JPH11186672A - Flexible printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the connections of leads and increase the mounting area to improve the reliability of power source circuits by forming these circuits on a flexible printed circuit board to eliminate interconnections between the flexible printed circuit boards. SOLUTION: Circuits are formed on a flexible printed circuit board unit 200, including a DC-DC circuit 210 for feeding a stable power to a camera circuit, drive circuit 220 for driving a motor for driving a mechanism for moving the camera mechanism, and strobe circuit 230 for feeding a power to a strobe mounted on the camera. Solder pads 260 for bonding circuits on the flexible printed circuit board unit are concentrated on one spot with this board unit 200 mounted on the camera to avoid dispersing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera mounting method in which a power supply circuit is mounted (mounted) on a single printed circuit board.

[0002]

2. Description of the Related Art Conventionally, a power supply circuit of a camera is divided and mounted on a plurality of circuit boards, and a circuit is created by connecting the respective circuit boards. In particular, since the strobe circuit is a high-voltage circuit as compared with other power supply circuits, it has been formed on another substrate.

FIG. 6 shows an example of an electric circuit arrangement of a typical conventional camera. In FIG. 6, 1 is a mirror box, 2 is a camera main body, 3 is a pentaprism, 4 is a main flexible printed circuit board, and a spool is mounted on the pentaprism 3 from the cartridge room side 2a of the main body 2. It is arranged on the room side 2b. 5 is D
It is an X-piece unit and is connected to a flexible printed circuit board 9 for extracting signals. Reference numeral 6 denotes a focus detection device, which is connected to the signal extraction board 11. 7 is a battery, 8 is a DC / DC circuit,
Reference numeral 12 denotes a flash circuit, and these power supply means are connected to the flexible printed circuit board 10 for power supply. These connection flexible printed circuit boards are connected to the main flexible printed circuit board 4, respectively.

[0004]

If the power supply circuit is formed separately on a plurality of substrates, a solder pad or a comb-like shape for connecting each power supply circuit is required. Also, the area is reduced due to the shape of the board connecting portion, and the area for actually mounting the components is considerably reduced. Further, since the substrates are connected to each other, there is a possibility that the resistance at the connection portion increases or a connection failure occurs.

Further, the shape of the connecting portion of the substrate must be formed in a flat portion, or the bulge of the solder in the comb-shaped portion and the soldering pad portion, and the connection of the lead wires in the height direction of the substrate. Space is taken up, which limits the arrangement of the substrates.

When an oscillation circuit such as a strobe circuit is outside the flexible printed circuit board, noise generated from the circuit may affect other circuits. Also, if the mounting element is exposed to the outside, it is necessary to prepare a separate insulating member for maintaining insulation from an external material in order to prevent a short circuit between another member and the circuit.

Therefore, an object of the present invention is to provide a strobe circuit,
By forming a plurality of power supply circuits such as DC / DC circuits on a single flexible printed circuit board, a connection portion between the flexible printed circuit boards is eliminated, and a connection between the flexible printed circuit boards is reduced, so that a flexible printed circuit board is reduced. To increase the mounting area above,
An object of the present invention is to improve the reliability of the power supply circuit by reducing the number of connection parts.

[0008]

According to a first aspect of the present invention, in a circuit including a digital processing circuit, an analog processing circuit, and a power supply circuit for supplying a large current, at least the power supply circuit is a single circuit. The circuit is formed on a flexible printed circuit board, and each of the circuits is folded so as to overlap at least three layers.

According to this configuration, since the circuit is formed on a single flexible printed circuit board, it is possible to reduce the number of circuit connecting portions and to achieve a reduction in the size of the flexible printed circuit board unit. become. Further, the number of connections between the flexible printed circuit board and the lead wires during assembly can be reduced, and the flexible printed circuit board can be easily incorporated.
In addition, it is possible to reduce an increase in resistance at the connection portion and reduce a connection failure. In addition, since the board is formed of a flexible printed circuit board having easiness, the board can be freely arranged, and the degree of freedom in arranging mounted components is improved.

