Manufacturing advances solve free-form display design challenges

For many years, mobile device and automotive designs have been limited by manufacturing capabilities. This has limited designer creativity, display complexity and even the number of features that can be added to displays.

Today, many display technologies have matured to the point where display design is not limited to square corners and straight lines. Free form displays bring freedom from a geometric perspective in which display geometries can not only be designed in any shape along the display’s outer perimeter but also within the display plane itself. Leveraging new inspection and testing advances, designers can include features, such as cameras and sensors, in free form display designs.

Traditional and new display formats

Today, many display technologies have matured to the point where display design is not limited to square corners and straight lines.

Traditional displays of all types are rectangular in shape. Even the first smart watches with round faces were square; that is, a round bezel encircled the actual display which itself was square. Mobile phones were the same. Older generations of smart phones often had rounded corners on the body of the phone, but the displays themselves were always restricted to 90-degree corners because that was what could be manufactured.

Manufacturing is a pain

Free-form displays present real manufacturing challenges. Due to the differentiation in shape and irregularity of pattern mainly in the peripheral or outer area of the display, the circuit pattern is more complex, is higher in density and includes integrated drivers from the peripheral area. This can lead to significant yield loss and makes it difficult to detect defects in the early stages of the production when the display can still be repaired and saved.

Manufacturing inspection systems, such as automated optical inspection (AOI), have typically used algorithms that require display shapes to be more uniform with straight lines and 90-degree angles. 

The move toward free form requires smart algorithms that can inspect constantly varying shapes and geometries for defects. While 90-degree corners are simple because each inspection area is identical, the circumference of a round smart watch display is different throughout. Array testing and repair systems are presented with the same challenges as inspection, requiring like new algorithms to support free form display designs.

Without these new algorithms that can cope with free form shapes, inspection systems require more manual, time-intensive set up and work. This introduces an increased margin of error, which means that display defects may go undetected.

Significant advances in inspection and repair technologies are eliminating these limitations, opening up new possibilities for designers. Smart watches, automotive displays and phones were among the first devices to be successfully manufactured with free form designs, with many benefits including increased display area and the ability to integrate sensors within the display.

By making the display in a smart watch round instead of rectangular, the display area increases by nearly 20 percent. As a result, designers can pack in more features and functionality without increasing the size of the watch face.

Likewise, rounded corners in smart phone displays enable a larger display area within the same size phone. Additionally, cameras and sensors can be added, and the displays manufactured more easily. The same opportunity exists for televisions and public information displays (PID) that can also include cameras and sensors within the display area.

One of the greatest opportunities for free form displays is for the automotive industry. Current vehicle designs incorporate growing numbers of free form displays every year and as autonomous vehicles become a reality, these displays will become more diverse. Imagine a dashboard display that includes all vehicle monitoring – tachometer, speedometer, odometer, fuel gauge, among others – in one smooth, continuous display.

This, by definition, will be completely free form because all the sensors and gauges will create irregular shapes within the display. The design limitations are removed with new inspection and repair technologies that enable this complex design. 

Intelligent algorithms enable detection for any area, any shape, any form and any pattern design of display. The algorithms “learn” the shapes within such free form displays, eliminating the need for custom inspection setups for each design. Ease of use for inspection operators is equally important to the process.

Displays are inspected at each stage of the manufacturing process, so setup and inspection are not one-time occurrences. The manufacture of mobile device displays will generally require at least 50 inspections points for each new device. Difficult setup and manual inspection can make this process costly and prone to error with defects going undetected.

Advanced inspection and test capabilities can result in increased yield with more accurate detection and repair, faster production ramp-up and faster time to market (TTM).

With new methods of inspecting defects in free form display designs, manufacturers have greater flexibility to produce highly accurate, any-shape displays, as well as predict potential defects. AI-driven technology enhances detection, classification and automation capabilities for even more accurate results right from the initial setup.

The greatest challenge to a display design has always been its manufacturability. But recent advances are giving designers the upper hand by removing manufacturing limitations, while increasing inspection and repair ease of use and accuracy. Designers, as Shakespeare wrote: “the world is your oyster.”

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