This white paper provides an overview of the supply chain touch screen. He described the supply chain and the touch screen on the market a major component of the module.
A supply chain to learn more about capacitive touch screen is very important, the final touch-screen products to customers. Mode of cooperation and resources to the internal design, component supplier of value added, while the choice of module design and supply.
Controller IC Suppliers
Capacitive touch screen controller is a semiconductor device capable of sensing finger position on the touch sensor. Silicon structures and different detection methods by a number of suppliers, which is beyond the scope of this article. Capacitive controller can be divided into two categories.
To detect the location of the finger in the electric field sensor through the substrate design. It is usually with one or more patterned ITO layer implementation for one or more transparent substrates. Projected capacitive is very durable, because the user to touch the glass or plastic substrate, and the following ITO layer protection. Ito from the OFF position coordinates with a deterministic pattern measurement signal calculation. This is designed to detect more accurate than other capacitive sensing method and good reproducibility. Projected capacitive controllers usually require a larger screen detected more input pins. Specifically, but only about a 10 “screen diagonal single-chip solution. Workarounds using multiple or single controller IC standardized Ito is also possible.
The method uses a single sensor for transparent conductive substrate, usually glass, plastic or ITO conductive film. The method is cost-effective, with many well-known technique is suitable for mass production. Since the position of the fingers or by the edge sensor to determine the four corners of panels, touch screen can also be extended to thirty centimeters or more, without increasing the pin count IC control. There are significant drawbacks, especially the small screen. First of all, testing the implementation of ITO substrate, the top of the touch screen. Even if the OIC can be protected thin, hard, are susceptible to finger rings, keys and other risks. In addition, the capacitance sensor to the surface the inherent nonlinear field must be corrected, and standardized tip, software, hardware, or methods. This linear effect becomes more apparent with the small screen. Other implementation details, such as proximity effect and the shadow of the fingers, must also be addressed.
Flexible printed circuit board (flexible) The General Assembly is used to touch the sensor is connected to the controller card system. Flex and sometimes with a touch-sensitive controls installed to provide a “flexible module. Besides, there is no single flex circuit can be provided to the sensor controller manufacturer, in this case, an IC controller integrated into the Council’s customer system control device implementation.
Often referred to as “glass” or “movie” of suppliers, the supply chain members have the ability to create an internal transparent conductive substrate material model. The most common driver is indium tin oxide (ITO) as the relatively low strength and high optical resolution to use. Other transparent conductors used or under development, but not yet mainstream. Sensor substrate glass, polycarbonate and plastic products, a typical film. Some manufacturers of vertical integration more sensors, such as touch screen controller chip ASIC products, electrical engineering control card, LCD monitor power supply, power connector or bend the complete module integration.
General use of the touch screen video monitor together, then it is logical to LCD manufacturers in the supply chain is essential. Have been involved in their design of the glass core deposits and flexible circuit manufacture of liquid crystal display Ito. Therefore, they are more likely to vertically integrate the supply chain of these key elements of the touch screen. LCD manufacturers have chosen simply to a third party touch screen module, integration, or integrated controller, sensor, lens, or in your flex circuit assembly.
Logistics Supply Chain
Touch-screen manufacturing logistics supply chain depends on the sale of preferred suppliers and customers to the customer’s business model, each supplier of vertical integration of several variations. Customers can initially considered a control touch screen, sensors, flexible and LCD direct purchase from each vendor to make their own design and integration. While this may have been aware of the advantages of cost, it put all the design, performance and quality issues directly to the client. Each project is unique touch screen, so that the controller must be configured to use the sensor, LCD noise, environmental factors and industrial design and features, correct. This capability is often out of the customer first item. Used method is to let customers buy a supply chain design, and in good condition, “module” custom touch screen test.
Touch Screen Module
The three main varieties of the touch screen module to the final customer specific sales:
This is a controller IC and the flexible printed circuit combination. Flex module, mainly to purchase the ITO conductive sensor suppliers to reduce design cycle and increase the yield of touch screen touch screen. Flex module includes a flexible circuit, touch screen control IC fixed in good condition as a unit test. Flex Modules are usually provided to the Ito distribution design the controller IC through distributors or end customers. For the Asian market, is a typical “stocking sales representative”, it functions as a manufacturer and value of the binding sites to increase supply chain management.
Touch Screen Module
This product combines the sensor and the flexural modulus of the ITO. Flex modules using the time to market, improved product reliability, while maintaining flexibility in the design of the sensor. Touch screen module are usually those from the sensor or film ITO conductive glass supplier end customers or large OEM ODM design. Some vendors also offer a complete integrated circuit module, touch screen controller, easy to project design, although this offer is usually limited to large customers directly. Most large industrial customers and product design is very specific marketing needs of the “look and feel.” Subsequently, a number of companies using a touch screen module of the finished product. The most direct design and component suppliers.
Touch Screen LCD Module
This is the highest level of integration. It combines the LCD touch screen to create a complete touch-sensitive video equipment modules. Design of high-end customers to see this black box device, touch display images and send coordinates to the main system capacity. This is a high degree of reliability of the manufacturing desirable, because each unit to provide a good display and touch interface known. Some manufacturers offer the market the product as a general type of LCD modules. For large volume OEM customers, manufacturers of LCD touch sensor has a mission, and produce a module touch screen LCD display glass, Flex and controller IC components.
Understanding of the touch-screen technology will help make the right technology and touch screen capabilities of the equipment supplier for more information.