Laser welded inkjet printhead assembly utilizing a combination laser and fiber optic push connect system

Abstract

The disclosure describes a method for the solderless laser welding of two materials by using a laser light beam attached to a fiber optic system which directs the light to a region where the laser beam can shine through one of the materials to create a seam weld. By using a fiber optic system the laser beam is optimally converted into thermal energy and weld flaws due to underheating or destruction of the materials due to overheating does not occur. The method and apparatus provide rapid, reproducible laser welding even for the smallest of contact geometries. For example, the method results in solderless gold-to-gold compression laser welding of a silicon substrate to the material contained in a polymer flex circuit tape, such as a polyimide, without damaging the tape. A strong solderless gold-to-gold bond can be formed between a gold bond line, or complex weld seam pattern, on the flex circuit tape and a mating gold bond line or weld seam pattern on a semiconductor chip. Such a bond is formed without any damage to the tape and prevents delamination and nozzle skewing during the adhesive curing process of other methods. The reduced nozzle skewing provides less dot placement error for print cartridges, and therefore better print quality. Disclosed is an improved printhead configuration for facilitating the attachment of a nozzle member to the substrate which increases nozzle area stiffness and nozzle camber angle and directionality as well as, the substrate/tape interface bond strength, and reduces deformation of the nozzle member. The configuration thereby provides higher consistent ink chamber refill speeds, and reduces ink trajectory errors and delamination. In addition, in particular embodiments increased tolerance to aggressive solvents in inks and more consistent chamber geometry result in better control over drop volume. The method improves the quality, repeatability and reliability of the pen and results in fewer process steps, thereby improving processing time, cost and reduced in-process handling. The above in turn results in ease of assembly, higher yields, improved reliability, ease of nozzle serviceability, and overall material and manufacturing cost reduction.