JP4314809B2 - Electronic device having a plurality of printed circuit boards - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic device having a plurality of printed circuit boards, and is particularly suitable for a space-saving high-pressure discharge lamp lighting device that can be built in a wiring duct or the like.
[0002]
[Prior art]
[Patent Document 1]
JP-A-5-327161
Patent Document 1 includes a pair of substrate support portions projecting toward the mother substrate side at both ends of the long side of the mother substrate side of the auxiliary substrate mounted vertically on the mother substrate, and each substrate support portion is provided on the mother substrate side. A mounting structure including a fixing hole to be inserted is disclosed.
[0004]
[Problems to be solved by the invention]
In the mounting structure disclosed in Patent Document 1, the plurality of terminal pads arranged along the long side of the auxiliary substrate and the plurality of terminal pads arranged on the surface of the mother substrate are the component surface side of the mother substrate. It is soldered with. For this reason, for example, when the auxiliary board is mounted on the component surface of the mother board and the solder surface of the mother board is immersed in a solder bath to solder the component leads of the mother board, the auxiliary board is simultaneously connected to the mother board. I couldn't do that. Of course, in Patent Document 1, if all components on the mother board are surface-mounted simultaneously with the auxiliary board, it is possible to perform soldering of the parts on the mother board and soldering of the auxiliary board and the mother board at the same time. As pointed out in the literature, there is another problem that the components mounted on the auxiliary board are displaced due to heating during reflow soldering for surface mounting, in order to hold the parts on the auxiliary board This member was required separately, which caused an increase in cost. In addition, there is a problem that the substrate support portions provided so as to protrude toward the mother substrate at both ends of the long side of the auxiliary substrate are easily broken, and the entire substrate cannot be used if it is damaged. Furthermore, since the long side of the auxiliary board on the mother board side is located on the surface (component surface) of the mother board, the terminal pads of the auxiliary board exist above the surface (component surface) of the mother board. Therefore, the component mounting space on the auxiliary board is located further upward from the surface of the mother board with the terminal pad of the auxiliary board interposed therebetween, and as a result, the auxiliary board protrudes from the mother board surface. There was a problem that the height could not be lowered.
[0005]
The present invention has been made in view of the above points, and by effectively utilizing the space of the component lead of the mother board protruding to the solder surface side of the mother board, the terminal pad of the auxiliary board is used as the component of the mother board. It is an object of the present invention to reduce the height of the auxiliary board protruding from the mother board surface by arranging the board on the solder side rather than on the side of the face, and to realize a reduction in the height of an electronic device having a plurality of printed boards.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, as shown in FIG. 2, in the electronic device having the mother board 10 and the auxiliary board 11, as shown in FIG. A plurality of pairs of terminal pads P are provided so as to be electrically different from each other between the front and back sides, and the auxiliary substrate 11 is directly inserted and connected to the auxiliary substrate insertion slit S opened in the mother substrate 10 The slit S formed in the mother board 10 has a first slit width for electrically connecting the plurality of pairs of terminal pads P provided on the front and back surfaces of the lower side of the auxiliary board 11 separately by soldering. A portion A and a portion having a second slit width B for holding the auxiliary substrate 11 substantially perpendicular to the mother substrate 10 after the auxiliary substrate 11 is inserted and soldered; Slit width A is second slit width B The second slit width B is substantially equal to or less than the thickness d of the auxiliary substrate 11, and the second slit width B is a portion of the first slit width A where the solder connection between the mother substrate 10 and the auxiliary substrate 11 is performed. The distance between the front and back surfaces of the auxiliary substrate 11 is substantially the same as the distance between the front and back surfaces of the auxiliary substrate 11.
[0007]
According to the invention of claim 2, in claim 1, as shown in FIG. 13, the output adjustment variable resistor 18 attached to the auxiliary board 11 is attached to the component surface on the upper surface of the mother board 10. It is characterized in that it is mounted closer to the connecting portion of the mother board 10 and the auxiliary board 11 than the distance of half the height of the board.
[0008]
According to a third aspect of the invention, in any one of the first and second aspects, as shown in FIG. 14, the electrical wiring pattern of the auxiliary board is applied with a portion controlled by a low voltage and a relatively high voltage. The pattern of the part to which a relatively high voltage is applied is arranged on the outer periphery on the auxiliary substrate.
