Abstract:
Certain examples disclosed herein are directed to materials that are designed for use in interconnects of electrical devices such as, for example, printed circuit boards and solar cells. In certain examples, a two-step solder may be used to reduce stresses on the materials used in the production of the electrical devices.
Abstract:
A semiconductor device with an improved solder joint system is described. The solder system includes two copper contact pads connected by a body of solder (120) and the solder is an alloy including tin, silver, and at least one metal from the transition groups IIIA, IVA, VA, VIA, VIIA, and VIIIA of the Periodic Table of the Elements. The solder joint system also includes, between the pads and the solder, layers of intermetallic compounds, which include grains of copper and tin compounds and copper, silver, and tin compounds. The compounds contain the transition metals. The inclusion of the transition metals in the compound grains reduce the compound grains size and prevent grain size increases after the solder joint undergoes repeated solid/liquid/solid cycles.
Abstract:
What is provided is a multi-layer PCB having a plurality of stacked dielectric layers, a conductor disposed on at least one of the plurality of dielectric layers, and a non-conductive via extending through at least a portion of the plurality of dielectric layers to intersect the conductor. A conductive body in an activated state is introduced into the non-conductive via, and upon contacting the conductor, the activated state conductive body adheres to the conductor. The activated state conductive body is then effected to a deactivated state, wherein the conductive body is affixed to the conductor to provide an electrical connection thereto.
Abstract:
The invention relates to a contact arrangement (10) linking two substrates (11,12) and to a method for producing said contact arrangement, comprising the following steps: soldering material (23) is deposited on contact areas (16) of a first substrate to form spaced metallic coatings (19), and the first substrate (11) is contacted to a second substrate (12) whereby contacting occurs between the contact areas (16) of the first substrate (11) and a contact surface of the second substrate (12) by means of an electroconductive adhesive material (20).
Abstract:
An interposer (10) obtained by forming a laminate comprising a first sheet of electrically insulating material (12) and a second sheet of conductive material (30). The first sheet has a first plurality of apertures (16) therethrough and the second sheet is laminated to the first sheet to close the first plurality of apertures (16). Material is removed from the second sheet around the first plurality of apertures (16) to form conductive pads (24), the pads (24) closing the first plurality of apertures (16). A third sheet of electrically insulating material (14) is attached to the second sheet (30). The third sheet has a second plurality of apertures (20) therethrough, the third sheet being positioned relative tto the second sheet such that the apertures (20) of the second plurality are closed by the conductive pads (24). In a preferred form, the third sheet (14) is positioned relative to the first sheet (12) so that the apertures (20) of the second plurality are not in registration with the apertures (16) of the first plurality.
Abstract:
A connective medium is provided for use in ball grid assemblies for detachable connections between electronic devices and circuit boards. The medium includes novel, discrete spheres defining an inner metallic, spherical core and one or more outer, electrically conductive concentric, hard and non-deformable metallic layers.
Abstract:
An improved process for the manufacture of uniformly and accurately sized metal spheres, particularly copper spheres, which comprises the steps of classifying a starting lot of spheres into closely sized fractions; separately electroplating each size fraction to a desired final mean diameter and size distribution; and then combining the plated fractions to give a metal sphere product having the requisite mean particles size and size distribution. The electroplating build-up step is characterized by a high level of precision. Additional benefits derive from the high hardness of copper electroplate on relatively soft copper starting particles which facilitates grinding or polishing irregularly shaped plated particles down to the desired sphericity and mean diameter, from the ability of metal such as copper electroplate to cover and envelop contaminated surfaces of starting particles, and from the ability to produce spheres having a unique combination of bulk and surface properties.