JP3202714B2 - Backup battery structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a backup battery, and more particularly to a structure of a backup battery suitable as a backup battery in a portable radio selective calling receiver or the like.

[0002]

2. Description of the Related Art A radio selective calling receiver is generally constructed as shown in FIG.
5, current is supplied to the memories 86, 87 and the display means or other active elements. Then, when the battery voltage of the main battery 71 decreases, the main battery 71 is replaced.
A backup battery 78 is provided to retain the contents of the memory by the backup circuit while removing 1.

[0003] That is, in FIG.
In order to back up the information in the message storage unit 87 and the schedule message storage unit 86 of the radio selective calling receiver when the power is turned off, the backup battery 78 supplies power to the CPU 75, the message storage unit 87, and the schedule message storage unit 86. Is supplied to prevent the stored contents from being erased.

A backup battery used in a backup circuit of a radio selective calling receiver has a button-type or coin-type battery structure as shown in FIG. In FIG. 14, reference numeral 51 denotes a positive electrode active material;
2 is a negative electrode active material, 53 is a gasket, 54 is a separator, 13 is a positive electrode case, 15 is a negative electrode case, 18 is a crank-shaped positive terminal plate, and 20 is a flat negative terminal plate. The tip portion of the crank-shaped positive electrode terminal plate 18 and the flat-plate-shaped negative electrode terminal plate 20 are configured to be located on the same plane, so that they can be mounted as they are on the surface of the printed circuit board.

[0005]

In a device provided with such a backup circuit, when the backup process, that is, the switch 76 is turned off, the CPU 75 makes the time or the like displayed on the LCD display unit 93 non-display. The processing is started. In order to shorten the backup time, the operation speed of the CPU 75 is increased during the backup processing to shorten the processing time. Therefore, the current consumption of the CPU 75 increases, and the voltage drop of the backup battery 78 increases.

Therefore, when the internal resistance of the backup battery 78 is high, the power supply voltage VDD supplied to the CPU 75 by the backup battery 78 drops below the reset voltage of the CPU 75 during the replacement of the main battery 71. As a result, there is a problem that the CPU 75 is reset.

In order to reduce the size of the radio selective calling receiver, it is preferable to use a button-type battery or a coin-type battery having a small diameter. Since the resistance R and the chemical reaction area S are inversely proportional, if the diameter of the button-type battery or coin-type battery used as the backup battery is reduced, the internal resistance of the backup battery increases, and the size of the radio selective calling receiver can be reduced. It is a hindrance factor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backup battery structure capable of reducing the internal resistance of the backup battery without increasing the diameter of the button battery or coin battery used as the backup battery. It is in.

[0009]

The backup battery used in the memory backup circuit of the radio selective calling receiver according to the present invention is a button-type battery or a coin-type battery cell having a positive electrode case and a negative electrode case. The case and the negative electrode case are integrated by using two crank-shaped electrode lead terminals and two plate-shaped electrode lead terminals,
It is characterized in that it is electrically connected in parallel.

By adopting such a configuration, the diameter of the battery is not changed from the conventional one and the chemical reaction area can be substantially doubled, so that the internal resistance of the backup battery can be reduced to half. Therefore, it is possible to provide a backup battery suitable for solving the above problems.

[0011]

FIG. 1 is a front view of a backup battery 10 showing a first embodiment of the present invention. FIG. 2 is an external view thereof. In FIG. 1, the battery cell 11
The battery cell 12 is a button-type battery or a coin-type battery, and the battery cell 11 is a positive electrode case 13 and a negative electrode case 1.
5, and the battery cell 12 has a positive electrode case 14 and a negative electrode case 16.

A flat cathode lead terminal 17 is fixed to the cathode case 13 of the battery cell 11 by welding at welding locations 25 and 26, and the terminal 34 is solder-plated on the cathode case 14 of the battery cell 12. The terminal 18 is fixed by welding at welding points 27 and 28. Then, the positive electrode case 13 of the battery cell 11 to which the plate-shaped positive electrode lead terminal 17 is welded.
And the positive electrode case 14 of the battery cell 12 to which the crank-shaped positive electrode lead terminal 18 is welded is opposed to each other, and the central axis l of the battery cell 11 and the central axis l of the battery cell 12 are stacked so as to be on the same straight line. Further, the plate-shaped positive electrode lead terminal 17 and the crank-shaped positive electrode lead terminal 18 are fixed by welding at welding locations 29 and 30.