In addition, when the flexible printed circuit board is incorporated in a camera, the flexible printed circuit board is folded so as to be stacked, so that the space required for mounting can be reduced while securing a large mounting area.

Further, in the invention according to claim 2, the power supply circuit comprises a motor drive circuit, a strobe circuit, and a DC / DC circuit for keeping the power supply voltage constant.

With this configuration, a motor drive circuit, a strobe circuit,
By configuring a power stabilizing circuit (DC / DC circuit), the number of connection points can be reduced.

According to a third aspect of the present invention, the power supply circuit comprises:
Strobe circuit on flexible printed circuit board,
The motor drive circuit and the DC / DC circuit are formed in this order.

According to this configuration, interference between power supply circuits can be reduced by disposing power supply circuits having different functions separately.

According to a fourth aspect of the present invention, the power supply circuit is incorporated by folding a DC / DC circuit on a motor drive circuit and further stacking a strobe circuit on the DC / DC circuit. It is.

According to this configuration, various power supply circuits are formed on a single flexible printed circuit board. A strobe circuit, a motor drive circuit, and a DC / DC circuit are arranged in this order, and a DC / DC circuit is placed on the motor drive circuit. By folding the DC circuit and folding the strobe circuit thereon, it is possible to separate the strobe circuit from other power supply circuits. With this configuration, it is possible to protect another power supply circuit from a strobe circuit through which a large current flows.

According to a fifth aspect of the present invention, the mounting state of each component mounted on the flexible printed circuit board is such that the flexible printed circuit board is folded and wrapped therein.

According to this configuration, since the mounting parts and the connection portions are not exposed outside the flexible printed circuit board, it is possible to maintain the insulation from the external members, and it is necessary to separately prepare an insulating member for the flexible printed circuit board. Disappears.

According to a sixth aspect of the present invention, a GN is provided on a portion of the flexible printed circuit board where no wiring pattern exists.
This is one in which a D pattern is formed.

According to this configuration, by wrapping the mounted components in the flexible printed circuit board, the flexible printed circuit board becomes a shield, prevents the diffusion of noise from the power supply circuit to the outside, and reduces the influence of external noise on the power supply circuit. It becomes possible to reduce.

According to a seventh aspect of the present invention, the solder pads for connection with other circuits not mounted on the flexible printed circuit board are concentrated in one place in a state where the flexible printed circuit board is assembled. Is to be configured to exist.

According to this configuration, the solder pads can be integrated into one place, so that the soldering workability at the time of assembling can be improved, and the insulation of the terminal exposed portion can be relatively easily performed. become.

According to an eighth aspect of the present invention, a component having a size equal to or greater than a predetermined value among the components constituting the component is arranged at a position deviated from the bent portion.

[0024] With this configuration, by mounting components having a size equal to or larger than a predetermined value outside the bent portion of the flexible printed circuit board, the mounting density of the bent portion can be improved.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An apparatus shown in this embodiment includes a digital processing circuit for processing a digital signal, an analog processing circuit for processing an analog signal, and a power supply unit for handling a large current. There is a circuit board including a certain power supply circuit. Hereinafter, the configuration of the power supply circuit will be described.

FIGS. 1 to 4 show various forms of the flexible printed circuit board shown in this embodiment. FIG. 1 is an assembled view of a flexible printed circuit board. 2 and 4 are views showing a process of incorporating the flexible printed circuit board into the camera. FIG.
FIG. 3 shows a state in which the flexible printed circuit board is attached to the camera body, FIG. 3 shows a state in which the DC / DC circuit is folded over the motor drive circuit, and the flexible printed circuit board is fixed, and FIG. The DC / DC circuit is folded and fixed, and then the flash circuit is folded.

The flexible printed circuit board shown in this embodiment has a DC / DC for maintaining a constant power supply voltage.
Circuit, a motor drive circuit for driving the motor, and a strobe drive circuit for driving the strobe. here,
Each circuit included in the flexible printed circuit board is arranged such that each circuit is divided into blocks on a space on the flexible printed circuit board.

