JP7797138B2 - Positive electrode terminal for button battery and electronic device - Google Patents

Description

The present invention relates to a positive electrode terminal for a button battery that has a contact point that comes into contact with the positive electrode side of the button battery, and to an electronic device equipped with this positive electrode terminal for a button battery.

Disc-shaped button batteries with a positive side and a negative flat surface have traditionally been used in a variety of electronic devices. These electronic devices include a positive terminal with a contact that contacts the positive side of the button battery, a negative terminal with a contact that contacts the negative flat surface of the button battery, and a substrate on which the positive and negative terminals are mounted. In recent years, with the trend toward SMD (Surface Mounted Devices) for electronic components, there has been a demand for button battery terminals that can be surface-mounted to a substrate. Patent Documents 1 and 2 describe positive terminals for button batteries that are surface-mounted to a substrate.

Japanese Patent Application Laid-Open No. 2004-87191 JP 2015-95309 A

Positive terminals for button batteries that are surface-mounted on a circuit board must have a flat surface that can be picked up by the suction nozzle of a mounting machine (chip mounter), and must be able to stand on the board. Furthermore, from the perspective of freedom in designing the circuit pattern on the board, it is desirable that the size of the land used to join the positive terminal to the board be small, and that the positive terminal itself be compact.

The present invention aims to provide a positive terminal for a small button battery that can be surface-mounted on a substrate, and an electronic device equipped with the same.

In order to achieve the above-mentioned object, the present invention provides a positive electrode terminal for a button battery that is mounted on a substrate and has a contact that abuts the positive electrode side of the button battery, the positive electrode terminal comprising: a base portion with a flat substrate bonding surface that is bonded to the substrate; a protrusion portion that extends from the base portion toward the button battery and is not bonded to the substrate; a body portion that rises from the end of the protrusion portion on the button battery side; an arm portion that extends from the body portion in a direction parallel to the substrate and has the contact at its tip; and a weight balance portion that rises from the end of the base portion on the opposite side to the button battery, and which is capable of standing on its own with respect to the horizontally positioned substrate before the substrate bonding surface is bonded to the substrate .

In order to achieve the above-mentioned objectives, the present invention also provides an electronic device having a storage space for a button battery, the electronic device comprising: a positive terminal having a contact point that contacts the positive electrode side surface of the button battery; a negative terminal having a contact point that contacts the negative electrode flat surface of the button battery; and a substrate on which the positive electrode terminal and the negative electrode terminal are mounted, wherein the positive electrode terminal is the positive electrode terminal for the button battery described above.

The present invention provides a positive electrode terminal for a small button battery that can be surface-mounted on a substrate, and an electronic device equipped with the same.

1A and 1B are perspective views of a programmable controller using a positive electrode terminal for a button battery according to an embodiment of the present invention. FIG. 2 is a perspective view showing a positive electrode terminal and a negative electrode terminal for a button cell mounted on a substrate. 1A and 1B show the positive and negative terminals without a button battery inserted therein, where FIG. 1A is a top view and FIG. 1B is a cross-sectional view taken along the line AA in FIG. 1A. 1A and 1B show the positive and negative terminals with a button cell battery inserted therein, where FIG. 1A is a top view and FIG. 1B is a cross-sectional view taken along the line BB of FIG. 1A. 10 is a cross-sectional view showing a state in which the positive electrode terminal is pressed strongly against the button battery along the insertion direction of the button battery. FIG.

[Embodiment Mode]
An embodiment of the present invention will be described with reference to Figures 1 to 5. The embodiment described below is shown as a preferred specific example for carrying out the present invention, and although various technically preferable technical matters are specifically exemplified, the technical scope of the present invention is not limited to this specific embodiment.

Figures 1(a) and (b) are perspective views showing a programmable controller 100 as an electronic device using a button cell battery terminal according to an embodiment of the present invention. Figure 1(a) shows a state in which a button cell battery 2 is housed in a case 101 of the programmable controller 100. Figure 1(b) shows a state in which the button cell battery 2 is housed in the case 101 of the programmable controller 100.

The programmable controller 100 controls controlled equipment such as machine tools, and operates the controlled equipment based on a sequence program that defines the operating procedures and various interlocks of the controlled equipment. The button battery 2 is used to back up the memory that stores the sequence program and to operate the RTC (Real Time Clock) circuit when power is not supplied to the programmable controller 100.

The programmable controller 100 houses a circuit board (described below) and various electronic components mounted on the circuit board in a case 101. The programmable controller 100 also has a holder 102 that holds a button battery 2. The holder 102 is normally housed in the case 101 as shown in FIG. 1(a), and can be protruded from the case 101 as shown in FIG. 1(b) when the button battery 2 is to be replaced. When the holder 102 protrudes from the case 101, the button battery 2 can be inserted or removed from the button battery 2 storage compartment 102a in the holder 102.

