In 1965, the first commercial LED (red light) was introduced with an efficiency of only 0.1 lm /W. In 1968, LEDs made from GaAsP materials have reached 1 lm / W efficiency and emit red, orange and yellow light. In the early 1990s, the development of two new materials, GaAlInP with red and yellow light and Ga InN with green and blue light, led to a significant improvement in the efficacy of LEDs. In 1998, the successful development of white LEDs marked the arrival of the lighting technology revolution.
1 The latest development of white LED
In the case of the incandescent lamp, the illuminating efficiency of the fluorescent lamp is about 1.7 times, and the luminous efficiency is about 1.7 times. The lamp is 11. 5 times, even exceeding the high pressure sodium lamp which is generally considered to have the highest luminous efficiency. The Showa Denko Group (SDK) has developed a new process for the manufacture of gallium nitride (GaN) based and other nitride based high quality composite semiconductors, primarily for blue and white LEDs. In February 2007, Philip s Lumileds announced the LED epitaxial technology (which basically solves the problem that the white light high-power LED light effect decreases with current climbing, which can increase the light efficiency with the increase of the drive current. Cyberlux claims to use plastic material. The white LED is cheaper, this technology can significantly reduce manufacturing costs, and the brightness is better than traditional white LED. In March 2007, Seoul Semiconductor (SSC) launched 35,000 hours, luminous flux 96 lm of eight The angled 2 W single-chip Acriche can be plugged directly into a 110 V or 220 V AC power supply without the need for an AC/DC converter. The SSC plans to increase the Ariche efficacy to 120 lm /W by 2008.
At present, the thickness of the LED chip is only 0.4 mm, and the light extraction technology of the LED is also greatly improved. Therefore, backlights with LEDs are gradually being used in small displays such as third-generation mobile phones, PDAs, portable DVDs, and digital video cameras. In addition, various lights on the car, such as front and rear lights, side lights, headlights, interior lights and dashboard displays, will fully enter the development application. According to the statistics of Strategies Un2limited, Japan's large-scale headlight factory, Kohido, estimates that by 2008 all new cars will use LEDs as lights.
2 white LED card light
A domestic optoelectronic device Co., Ltd. is a new white LED product for Japan, named "Card Light". The product is shown in Figure 1. This is a new application of white LED and has been patented.
Figure 1 White LED card light
2. 1 LED card light structure and principle
The LED card lamps currently manufactured are mostly small in size, and the area of ​​the light-emitting portion is from 3.81 cm (1.5 å‹) to 6. 0 cm (2.4 å‹). The structure is divided into five parts: frame, backlight module, flashing circuit, power supply part and switch:
(1) Framework
The frame is used to install and integrate other parts, so that it can be processed into different geometric shapes according to different needs. The card lamp in Figure 1 is rectangular.
(2) backlight module
The backlight module is the most important part of the card light, and determines the light-emitting area and the light-emitting quality of the card light. The backlight module is composed of an LED lamp, a reflector, a light guide plate, a diffuser plate, a visor, a penetrating prism and a backlight frame. The LED lamp is a light source. The light guide plate extends the light emitted by several LED lamps to the entire light-emitting surface. The diffuser plate makes the emitted light more uniform by the principle of diffuse reflection. The anti-reflection prism can change the angle of the emitted light and concentrate more light. In the direction of the front viewer, the visor is used to control the illuminating area and the shape of the illuminating surface.
(3) flashing circuit
The internal installation of the card lamp usually installs a flashing circuit, and through the control switch, the light-emitting portion of the adjustment lamp emits several different modes of light.
Ordinary flashing circuits can provide three modes: constant light, long interval flashing, and fast flashing.
(4) Power supply part
The working voltage of the LED is about 3 V. Since the LED has the characteristics of power saving, the power supply for the card light can be a button battery. The button-powered card light is compact and can be made into a smaller thickness. It is also possible to use a detachable rechargeable lithium battery, and the advantage of using a rechargeable lithium battery is to save resources. If the card light is used frequently, the structure of the rechargeable lithium battery is more reasonable.
