fracture could be detected by visual inspection or inspection using an imaging device. Alternatively, or in addition to this, a configuration in which solder fracture could be detected by electrical inspection may be provided.

[0047] Figure 9 is a plan view showing an example of an electronic device according to this embodiment. Figure 9 shows the area around the spring member. Similar to Figure 3, it shows a configuration with the housing excluded (omitted). For convenience, the solder resist is omitted. The electronic device 10 includes a substrate 30, electronic components 40, and a spring member 50, similar to the previous embodiment. The spring member 50 is formed using a conductive material such as metal. The spring member 50 is formed to form part of the current-carrying path.

[0048] Electronic component 40 includes electronic components 40R and 40S. Electronic component 40R is a resistive element. Electronic component 40R is connected in series with the spring member 50 between the power supply and ground. Electronic component 40R forms a series circuit with the spring member 50. The example electronic component 40R is located on the power supply side. Alternatively, electronic component 40R may be located on the ground side. Electronic component 40S is, for example, an IC that has the function of detecting the breakage of solder 80. Electronic component 40S is electrically connected to either wiring 351 or 352, which will be described later. The example electronic component 40S is connected to wiring 351.

[0049] The circuit board 30 has wirings 351, 352, 353, 354, and 355 as conductors 32. Wiring 351 is soldered to the mounting portion 51. Wiring 351 includes lands 351a and 351b. Land 351a is provided at one end of wiring 351 and is soldered to the mounting portion 51. Land 351b is provided at the other end of wiring 351 and is soldered to one of the terminals of the electronic component 40R.

[0050] Wire 352 is electrically connected to the fixed part 52. Wire 352 includes a land 352a. The land 352a contacts the fixed part 52 and is electrically connected to the fixed part 52 when the fixed part 52 is fixed to the substrate 30. The land 352a may be a land provided on one surface 30a as illustrated, or a through-hole land provided on the wall surface of the through-hole 34. In addition to the wall surface of the through-hole 34, the through-hole land may also be provided around the opening. Wire 352 is electrically connected to the ground terminal (GND) of the connector 60. Wire 352 is a wire that provides ground potential. Wire 353 is a wire that electrically connects electronic component 40R and electronic component 40S. Wire 353 includes a land 353a. The land 353a is provided at one end of wire 353 and soldered to one of the terminals of electronic component 40R. The other end of wire 353 is electrically connected to the power output terminal (OUT) of electronic component 40S.

[0051] Wire 354 is connected to wire 351. One end of wire 354 is connected to, for example, land 351b. The other end of wire 354 is electrically connected to the signal input terminal (IN) of electronic component 40S. Wire 355 is connected to wire 352. Wire 355 is a ground wire. One end of wire 355 is electrically connected to the ground terminal (GND) of electronic component 40S.

[0052] Figure 10 shows the equivalent circuit of Figure 9. As described above, the electronic component 40R and the spring member 50 are connected in series between the power output terminal of the electronic component 40S and ground, with the electronic component 40S on the high side. The connection point (midpoint) of the series circuit is electrically connected to the signal input terminal of the electronic component 40S. The electronic component 40S monitors the potential at the connection point and detects whether or not a fracture has occurred based on the potential. The potential at the connection point rises when the solder 80 fractures. The electronic component 40S detects that a fracture has occurred, for example, when the potential at the connection point exceeds a predetermined threshold voltage. The electronic component 40S may output the detection result to the outside via the connector 60. The other configurations are the same as those described in the prior embodiment.

[0053] <Summary of the second embodiment> As illustrated, the spring member 50 may be formed using a conductive material and have a first wiring connected to the mounting portion 51 by soldering and a second wiring electrically connected to the fixing portion 52. The spring member 50 may electrically connect the first wiring and the second wiring when the mounting portion 51 is soldered to the substrate 30 and the fixing portion 52 is fixed to the substrate 30, and may interrupt the conductivity between the first wiring and the second wiring when the solder 80 breaks. Wiring 351 corresponds to the first wiring, and wiring 352 corresponds to the second wiring. By using the spring member 50 as an electrical path connecting the first wiring and the second wiring, the breakage of the solder 80 can be detected by electrical inspection. Note that electrical inspection may be performed instead of visual inspection or inspection using an imaging device. Visual inspection or inspection using an imaging device may be used in combination with electrical inspection.