After the button battery 2 is stored in the storage section 102a of the holder 102 protruding from the case 101, the holder 102 is then placed in the case 101 together with the button battery 2, placing the button battery 2 in the storage space within the case 101. The button battery 2 is disc-shaped, and its outer peripheral surface forms the positive electrode side surface 21. One flat surface of the button battery 2 forms the negative electrode flat surface 22. A positive electrode terminal that contacts the positive electrode side surface 21 of the button battery 2 and a negative electrode terminal that contacts the negative electrode flat surface 22 of the button battery 2 are mounted on a circuit board placed within the case 101.

(Configuration of positive electrode terminal and negative electrode terminal)
Fig. 2 is a perspective view showing the positive and negative terminals 3 and 4 for a button battery mounted on the substrate 1 of the programmable controller 100. Fig. 3 is a structural diagram of the positive and negative terminals 3 and 4 when a button battery 2 is not inserted, with (a) being a top view and (b) being a cross-sectional view taken along line A-A of (a). In Fig. 3, the outline of the button battery 2 when inserted is shown by a virtual line (two-dot chain line). Fig. 4 is a structural diagram of the positive and negative terminals 3 and 4 when a button battery 2 is inserted, with (a) being a top view and (b) being a cross-sectional view taken along line B-B of (a).

The substrate 1 has a circuit pattern (not shown) formed on the surface of a flat base material 11 made of an insulating material such as glass epoxy. A storage space 10 is provided on the substrate 1 to store a button battery 2 held in a holder 102.

A button battery 2 is inserted into the storage space 10 parallel to the substrate 1 in the insertion direction indicated by the arrow in Figure 2. A positive terminal 3 is surface-mounted on the mounting surface 1a of the substrate 1 so as to contact the positive side surface 21 of the button battery 2, and a negative terminal 4 is surface-mounted so as to contact the negative flat surface 22 of the button battery 2. The positive terminal 3 and negative terminal 4 are formed by press-forming a stainless steel plate, for example, 0.2 mm thick.

The negative electrode terminal 4 integrally comprises a pair of legs 41 provided at both ends in the insertion direction of the button battery 2 into the storage space 10, a rectangular flat plate 42 between the pair of legs 41 and facing parallel to the mounting surface 1a of the board 1 with a gap between them, a pair of step portions 43 between the pair of legs 41 and the flat plate 42, and a pair of tongue portions 44 with contact points 441 that come into contact with the negative electrode flat surface 22 of the button battery 2.

The pair of legs 41 of the negative terminal 4 have a substrate joining surface 41a on the substrate 1 side, which is soldered to the negative land 12 provided on the substrate 1. The flat plate portion 42 has two openings 420 aligned perpendicular to the insertion direction of the button battery 2, and a pair of tongue portions 44 extend from one end of the openings 420 to the other in the insertion direction of the button battery 2. A contact 441 is provided at the tip of each of the pair of tongue portions 44, and makes elastic contact with the negative flat surface 22 of the button battery 2.

The positive terminal 3 is located further back than the negative terminal 4 in the insertion direction of the button battery 2. The positive terminal 3 integrally comprises a base 31 having a flat substrate bonding surface 31a that is bonded to the substrate 1, a flat protrusion 32 extending from the base 31 toward the button battery 2, a body 33 extending from the end of the protrusion 32 on the button battery 2 side, a pair of arms 34 extending from the body 33 in a direction parallel to the substrate 1, and a weight balance 35 extending from the end of the base 31 opposite the button battery 2. The pair of arms 34 have contacts 341 at their tips that come into contact with the positive side surface 21 of the button battery 2.

The base portion 31 is flat and has a pair of flat plate portions 311 that sandwich the protruding piece portion 32, and a connecting plate portion 312 that connects the pair of flat plate portions 311. The pair of flat plate portions 311 are aligned in a direction perpendicular to the insertion direction of the button battery 2, and sandwich the protruding piece portion 32 in the same direction. Each of the pair of flat plate portions 311 has a board bonding surface 31a. The connecting plate portion 312 connects the ends of the pair of flat plate portions 311 on the side opposite the button battery 2 side.

A notch 310 is provided between each pair of flat plate portions 311 and protruding pieces 32. The notch 310 extends parallel to the insertion direction of the button battery 2 from the end of the base portion 31 on the button battery 2 side toward the connecting plate portion 312.

The surfaces of the pair of flat plate portions 311 facing the substrate 1 serve as substrate bonding surfaces 31a, and these substrate bonding surfaces 31a are respectively soldered to a pair of positive electrode lands 13 provided on the substrate 1. Each of the pair of flat plate portions 311 is approximately square in shape. The positive electrode lands 13 are formed to be slightly larger than the flat plate portions 311.

