Array Substrate And Method Of Mounting Integrated Circuit Using The Same

What is this patent about?

’503 is related to the field of electronic devices, specifically addressing the mounting of integrated circuits onto array substrates, such as those used in display devices like LCDs and OLEDs. These array substrates often utilize flexible materials like polyimide, which are susceptible to size changes (expansion or contraction) during manufacturing. This dimensional instability can lead to misalignment between the integrated circuit's bumps and the substrate's pads, causing connection issues.

The underlying idea behind ’503 is to compensate for the misalignment caused by the expansion or contraction of flexible array substrates. This is achieved by using inclined pads on the substrate and corresponding inclined bumps on the integrated circuit. The inclination allows for a degree of lateral movement of the integrated circuit relative to the substrate, effectively accommodating the dimensional changes without compromising the electrical connection.

The claims of ’503 focus on an electronic device comprising an array substrate, a pad portion on the substrate, and an integrated circuit with a bump portion mounted on the pad portion. The key feature is that the pad portion includes a first sub-pad unit with an inclined first pad and a second sub-pad unit with an inclined second pad. These pads are symmetrically inclined about an imaginary line dividing the pad portion. The bump portion mirrors this arrangement with inclined bumps.

In practice, the inclined pads and bumps allow the integrated circuit to 'slide' slightly along the direction of the inclination to maintain contact even if the substrate expands or contracts. The symmetrical arrangement ensures that the compensation works regardless of whether the expansion/contraction occurs on one side or is uniform. This sliding action maintains the electrical connection between the pads and bumps, ensuring proper device operation.

This approach differs from traditional methods where pads and bumps are rectangular and strictly aligned. Prior solutions might involve tighter manufacturing tolerances or complex alignment procedures to minimize misalignment. By introducing the inclined geometry , ’503 provides a more robust and adaptable solution that can tolerate greater variations in substrate dimensions, leading to improved manufacturing yields and device reliability. The symmetrical arrangement of the inclined pads and bumps is also a key differentiator, ensuring consistent performance regardless of the direction of substrate deformation.