Abstract: A method for making moisture resistant semiconductor devices having organic substrates targets each of the potentially critical interfaces within a semiconductor device having the potential for delamination and cracking. An organic substrate (110) is designed to include a solid pad (116) having a chemically created oxide layer (118) formed thereon. A silicone-based die attach material (108) is dispensed and gelled very soon after dispensing to prevent excessive bleed. A semiconductor die (102) is mounted to the substrate after undergoing a cleaning operation to remove contaminants from the backside of the die. Prior to molding compound encapsulation and subsequent to die attach material cure, the substrate is cleaned to improve adhesion to the die attach material fillet (122).

Abstract: A leadframe (11) and a method for improving adhesion of a polymer (17, 19) to the leadframe (11). The leadframe (11) has a flag (14) having a top surface (15) and a bottom surface (18), and leads (12). Microscopic locking features (31) are formed in the top surface (15) and the bottom surface (18) of flag (14) by bombarding the flag (14) with a grit material. Thus, the top and bottom surfaces (14, 18) are roughened. A semiconductor die (13) is attached to the flag (14) by a die attach material (17) and the flag (13), the semiconductor material (13), and portions of the leads (12) are encapsulated by a molding compound. The pits improve the adhesion of the die attach material (17) and the molding compound (19) to the leadframe (11).

Abstract: A semiconductor chip is flip chip bonded to a substrate having a cavity or a through hole formed therein. The cavity or through hole is preferably large enough to substantially remove the narrow gap which is formed between the portion of the substrate which does not have the cavity or through hole formed therein. This allows for use of mold processes to encapsulate and underfill the semiconductor chip and for line of sight cleaning of the semiconductor chip after bonding.

Abstract: A fast and simple method of determining a desired level of cleanliness of an inorganic surface is performed by correlating a level of cleanliness of many inorganic surfaces having varying thicknesses of organic contamination with reliability tests. The level of cleanliness is in terms of a measurement from a water drop test. The level of cleanliness between two inorganic surfaces can also be compared by utilizing the combination of a UV/ozone clean and the level of cleanliness to determine the relative amount of contamination present on one inorganic surface as compared to the other.

Abstract: A semiconductor package for use in fiber optics systems is disclosed wherein optical performance is enhanced by a lens between a fiber segment and the photoactive area of the semiconductor. The lens is spaced a predetermined distance from the fiber by a layer of elastomer. During assembly of the package, the fiber provides a convenient means for handling the lens.

Abstract: An assembly method is described in which low level light is used to align an optical fiber to the emitting area of an LED. When alignment is achieved, the power dissipated by the LED is increased to gel or partially cure an adhesive, thereby securing the aligned fiber to the LED.

Abstract: A relatively thick ring of polymer or metal encircles the emitting area of a light emitting diode. A spherical lens rests on the ring and is both accurately located with respect to and spaced from the emitting area.

Abstract: A package for fiber optic semiconductor devices is disclosed in which heat is conducted by both a heat spreader and through a plastic enclosure portion of the package.

Abstract: A process is described for attaching optical fiber to a semiconductor die in which a first droplet of adhesive is applied to the die and partially gelled to form a cushion for receiving the end of the optical fiber to be attached thereto.