Next, the negative electrode case 15 of the battery cell 11
The crank-shaped negative electrode lead terminal 19 was welded and fixed at welding locations 21 and 22, and the flat plate-shaped negative electrode lead terminal 20 whose terminal portion 33 was solder-plated was fixed to the negative electrode case 16 of the battery cell 12 by welding points 23 and 24. Then, the flat-plate-shaped negative lead terminal 20 and the crank-shaped negative lead terminal 19 are welded at the welding point 3.
The battery cell 11 and the battery cell 12 are connected by welding at step 1.

As the material of the lead terminals 17, 18, 19 and 20, a metal such as stainless steel is used. The portions 34 and 33 of the positive electrode lead terminal 18 and the negative electrode lead terminal 20 connected to the printed board are on the same straight line. Welding points 21 to
31 is welded by spot welding using laser or electricity.

The backup battery 1 configured as described above
0 indicates that the positive electrode lead terminal 18 is in a crank shape, and the positive electrode terminal portion 34 plated with solder and the negative electrode terminal portion 33 of the flat negative electrode lead terminal 20 are located on the same plane. Can be surface-mounted on the printed circuit board 98.

As can be seen from the configuration of FIG. 1, the backup battery 10 of the present invention has a crank-shaped negative lead terminal 19.
And the flat-plate-shaped negative electrode lead terminal 20 are connected at a welding point 31,
Since the crank-shaped positive electrode lead terminal 18 and the plate-shaped positive electrode lead terminal are connected at welding points 29 and 30, the battery cell 1
1 and the battery cell 12 are electrically connected in parallel. Therefore, as shown in FIG.
Assuming that the battery electromotive force is E11, the internal resistance of the battery cell 12 is r12, and the battery electromotive force is E12,
The internal resistance r10 of the battery cell 10 in which the battery cell 12 is connected in parallel is r10 = r11 × r12 / (r11 + r12), and the battery electromotive force E10 is E10 = (r12 × E11 + r11 × E12) / (r1
1 + r12).

If the battery cells 11 and 12 are charged with the same voltage, the battery electromotive force E10 and the battery electromotive forces E11 and E12 have E1.
There is a relationship of 0 ≒ E11 ≒ E12. In addition, battery cell 1
Internal resistance r where internal resistances r11 and r12 of 1, 12 are equal
, The internal resistance r10 = r / 2, which is reduced to about half.

Next, the operation of the backup battery used in the backup circuit of the radio selective calling receiver will be described with reference to FIGS.

In FIG. 5, a memory 77 stores information such as a received message and time. Normally,
Operating power is supplied from the main battery 71 to the CPU 75 and the memory 77. The backup battery 78 is connected to the memory 77 via the diode 73. The DC-DC converter 74 boosts the voltage of the main battery 71 to VDD, which is a driving voltage of the CPU, for example, 3.0 V. Main battery 7
When the main battery 71 is replaced due to a decrease in the battery voltage of the battery 1, the backup battery 78 supplies a current for performing the backup process of the CPU 75 and further functions to hold information in the memory 77.

The battery voltage of the main battery 71 drops, and the main battery 7
When replacing 1, the switch 76 is turned off, the main battery 71 is removed, the main battery 71 is replaced with a new battery, and then the switch 76 is turned on. When the switch 76 is turned off, the CPU 75 that has sensed the switch-off signal performs backup processing.

FIG. 6 shows the relationship between the backup current and the voltage when the main battery is replaced. The current consumption of the CPU 75 is normally i1 = several tens of μA, but when the backup process is started, i2 = several mA. This CPU 7
5 is supplied from the backup battery 78,
The voltage drop of the backup battery 78 at this time is “discharge current × internal resistance of the backup battery 78”.

When one backup battery 11 or 12 having an internal resistance r is used, the discharge characteristic shown by the dotted line in FIG. 6 is obtained.
Reset voltage: VDD drops to V2. If the time required for the backup process is t0, t2 <t
Since it is 0, the CPU 75 resets before the CPU 75 completes the backup process.