[0054] As illustrated, the electronic component 40 may include a component that is electrically connected to either the first or second wiring and detects breakage. The electronic component 40S corresponds to the component that detects breakage. The electronic component 40(40S) mounted on the substrate 30 can detect the breakage of the solder 80. For example, in a configuration with a housing 20, the breakage of the solder 80 can be detected without opening the housing 20.

[0055] (Third embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, a circuit including a spring member was formed, and an electronic component detected the solder fracture. Alternatively, a configuration that allows electrical inspection by connecting an external device may be used.

[0056] Figure 11 is a plan view showing an example of an electronic device according to this embodiment. Figure 11 corresponds to Figure 3. Of the conductors, only the wiring electrically connected to the spring member is shown. The electronic device 10 includes a substrate 30, electronic components 40, and a spring member 50, similar to the prior embodiment. Similar to the third embodiment, the spring member 50 is formed using a conductive material such as metal. The spring member 50 is formed to form part of the current-carrying path.

[0057] The substrate 30 has wiring 36 as a conductor 32. Of the wiring 36, wiring 361 is soldered to the mounting portion 51. Wiring 361 includes a land 361a. Land 361a is provided at one end of wiring 361 and is soldered to the mounting portion 51. Of the wiring 36, wiring 362 is electrically connected to the fixing portion 52. Wiring 362 includes a land 362a. Land 362a is provided at one end of wiring 362 and, when the fixing portion 52 is fixed to the substrate 30, it contacts the fixing portion 52 and is electrically connected to the fixing portion 52. In the electronic device 10, wirings 361 and 362 are electrically connected only to the spring member 50. Wirings 361 and 362 are dummy wirings that do not provide wiring function on the substrate 30. The other configurations are the same as those described in the prior embodiment.

[0058] <Summary of the third embodiment> In this embodiment as well, the spring member 50 is formed using a conductive material and has a first wiring connected to the mounting portion 51 by soldering on the substrate 30 and a second wiring electrically connected to the fixing portion 52. The spring member 50 electrically connects the first wiring and the second wiring when the mounting portion 51 is soldered to the substrate 30 and the fixing portion 52 is fixed to the substrate 30, and interrupts the conductivity between the first wiring and the second wiring when the solder 80 breaks. Wiring 361 corresponds to the first wiring, and wiring 362 corresponds to the second wiring. By using the spring member 50 as an electrical path connecting the first wiring and the second wiring, the breakage of the solder 80 can be detected by electrical inspection.

[0059] As illustrated, the first and second wirings may be dummy wirings that do not provide any wiring function. Wiring 36 (361, 362) corresponds to dummy wiring. By providing dummy wiring, testing can be performed without affecting the circuit operation.

[0060] (Fourth Embodiment) This embodiment is a modification based on the prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, the fixing part was fixed to the substrate by fastening. Alternatively, the fixing part may be fixed to the substrate by a mechanical joint other than fastening.

[0061] Figure 12 is a cross-sectional view showing an example of an electronic device according to this embodiment. Figure 12 shows the area around the spring member and corresponds to Figure 7. The electronic device 10 comprises a housing 20 including a case 21 which is a support member, a substrate 30, electronic components 40 (not shown), and a spring member 50. The substrate 30 has a through hole 34 provided corresponding to the fixing portion 52.

