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AssigneeSt Assembly Test Services Pte Ltd
InventorsIl Kwon Shim, Jian Jun Li, Sheila Marie Alvarez
Estimating the term…
A new method is provided for the creation of high-accuracy and low-accuracy openings overlying points of electrical access over the surface of a semiconductor device supporting substrate. Openings are first created for access to the substrate followed by copper plating and then patterning of the plated layer of copper, creating the interconnect metal over the surface of the substrate. A first solder mask is coated over the surface of the substrate, this first solder mask must be provided with a first array of low-accuracy openings for electrical access there-through for the placement of contact balls. The first openings can be created using conventional film artwork since low accuracy is required for the contact ball openings, resulting in a low-cost process for the creation of the first openings. A second solder mask is next coated over the surface of the first solder mask. Through this second solder mask is created a second array of high-accuracy second openings that provide access to solder bumps using methods of laser ablation, resulting in a low-throughput process which however is only applied to create access to solder bumps.
A method of creating solder masks providing both high accuracy and low accuracy there-through, comprising steps of:
A method of reducing cost of creating a substrate for mounting flip devices over the surface thereof, comprising steps of:
A method of creating a substrate for mounting flip chip devices over the surface thereof, comprising steps of:
Dependencies are inferred from the claim text.