[0009]
According to the invention of claim 4 , in any one of claims 1 to 3 , as shown in FIG. 2, the component placement on the mother board 10 is arranged such that the auxiliary boards 11 and 12 are on the outer periphery. And
[0010]
According to a fifth aspect of the invention, there is provided a discharge lamp lighting device having a mounting structure for an electronic device having the plurality of printed circuit boards according to any one of the first to fourth aspects.
According to a sixth aspect of the present invention, in the fifth aspect , as shown in FIGS. 2 and 3, a lighting device for a high-pressure discharge lamp that supplies approximately 20 to 40 W of load power consumption is provided. The height H from the component lead protruding from the surface to the tallest component is about 26 mm or less.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 3 is a circuit diagram of one embodiment of the present invention. FIG. 2 shows a structure in which the circuit shown in FIG. 3 is mounted on a plurality of printed boards. In the figure, 10 is a mother board, 11 is a first auxiliary board, and 12 is a second auxiliary board. This electronic device is a lighting device for a high-pressure discharge lamp that supplies approximately 20 to 40 W of load power consumption, and all components are mounted on a printed circuit board having a width W = 70 mm and a length L = 77 mm. Auxiliary boards 11 and 12, which are elements that limit the height direction, which has always been a detrimental effect for small-sized mounting, have a structure in which the auxiliary boards 11 and 12 can be directly inserted and connected to the parts surface on the upper surface of the mother board 10 to achieve low component placement. Realized. In this mounting structure, component leads protruding from the solder surface on the lower surface of the mother board 10 are managed at 3 mm below the substrate, and the height H from the bottom 3 mm to the tallest component is 26 mm or less. .
[0012]
FIG. 1 illustrates a connecting portion between the auxiliary substrate 11 and the mother substrate 10. Terminal pads P for soldering to the mother board 10 are provided on both the front and back surfaces of the lower part of the auxiliary board 11, and the lower end of the auxiliary board 11 is directly inserted and connected to the auxiliary board insertion slit S formed in the mother board 10. Is. The auxiliary substrate insertion slit S in the mother substrate 10 is inserted into the auxiliary substrate 11 with a portion having a first slit width A provided with a terminal pad P so as to be electrically connected to the auxiliary substrate 11 with solder. There is a portion having a second slit width B for holding the auxiliary substrate 11 perpendicularly to the mother substrate 10 until after soldering. The first slit width A is larger than the second slit width B, and the second slit width B is substantially equal to or less than the thickness d of the auxiliary substrate 11. By providing such a slit S for inserting the auxiliary board in the mother board 10, the arrangement height of the components on the auxiliary board 11 can be lowered to the immediate vicinity of the surface of the mother board 10. Therefore, it is possible to reduce the height of protrusion of the auxiliary substrate 11 from the surface of the mother board 10. In addition, at the time of manufacture, the assembly of the mother board 10 and the auxiliary board 11 can be allowed to flow as it is into the solder bath without using large jigs for holding the auxiliary board 11 perpendicular to the mother board 10. In addition, effects such as simplification of the manufacturing process and cost reduction can be obtained.
[0013]
That is, the auxiliary substrate 11 is mounted on the component surface of the mother substrate 10 and the solder surface of the mother substrate 10 is immersed in a solder bath so that the component substrate of the mother substrate 10 is soldered to the mother substrate 10 at the same time. It can be connected to the substrate 10. In FIG. 1A, the terminal pads P of the mother board 10 are provided on the solder surface side (not the component surface side) of the mother board 10, and a plurality of terminal pads P are arranged on both sides of the slit S. Yes. FIG. 1C illustrates the terminal pads P provided on one surface of the auxiliary substrate 11, but a plurality of terminal pads are also arranged on the opposite surface. As shown in FIG. 2, the lower end of the auxiliary board 11 (the side on which the terminal pads P are arranged) is inserted into the slit S of the mother board 10 to solder a plurality of components mounted on the component surface of the mother board 10. When performing, the terminal pads of the auxiliary substrate 11 and the terminal pads of the mother substrate 10 are connected by soldering.