[0062] Case 21 has a support portion 213 that supports the substrate 30. Case 21 has a support projection 215 that passes through a through hole 34 and fits into a fixing portion 52. The support projection 215 extends from the upper surface of the support portion 213 in the Z direction toward the substrate 30. With the support portion 213 supporting the substrate 30, the support projection 215 passes through the through hole 34 in the substrate 30 and the through hole 55 in the spring member 50. The fixing portion 52 is fixed to the substrate 30 by heat crimping the portion of the support projection 215 that passes through the through hole 55 and extends upward toward the spring member 50. When crimped, the support projection 215 has a head located on the spring member 50 and a column portion connected to the head. The fixing portion 52 is fixed between the head of the support projection 215 and the substrate 30. The fixing portion 52 is displaced as it is fixed to the substrate 30. When the mounting portion 51 is soldered to the substrate 30 and the fixing portion 52 is fixed to the substrate 30, the elastic portion 53 deforms in accordance with the fixing of the fixing portion 52. The elastic portion 53 is held in a deformed state between the mounting portion 51 and the fixing portion 52 so as to apply a reaction force due to the deformation to the solder 80. The other configurations are the same as those described in the prior embodiment.

[0063] <Summary of the fourth embodiment> As illustrated, the substrate 30 may be provided with a support member that supports it from the back surface 30b. The substrate 30 may have a through hole 34 provided corresponding to the fixing portion 52, and the support member may have a support projection 215 that passes through the through hole 34 and fits into the fixing portion 52. The case 21 of the housing 20 corresponds to the support member. The substrate 30 can be fixed to the support member and the spring member 50 can be fixed to the substrate 30 by fitting. Therefore, the number of parts can be reduced and the manufacturing process can be simplified.

[0064] The electronic device 10 shown in this embodiment can detect the fracture of the solder 80 by at least one of the following methods: visual inspection, inspection using an imaging device, electrical inspection as exemplified in the second embodiment, and electrical inspection as exemplified in the third embodiment.

[0065] (Fifth embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be referenced. In the preceding embodiment, the spring member was made self-supporting by providing a contact portion. Instead of this, Figure 13 is a plan view showing an example of an electronic device according to this embodiment. Figure 13 shows the area around the spring member and corresponds to Figure 4. However, it shows the fastening member 70. Figure 14 is a cross-sectional view along the line XIV-XIV in Figure 13, showing the state before fastening. Figure 14 corresponds to Figure 6. Figure 15 shows the fastened state. Figure 15 corresponds to Figure 7. Figure 16 shows the state after the solder has broken. Figure 16 corresponds to Figure 8.

[0066] The spring member 50 has a mounting portion 51, a fixed portion 52, an elastic portion 53, an extension portion 57, and a protruding portion 58. The extension portion 57 is connected to the fixed portion 52 at a different position from the elastic portion 53. The protruding portion 58 protrudes from the extension portion 57 toward the substrate 30. The protruding portion 58 may be formed continuously using the same material as the other parts of the spring member 50, or it may be formed using a different material. In the example spring member 50, the elements of the spring member 50 are arranged in the X direction in the order of mounting portion 51, elastic portion 53, fixed portion 52, and extension portion 57. The protruding portion 58 is formed using a resin material, and the other parts of the spring member 50 are formed using a metal material. The protruding portion 58 is fixed to the extension portion 57 by press-fitting, adhesive, or the like.

[0067] The substrate 30 has a hole 37 provided corresponding to the protrusion 58. The hole 37 may be a through hole or a non-through hole. The example hole 37 is a non-through hole. The hole 37 is a recess that opens on one surface 30a. In a plan view, the area of ​​the hole 37 is approximately the same as or slightly smaller than the protrusion 58.

[0068] When the spring member 50 is placed on the substrate 30, that is, before the mounting portion 51 is soldered to the substrate 30, it contacts the substrate 30 at multiple points, including the protruding portion 58 and the mounting portion 51, and stands upright on the substrate 30. When the fixing portion 52 is fixed to the substrate 30, the protruding portion 58 is inserted into the hole 37. In the example electronic device 10, when the fixing portion 52 is pushed and displaced by the fastening member 70, the protruding portion 58 connected to the extension portion 57 is also displaced downward. Receiving the downward force from the fastening member 70, the protruding portion 58 deforms and is pushed into the hole 37, and as the protruding portion 58 is inserted into the hole 37, the fixing portion 52 is displaced to its fixed position.