The protrusion 32 is not joined to the substrate 1, but extends from the connecting plate 312 of the base 31 toward the button battery 2. When no external force is applied to the positive terminal 3, the protrusion 32 is parallel to the substrate 1. Furthermore, when the pair of arms 34 are pressed strongly in the insertion direction of the button battery 2, the protrusion 32 is elastically deformable so that the end on the body 33 side moves away from the substrate 1.

The body 33 is flat and positioned perpendicular to the insertion direction of the button battery 2, facing the positive electrode side surface 21 of the button battery 2 across a gap. A pair of arms 34 extend in opposite directions along the circumferential direction of the button battery 2 from both ends of the body 33 perpendicular to the insertion direction of the button battery 2. As shown in Figure 4(a), the pair of arms 34 are elastically deformed when the contacts 341 come into contact with and are pressed against the positive electrode side surface 21 of the button battery 2 housed in the housing space 10. The restoring force of the elastically deformed arms 34 causes the contacts 341 to elastically come into contact with the positive electrode side surface 21 of the button battery 2.

The weight balance portion 35 is erected perpendicular to the substrate 1, continuing from the pair of flat plate portions 311 and connecting plate portion 312 of the base portion 31. This weight balance portion 35 ensures that the center of gravity P (see Figure 3(a)) of the positive terminal 3 when viewed from a direction perpendicular to the substrate 1 is located at the protruding piece portion 32. This allows the positive terminal 3 to stand on its own on the horizontally placed substrate 1 before the substrate bonding surface 31a is bonded to the substrate 1.

(Method for manufacturing positive electrode terminal)
The positive electrode terminal 3 is manufactured from a long rolled plate material using a progressive die that feeds the material in sequence. More specifically, the positive electrode terminal 3 is manufactured by punching and bending the plate material using a die multiple times. The positive electrode terminal 3 has a rectangular shape close to a square when developed into a single plate before bending. More specifically, the ratio of the long side width to the short side width is within 2. The positive electrode terminal 3 has a shape in which the area ratio used as a product exceeds 50% within this rectangular shape.

In addition, before bending, the product, which is unfolded into a single plate, may be cut so that the axis of symmetry of the product is tilted at approximately 45 degrees to the longitudinal direction of the long plate material. Metal plates generally have directional bending characteristics, but by cutting the product so that the axis of symmetry is tilted, the effects of this directionality can be reduced.

(Method of mounting positive and negative terminals)
The positive electrode terminal 3 and the negative electrode terminal 4 are mounted on the substrate 1 by a mounting machine. As a preparation step for mounting, cream solder is applied to the pair of positive electrode lands 13 and the pair of negative electrode lands 12 of the substrate 1 by screen printing or the like. The substrate 1 to which the cream solder has been applied is set horizontally in the mounting machine so that the mounting surface 1 a faces vertically upward.

The positive terminal 3 is vacuum-sucked by the mounting machine's suction nozzle and transported, and placed on the mounting surface 1a so that the pair of board joining surfaces 31a of the base portion 31 face the pair of positive electrode lands 13 on the board 1. At this time, the suction nozzle sucks the protruding piece 32 of the positive terminal 3. The area that is picked up by the suction nozzle includes the center of gravity P. Similarly, the negative terminal 4 is placed on the mounting surface 1a by the suction nozzle so that the board joining surfaces 41a of the pair of legs 41 face the pair of negative electrode lands 12 to which cream solder has been applied.

The board 1, on which the positive terminal 3 and negative terminal 4 are mounted, is placed in a reflow furnace with the mounting surface 1a facing up. In the reflow furnace, the cream solder applied to the positive electrode land 13 and negative electrode land 12 melts due to heat, soldering the board joining surface 31a of the positive electrode terminal 3 to the positive electrode land 13 and the board joining surface 41a of the negative electrode terminal 4 to the negative electrode land 12.

(Positive terminal operation)
5 is a cross-sectional view showing the state when the positive terminal 3 is strongly pressed against the button battery 2 in the insertion direction of the button battery 2. The positive terminal 3 is strongly pressed against the button battery 2, for example, when the holder 102 of the programmable controller 100 is pushed into the case 101. The positive terminal 3 may also be strongly pressed against the button battery 2 when the programmable controller 100 is subjected to strong vibrations or impacts in the vertical direction, for example.

When the positive terminal 3 is pressed firmly against the button battery 2, the pair of arms 34 elastically deform to open, and the end of the protruding piece 32 on the body 33 side elastically deforms away from the board 1 to absorb the impact. As the protruding piece 32 deforms, the end of the body 33 opposite the board 1 tilts away from the button battery 2. This deformation of the protruding piece 32 and the pair of arms 34 reduces the load acting on the joint between the board joint surface 31a of the positive terminal 3 and the positive land 13, compared to a case in which the positive terminal 3 does not have the protruding piece 32 and the body 33 is erected from the base 31, thereby preventing cracks and peeling in the solder at this joint.