[0014]
Here, a supplementary description of the circuit of FIG. 3 will be given. In the figure, 1 is an AC power source, 2 is a rectifier circuit unit, 3 is a lighting circuit unit, 4 is a control circuit unit, 5 is a resonance circuit unit, and 6 is a power factor correction control circuit. The AC power supply 1 is connected to the AC input terminal of the diode bridge DB in the rectifier circuit unit 2 through a noise filter circuit and a circuit protection element. One end of an inductor L3 is connected to the high-voltage side of the DC output of the diode bridge DB. A switching element Q5 is connected between the low-voltage side of the DC output of the diode bridge DB and the other end of the inductor L3. The anode side of the diode D5 is connected to the connection point between the inductor L3 and the switching element Q5, and the capacitor C5 is connected between the cathode side of the diode D5 and the ground. The power factor correction control circuit 6 performs ON / OFF control of the switching element Q5 of the rectifier circuit unit 2 in accordance with the full-wave rectified waveform output from the diode bridge DB, so that the peak of the triangular current waveform flowing through the inductor L3 is all. It is a control circuit that sends a PWM signal so as to follow a wave rectification waveform. (Here, the case where the AC power source 1 and the chopper circuit type rectifier circuit unit 2 are used as the power source of the lighting circuit unit 3 has been described. However, any device that can supply DC power to the lighting circuit unit 3 may be used. Battery or commercial DC power supply may be used.)
[0015]
The lighting circuit unit 3 forms a full bridge circuit with the switching elements Q1 to Q4 in order to convert the DC power supplied from the rectifier circuit unit 2 into AC and supply it to the load DL. One end of each of the switching elements Q1 and Q3 is connected to the high potential side of the DC power supply, the other end of the switching element Q1 and one end of the switching element Q2 are connected in series, and the other end of the switching element Q3 and the switching element Q4 One end is connected in series, and the other ends of the switching elements Q2 and Q4 are connected to the ground. In order to limit the load current, an inductor L1 is connected in series between the connection point of the switching elements Q3 and Q4 and the load DL, and a capacitor C1 is connected in parallel with the load DL to remove a ripple component of the load current. It is connected. The load DL of the lighting circuit unit 3 is a high-pressure discharge lamp (hereinafter simply referred to as a lamp DL).
[0016]
The control circuit unit 4 controls the switching elements Q1 to Q4 constituting the lighting circuit unit 3 to a desired operation, and includes a control IC 40 and drive circuits 41 and 42. The control IC 40 is composed of, for example, a microcomputer (hereinafter simply referred to as a microcomputer). The drive circuits 41 and 42 are composed of driver ICs that drive the switching elements Q1 to Q4 by the output signal of the microcomputer.
[0017]
In order to generate a resonance voltage for starting the lamp DL, the resonance circuit unit 5 includes an inductor L2 connected in series between the connection point of the switching elements Q1 and Q2 and the load DL, and a winding of the inductor L2. The capacitor C2 has one end connected to a part of the capacitor C2 and the resistor R1 connected in series to the other end of the capacitor C2. The diodes D1 and D2 are bypassed so that the resonance current flowing through the resonance circuit unit 5 does not flow through the current detection resistor R2.
[0018]
Hereinafter, the operation of the high pressure discharge lamp lighting device will be described with reference to FIGS.
(Start mode)
First, in order to start a high pressure discharge lamp, it is necessary to apply a high voltage between the electrodes of the lamp DL to break the insulation between the electrodes. In this discharge lamp lighting device, a pair of switching elements Q1 and Q4 and a pair of switching elements Q2 and Q3 are arranged at a frequency of 120 KHz, which is 1/3 of the resonance frequency f2 (≈360 KHz) of the inductor L2 and the capacitor C2, as shown in FIG. Alternately, they are turned on and off at a duty of approximately 50%. This operation (referred to as operation A) is repeated the number of times set by the microcomputer (50 times). Then, after performing the operation A 50 times, the voltage application is stopped for 800 μsec in order to reduce the heat generation of the lamp. Next, after the elapse of 800 μsec, the operation A is repeated again. After the combination of the operation A and the pause operation of 800 μsec (referred to as operation B) is repeated for 20 seconds, the voltage application is stopped for 2 minutes in order to reduce the heat generation of the lamp. Next, after this 2-minute pause, the operation B is repeated again. If the combination of this operation B and the pause operation for 2 minutes (referred to as operation C) is repeated for 30 minutes and the lamp does not turn on, the circuit stops operating.
