摘要:
A fluid-cooled electronic assembly including a base having a fluid inlet and a fluid outlet therein, a cap attached to the base to form a fluid containment chamber therebetween, wherein the fluid containment chamber is in fluid communication with the fluid inlet and the fluid outlet, and an electronic device disposed within the fluid containment chamber and connected to the base, the electronic device having a plurality of microchannels adapted to receive a cooling fluid flow therethrough, wherein the cap is shaped to direct a fluid flow from the fluid inlet to the microchannels such that a pressure drop between the fluid inlet and the fluid outlet is reduced.
摘要:
A corrosive resistant electronics assembly 10 is provided including at least one heat generating electronics component 12 mounted on a substrate 14 and positioned within potting material 18. A thermally conductive block element 24 is thermally mounted to the at least one heat generating electronics component 12 and positioned within the potting material 18, thereby providing a corrosive resistant electronics assembly 10 with improved thermal dissipation.
摘要:
A belt tension sensor includes an armature that is displaced in relation to belt tension and an optical sensing mechanism that detects armature displacement as a measure of belt tension. In a first mechanization, a lens element is mounted on the armature for movement therewith, and light emitted by a light source passes through the lens element before impinging on a light responsive element; the lens element variably diffuses the emitted light in relation to the belt tension, and the light impinging on the light responsive element provides a measure of the belt tension. In a second mechanization, the armature includes a protuberance that abuts and variably collapses a compressible optical waveguide to vary its optical transmissivity in relation to the armature displacement, and the optical transmissivity of the optical waveguide provides a measure of the belt tension.
摘要:
An adhesive material is provided which is particularly suitable for potting a sensing element within a container. The adhesive material is characterized by mechanical and physical properties which enable the adhesive material to maintain its adhesive and structural integrity under intense thermal cycling conditions, so as to exclude foreign elements from the sensing element when potted within a container with the potting material. The adhesive material can be formulated so as to be sufficiently adherent for use with containers formed from materials such as polybutylene terephthalate, polyethylene terephthalate, and E-coated steel, by including additions of a flexibilized polyol/polyepoxide epoxy novolac in an amount of up to about 15 parts by weight.
摘要:
A method is provided for processing an electronic circuit assembly having surface mount integrated circuit packages mounted to its substrate, in which ingress of a conformal coating into a void present between the IC package and the substrate is prevented by a masking composition which forms a barrier around the IC package prior to the conformal coating process. The masking compositions are hot melt materials, in that each is initially a solid at roughly room temperature, melts to become a liquid at an elevated temperature at which the masking composition is applied to the electronic assembly, and forms a solid upon cooling to a temperature corresponding to a service temperature of the electronic assembly. As such, the masking compositions can be rapidly applied through various highly controllable techniques, and will quickly and sufficiently solidify upon cooling to allow handling of the electronic assembly. The masking compositions may be nonreactive, indicating that the barrier can be remelted, or reactive, indicating that a post-application curing process occurs over time at a temperature less than the elevated application temperature.
摘要:
A capacitive load cell includes upper and lower capacitor plates and an intermediate array of dielectric pads formed of silicone-impregnated open-cell urethane foam (i.e., gel pads). The silicone essentially displaces air that would otherwise be trapped in the foam, contributing to a dielectric having minimal humidity-related variability. The upper capacitor plate is defined by an array of individual charge plates, the lower capacitor plate defines a ground plane conductor common to each of the charge plates, and the dielectric pads are disposed between the ground plane conductor and each of the charge plates, leaving channels between adjacent dielectric pads. When occupant weight is applied to the seat, the dielectric pads transmitting the weight distend laterally into the channels to reduce the separation between the respective upper and lower capacitor plates, and the consequent change in capacitance is detected as a measure of the applied force and the force distribution.
摘要:
Conformal coating materials are provided for forming a protective conformal coating on the surface of an electronic assembly. The conformal coating materials are characterized by being hot melt materials, in that they are each initially a solid or semisolid at approximately room temperature, a liquid at an elevated temperature at which the coating material is applied to the electronic assembly, and solidify upon cooling to a temperature corresponding to a service temperature of the electronic assembly. As such, the coating systems can be rapidly applied through various highly controllable techniques associated with hot melt dispensing equipment. In addition, the coating systems quickly solidify upon cooling to allow handling of the electronic assembly. The conformal coating systems may be nonreactive, indicating that the system can be remelted, or reactive, indicating that a post-application curing process occurs over time at a temperature less than the elevated application temperature.
摘要:
A capacitive load cell apparatus includes upper and lower capacitor plates and an intermediate dielectric in the form of a synthetic knit spacer material having upper and lower fabric layers interconnected by an array of deflectable synthetic fibers. When occupant weight is applied to the seat, the synthetic fibers deflect to locally reduce the separation between the upper and lower capacitor plates, and the consequent change in capacitance is detected as a measure of the applied weight. The load cell or just the dielectric may be encased in a polymeric sheath to prevent intrusion of foreign matter, and a fluid such as silicone may be dispersed in woven dielectric.
摘要:
An electronic package and a method for packaging an electronic component, particularly a shock-sensitive component such as a yaw rate sensor or an accelerometer mounted to a circuit board. The package includes a case having an opening through which the circuit board is placed within the case, so that a peripheral edge of the circuit board is adjacent but spaced apart from a wall of the case. A thixotropic gel is present in the space between the peripheral edge of the circuit board and the wall of the case, so as to separate and control the mechanical decoupling of the circuit board and case. An optional spacer can be used to space the circuit board from the shelf. Alternatively, the gel may be filled with a polymer particulate material. A potting material preferably fills an upper cavity within the case to encapsulate and secure the circuit board within the case.
摘要:
An acceleration sensor is packaged in an open can and encapsulated in an elastomeric polybutadiene compound which maintains its mechanical properties over a range of -40.degree. C. to 105.degree. C. and transmits acceleration to the sensor with a unity transfer function. The encapsulation material comprises about 90 to 100 pbw of polyol and about 20 pbw of isocyanate, the polyol consisting of at least 70% of hydroxy-polybutadiene. For enhanced adhesion a foaming agent and/or an epoxy is added to the mixture.