KR101308698B1 - Thermally superior led circuit board - Google Patents

Abstract

PURPOSE: An LED circuit board with excellent heat radiation performance prevents the degradation of the whole product lifetime by not using unnecessary components. CONSTITUTION: An LED circuit board includes a rectifier part (100), an LED part, an AC driver IC chip part (300), and an array part (400). The rectifier part rectifies a commercial AC voltage. The LED part has multiple arranged LEDs. The AC driver IC chip part supplies a constant current source to the LED part. The array part electrically connects the IC chip part. The IC chip part additional includes a resistor and a capacitor. The IC chip is composed of 16 pins including a VDD pin, an RISET pin, and an OTEN pin. The LED part is successively arranged on the array part in a circle based on the center point of a first array source of the array part and additional arranged based on a second array source with a smaller diameter than that of the first array source.

Description

Thermally superior LED circuit board

The present invention relates to an LED circuit board used in the LED luminaire, the component is simplified and the product life is long, and more particularly, the LED circuit board does not have a switching mode power supply (SMPS), the rectifier; LED unit; IC chip unit; And an array unit.

In general, the LED circuit board is a light emitting diode is a white light can be implemented, due to the advantages such as low power and long life time is widely used in lighting devices.

However, in the past, most LED circuit boards used a separate large converter connected to the LED circuit board in order to rectify AC power to DC power, which is not necessary for LED lighting, and thus the efficiency of LED lighting is increased. It caused the lowering.

Therefore, in order to solve the above inconvenience, the LED circuit board is constructed by using a power supply device (SMPS) composed of about 50 components such as transformer, PWM IC, MosFET, electrolytic capacitor, etc. Korean Patent Publication No. 10-0880561 (Driver for LED Lamp without Inverter) is disclosed.

The background art is specifically an LED lamp having a plurality of LED elements, a power input unit for receiving AC power from the outside, a rectifier circuit unit for full-wave rectifying the AC power input through the power input unit, and the rectifier circuit unit And a PWM constant current circuit unit for controlling the pulse width of the AC power propagated and applied to the LED elements at a reference current value, and a surge protection circuit unit for suppressing the loss of the LED light from the surge. Is composed of a diode, a capacitor, an inductor, and a driver controller IC, and the driving power input to each of the LED elements is constant at a reference current value determined according to the capacitance value of the inductor under pulse width control of the driver controller IC. Drive field of LED lamp without inverter, characterized by maintaining Invention relates to a.

However, the LED lamp driving apparatus according to the present invention, there is still the use of unnecessary elements even if the inverter is excluded, there is a concern that there is a heat generation phenomenon that can be caused by not considering the interval and angle of the LED element arrangement. Remains a problem

The present invention has been made to solve the above problems of the prior art, the use of unnecessary parts such as electrolytic capacitors, such as consumables, which can cause the rise of the price and complicated circuit configuration of the LED circuit board, and particularly economical For this reason, it is intended to solve the problem of heat generation by using HV LEDs to minimize the number of LED devices.

Features of the present invention for solving the above problems and performing the characteristic functions of the present invention described below are as follows.

An LED circuit board having no switching mode power supply (SMPS), comprising: a rectifying unit for rectifying a commercial AC voltage; An LED unit arranged in a plurality of LEDs; An AC driving driver IC chip unit for supplying a constant current source to the LED unit by applying the power rectified from the rectifying unit; An LED circuit board comprising a rectifier, an LED unit, and an array unit on which a pattern for electrically connecting the IC chip unit is mounted.

In addition, the IC chip part suggests that an external terminal may be added with a resistor and a capacitor. The LED element may be limited to five or ten LED parts of the LED part so that the limited number of the LED elements may be Presenting LED circuit boards that are circularly arrayed with limited control of angle and spacing.

The LED circuit board according to the present invention as described above does not use unnecessary components such as an electrolytic capacitor, which is a life component, thereby preventing the life degradation of the entire product due to the life of the electrolytic capacitor, and is directly connected to the AC direct type driver IC chip. By outputting the constant current which is optimal for driving LED, it can bring electrical characteristics close to PF 0.99 and excellent characteristics of less than 10% of THD. Especially, by controlling the arrangement, spacing, and angle of many LED elements, heat dissipation is possible even with minimal LED elements. It is effective to realize high efficiency LED lighting.