[0019]
Hereinafter, a case will be described in which the lamp breaks down during high voltage application and shifts to the lighting mode. By the operation A, a resonance voltage of several KV with respect to the ground GND is generated at the connection point between the primary winding N1 of the inductor L2 and the capacitor C2, and the number of turns of N1: N2 is passed through the secondary winding N2 of the inductor L2. The resonance voltage boosted by the ratio is applied to the lamp DL, and the lamp DL is started. At this time, the start of the lamp DL is detected by detecting the voltage that is full-wave rectified by the diodes D3 and D4 from the secondary winding of the inductor L1 shown in FIG. 3, and the process proceeds to the next lighting mode. .
[0020]
(Low Vla mode)
After the dielectric breakdown of the lamp DL, the control circuit unit 4 switches the switching mode of the switching elements Q1 to Q4 as shown in FIG. The operation will be described below.
[0021]
a) First, the control circuit 4 turns off the pair of the switching elements Q2 and Q3 and turns on the pair of the switching elements Q1 and Q4 so that the lamp current I _DL reaches a desired current value. After switching to voltage and detecting, switching element Q4 is turned off. When a predetermined time passes after the switching element Q4 is turned off, the switching element Q1 is also turned off, and the lamp current I _DL is released from the energy stored in the inductor L4, so that the body diode of the switching element Q2 (not shown in the figure) → lamp A loop returning to the capacitor C5 is formed through a route of DL → inductor L4 → body diode (not shown) of the switching element Q3. By this operation, the zero cross point at which the lamp current _IDL becomes 0 is detected, the pair of the switching elements Q1 and Q4 is turned on, and the same operation is repeated again.
[0022]
b) Next, the control circuit unit 4 turns off the pair of switching elements Q1 and Q4, turns on the pair of switching elements Q2 and Q3, and flows a lamp current _IDL in the opposite direction to the operation of a). . After detecting that the lamp current _IDL reaches a desired current value by converting it into a voltage with the current detection resistor R2, the switching element Q3 is turned off. When a predetermined time elapses after the switching element Q3 is turned off, the switching element Q2 is also turned off, and the lamp current I _DL is released from the energy stored in the inductor L4. Therefore, the body diode of the switching element Q4 (not shown) → inductor A loop is formed to return to the capacitor C5 through the route of L1 → lamp DL → body diode (not shown) of the switching element Q1. By this operation, the zero cross point at which the lamp current I _DL becomes 0 is detected, the pair of the switching elements Q2 and Q3 is turned on, and the same operation is repeated again.
[0023]
The control circuit unit 4 alternates the operations of a) and b) at a frequency of 100 Hz to 200 Hz, so that the lamp voltage reaches 0 to 110 V (due to variations among lamps) that is substantially the rated lighting voltage. In a low lamp voltage region of about 60 V, control is performed so that a large amount of lamp current I _DL flows through the lamp DL so as to prevent the lamp from turning off and to quickly warm the lamp.
[0024]
(Stable lighting mode)
When the lamp DL is warmed and the tube voltage reaches the vicinity of the rated lamp voltage, the control circuit unit 4 switches the switching modes of the switching elements Q1 to Q4 as shown in FIG. The operation will be described below.
[0025]
A) The control circuit unit 4 turns off the pair of the switching elements Q2 and Q3 and turns on the pair of the switching elements Q1 and Q4 so that the lamp current I _DL reaches a desired current value. After switching to voltage and detecting, switching element Q4 is turned off. A zero-cross point at which the lamp current I _DL becomes 0 is detected, the switching element Q4 is turned on again, and the same operation is repeated again to pass a triangular wave-shaped lamp current I _DL as shown in FIG.
[0026]
B) Next, the control circuit unit 4 turns off the pair of switching elements Q1 and Q4, turns on the pair of switching elements Q2 and Q3, and flows a lamp current I _DL in the opposite direction to the operation of A). . After detecting that the lamp current _IDL reaches a desired current value by converting it into a voltage with the current detection resistor R2, the switching element Q3 is turned off. The zero cross point at which the lamp current I _DL becomes 0 is detected, the switching element Q3 is turned on again, the same operation is repeated again, and a triangular wave lamp current I _DL as shown in FIG.
