摘要:
A differential pressure sensor (10) has a sensor die (16) attached to a stress isolation package base (12) with a bonding glass (27) having a similar coefficient of thermal expansion. The bonding glass, and alternately an aluminum layer, provides a hermetic seal between the stress isolation base and sensor die. Pressure is applied to the sensor die port (24). A plastic housing (14) is attached to the stress isolation base with an adhesive (29). A port (23) in the plastic housing is filled with a silicone gel (22). A second pressure source is transferred by way of the silicone gel to the sensor die. Any hostile chemical entering the via contacts the first surface of the sensor die to assert pressure against a transducer circuit (25) to generate the electrical signals representative of the applied pressure but are isolated from the sensitive interconnects by the hermetic seal.
摘要:
A semiconductor package (20) includes an organic substrate (24) and a semiconductor die subassembly (22). A method (50) for making the semiconductor package (20) entails providing (52) the organic substrate (24) having an opening (26) and electrical contacts (36). The subassembly (22) is formed by producing (64) a semiconductor die (28) and bonding it to a platform layer (30). An elastomeric adhesive (38) is utilized (92) to secure the subassembly (22) in the opening (26). Electrical interconnects (32) are provided (106) between the semiconductor die (28) and the electrical contacts (36) of the organic substrate (24). The organic substrate (24), semiconductor die (28), elastomeric adhesive (38), and electrical interconnects (32) are encapsulated (114) in a packaging material (46). The elastomeric adhesive (38) provides mechanical anchoring of the subassembly (22) to the substrate (24) and provides mechanical stress isolation of the semiconductor die (28) within the semiconductor package (20).
摘要:
A leadframe (10) architecture provides placement of multiple optocoupler pair devices (45, 50) in a minimum size footprint package. A detector flag (20) and LED flag (12) are placed on a common centerline (26) within the footprint. A critical length is determined for packaging factors lying along the centerline. The angle (28) formed between the centerline and the longitudinal axis (24) controls the optocoupler pair fit within the package. The angle (28) is calculated by taking the arc-sine function of the critical length divided by the footprint width.
摘要:
A leadframe (20) for a semiconductor device includes a first leadframe portion (12) having a perimeter that defines a cavity (16) and a plurality of leads (14) extending inwardly from the perimeter and a first thickness. A second leadframe portion (18) is attached to the first leadframe portion (16). The second leadframe portion (18) has a die paddle (20) received within the cavity (16) of the first leadframe portion (12). The second leadframe portion (18) has a second thickness that is greater than a thickness of the first leadframe portion (12). Such a dual gauge leadframe is suitable especially for high power devices in which the die paddle acts as a heat sink.
摘要:
A dual absolute pressure sensor independently converts first and second external pressures to first and second electrical signals respectively. A package body has first and second openings for receiving the first and second external pressures to outside surfaces of first and second sensor die attached to opposite surfaces of an internal glass substrate that separates the first and second openings. The first sensor die includes a first cavity having a reference pressure to measure against the first external pressure and develop a first differential pressure. A first piezoelectric network converts the first differential pressure to the first electrical signal representative of that pressure. The second sensor die includes a second cavity having a reference pressure to independently measure against the second external pressure and develop a second differential pressure. A second piezoelectric network converts the second differential pressure to the second electrical signal representative of that pressure.
摘要:
A semiconductor package (20) includes an organic substrate (24) and a semiconductor die subassembly (22). A method (50) for making the semiconductor package (20) entails providing (52) the organic substrate (24) having an opening (26) and electrical contacts (36). The subassembly (22) is formed by producing (64) a semiconductor die (28) and bonding it to a platform layer (30). An elastomeric adhesive (38) is utilized (92) to secure the subassembly (22) in the opening (26). Electrical interconnects (32) are provided (106) between the semiconductor die (28) and the electrical contacts (36) of the organic substrate (24). The organic substrate (24), semiconductor die (28), elastomeric adhesive (38), and electrical interconnects (32) are encapsulated (114) in a packaging material (46). The elastomeric adhesive (38) provides mechanical anchoring of the subassembly (22) to the substrate (24) and provides mechanical stress isolation of the semiconductor die (28) within the semiconductor package (20).
摘要:
An optocoupler package made up from a pre-assembled package having a leadframe, a voltage isolation barrier, and a body molded from a reflective plastic material. The voltage isolation barrier is fabricated as part of the body and positioned in such a way as to substantially increase the electrical flashover path between the optical source and the optical detector. An optical source mounted in the pre-assembled package subsequent to fabrication of the molded body. An optical detector is optically coupled to the optical source by reflection within the pre-assembled package, the optical detector being mounted in the pre-assembled package subsequent to fabrication of the molded body A reflective plastic cover is bonded to the pre-assembled package.
摘要:
A technique for encapsulating an optocoupler apparatus to improve light coupling efficiency, reliability and cost. An optocoupler apparatus comprises a light emitting device (10) and a light detecting device (11) mounted to conductors (12A,12B). A light coupling material (14) surrounds the optocoupler apparatus. The light coupling material (14) is an electrical dielectric which is transparent to light. A portion of the light coupling material (14) is coated with a light reflective material (16). The light reflective material (16) is a mixture of the light coupling material (14) and titanium dioxide. The benefit of coating the light coupling material (14) with the light reflective material (16) is the two materials have similar chemical properties, and the reflective property of the light reflective material (16) arises from the titanium dioxide; the second most reflective material available. An encapsulating material (17 or 19) further envelops the encased optocoupler apparatus.
摘要:
A differential pressure sensor (10) has a sensor die (30) eutectically attached to a mounting flag (14). The mounting flag has a similar coefficient of thermal expansion to the sensor die. The eutectic attachment provides a hermetic seal between the mounting flag and the sensor die. Pressure is applied to sensor die port (20). A molded housing (12) is molded around the sensor die-mounting flag assembly. Port (22) in the molded housing is filled with a silicone gel (52). A second pressure source is transferred by way of the silicone gel to the sensor die. Any media entering port (20) contacts the first surface of the sensor die to assert pressure against a piezoresistive transducer circuit (32) to generate the electrical signals representative of the applied pressure but are isolated from the sensitive interconnects by the hermetic seal.
摘要:
An electronic pressure sensor (10) is enhanced by attaching a sensor die (18) to a stress isolation platform (12) using an adhesive (42) having a similar thermal coefficient of expansion. The adhesive provides a hermetic seal between the stress isolation platform and the pressure sensor die. A via (20) in the stress isolation platform provides an opening for pressure to be applied to the sensor die. The stress isolation platform is attached to a plastic package body (16) via a semi-rigid adhesive (40) for providing stress isolation and a hermetic seal between the package body and the stress isolation platform. Any hostile chemical entering the via contacts an exposed diaphragm (50) of the sensor die to assert pressure against its piezoelectric network (52) to generate the electrical signals representative of the applied pressure but are kept away from the sensitive interconnects by the hermetic seals.