(5) Switch
Used to connect the circuit and power supply, adjust the card light on, off and light mode.
2. 2 brightness test
The brightness of the test card lamp adopts multi-point luminance meter (BM-7), and the BM-7 has 2 measuring points of 2°/1°/0. 2°/0. 1°, etc., and the minimum measuring area can reach φ0. . 1 mm. It can measure the brightness L, the chromaticity X, the Y, the three color values ​​X, Y, Z, the color temperature, the response time, the contrast, and the like. Widely used in the measurement of LCD, BLU, LCM and other fields, is the standard of the liquid crystal industry.
3. 8 cm (1.5 å‹) of the card light has two white LEDs, using BM-7, the brightness of the card light with a light area of ​​3. 8 cm (1.5 å‹), the brightness test uses nine points Test method. The test point location is shown in Figure 2.
Figure 2 Schematic diagram of the nine-point test
Select 5 LED backlights, select the test instrument TOPCONBM-7, test distance is 50 cm, the test condition is current I = 20mA. The brightness values ​​measured at 9 points are shown in Table 1 (unit is cd / m2):
2. 3 data analysis
The formula for calculating the uniformity R is:
According to the above formula, the uniformity of the effective light-emitting portions of the five groups of backlights is 92%, 86%, 93%, 92%, and 88%, respectively, wherein the maximum uniformity has reached 93%, and the minimum value is also 86%. All uniformities are above 85%, which means that the card light and so on are already very high in terms of light source uniformity. The last item in the table is the average of the brightness of the 9 points in each group, and the value in the fourth group is lower. The analysis may be the cause of the installation process.
Except for the fourth group, both exceeded 3 400 cd / m2. However, the brightness is usually better than 200 cd / m2.
In order to visually compare the brightness of each test point, five points of average values ​​are taken for each point to make a three-dimensional surface map as shown in Fig. 3. The horizontal and vertical axes of the horizontal plane indicate the position of the measuring point, and the numerical number of the point is used. Marked, the vertical value axis represents the average brightness of 9 points in cd / m2.
The above data shows that the brightness and uniformity of the card light are very good. However, as can be seen from Fig. 3, the brightness of the edge of the light-emitting surface is high and the brightness of the center is low, which needs to be improved in the future.
Figure 3 card lamp brightness value distribution
2. 4 application of the card light
LED card lights have many applications in everyday life. The white LED card light is light in size and environmentally friendly. It is usually integrated in other commodity structures. Semi-transparent cards (such as business cards, labels, holiday cards, etc.) can be attached to the light-emitting part of the card light. When the card light is on, especially in the dark, the card content will be highlighted. In addition to white card lights, red, green, and yellow LEDs have been used to make color card lights. The gift box is equipped with this color card light, which can play a decorative role. In addition, since the flashing circuit is mounted on the card light, the flashing light can attract people's attention, so the card light is also used for safety.
3 Conclusion
With the successful development of 100 lm / W white LEDs, white LEDs have taken a step forward in the popularization of display and lighting applications, and more and more new devices are produced by white LEDs. The EU has indicated that it will completely replace incandescent lamps with LEDs within two years, and the Chinese government has also launched green lighting projects. To be sure, with the increasing use of white LEDs in automobiles, display backlights, and lighting appliances, the LED era is bound to come soon.
1.0mm (.039″) Pitch Pin Headers
Overview
Antenk offers a variety of high quality and competitively priced 1.0mm pitch single, dual, three, quad row pin (male) headers used in many board-to-board PCB connections, fitting small-sized, densely-packed devices.
This low-profile component is made from high-temperature thermoplastic and is offered with several means of connections and mounting styles such as through-hole (THM) or surface mount (SMT) and can be in vertical (straight), elevated or at a right angle configuration/orientation dissipating current of about 1.0 A or less.
The pin (male) header is generally mated with receptacle or stackable header connectors (female sockets). This types of pin headers are suitable for PCB board to board connection or for signal transmission application.