[0027]
The control circuit unit 4 alternates the operations A) and B) at a frequency of 100 Hz to 200 Hz to supply stable power to the lamp DL.
In the operations in the low Vla mode and the stable lighting mode, the output power is controlled by the microcomputer based on the characteristic diagram of the lamp power Wla and the lamp voltage Vla in FIG.
[0028]
With the above high pressure discharge lamp lighting device, it is possible to reduce the size of the inductance components that could not be significantly reduced in the past, and to switch by resonating with the harmonic component to generate a high voltage for starting Since it is not necessary to increase the frequency, the switching loss does not increase, and the high voltage necessary for the lamp dielectric breakdown can be maintained at the same level as the conventional one.
[0029]
In the conventional lighting fixture for mounting a duct, the outer portion disposed below the wiring duct has a size for positioning the down transformer portion below the lower surface of the wiring duct. Accordingly, there is a problem that the outer portion becomes large and is not preferable in appearance. In order to improve this problem, a duct mounting illuminator that is preferable in appearance has been proposed in Japanese Patent Application Laid-Open No. 11-1111040. However, incandescent lamps that are lit with a down transformer, halogen lamps, and the like have been used as the lamps of the luminaires for mounting ducts that have been provided so far. On the other hand, duct mounting luminaires using high-pressure discharge lamps such as HID lamps conventionally have a circuit configuration as shown in FIG. We had problems such as being unable to make it small.
[0030]
FIG. 8 shows a circuit of a conventional high pressure discharge lamp lighting device, in which a rectifier circuit unit 2 composed of a step-up chopper, a power adjustment circuit unit 7 composed of a step-down chopper, a polarity inversion circuit unit 3 composed of a full bridge circuit, It comprises a high voltage pulse voltage generation circuit Ig, a control circuit 6 for controlling the driving of the step-up chopper switching element Q5, and a control circuit 8 for controlling the driving of the step-down chopper switching element Q6. The rectifier circuit unit 2 uses a so-called step-up chopper circuit composed of a switching element Q5 such as an inductor L3, a diode D5, a capacitor C5, and a MOSFET to obtain a pulsating voltage obtained by full-wave rectifying the commercial AC power supply AC with a full-wave rectifier DB. It converts to DC voltage. The power adjustment circuit unit 7 includes a switching element Q6 such as a MOSFET that is turned on / off at several tens of KHz, a diode D6, an inductor L4, and a capacitor C6, and its output current is triangular. The voltage generated in the secondary winding of the inductor L4 is sent to the control circuit 8 as an output current detection output via the resistor R4 connected in series, and the switching element Q6 for the step-down chopper is driven through the control circuit 8 to zero-cross switching. This is a feedback signal for control. The capacitor C6 removes a high frequency component from the output current of the step-down chopper circuit 2 in the previous stage. The polarity inversion circuit unit 3 converts the DC output from the power adjustment circuit unit 7 configured by the step-down chopper in the previous stage into a low-frequency rectangular wave AC voltage by a full bridge circuit configured by switching elements Q1 to Q4 such as MOSFETs. The low-frequency rectangular wave alternating current of several 100 Hz is supplied to the high-pressure discharge lamp DL. The high-voltage pulse voltage generation circuit Ig generates a high-voltage pulse voltage for dielectric breakdown of the high-pressure discharge lamp DL at the start, and stops operation after the high-pressure discharge lamp DL is lit. A high pressure discharge lamp including an HID lamp that can be lit by the circuit as described above is disclosed in Japanese Patent Application Laid-Open No. 14-75045. To further reduce the size, the circuit system is changed and the component size is reduced. It was hoped that
[0031]
In the conventional circuit shown in FIG. 8, since it is difficult to reduce the size of the inductance component, a small electronic ballast that can be built in the wiring duct is realized as in the case of using the circuit of FIG. It was difficult. On the other hand, in the circuit of FIG. 3, since the inductance component can be reduced in size by utilizing the resonance action with respect to the harmonic component, it is possible to realize a small electronic ballast that can be incorporated in the wiring duct. It became. In the following second to fifth embodiments, the structure for mounting the circuit shown in FIG. 3 is assumed, but it goes without saying that the application of the present invention is not limited to the circuit shown in FIG. Yes.
