Abstract:
An electrical component includes a conductive substrate (18), a tin layer (19) formed on the substrate, and a coating (22) of a foam formed on the tin layer to impede tin whisker growth, the coating comprising a foam (28) having voids (30) dispersed therethrough. A method for impeding tin whisker growth from a tin plating or finish formed over an electrical component includes covering the tin plating or finish with a coating of intumescent paint, and thereafter expanding the intumescent paint into a foam having voids dispersed therethrough.
Abstract:
The principles described herein relate to methods for soldering electrode terminals, pins or lead-frames of commercial electric components for high temperature reliability. In one embodiment, prior to soldering the electric components, a pre-plated solder layer is removed from the lead frame or pins, and nickel and/or gold films are formed with electroless plating. The removal of the pre-plated solder layer avoids excess pre-plated Sn with high-Pb solder that lowers the melting point to between 180°C and 220°C and weakens solder joints. The nickel layer formed with an electroless plating acts as a barrier to the interdiffusion of tin from solder with copper of the lead frame material, which may otherwise occur at high temperatures. Interdiffusion forms an intermetallic compound layer of copper and tin and degrades solder joint strength. The novel soldering processes improve high temperature reliability of solder joints and extend electronics life-time.
Abstract:
A method for removing an undesirable material from an electronic or electrical component and introducing a desirable material in place of the undesirable material. The method can include the replacement of a leaded material found on the component with a no-lead material to meet governmental directives including those of the European Union.
Abstract:
The present invention aims to supply an electronic component which is manufactured in a manufacturing process at low cost, and realize improvement of shock resistance, endurance, flexure resistance, mounting reliability etc. at the same time, without requiring fine adjustment etc. The invention is an electronic component 1 which has an element 2, a pair of terminal portions 4 which were disposed on the element 2, and an external covering material 5 which covers the a part of the terminal portions 4 and the element 2, and configured in such a manner that inclined portions 10 are disposed on corner portions of a bottom surface 9 and side surfaces of the external covering material 5, and the terminal portions 4 are protruded from corner portions where the inclined portions 10 and the bottom surface 9 of the external covering material intersect.
Abstract:
A method for reducing whisker formation and preserving solderability in tin coatings over metal features of electronic components. The tin coating has internal tensile stress and is between about 0.5 m and about 4.0 m in thickness. There is a nickel-based layer under the tin coating.
Abstract:
A circuit board (1) having a pad (7) and a through hole (2a). When a surface-mount component (6) is mounted on the circuit board (1) by soldering, a lead (5) of the surface-mount component (6) is solder to the pad (7), and an alloy layer composed of a part of elements constituting the solder (8), the pad (7), and the lead (5) is formed at the soldering part of the lead (5) and the pad (7). The through hole (2a) connected to the lead (5) is made of nickel or palladium having a thermal conductivity of 100 W/m•k or less. Since the amount of heat transferred to the soldering part through the through hole (2a) is reduced and therefore the temperature of the soldering part is maintained below the melting point of the alloy layer, the interface of the soldering part is prevented from separating when the back of the circuit board (1) is solder-reflowed after the mounting. Thus the reliability of connection between the lead (5) and the pad (7) is improved.
Abstract:
Products and assemblies are provided for socketably receiving elongate interconnection elements, such as spring contact elements, extending from electronic components, such as semiconductor devices. Socket substrates are provided with capture pads for receiving ends of elongate interconnection elements extending from electronic components. Various capture pad configurations are disclosed. A securing device such as a housing positions the electronic component securely to the socket substrate. Connections to external devices are provided via conductive traces adjacent the surface of the socket substrate. The socket substrate may be supported by a support substrate. In a particularly preferred embodiment the capture pads are formed directly on a primary substrate such as a printed circuit board.