[0069] Similar to the prior embodiment, the elastic portion 53 deforms in accordance with the displacement of the fixing portion 52 during the process in which the fixing portion 52 is fixed to the substrate 30. When the solder 80 breaks, the elastic portion 53 displaces to eliminate its deformed state. As a result, the mounting portion 51 moves away from the object to be joined. The other configurations are the same as those described in the prior embodiment.

[0070] <Summary of the Fifth Embodiment> As illustrated, the spring member 50 may have an extended portion 57 connected to the fixing portion 52 and a protruding portion 58 projecting from the extended portion 57 toward the substrate 30. The substrate 30 may have a hole 37 provided corresponding to the protruding portion 58. The spring member 50 may be configured to stand on its own on the substrate 30 by contacting the substrate 30 at multiple points, including the protruding portion 58 and the mounting portion 51, when placed on the substrate 30, and the protruding portion 58 may be inserted into the hole 37 when the fixing portion 52 is fixed to the substrate 30. Since the spring member 50 stands on its own, similar to the contact portion 54, positioning is made easier when soldering the mounting portion 51 and when fixing the fixing portion 52.

[0071] Furthermore, since the protruding portion 58 contacts the substrate 30 in the self-supporting state, the extension portion 57 is positioned above the protruding portion 58. This allows for increased displacement of the fixing portion 52 during fastening. For example, as shown in Figure 14, even without providing an inclined portion on the spring member 50, the elastic portion 53 can be deformed by displacing the fixing portion 52 downward through fastening. In the self-supporting state, the plate thickness direction of the fixing portion 52 and the extension portion 57 can be made substantially parallel to the Z direction, making it easier to fix the fixing portion 52 to the substrate 30 using the fastening member 70 and the support projection 215.

[0072] The electronic device 10 shown in this embodiment can detect the fracture of the solder 80 by at least one of the following methods: visual inspection, inspection using an imaging device, electrical inspection as exemplified in the second embodiment, and electrical inspection as exemplified in the third embodiment.

[0073] (Other embodiments) The disclosures in this specification and drawings are not limited to the exemplary embodiments. The disclosures include the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to combinations of parts and / or elements shown in the embodiments. The disclosures are implementable in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures include those in which parts and / or elements of the embodiments have been omitted. The disclosures include substitutions or combinations of parts and / or elements between one embodiment and another. The scope of the disclosed technical areas is not limited to the descriptions of the embodiments. Some of the scope of the disclosed technical areas are indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.

[0074] The disclosures in the specification and drawings are not limited by the claims. The disclosures in the specification and drawings encompass the technical ideas described in the claims and extend to a wider and more diverse range of technical ideas than those described in the claims. Therefore, a variety of technical ideas can be extracted from the disclosures in the specification and drawings without being bound by the claims.

[0075] When an element or layer is referred to as “on top of,” “connected to,” “linked to,” or “joined,” it may be directly on top of, connected to, or joined to another element or layer, and there may also be an intervening element or layer. In contrast, when an element is referred to as “directly on top of,” “directly connected to,” “directly linked to,” or “directly joined to” another element or layer, there is no intervening element or layer. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used in this specification, the term “and / or” includes any combination and all combinations relating to one or more of the enumerated items relating to each other. That is, the statement A and / or B means at least one of A and B.