[0032]
(Embodiment 2)
9 to 12 show a second embodiment. In the present embodiment, a space between a terminal pad P for connecting to a mother board 10 provided below the auxiliary board 11 and a group of components mounted on the auxiliary board 11 is provided on the mother board 10. Protrusions that come into contact with the upper surface of the mother board 10 when 11 is inserted are provided on both the front and back surfaces of the auxiliary board 11. Thus, in the structure of the auxiliary board 11 that can be directly inserted into the mother board 10, the auxiliary board 11 can be surely kept perpendicular to the mother board 10 in the manufacturing process up to soldering.
[0033]
First, in the example of FIG. 9, the front and back sides of the auxiliary board 11 are arranged in a space between the terminal pads P for soldering to the mother board 10 provided below the auxiliary board 11 and the component group mounted on the auxiliary board. A hole 13 penetrating both surfaces is provided, and the illustrated vertical holding rod 14 (a length that does not hit a component adjacent to the auxiliary substrate 11 on the mother substrate 10) is inserted therein. By inserting the auxiliary substrate 11 into the mother substrate 10 in this state, the auxiliary substrate 11 can be held vertically without a large jig until soldering in the manufacturing process.
[0034]
Further, as shown in FIG. 10, a protrusion 15 that contacts the upper surface of the mother board 10 is provided below the auxiliary board 11, and the auxiliary board 11 and the mother board 10 are held vertically by the protrusion 15 until soldering. You may make it do. In the example of FIG. 10, the protrusions 15 that are in contact with the upper surface of the mother board 10 provided at the lower part of the auxiliary board 11 are arranged below any components mounted on both the front and back surfaces of the auxiliary board 11. 10 is disposed above the terminal pad P for solder connection.
[0035]
In addition, as shown in FIG. 11, the component 16 is mounted on the contact point between the auxiliary substrate 11 and the upper surface of the mother substrate 10. Alternatively, as shown in FIG. A structure with 17 is also possible. In the example of FIG. 12, a U-shaped jig 17 surrounding both the front and back surfaces of the auxiliary substrate 11 is attached to at least one end in the longitudinal direction of the auxiliary substrate 11.
[0036]
(Embodiment 3)
FIG. 13 shows a third embodiment. This embodiment relates to the arrangement of the variable resistor 18 used for adjusting the output of the discharge lamp ballast. The output adjusting variable resistor 18 attached to the auxiliary board 11 is closer to the connection part between the mother board 10 and the auxiliary board 11 than a distance less than half the height of the auxiliary board 11 mounted on the component surface on the upper surface of the mother board 10. Is implemented. When adjusting the variable resistor 18 mounted on the auxiliary substrate 11 using the output adjustment rod 19 in the output adjustment step after component mounting, the force F shown in FIG. 13 is applied to the solder joint between the mother substrate 10 and the auxiliary substrate 11. (N) is added. Therefore, the mother of the auxiliary board 11 that is less than half of the auxiliary board 11 that rides on the upper surface (component surface) of the mother board 10 at a height of 21 mm so that the arrangement of the variable resistor 18 is as close as possible to the solder joint (shown by a black circle). It was mounted so that the center of the variable resistor 18 was at a position of R = 7 mm from the substrate 10. As a result, the torque T (N · m) = F (N) × R (m) due to the moment of force could be minimized. Here, R is the distance (m) from the solder joint.
[0037]
(Embodiment 4)
FIG. 14 shows a fourth embodiment. (A) is the component surface of the 1st auxiliary substrate 11, (b) is the same wiring pattern, (c) is the component surface of the 2nd auxiliary substrate 12, (d) is the same wiring pattern. The present embodiment relates to wiring when high voltage wiring and low power wiring for control are provided on one auxiliary substrate for circuit miniaturization. In particular, when designing a compact design, the components are densely packed, so the circuit should be resistant to self-noise. Therefore, by arranging the control circuit so as to be surrounded by the high-voltage wiring as shown in FIG. 14, the high-voltage wiring acts as a guard ring to prevent noise to the control circuit, thereby preventing the control circuit from malfunctioning.
[0038]
In each of the above embodiments, the terminal pads provided on both the front and back surfaces of the lower part of the auxiliary board for solder connection with the mother board are preferably provided at symmetrical positions on the auxiliary board. In this case, the terminal pads provided for soldering connection with the mother board at the symmetrical positions on the front and back sides of the lower part of the auxiliary board may not be electrically at the same potential.