In FIG. 1, reference numeral 100 denotes a main body which is a structural member of the camera, and 200 denotes a flexible printed circuit board unit on which various power supply circuits are formed. A plurality of circuits are formed in the flexible printed circuit board unit 200. 210 is a DC / DC circuit for supplying a stable power supply to the camera circuit, 220 is a motor drive circuit for driving a motor (not shown) for driving a mechanism for moving the camera mechanism, and 230 Is a flash circuit for supplying power to a flash mounted on the camera.

Each circuit on the flexible printed circuit board unit 200 used in the present embodiment has a DC / D
C circuit 210, motor drive circuit 220, strobe circuit 2
30 are arranged in order. Reference numeral 260 denotes a solder pad for connecting to another circuit. Solder pad 26
0 is provided in a portion connecting each circuit formed on the flexible printed circuit board unit 200 as shown in FIG. Furthermore, this solder pad 260 is used for the flexible printed circuit board unit 20.
In a state where 0 is incorporated in the camera, it is configured so as to be concentrated at one place, and arranged so as not to be dispersed.

Further, the soldering pad 260 is mounted on the flexible printed circuit board unit 200 so as to be exposed to the outside of the flexible printed circuit board unit 200 when the flexible printed circuit board is mounted.
Is formed on the surface opposite to the component mounting surface.

By concentrating the solder pads 260 on the flexible printed circuit board unit 200 at one location, the terminal portions exposed to the outside of the flexible printed circuit board unit 200 can be easily insulated. Furthermore, the workability of soldering lead wires to the flexible printed circuit board unit 200 is improved by concentrating the solder pads 260 at one location.

Next, the incorporation of the flexible printed circuit board of the present embodiment into a camera will be described with reference to FIGS.

As shown in FIG. 2, the camera body 10 of the flexible printed circuit board unit 200 is provided.
First, the motor drive circuit 2 configured on the flexible printed circuit board unit 200
20 is positioned and fixed on the main body 100 of the camera.
Flexible printed circuit board unit 20 in this case
Positioning and fixing of 0 are performed by insertion into a positioning shaft 110 formed on the main body, and connection to a contact piece 300 which is attached to a camera in advance.

At this time, a motor driving circuit 220 is formed in a portion of the flexible printed circuit board unit 200 fixed to the camera, and leads 500a and 500b extending from a motor (not shown) are driven by the motor. Soldering pad 221 formed in circuit section
a, 221b. Thus, the connection between the terminal of the motor and the drive circuit can be made in a short distance.

Next, as shown in FIG. 3, the flexible printed circuit board unit 20 fixed on the main body 100
0 on the DC / DC circuit 21
0 is folded with the mounted component inside. At this time, the insulating section 215 formed on the flexible printed circuit board unit 200 is bent so as to cover the DC / DC circuit 210, and the state is maintained.

In the case of the above configuration, the motor drive circuit 22
0 and the DC / DC circuit 210 have a relationship in which the mounting elements of the respective circuits are opposed to each other in a state where the flexible printed circuit board unit 200 is incorporated in the camera. By arranging the insulating sheet 215 formed on the flexible printed circuit board unit 200 between the circuits, the terminals of the mounting elements are prevented from coming into contact with each other, so that a short circuit does not occur between the circuits.

Then, by connecting the DC / DC circuit 210 folded on the motor drive circuit 220 to a battery contact piece (not shown), the flexible printed circuit board unit 200 is electrically connected to the battery contact piece (not shown). And the positioning of the bent flexible printed circuit board unit 200 to the main body 100 and the fixing to the main body 100 are also performed.

As described above, by incorporating the flexible printed circuit board unit 200 into the main body 100, the DC / DC circuit 210 and the motor drive circuit 220 are mounted.
Can be configured to wrap the mounted components in the flexible printed circuit board unit 200. Therefore, the flexible printed circuit board unit 200
Of the motor drive circuit 220 and D
The components of the C / DC circuit 210 can be isolated.