When the backup battery 10 according to the present invention, in which two battery cells 11 and 12 are connected in parallel, is used, the battery cells 11 and 1 constituting the backup battery 10 are used.
2, the backup battery 10
The internal resistance of the CPU 75 can be reduced to r / 2, so that the voltage drop of VDD can be suppressed to １ ／. As shown by the solid line in FIG. Can be higher and C
PU 75 does not reset.

FIG. 7 is a front view of a backup battery 90 showing a second embodiment of the present invention. The battery 90 faces the positive electrode case 13 of the battery cell 11 to which the plate-shaped positive electrode lead terminal 17 is welded, the crank-shaped positive electrode lead terminal 18, and the positive electrode case 14 of the battery cell 12 to which the plate-shaped negative electrode lead terminal 20 is welded. The central axis l of the battery cell 11 and the central axis l of the battery cell 12 are stacked so as to be on the same straight line. Further, the plate-like positive lead terminal 17 and the crank-like positive lead terminal 18 are soldered at a soldering point 96A, and the crank-like negative lead terminal 19 and the plate-like negative lead terminal 20 are soldered at a soldering point 96B. 11 and battery cells 12 are connected in parallel.

FIG. 8 is a front view of a backup battery 100 showing a third embodiment of the present invention. Battery 100
Are stacked so that the positive electrode case 13 of the battery cell 11 and the positive electrode case 14 of the battery cell 12 face each other, and the central axis l of the battery cell 11 and the central axis l of the battery cell 12 are in the same straight line. Further, the plate-shaped negative electrode lead terminal 20 and the crank-shaped positive electrode lead terminal 19 are fixed by welding, and the L-shaped positive electrode lead terminal 61 is fixed by welding to the positive electrode cases 13 and 14 at welding points 17A and 17B, respectively. 12 are connected in parallel.

In this embodiment, the height of the battery 100 can be reduced by the thickness of two lead terminal plates, and the height of the backup battery can be reduced accordingly. Since the thickness of the lead terminal is usually about 0.1 mm, the battery 10
The height of 0 is reduced by about 0.2 mm, which is equivalent to two lead terminal thicknesses.

FIG. 9 is a front view of a backup battery 110 showing a fourth embodiment of the present invention. Battery 110
Has a structure in which the negative electrode cases of the battery cells 11 and 12 face each other and are connected in parallel. Although the polarity of this embodiment is opposite to that of the first embodiment, the operation and effect are the same.

FIG. 10 is a front view of a backup battery 120 showing a fifth embodiment of the present invention. Battery 120
Has a structure in which the negative electrode cases of the battery cells 11 and 12 face each other and are connected in parallel. In this embodiment, similarly to FIG. 8, the L-shaped positive lead terminal 61 is welded and fixed to the positive cases 13 and 14 at welding locations 17A and 17B, respectively, and the battery cells 11 and 12 are connected in parallel. In addition, the height of the backup battery can be reduced.

In each of the above embodiments, the lead terminal plates are arranged such that the portions 34 and 33 of the positive lead terminal 18 and the negative lead terminal 20 which are connected to the printed board are on the same straight line. 18 and negative lead terminal 20
The parts 34 and 33 to be connected to the printed board need not necessarily be arranged on the same straight line, and can be appropriately changed according to the positional relationship of the wiring on the printed board.

FIG. 11 shows an example in which, in the first embodiment, the portions 34 and 33 of the positive electrode lead terminal 18 and the negative electrode lead terminal 20 which are connected to the printed board are arranged at positions shifted from each other. FIG. 12 shows an example in which the positive lead terminal 18 is arranged at an angle of 90 degrees with the negative lead terminal 20. Note that the angle is not limited to 90 degrees and can be changed to any angle.

[0031]

According to the present invention, since the internal resistance of the backup battery is reduced by half, the voltage drop due to the battery can be reduced, and the capacity of the backup battery is doubled, thereby increasing the backup time. In addition, despite the use of two battery cells, the mounting area remains the same for one battery cell, so the area for mounting other parts on the printed board can be saved by one battery cell. become,
The size of the battery-equipped device can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of a backup battery of the present invention.

FIG. 2 is a perspective view of the first embodiment of the present invention.

FIG. 3 is a front view in which the backup battery of the present invention is mounted on a printed circuit board.

FIG. 4 is an equivalent circuit for explaining the backup battery of the present invention.

FIG. 5 is a circuit diagram illustrating a backup circuit of the radio selective calling receiver.