[0039]
(Embodiment 5)
FIG. 2 shows a fifth embodiment. The present embodiment relates to component arrangement when components are densely arranged for circuit miniaturization, and the component arrangement on the mother board 10 is such that the auxiliary boards 11 and 12 are arranged on the outer periphery. To do. In particular, by mounting a semiconductor component to avoid heat generation on the auxiliary boards 11 and 12, and arranging the auxiliary boards 11 and 12 on the outer periphery of the mother board 10 avoiding heat generating parts with high self-temperature rise such as resistors and choke coils. The thermal influence on the semiconductor component can be suppressed.
[0040]
【The invention's effect】
According to the first aspect of the present invention, in an electronic device having a mother board and an auxiliary board, terminal pads for soldering to the mother board on both the front and back surfaces of the lower part of the auxiliary board can be electrically separated from each other. A plurality of pairs are provided, and the auxiliary board is directly inserted into and connected to the auxiliary board insertion slit formed in the mother board. The slit provided in the mother board is provided on both front and back surfaces of the lower part of the auxiliary board . A portion of the first slit width for electrically connecting the plurality of pairs of terminal pads to the front and back separately by solder, and between the insertion of the auxiliary substrate and soldering, the auxiliary substrate is substantially omitted from the mother substrate. A second slit width portion for holding vertically, the first slit width is larger than the second slit width, and the second slit width is substantially equal to or less than the thickness of the auxiliary substrate. The part of the first sleeve Since the distance between the solder connection between the mother board and the auxiliary board at the width-width portion is substantially uniform on both the front and back surfaces of the auxiliary board, the same dimension protrudes from the mother board to the front and back faces of the auxiliary board. In the manufacturing process in which the auxiliary board is inserted and connected, the auxiliary board can be prevented from falling before being soldered, so that manufacturing costs and component costs can be reduced. Also, by arranging the terminal pads of the auxiliary board on the solder side rather than on the component side of the mother board, the auxiliary board effectively utilizes the space of the component lead on the mother board that protrudes toward the solder side of the mother board. The height of the protrusion from the surface of the mother board can be reduced, and the height of the electronic device having a plurality of printed boards can be reduced.
[0041]
According to the invention of claim 2, the variable resistor for output adjustment attached to the auxiliary board is connected to the mother board and the auxiliary board more than a distance half the height of the auxiliary board to be mounted on the component surface on the upper surface of the mother board. Since the radius of the moment of force is small, it is possible to realize a structure in which no stress is applied to the solder joint between the auxiliary board and the mother board during output adjustment.
[0042]
According to the invention of claim 3 , the electrical wiring pattern of the auxiliary substrate is divided into a portion controlled by a low voltage and a portion to which a relatively high voltage is applied. By arranging the pattern on the outer periphery on the auxiliary substrate, it is possible to realize a circuit in which the control circuit does not malfunction due to self-noise even in a small device.
[0043]
According to the fourth aspect of the present invention, the components on the mother board are arranged so that the auxiliary board is located on the outer periphery, so that the heat generation of the circuit on the auxiliary board can be kept low.
[0044]
According to the invention of claim 5 , in a discharge lamp lighting device having a plurality of printed boards, a compact and low-cost discharge lamp lighting device is realized by using the mounting structure according to any one of claims 1 to 4. can do.
According to the sixth aspect of the present invention, in the high pressure discharge lamp lighting device that supplies approximately 20 to 40 W as the load power consumption, by using the mounting structure described above, the component lead that protrudes from the solder surface on the lower surface of the mother board is the first. Since the height to the tall parts is about 26 mm or less, the occupied area in the instrument can be greatly reduced compared to the conventional one, which has the effect of greatly contributing to the freedom of instrument design.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram of Embodiment 1 of the present invention, where (a) is a front view of a solder surface side of a mother board, (b) is a side view of the auxiliary board, and (c) is a front view of the auxiliary board. It is.
FIG. 2 is a perspective view showing an appearance of Embodiments 1 and 5 of the present invention.
FIG. 3 is a circuit diagram according to the first embodiment of the present invention.
FIG. 4 is an operation explanatory diagram of a start mode according to the first embodiment of the present invention.
FIG. 5 is an operation explanatory diagram of a low Vla mode according to the first embodiment of the present invention.