1 is a layout view of a circuit board in which 12 LED elements are arranged in two terminals.
FIG. 2 is a circuit diagram illustrating the layout of FIG. 1 in detail.
3 is a layout view of a circuit board in which ten LED elements are arranged in four terminals;
4 is a layout view showing in detail the arrangement, interval, angle of the LED configuration of FIG.
Figure 5 is a block diagram of the IC chip used in the present invention.
Figure 6 is a pin configuration of the IC chip used in the present invention.
FIG. 7 is a circuit diagram illustrating the layout of FIG. 3 in detail.
8 is a layout view of a circuit board in which eight LED elements are arranged in two terminals;

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements throughout.

The present invention is a LED circuit board having no switching mode power supply (SMPS), as shown in Figures 3 and 7, the rectifier 100 for rectifying the commercial AC voltage; An LED unit arranged in a plurality of LEDs; An AC driving driver IC chip unit 300 for supplying a constant current source to the LED unit by applying the rectified power from the rectifying unit 100; The rectifier 100, the LED unit, the array unit 400 is mounted with a pattern for electrically connecting the IC chip 300; consisting of, a separate AC power input unit for driving, that is, an external power supply wire is added Can be.

First, the rectifying unit 100,

It is a full-wave rectification to drive the LED circuit board by receiving AC power of 110V or 220V applied from commercial power. In the embodiment of the present invention, a bridge circuit is implemented. The diode is connected to the output terminal of the power input.

The LED unit,

A plurality of LED elements are connected in series or in parallel to each other, and each LED element is implemented to emit light of a set color or a variety of colors when the power is input, while the number is also directly and as desired. It can be used in parallel arrangement. However, the reason for using 12 LED elements as shown in FIG. 2 or 10 LED elements as shown in FIG. 7 will be described later in relation to the efficiency aspect according to the present invention. In addition, in order to implement the minimum number of LED devices as an embodiment of the present invention configuration, the LED device may be used with a 12V HV LED device.

The IC chip unit 300,

As an AC driver IC chip for supplying a constant current source to the LED part by applying the rectified power from the rectifier 100, an IC chip of the same purpose can be used, but in particular, as an embodiment of the present invention, the following IC chip This is used.

As an LED driver which is directly connected to an AC power line and driven, two external devices may be used (only in a normal environment). In this case, the external device may be composed of one resistor and one capacitor. The example presents a configuration in which a resistor for adjusting the driving power of the LED and a capacitor for applying a stable voltage to the IC chip internal circuit are added to the external terminal of the IC chip. That is, one resistor adjusts a constant current source for the power of the LED to be driven, and one capacitor serves to apply a stable voltage to a shunt regulator inside the IC chip. In particular, in order to obtain stable circuit operation, it is preferable to use the resistor having 100 kΩ and the capacitor having 1 kΩ.

In this case, the IC chip has 16 pins as shown in FIGS. 5 and 6, and specifically, the VIN pin is supplied with AC input power rectified by the rectifier 100 to drive a driver IC. It is connected to the said rectification part 100 (bridge diode) as a place.

LED1, LED2, LED3, and LED4 (Nos. 3, 5, 7, and 12, respectively) are control terminals for outputting the constant current of the LED channel, and connect several parallel LED groups in series as shown in FIG. In this case, as shown in FIG. 2, when some of the four pins are not used, the remaining pins (pins 3 and 7 in FIG. 2) should be left unconnected.

The VDD pin is an IC operating voltage which lowers the power received through VIN to the driving voltage of the IC. The driving voltage is applied to the IC chip internal circuit, and a 17.4V shunt regulator is internally connected to the VDD pin. . At this time, side (bypassing) capacitors can be added for filtering to reduce noise generated from the VIN pin.

The MODE pin is connected to the VDD pin, and the RISET pin controls the current flowing to each LED group by designating the desired constant current value as the resistance value. OTEN pin is used to protect the circuit from high heat by connecting to GND pin if necessary to cut off the current to LED temporarily when temperature inside IC rises to the specified temperature. Due to the role of OTEN pin, it is possible to know the heat dissipation status of IC at the development stage, and it is a function for more effective heat dissipation design.

The driving principle of the IC chip and the LED circuit board will be described with reference to FIGS. 5 and 7 as follows.

First, the voltage VIN rectified by the rectifier 100 is applied to the IC driving voltage and the driving voltage of the LED. At this time, the voltage of VIN is transferred to the LED to apply the LED Forward Voltage so that the constant current flows to the LED. According to the resistance value of the RISET pin, the current flowing in the lines of the LED elements increases and reaches a predetermined value to reach the forward voltage of each of the LED elements and at the same time the LED currents of the headroom are automatically matched. Lights up.

The current flowing in each LED element increases to the specified level and maintains this level until it has headroom coming to the next channel. By using the mechanism leading to the sequential lighting in this way, it is possible to use the LED by maintaining the constant current of the AC current.

