Guide: An LED chip, also known as a light-emitting diode (LED) chip, is the core component of an LED light source. It is commonly referred to as a PN junction, and its main function is to convert electrical energy into light energy. But what are the dimensions of an LED chip, and how is it manufactured? Let’s take a closer look at these details.
What sizes do LED chips come in?
High-power LED chips are typically available in three common sizes: 38x38 mil, 40x40 mil, and 45x45 mil. These are standard specifications used in the industry. A "mil" is a unit of measurement equal to one-thousandth of an inch. So, 40 mils are approximately 1 millimeter. These sizes are commonly used for 1W high-power LED chips. In theory, larger chips can handle more current and power, but other factors such as material quality and manufacturing process also play a significant role. For example, two LEDs of the same size may have different power ratings—some can handle up to 3W, while others only reach 2W.
The Manufacturing Process of LED Chips
The production of an LED chip generally involves two main stages. First, a gallium nitride (GaN)-based epitaxial wafer is created on a substrate using a process called metal organic chemical vapor deposition (MOCVD). This process takes place in a specialized furnace where high-purity gases and materials are used to grow the GaN layer. Common substrates include sapphire, silicon carbide, silicon, and even materials like GaAs, AlN, and ZnO.
MOCVD works by reacting gas-phase precursors, such as group III organometallic compounds and ammonia (NH3), on the surface of the substrate. By carefully controlling temperature, pressure, reactant concentration, and gas ratios, the composition and crystal quality of the deposited layer can be precisely controlled. This equipment is essential for producing high-quality LED wafers.
Once the epitaxial wafer is ready, the next step is to create the electrodes of the LED's PN junction. This electrode processing is a critical part of the manufacturing process and includes steps like cleaning, evaporation, yellowing, chemical etching, fusion, and grinding. After that, the chips are cut (diced), tested, and sorted to select the best ones for use.
If the cleaning isn’t thorough enough, or if the evaporation system isn’t functioning properly, the metal layers (which become the electrodes after etching) might peel off, leading to discoloration or abnormal gold bubbles. During the evaporation stage, the LED chip is often secured with a spring clip to create a "pinch," which must be removed during visual inspection.
The yellowing process involves baking, applying photoresist, exposing it to light, and developing the pattern. If the development isn't complete, the mask may have holes, causing excess metal to appear in the light-emitting area. Additionally, during the front-end process, tools like tweezers, flower baskets, and carriers are used, which can sometimes cause minor scratches on the electrode chips.
HP Chromebook 11MK G9 EE,hp chromebook parts,hp chromebook 11 g9 keyboard, hp google chromebook
S-yuan Electronic Technology Limited , https://www.syuanelectronic.com