FIG. 6 is a graph showing an output voltage and a supply current of a backup circuit of the radio selective calling receiver.

FIG. 7 is a front view showing a second embodiment of the backup battery of the present invention.

FIG. 8 is a front view showing a third embodiment of the backup battery of the present invention.

FIG. 9 is a front view showing a fourth embodiment of the backup battery of the present invention.

FIG. 10 is a front view showing a fifth embodiment of the backup battery of the present invention.

FIG. 11 is a perspective view and a plan view showing an example in which lead terminals are shifted from each other in the embodiment of the present invention.

FIG. 12 is a perspective view and a plan view showing an example in which lead terminals are arranged at right angles in the embodiment of the present invention.

FIG. 13 is a block diagram of a radio selective calling receiver.

FIG. 14 is a partial sectional view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 backup battery 11, 12 battery cell 13, 14 positive electrode case 15, 16 negative electrode case 17, 20 flat terminal 18, 19 crank-shaped terminal 21 to 31 welding location 33, 34 terminal portion 51 positive electrode active material 52 negative electrode active material 53 Gasket 54 Separator 61 L-shaped positive lead terminal 71 Main battery 73 Diode 74 DC-DC converter 75 CPU 76 Switch 77 Memory 78 Backup battery 96A, 96B Soldering part 97 Backup circuit 98 Printed circuit board 17A, 17B Welding location 90, 100 , 110,120 Backup battery

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 2/10 H01M 2/20

Claims (6)

(57) [Claims] 1. Button-shaped or coin-shaped first and second battery cells each having a positive electrode case and a negative electrode case,
An L-shaped positive lead terminal welded and fixed to the side surface of the positive electrode case of the first battery cell and the side surface of the positive electrode case of the second battery cell and having a terminal portion solder-plated; and a negative electrode case of the first battery cell A crank-shaped negative electrode lead terminal welded and fixed to the surface; and a plate-shaped negative electrode lead terminal welded and fixed to the surface of the negative electrode case of the second battery cell and having a terminal portion solder-plated. Is welded to the side of the positive electrode case of each of the battery cells in a state where the first and second battery cells are stacked such that their positive electrode cases are closely contacted and opposed to each other and their central axes are on the same straight line. At the same time, the crank-shaped negative electrode lead terminal and the plate-shaped negative electrode lead terminal are welded or solder-fixed, and the terminal portion of the L-shaped positive electrode lead terminal and the plate-shaped negative electrode lead terminal are made the same. A backup battery structure, which is located on one plane. 2. A button-shaped or coin-shaped first and second battery cell having a positive electrode case and a negative electrode case,
An L-shaped positive lead terminal welded and fixed to the side surface of the positive electrode case of the first battery cell and the side surface of the positive electrode case of the second battery cell and having a terminal portion solder-plated; and a negative electrode case of the first battery cell A crank-shaped negative electrode lead terminal welded and fixed to the surface, and a plate-shaped negative electrode lead terminal having a terminal portion solder-plated and fixed by welding to the surface of the negative electrode case of the second battery cell; The crank-shaped negative lead terminal is fixed to the first and second terminals by welding or soldering.
The battery cells are stacked so that their negative electrode cases face each other, and their central axes are on the same straight line.
A backup battery structure, wherein a terminal portion of the crank-shaped negative electrode lead terminal and a terminal portion of an L-shaped positive electrode lead terminal welded and fixed to a side surface of the positive electrode case of each battery cell are located on the same plane. 3. The terminal according to claim 1, wherein the terminal portions of the positive electrode lead terminal and the negative electrode lead terminal having the solder-plated terminal portions are arranged in a straight line. Backup battery structure. 4. The terminal according to claim 1, wherein said positive electrode lead terminal and said negative electrode lead terminal having said solder-plated terminal portions are arranged in a positional relationship deviated parallel to each other. The backup battery structure according to any one of the above. Wherein each terminal portion of the positive electrode lead terminal and the negative electrode lead terminal having the solder plated terminal portion claims 1 to 4, characterized in that it is arranged in a positional relationship to each other a predetermined angle The backup battery structure according to any one of the above. 6. The semiconductor device according to claim 1, wherein the positive electrode lead terminal and the negative electrode lead terminal having the terminal portions plated with solder are surface-mounted on a printed circuit board.
6. The backup battery structure according to any one of items 5 to 5.