(Effects of the embodiment)
According to the present embodiment described above, the projection portion 32 is interposed between the base portion 31 and the trunk portion 33, and thus the load acting on the joint between the substrate joint surface 31 a and the positive land 13 when the positive terminal 3 is pressed strongly against the button-type battery 2 is alleviated. This allows the sizes of the substrate joint surface 31 a and the positive land 13 to be reduced, making it possible to miniaturize the positive terminal 3 and also increasing the degree of freedom in designing the circuit pattern on the substrate 1.

Furthermore, according to this embodiment, the pair of flat plate portions 311 on the base portion 31 of the positive terminal 3 sandwich the protruding piece portion 32, and the protruding piece portion 32 extends from the connecting plate portion 312 connecting the pair of flat plate portions 311 toward the button battery 2, making it possible to further reduce the size of the positive terminal 3.

In addition, according to this embodiment, the weight balance section 35 is erected from the end of the base section 31 opposite the button battery 2, so the weight balance section 35 does not increase the area occupied by the positive terminal 3 on the mounting surface 1a. In other words, this weight balance section 35 configuration also makes it possible to reduce the size of the positive terminal 3, thereby increasing the degree of freedom in designing the circuit pattern on the board 1.

(Additional Note)
Although the present invention has been described above based on the embodiments, the invention according to the claims is not limited to these embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention.

Furthermore, the present invention can be implemented by omitting some components or adding or substituting components without departing from the spirit of the invention. For example, the following modifications are possible:

In the above embodiment, a notch 310 is formed between a pair of flat plate portions 311 and protruding pieces 32, but this is not limiting. For example, the protruding pieces may extend from the ends of a rectangular base portion. Furthermore, the protruding pieces do not have to be parallel to the substrate 1, and may be shaped to be easily elastically deformed by the force from the body portion, for example by sloping the end on the body portion side so that it rises above the substrate.

In addition, in the above embodiment, the weight balance portion 35 is described as being flat and bent perpendicular to the base portion 31, but this is not limiting and the weight balance portion 35 may be bent at an angle relative to the base portion 31.

In addition, in the above embodiment, the base portion 31 is described as being flat, but this is not limiting; the connecting plate portion may be spaced apart from the substrate between a pair of flat plate portions. In this case, the weight balance portion may be erected, for example, at the end of the pair of flat plate portions opposite the button battery, or at the end of the connecting plate portion opposite the button battery.

In addition, while the above embodiment describes a case where the positive and negative terminals 3 and 4 are mounted on the board 1 of the programmable controller 100, the positive and negative terminals 3 and 4 may also be mounted on the board of other electronic devices. More specifically, the positive and negative terminals 3 and 4 can be used in a variety of electronic devices, such as wireless car keys, various remote controls, thermometers, toys, etc.

1... Substrate 10... Storage space 100... Programmable controller (electronic device)
2... Button battery 21... Positive electrode side surface 3... Positive electrode terminal 31... Base portion 31a... Board joining surface 310... Notch 311... Flat plate portion 312... Connecting plate portion 32... Projection portion 33... Body portion 34... Arm portion 341... Contact 35... Weight balance portion

Claims (3)

A positive electrode terminal for a button battery is mounted on a substrate and has a contact point that contacts a positive electrode side surface of the button battery,
a base portion having a flat substrate bonding surface to be bonded to the substrate;
a protruding piece portion extending from the base portion toward the button battery and not joined to the substrate;
a body portion provided to rise from an end of the protruding piece on the button battery side;
an arm portion extending from the body portion in a direction parallel to the substrate and having the contact point at a tip thereof;
a weight balance portion provided to stand up from an end of the base portion opposite to the button battery ,
The substrate bonding surface is capable of standing on its own with respect to the horizontally placed substrate before being bonded to the substrate.
Positive terminal for button cell batteries. the base portion has a pair of flat plate portions sandwiching the protruding piece portion therebetween and a connecting plate portion connecting the pair of flat plate portions, each of the pair of flat plate portions having the board joining surface;
a notch is provided between the pair of flat plate portions and the protruding piece portion,
The protruding piece extends from the connecting plate toward the button battery.
The positive electrode terminal for a button battery according to claim 1 . An electronic device having a storage space for storing a button battery,
a positive electrode terminal having a contact point that contacts the positive electrode side surface of the button battery, a negative electrode terminal having a contact point that contacts the negative electrode flat surface of the button battery, and a substrate on which the positive electrode terminal and the negative electrode terminal are mounted,
The positive electrode terminal is the positive electrode terminal for a button battery according to claim 1 or 2 .
electronic equipment.