In other words, unlike the existing SMPS, LEDs are turned on by using a small number of components (bridge diodes, capacitors, and resistors), which is a competitive item that can satisfy consumers' need for product design and product life.

At this time, the design difference between the LED circuit boards of FIGS. 1, 8 and 3 (exactly the difference in the number of parallel LED groups connected to each other in series rather than the number of LED elements) is different from the operation structure of the IC. Correlates with the behavior of. In other words, the difference in interworking with an external device that consumes a lot of power is large at the moment of using a general commercial power supply.

 The LED circuit board of FIG. 3 uses four control pins (3, 5, 7, and 12) to efficiently control the constant current source of each LED, whereas the IC chip of FIG. 3 and the LED circuit board of FIG. In case of using 2 terminal (No.5,12 pin) like this, there is a noticeable blurring of the product during operation of external devices such as heaters that use instantaneous high current. For example, when the heating device is operated, a voltage drop from the commercial power source to the 205 to 210 VAC instantaneously occurs at 220 VAC. The IC is vulnerable to this part as an IC for driving the LED using a commercial power source as it is. Of course, not only such ICs, but also lighting, electronics, and general fluorescent lamps using SMPS have the same degree of lag, but the same phenomenon occurs.

In the case of the two-stage as shown in the design in Fig. 1, 9 LED out of 12 LEDs can be enlarged to the overall blur due to the blur, while in Fig. 3 only 2 out of 10 LEDs in the product The lagging becomes very fine. This difference can be extended to the standard of the product itself.

Therefore, in the embodiment of the present invention, the LED elements arranged on the first array source 410 and the second array source 420 suggest a configuration in which four parallel LED groups are connected to each other in series. In this case, the four parallel LED groups are connected to each other in series means that the four stage control pins (pins 3, 5, 7, and 12 of Figure 6).

On the other hand, the IC chip is used because it exhibits the effect of a high power factor (PF) of about 0.99 and a total harmonic distortion factor (THD) of about 15% under normal conditions, and is particularly suitable for high efficiency LED systems.

The array unit 400,

As a structure in which a pattern for electrically connecting the rectifying part 100, the LED part, and the IC chip part 300 is mounted, in the present invention, a first array source 410 and a second array source 420 are illustrated. The center points of the first array source 410 and the second array source 420 are the same. In this case, the first and second array sources are not actually mounted, and may be omitted from the actual substrate because they are not electrically connected as arbitrary virtual circles for more easily indicating angles and distances between the LEDs.

First, in FIGS. 1 and 4, 12 and 10 LED elements are arranged in the disk-shaped array unit 400, respectively. At this time, it is noted that the configuration of the other elements are omitted in order to characterize the arrangement of the LED elements.

First, as an embodiment of the configuration of the present invention, the LED unit is composed of five LED elements, so that the angle (A) between the continuous LED elements relative to the center point of the array unit 400, the first array source 410 is 72 ° It is possible to form a circular array in the array unit 400. That is, in this case, the LED element does not exist on the second array source 420 (not shown), which is an arrangement suitable for the small size of the LED light fixture.

In addition, the five LED elements arranged in the first array source 410, five LED elements continuous to the center point of the second array source 420 having a smaller diameter than the first array source 410 It is possible to form an additional circular array to the array unit 400 to be 72 °. That is, as shown in FIG. 4, the second array is arranged such that five LED elements are arranged in a regular pentagonal shape in the first array source 410 and intersects between the five LED elements arranged in the first array source 410. By adding five LED elements of the circle 420, the illuminance range and the diffusion angle of each other are complemented and canceled to emit light evenly so that the LED circuit board can be realized by minimizing the heat dissipation with the minimum LED elements.

In another embodiment, as shown in FIG. 1, in the disk-shaped array unit 400, eight LED elements are circular to have an angle of 45 ° between successive LED elements with respect to the center point of the first array source 410. A total of 12 elements may be arranged in a circular arrangement such that an angle between successive LED elements of the second array source 420 having a diameter smaller than that of the first array source 410 is 90 °. .

At this time, the LED elements arranged on the first array source 410 and the second array source 420, four parallel LED groups may be connected in series with each other and connected to the IC chip.

However, when using 12 LED devices, there are the following differences compared to using 10 LED devices. At this time, the difference is revealed that the difference according to the number of LED elements when the same four-terminal configuration.