Applications of 1.0mm Pitch Pin Headers
Its small size is most suitable for PCB connections of small equipment and devices such as WiFi equipment, gaming consoles, measurement instruments, and other equipment in need of a special interface to become interconnected
Mount Type: Through-hole vs Surface Mount
At one side of this pin header is a series of pins which can either be mounted and soldered directly onto the surface of the PCB (SMT) or placed into drilled holes on the PCB (THM).
Through-Hole (Poke-In)
Best used for high-reliability products that require stronger connections between layers.
Aerospace and military products are most likely to require this type of mounting as these products experience extreme accelerations, collisions, or high temperatures.
Useful in test and prototyping applications that sometimes require manual adjustments and replacements.
1.0mm vertical single row header, 1.0mm vertical dual row header, 1.0mm Elevated single row pin header, 1.0mm Elevated dual row pin Header, 1.0mm Right-angle single row header and 1.0mm Right-angle dual row header are some examples of Antenk products with through-hole mount type.
Surface-Mount
The most common electronic hardware requirements are SMT.
Essential in PCB design and manufacturing, having improved the quality and performance of PCBs overall.
Cost of processing and handling is reduced.
SMT components can be mounted on both side of the board.
Ability to fit a high number of small components on a PCB has allowed for much denser, higher performing, and smaller PCBs.
1.0mm Right-angle Dual Row pin header, 1.0mm SMT Single row pin header, 1.0mm SMT Dual row pin header and 1.0mm Elevated Dual Row Pin Header are Antenk`s SMT pin headers.
Soldering Temperature for 1.0mm Pitch Pin Headers
Soldering SMT pin header can be done at a maximum peak temperature of 260°C for maximum 60 seconds.
Pin-Type: Vertical (Straight) and Right-Angle
1.0mm pitch headers may be further classified into pin orientation as well, such as vertical or straight male header or right-angle male header.
Vertical or Straight Pin (Male) Header Orientation
One side of the series of pins is connected to PCB board in which the pins can be at a right-angle to the PCB surface (usually called "straight" or [vertical") or.
Right-Angle Pin (Male) Header Orientation
Parallel to the board's surface (referred to as "right-angle" pins).
Each of these pin-types have different applications that fit with their specific configuration.
PCB Connector Stacking
Elevated Pin Header Orientation
Elevated pins aka Stacked Pins or Mezzanine are simply stacked pin headers providing an exact distance requirement between PCBs that optimizes electrical reliability and performance between PCB boards.
Profile Above PCB
This type of configuration is the most common way of connecting board-to-board by a connector. First, the stacking height is calculated from one board to another and measured from the printed circuit board face to its highest insulator point above the PCB.
Single, Dual or Multiple Number of Rows
For a 1.0mm straight or vertical male pin header, the standard number of rows that Antenk offers ranges from 1 to 2 rows. However, customization can be available if 3 ,4 or n number of rows is needed by the customer. Also, the number of contacts for the single row is about 2-50 pins while for dual row, the number contacts may vary from 4-100 pins.
Pin Material
The pins of the connector have been designed with copper alloy. With customer`s demand the pins can be made gold plated.
Breakaway design
The pin headers are also equipped with a breakaway design making them fully compatible with their female receptacles.
Custom 1.0mm Pitch Pin Headers
Customizable 1.0 mm pitch pin headers are also available, making your manufacturing process way faster as the pins are already inserted in the headers, insulator height is made at the right size and the accurate pin length you require is followed.
Parts are made using semi-automated manufacturing processes that ensure both precision and delicacy in handling the headers before packaging on tape and reel.
The tape and reel carrier strip ensures that the headers are packaged within accurately sized cavities for its height, width and depth, securing the headers from the environment and maintaining consistent position during transportation.
Antenk also offer a range of custom Tape and reel carrier strip packaging cavities.
Male Header Pins,1.0Mm Male Header,1.0Mm Pin Header,1.0Mm Male Header Pins, 1.0mm THM Male Header, 1.0mm SMT Male Header
ShenZhen Antenk Electronics Co,Ltd , https://www.antenkconn.com