Wafer-level packaging differs from conventional manufacturing in the way the packaging is applied.
Wafer-level packaging refers to the fabrication of integrated circuits by applying packaging around each circuit before the wafer on which they are made is separated into individual circuits. This technique quickly grew in popularity in the integrated circuit industry due to the advantages in terms of component size as well as production time and cost. A component manufactured in this way is considered a chip-scale package type. This means that its size is almost equal to that of the matrix inside it, in which the electronic circuit is located.
Wafer-level packaging has allowed mobile phones, tablets, and computers to shrink in size while adding features.
Conventional manufacturing of integrated circuits usually starts with the production of silicon wafers on which the circuits will be manufactured. An ingot of pure silicon is typically cut into thin slices, called wafers, which serve as the foundation on which microelectronic circuits are built. These circuits are separated by a process known as dicing. Once separated, they are packaged into individual components and solder wires are applied to the package.
Wafer-level packaging differs from conventional manufacturing in the way the packaging is applied. Instead of separating the circuits and then applying the encapsulation and conductors before proceeding with the test, this technique is used to integrate multiple steps. The top and bottom of the package and solder cables are applied to each integrated circuit before the wafer is cut. Testing also normally takes place before cutting the wafer.
Like many other types of common component packages, integrated circuits made with wafer-level packages are a type of surface-mount technology. Surface mount devices are applied directly to the surface of a circuit board, melting solder balls attached to the component. Wafer-level components can be used similarly to other surface mount devices. For example, they can often be purchased on spools of tape for use in automated component placement systems known as pick and place machines.
A number of economic benefits can be achieved by implementing wafer-level packaging. It enables the integration of wafer fabrication, packaging and testing, thus streamlining the fabrication process. Reduced manufacturing cycle time increases production throughput and reduces cost per unit manufactured.
Wafer-level packaging also allows for reduced package size, which saves material and further reduces production cost. More importantly, however, the small package size allows the components to be used in a wide variety of advanced products. The need for smaller component size, especially reduced pack height, is one of the key market drivers for wafer-level packaging.
Components made with wafer-level packaging are widely used in consumer electronics such as cell phones. This is largely due to market demand for smaller, lighter electronics that can be used in increasingly complex ways. For example, many cell phones are used for a variety of functions beyond a simple call, such as taking pictures or recording videos. Wafer-level packaging has also been used in a variety of other applications. For example, they are used in automotive tire pressure monitoring systems, implantable medical devices, military data transmission systems, and more.