Simple introduction to USB Flash Drive application knowledge
Based on the USB Flash Drive now market USB Flash Drive is more and more widely application background and driving force comes from the two big development trend of wireless equipment market: size will be smaller, the price will be lower. As seen in the wireless terminal market, smaller, lighter and cheaper is also a trend in the market for wireless devices. The decrease in the size of the device also means that it can save space, reduce weight and leave more room for other designs of the system. And decreases the device's size request all the devices in the device integration is higher and higher, more and more small size, it also includes the widely used in the rf module and interconnection between rf coaxial USB Flash Drive and its cable components.
, for example, is widely used in the distributed base station system of RRH (remote radio head), in order to make it to be simple, convenient and reliable installation in the tower and the city dense environment, its design must be very tight, and we will try our best to control the size, which requires the bearing of the rf signal transmission coaxial interconnected systems must also be more concise and compact. The traditional multifarious cable assembly connection is being replaced by a simple, compact, reliable, and a "panel" USB Flash Drive connection that can carry more than 100W rf signal power.
Now more and more radio frequency and structure design engineer understanding of threatening the plate more and more familiar with degree is becoming more and more high, more and more design are connected by USB Flash Drive, which makes the designers to consider the cost of more and more, the market need to design more simple and lower cost of USB Flash Drive.
USB Flash Drive size have brought in the mechanical structure design challenges mainly has two aspects: one is a large relative to the size of USB Flash Drive, USB Flash Drive is more difficult to cooperate on small sizes. The second is the low mechanical strength of the small USB Flash Drive, which can be easily damaged if used improperly. A large size USB Flash Drive can withstand the use of a larger mechanical force when coupled, but smaller USB Flash Drives need to be more accurate.
Ultra narrow type of USB Flash Drive put forward new requirements of electroplating technology, in the 0.6 mm high, a single product is less than 0.4 mm height of products, how to guarantee the product based on tin plating thickness and the effect is not climb the tin, a USB Flash Drive miniaturization of the key problems, the practice of present common is blocking by laser to spin out the plating layer on tin path, so as to solve the problem of not climb tin, but this technique has a defect, is stripping gold, laser nickel plating layer can be damaged if they are same, so that the copper is exposed to the air, the corrosion and rust. At present, panasonic electrician has successfully solved this problem by plating a nickel area less than 0.08 mm through electroplating process at the base point of the terminal. The 0.08 mm of the nickel area is currently only available to some of the world's most powerful companies.
It is also important to note that USB Flash Drives can be constructed with a simple machine circuit design. By setting up the insulating wall on the base of USB Flash Drive, the wiring of the PCB and metal terminals is not allowed. The wiring of the face of the USB Flash Drive is carried out, which is beneficial for the miniaturization of the PCB board.
Pin spacing is becoming more and more narrow, on the phone at present are mainly composed of 0.4 mm pitch, panasonic, now JAE and other manufacturers have developed 0.35 mm pitch, should be the USB Flash Drive industry has the most narrow spacing, 0.35 mm pitch at present mainly for the apple mobile phone and domestic high-end models, the application of it will be the trend of nearly two years, it has the minimum volume, the highest precision, the advantages of high performance, but for the patch and other supporting technology of the more demanding, this is the most need to overcome a lot of USB Flash Drive manufacturer, otherwise the yield is low.
In order to meet the requirements of the SMT process, the entire product terminal welding area are strict with good degree of coplanar, usually the industry norms of coplanar degrees (Max) is 0.10 mm, otherwise it will lead to adverse effects and PCB welding use of the product.
Simple Introduction To USB Flash Drive Application Knowledge
- Jul 13, 2017-