Next, as shown in FIG. 4, the strobe circuit 230 is folded on the flexible printed circuit board of the DC / DC circuit 210 folded in advance so that the mounted components are on the inside. At this time, the portion of the flexible printed circuit board unit 200 where the strobe circuit 230 is formed is located on the positioning portion 12 of the main body 100 of the strobe circuit 230.
0, and the flexible printed circuit board unit 200 is positioned and fixed with respect to the main body 100 by connection with a circuit board (not shown) of another configuration.

At this time, the flexible printed circuit board unit 2
There is no mounting component of other circuits constituting 00, and only the non-mounting surface of the flexible printed circuit board of the folded DC / DC circuit 210 exists. Therefore, only the mounting element of the strobe circuit 230 exists in the space surrounded by the bent flexible printed circuit board.

By doing so, the strobe circuit 23
0 is insulated from other circuit components constituting the flexible printed circuit board unit 200, and the flash circuit 230 is provided even though a plurality of circuits are formed on a single flexible printed circuit board unit 200. In a state where the camera is installed, the flexible printed circuit board unit 200 is insulated from other constituent circuits.

Also, when the mounted parts are in a state of being built into a camera,
Since the high-voltage circuit portion of the flash circuit 230 is not exposed to the outside of the flexible printed circuit board unit 200 because of being wrapped inside the flexible printed circuit board unit 200, an additional operation for insulating the strobe circuit 230 is added. Becomes unnecessary.

As described above, by arranging the flexible printed circuit board units 200 in a three-tiered configuration, the flexible printed circuit board unit 200 can be made compact when assembled. By arranging the circuits arranged on the unit 200 collectively, interference between the circuits can be eliminated, and the characteristics of each circuit can be improved.

With the above configuration, the mounting elements are not exposed to the outside of the flexible printed circuit board unit 200 in a state where the flexible printed circuit board unit 200 is assembled. Circuit board unit 20
It is no longer necessary to consider insulation between 0 and peripheral components.

When a circuit is formed on the flexible printed circuit board unit 200, a portion where no circuit pattern exists is filled with a GND pattern. As a result, the shielding effect of the flexible printed circuit board is improved, and the flexible printed circuit board unit 2 of the noise generated from the power supply circuit wrapped by the flexible printed circuit board unit 200 is formed.
The divergence from 00 can be reduced.

(Second Embodiment) FIG. 5 is an assembled view of a flexible printed circuit board showing a form of a flexible printed circuit board unit used in the present invention.
5, the basic configuration of the flexible printed circuit board unit is the same as the configuration of the flexible printed circuit board unit described with reference to FIG.

Here, as shown in FIG.
Among the components 30 ', there is a mounting component 231 which is considerably larger than other mounting components. Mounted component 23
1 is a flexible printed circuit board unit 200 '
Bend and remove from the configuration that wraps the mounted parts inside,
The flexible printed circuit board unit 200 'is extended around the bent portion to form a mounting portion, and the mounting is performed at the mounting portion.

By doing so, the variation in the size of the mounted components existing in the bent portion of the flexible printed circuit board unit 200 'is suppressed, and the gap when the flexible printed circuit board unit 200' is assembled is reduced. As a result, the mounting density can be improved.

In each of the above embodiments, a flexible printed circuit board has been described. However, these flexible printed circuit boards can be used not only as one circuit board of a camera but also for optical equipment and electronic equipment. Of course, it can be used as a substrate.

[0050]

According to the first aspect of the present invention, since a circuit is formed on a single flexible printed circuit board, it is possible to reduce the number of circuit connections.
The size of the flexible printed circuit board unit can be reduced. Further, the number of connections between the flexible printed circuit board and the lead wires during assembly can be reduced, and the flexible printed circuit board can be easily incorporated. In addition, it is possible to reduce an increase in resistance at the connection portion and reduce a connection failure. In addition, since the board is formed of a flexible printed circuit board having easiness, the board can be freely arranged, and the degree of freedom in arranging mounted components is improved.

Further, when the flexible printed circuit board is incorporated in a camera, the flexible printed circuit board is folded so as to be stacked, so that a space required for mounting can be reduced while securing a large mounting area.

According to the second aspect of the present invention, the motor drive circuit, the strobe circuit, and the power supply stabilizing circuit (DC / DC circuit) are formed on one flexible printed circuit board, thereby reducing the number of connection points. Can be achieved.