FIG. 6 is an operation explanatory diagram of a stable lighting mode according to the first embodiment of the present invention.
FIG. 7 is a characteristic diagram showing output characteristics of the first embodiment of the present invention.
FIG. 8 is a circuit diagram of a conventional example.
9A and 9B are explanatory diagrams of Embodiment 2 of the present invention, in which FIG. 9A is a front view of an auxiliary board, and FIG. 9B is a side view of the auxiliary board inserted into the mother board.
10A and 10B are explanatory diagrams of a modification of the second embodiment of the present invention, in which FIG. 10A is a front view of an auxiliary board, and FIG. 10B is a side view of the auxiliary board inserted into the mother board.
11A and 11B are explanatory diagrams of another modification of the second embodiment of the present invention, in which FIG. 11A is a front view of an auxiliary board, and FIG. 11B is a side view of the auxiliary board inserted into the mother board. .
FIGS. 12A and 12B are explanatory diagrams of another modification of the second embodiment of the present invention, in which FIG. 12A is a front view of an auxiliary board, FIG. 12B is a side view of the auxiliary board inserted into the mother board, c) is a perspective view of a substantially U-shaped jig.
FIGS. 13A and 13B are explanatory diagrams of Embodiment 3 of the present invention, in which FIG. 13A is a front view of an auxiliary board, and FIG. 13B is a side view showing output adjustment in a state where the auxiliary board is inserted and connected to the mother board. It is.
14A and 14B are diagrams showing an auxiliary board according to a fourth embodiment of the present invention, where FIG. 14A is a front view showing a component surface of the first auxiliary board, and FIG. 14B is a wiring pattern of the first auxiliary board. FIG. 7C is a front view showing a component surface of the second auxiliary board, and FIG. 8D is a rear view showing a wiring pattern of the second auxiliary board.
[Explanation of symbols]
10 Mother board 11 Auxiliary board S Slit A First slit width B Second slit width d Auxiliary board thickness P Terminal pad

Claims (6)

In an electronic device having a mother board and an auxiliary board, a plurality of pairs of terminal pads are provided on both the front and back sides of the lower part of the auxiliary board so as to be electrically connected to the mother board between the front and back surfaces. Auxiliary board is directly inserted into and connected to the auxiliary board insertion slit formed in the substrate, and the plurality of pairs of terminal pads provided on both the front and back surfaces of the lower side of the auxiliary board are respectively connected to the front and back surfaces of the mother board. A portion having a first slit width for separately electrically connecting with solder and a second slit for holding the auxiliary substrate substantially perpendicular to the mother substrate after the auxiliary substrate is inserted and soldered. The first slit width is larger than the second slit width, the second slit width is substantially equal to or less than the thickness of the auxiliary substrate, and the second slit width portion is equal to the first slit width. Mother group at the site And a printed circuit board having a plurality of printed circuit boards protruding from the mother board to the front and back surfaces of the auxiliary board so that the distance between the solder connections of the auxiliary board and the auxiliary board is substantially uniform on both sides of the auxiliary board. apparatus.     2. The variable resistor for output adjustment attached to the auxiliary board according to claim 1 is mounted closer to a connection portion between the mother board and the auxiliary board than a distance of half the height of the auxiliary board to be mounted on the component surface on the upper surface of the mother board. An electronic device having a plurality of printed circuit boards.     3. The electrical wiring pattern of the auxiliary board according to claim 1, wherein the electrical wiring pattern of the auxiliary substrate is divided into a part controlled by a low voltage and a part to which a relatively high voltage is applied, and a part to which a relatively high voltage is applied. An electronic device having a plurality of printed boards, wherein the pattern is arranged on the outer periphery of the auxiliary board.     4. The electronic apparatus having a plurality of printed boards according to claim 1, wherein the component placement on the mother board is arranged such that the auxiliary board is located on the outer periphery.     A discharge lamp lighting device comprising a mounting structure of an electronic device having a plurality of printed circuit boards according to claim 1.     6. The lighting device for a high pressure discharge lamp according to claim 5, wherein the load power consumption is approximately 20 to 40 W, and the height from the component lead protruding from the solder surface on the lower surface of the mother board to the tallest component is about. A high pressure discharge lamp lighting device characterized by being 26 mm or less.

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