The big difference between a product using 12 LEDs and a product using 10 LEDs is whether it is designed to drive LED specifications. When using 12 LEDs as shown in FIG. 1 and using 10 LEDs as shown in FIG. 3 and light efficiency, the product in FIG. 3 using 2 fewer LEDs is measured about 5% higher. This is a big difference depending on whether the LED is designed to meet the operating specifications of the LED or not. Therefore, there is a problem in the case of designing without considering this, the relationship with LED life, influence on external devices, and the consistency of the current applied to each LED. In order to distribute the constant current source to each LED evenly, the LED array structure should be configured in series / parallel to supply the constant current source optimized for driving the LED. The optimized LED array structure is as shown in FIG. 3. This can be said to contribute the most in minimizing the high price of LED, which is the limit of LED industry.

In addition, in FIG. 4, the first array source 410 has a diameter of 30 to 35 mm, and the second array source 420 has a length of 70 to 75 mm in diameter. Five LED elements on the array source 420 may be circularly arranged (the distance between the first array source 410 and the second array source 420 is 17.5 mm to 22.5 mm), which is particularly 6 inches down. When used for lighting, it corresponds to an array spacing suitable for LED circuit boards with numerical limitations. In other words, ten LED elements arranged on the first array source 410 and the second array source 420 maintain the angle of 72 ° from the center point of the first array source 410 and the second array source. If 420 is shorter than the numerical length, sufficient illuminance may not be obtained and heat dissipation may not be efficient. If the length is longer than the length, the dot phenomenon may occur.

8 is a layout view of a circuit board in which eight LED elements are arranged in two terminals (pins 5 and 12).

In the case of using the eight LED elements and in the case of using the ten LED elements as in the present invention, there are the following differences with respect to the heat dissipation effect. At this time, the following measured value is the value which measured the side part of LED element.

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The reason for the difference in heat dissipation when using 8 LED elements and 10 uses as described above is that the current flowing through the LED increases when using 8 LED elements. Because. In other words, 8 LEDs consume 1.5W per 10, and 10 LEDs consume 1.2W per heat. It is confirmed that the temperature of the LED rises due to the mistake of the circuit design rather than the heat dissipation design and the excessive current flowing out of the LED specification. .

Therefore, because the power consumed by the LED is higher, it generates more heat, which is directly related to the life of the LED, so that it is stable to use 10 LED elements as in the present invention through circuit design arrangement through repeated experiments. Was derived.

The above has been described with reference to a preferred embodiment of the present invention, but is not limited to the above embodiment, the person having ordinary skill in the art to which the present invention pertains through the above embodiments without departing from the gist of the present invention It is obvious that various changes can be made in.

100: rectification part
200: LED unit
300: IC chip part
400: array unit
410: the first array source
420: second array source

Claims (6)

LED circuit board without a switching mode power supply (SMPS),
A rectifier 100 for rectifying the commercial AC voltage;
An LED unit arranged in a plurality of LEDs;
An AC driving driver IC chip unit 300 for supplying a constant current source to the LED unit by applying the rectified power from the rectifying unit 100;
An array unit 400 having a pattern for electrically connecting the rectifying unit 100, the LED unit, and the IC chip unit 300;
The IC chip unit 300,
Resistance to adjust the driving power of the LED,
A capacitor that applies a stable voltage to the internal circuit of the IC chip is added to the external terminal of the IC chip.
The IC chip,
Connected to the rectifying unit 100, the control terminal for outputting the constant current of the LED channel of the LED, LED1, LED2, LED3, LED4 pin, VDD pin for applying a driving voltage to the internal circuit, and the The RISET pin controls the current flowing to each LED group by setting the value as a resistance value, and when the temperature inside the IC chip rises to a specified temperature, the current is cut off for a short time to prevent heat generation of the IC chip. The state consists of 16 pins, including the OTEN pin,
The LED unit is circularly arranged in the array unit 400 so that the angle A between the continuous LED elements based on the center point of the first array source 410 of the array unit 400 consists of five LED elements to be 72 ° ,
In the array unit 400, an additional circular array is arranged such that five consecutive LED elements are 72 ° based on the center point of the second array source 420 having a smaller diameter than the first array source 410. LED circuit board with excellent heat dissipation effect.
delete delete delete The method of claim 1,
LED elements arranged on the first array source 410 and the second array source 420,
An LED circuit board with excellent heat dissipation, characterized in that four parallel LED groups are connected to each other in series.
6. The method of claim 5,
The first array source 410 has a diameter of 30 to 35mm, the second array source 420 has a length of 70 to 75mm in diameter and the five LED elements and the second array source 420 on the first array source 410. LED circuit board with excellent heat dissipation, characterized in that each of the five LED elements of the circular arrangement.

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