According to the third aspect of the present invention, interference between power supply circuits can be reduced by arranging power supply circuits having different functions separately.

According to the fourth aspect of the present invention, various power supply circuits are formed on one flexible printed circuit board, and a strobe circuit, a motor drive circuit, a DC / DC
By arranging the circuits in the order of the circuits, folding the DC / DC circuit on the motor drive circuit, and folding the strobe circuit thereon, it becomes possible to separate the strobe circuit from other power supply circuits. With this configuration, it is possible to protect another power supply circuit from a strobe circuit through which a large current flows.

According to the fifth aspect of the present invention, since the mounting parts and the connection portions are not exposed outside the flexible printed circuit board, it is possible to maintain the insulation from the external members, and the insulating member of the flexible printed circuit board can be maintained. There is no need to prepare a separate.

According to the sixth aspect of the present invention, by wrapping the mounted components in the flexible printed circuit board,
The flexible printed circuit board serves as a shield, preventing the diffusion of noise from the power supply circuit to the outside, and reducing the influence of external noise on the power supply circuit.

According to the seventh aspect of the present invention, it is possible to improve the workability of soldering at the time of assembling by putting the solder pads in one place, and furthermore, it is relatively easy to insulate the exposed portions of the terminals. Will be able to do it.

According to the eighth aspect of the present invention, the components having a certain size or more are arranged outside the bent portion of the flexible printed circuit board, so that the mounting density of the bent portion can be improved.

[Brief description of the drawings]

FIG. 1 is an assembled view of a flexible printed circuit board according to a first embodiment of the present invention.

FIG. 2 is a process diagram for assembling the flexible printed circuit board according to the first embodiment of the present invention.

FIG. 3 is a process diagram of assembling the flexible printed circuit board according to the first embodiment of the present invention.

FIG. 4 is a process diagram of assembling the flexible printed circuit board according to the first embodiment of the present invention.

FIG. 5 is an assembled view of a flexible printed circuit board according to a second embodiment of the present invention.

FIG. 6 is an electric circuit configuration diagram of a conventional camera.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 100 Main body 200, 200 'Flexible printed circuit board unit 210 DC / DC circuit 220 Motor drive circuit 230 Strobe circuit 231 Mounting parts

Claims (8)

[Claims] 1. A circuit comprising a digital processing circuit, an analog processing circuit, and a power supply circuit for supplying a large current, wherein at least the power supply circuit is formed on a single flexible printed circuit board, and each of the circuits is A flexible printed circuit board, wherein the flexible printed circuit board is folded so as to overlap at least three layers. 2. The flexible printed circuit board according to claim 1, wherein the power supply circuit comprises a motor drive circuit, a strobe circuit, and a DC / DC circuit for keeping the power supply voltage constant. 3. The power supply circuit includes a strobe circuit, a motor drive circuit, and a DC drive circuit on a flexible printed circuit board.
2. The flexible printed circuit board according to claim 1, wherein the flexible printed circuit boards are formed side by side in the order of / DC circuits. 4. The method according to claim 1, wherein the mounting of the power supply circuit is performed by folding a DC / DC circuit on a motor drive circuit.
2. The flexible printed circuit board according to claim 1, wherein a strobe circuit is further folded and overlapped on the circuit. 5. The flexible printed circuit board according to claim 1, wherein the mounting state of each component mounted on the flexible printed circuit board is such that the flexible printed circuit board is folded and wrapped therein. . 6. The flexible printed circuit board according to claim 1, wherein a GND pattern is formed on a portion of the flexible printed circuit board where no wiring pattern exists. 7. A solder pad for connection with another circuit which is not mounted on the flexible printed circuit board, wherein the solder pad is mounted on the flexible printed circuit board.
2. The flexible printed circuit board according to claim 1, wherein the flexible printed circuit board is configured to be concentrated at one place. 8. The flexible printed circuit board according to claim 1, wherein, among the mounted components, components having a size equal to or greater than a predetermined value are arranged at positions deviated from bent portions.