[0076] Spatially relative terms such as "inside," "outside," "back," "below," "low," "above," and "high" are used here to facilitate descriptions of the relationship between one element or feature and other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned upside down, an element described as "below" or "directly below" another element or feature will be oriented "above" the other element or feature. Thus, the term "below" can encompass both up and down orientations. The device may also be oriented in other directions (it may be rotated 90 degrees or in other directions), and the spatially relative descriptors used in this specification will be interpreted accordingly. [Explanation of Symbols]

[0077] 10...Electronic device, 20...Housing, 21...Case, 211...Bottom wall, 212...Side wall, 2121...Opening, 213...Support part, 214...Screw hole, 215...Support projection, 22...Cover, 30...Substrate, 30a...One side, 30b...Back side, 31...Insulating substrate, 32...Conductor, 33...Land, 34...Through hole, 35,351,352,353,354,355...Wiring, 36,361,3 62...Dummy wiring, 351a, 351b, 352a, 353a, 361a, 362a...Land, 37...Hole, 40, 40R, 40S...Electronic component, 50...Spring member, 51...Mounting part, 52...Fixing part, 53...Elastic part, 54...Contact part, 55...Through hole, 56...Notch, 57...Extended part, 58...Protruding part, 60...Connector, 70...Fastening member, 71...Washer, 80...Solder

Claims

1. The substrate (30) and An electronic component (40) soldered to the aforementioned substrate, A spring member (50) soldered to the substrate, Equipped with, The spring member has a mounting portion (51) soldered to the substrate, a fixing portion (52) mechanically fixed to the substrate at a position different from the mounting portion, and an elastic portion (53) provided between the mounting portion and the fixing portion. An electronic device in which the elastic part is held in a deformed state between the mounting part and the fixing part so as to apply a reaction force due to deformation to the solder (80) that joins the mounting part and the substrate.

2. The substrate is provided with a support member (21) that is positioned on the side opposite to the surface on which the spring member is arranged, and which supports the substrate. The substrate has a through hole (34) provided corresponding to the fixing portion, The electronic device according to claim 1, wherein the support member has a support projection (215) that passes through the through hole and fits into the fixing portion.

3. Equipped with a fastening member (70), The spring member is provided in the fixing portion and has a through hole (55) through which the fastening member is inserted. The electronic device according to claim 1, wherein the fixing portion is fixed to the substrate by fastening the fastening member while it is inserted through the through hole.

4. The spring member is connected to the fixed portion at a position different from the elastic portion and has a contact portion (54) that contacts the substrate. The electronic device according to any one of claims 1 to 3, wherein, before the mounting portion is soldered to the substrate, the spring member contacts the substrate at multiple locations, including the contact portion and the mounting portion, and stands upright on the substrate.

5. In a plan view of the substrate in the thickness direction, the contact portion, the fixing portion, and the mounting portion are aligned in a predetermined direction. In the self-supporting state before soldering the mounting portion to the substrate, The contact portion extends from the fixing portion along the surface on which the spring member is positioned on the substrate, The electronic device according to claim 4, wherein the fixing portion has an inclination that moves away from the contact portion and away from the arrangement surface.

6. The spring member has an extended portion (57) connected to the fixed portion and a protruding portion (58) that protrudes from the extended portion toward the substrate, The substrate has a hole (37) provided corresponding to the protrusion, Before the mounting portion is soldered to the substrate, the spring member is in contact with the substrate at multiple locations, including the protruding portion and the mounting portion, and stands upright on the substrate. The electronic device according to any one of claims 1 to 3, wherein the fixed portion is fixed to the substrate and the protruding portion is inserted into the hole.

7. The spring member is formed using a conductive material. The substrate has first wiring (351, 361) soldered to the mounting portion and second wiring (352, 362) electrically connected to the fixing portion. The spring member electrically connects the first wiring and the second wiring while the mounting portion is soldered to the substrate and the fixing portion is fixed to the substrate, and interrupts the conductivity between the first wiring and the second wiring when the solder joining the mounting portion and the substrate breaks, according to any one of claims 1 to 3.

8. The electronic device according to claim 7, wherein the electronic component is electrically connected to either the first wiring or the second wiring and includes a component (40S) for detecting the break.

9. The electronic device according to claim 7, wherein the first and second wirings are dummy wirings that do not provide wiring functionality.

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