摘要:
A method of removing a metal skin from a through-hole surface of a copper-Invar-copper (CIC) laminate without causing differential etchback of the laminate. The metal skin includes debris deposited on the through-hole surface as the through hole is being formed by laser or mechanical drilling of a substrate that includes the laminate as an inner plane. Removing the metal skin combines electrochemical polishing (ECP) with ultrasonics. ECP dissolves the metal skin in an acid solution, while ultrasonics agitates and circulates the acid solution to sweep the metal skin out of the through hole. ECP is activated when a pulse power supply is turned on and generates a periodic voltage pulse from a pulse power supply whose positive terminal is coupled to the laminate and whose negative terminal is coupled to a conductive cathode. After the metal skin is removed, the laminate is differentially etched such that the copper is etched at a faster rate than the Invar. To prevent the differential etching, a copper layer is formed on a surface of the substrate with an electrical resistance R1 between the copper layer and the positive terminal of the pulse power supply. Additionally, an electrical resistance R2 is formed between the laminate and the positive terminal of the pulse power supply. Adjustment of R1 and R2 controls the relative etch rates of the copper and the Invar.
摘要:
A colloidal metal seed formulation useful for catalytically activating a surface of a non-conductive dielectric substrate in an electroless plating process is provided. The colloidal metal seed formulation includes stannous chloride, palladium chloride, HCl and a surfactant selected from a diphenyloxide disulfonic acid or alkali or alkaline earth metal salt thereof, C30H50O10, an alcohol alkoxylate and mixtures thereof. A method of electroless plating of a conductive metal onto a non-conductive dielectric substrate using the colloidal metal seed formulation is also provided.
摘要:
A method of making a circuitized substrate (e.g., PCB) including at least one and possibly several internal optical pathways as part thereof such that the resulting substrate will be capable of transmitting and/or receiving both electrical and optical signals. The method involves forming at least one opening between a side of the optical core and an adjacent upstanding member such that the opening is defined by at least one angular sidewall. Light passing through the optical core material (or into the core from above) is reflected off this angular sidewall. The medium (e.g., air) within the opening thus also serves as a reflecting medium due to its own reflective index in comparison to that of the adjacent optical core material. The method utilizes many processes used in conventional PCB manufacturing, thereby keeping costs to a minimum. The formed substrate is capable of being both optically and electrically coupled to one or more other substrates possessing similar capabilities, thereby forming an electro-optical assembly of such substrates.
摘要:
A method for protecting a material of a microstructure comprising the material and a noble metal layer against undesired galvanic etching during manufacture, the method comprises forming on the structure a sacrificial metal layer having a lower redox potential than the material, the sacrificial metal layer being electrically connected to the noble metal layer.
摘要:
A method of preventing adhesive bleed onto the metal (e.g., gold) surfaces of a plurality of electrical conductors (e.g., wire-bond pads) positioned on a dielectric substrate when positioning an electronic component onto the dielectric substrate and electrically coupling (e.g., wire-bonding) the component to the metal surfaces. The method includes contacting the metal surfaces with a chemical composition which comprises a minor amount of a surface active agent (e.g., a thiol) and the remainder substantially being a non-reactive solvent (e.g., methanol). A circuitized substrate produced using this method is also provided.
摘要:
A method for forming a dielectric structure. A first layer is formed, wherein the first layer includes a first fully cured photoimageable dielectric (PID) material. A sticker lays is nonadhesively formed on the first layer, wherein the sticker layer includes a partially cured PID material. A second layer is nonadhesively formed on the sticker layer, wherein the second layer includes a second fully cured PID material, wherein the sticker layer is nonadhesively sandwiched between the first layer and the second layer such that the sticker layer is in non-adhesive contact with the first layer and in non-adhesive contact with the second layer, and wherein the sticker layer is capable of remaining in non-adhesive contact with the first layer and the second layer until the sticker layer is subsequently subjected to additional curing.
摘要:
A circuitized semiconductor substrate comprising a layer of dielectric material having holes therethrough, a catalyst seed layer lining the walls of the holes along the surface of the dielectric material, and a nickel layer in the openings and a layer of copper above the nickel layer, along with a method for its fabrication. The invention also provides copper-nickel laminate PTH barrels and methods for their fabrication.
摘要:
A circuitized substrate (e.g., PCB) including an internal optical pathway as part thereof such that the substrate is capable of transmitting and/or receiving both electrical and optical signals. The substrate includes an angular reflector on one of the cladding layers such that optical signals passing through the optical core will impinge on the angled reflecting surfaces of the angular reflector and be reflected up through an opening (including one with optically transparent material therein), e.g., to a second circuitized substrate also having at least one internal optical pathway as part thereof, to thus interconnect the two substrates optically. A method of making the substrate is also provided.
摘要:
A dielectric structure, wherein two fully cured photoimageable dielectric (PID) layers of the structure are nonadhesively interfaced by a partially cured PID layer. The partially cured PID layer includes a power plane sandwiched between a first partially cured PID sheet and a second partially cured PID sheet. The fully cured PID layers each include an internal power plane, a plated via having a blind end conductively coupled to the internal power plane, and a plated via passing through the fully cured PID layer. The dielectric structure may further include a first PID film partially cured and nonadhesively coupled to one of the fully cured PID layers. The dialectric structure may further include a second PID film partially cured and nonadhesively coupled to the other fully cured PID layer.
摘要:
A process for selective plating of a metal onto a substrate surface is provided. The process includes laminating a layer of conductive metal onto a dielectric substrate; and providing thru holes extending through said layer of conductive metal and said dielectric substrate.A thin layer of conductive metal is plated on the walls of the thru holes; and a photoresist layer is applied to the surface of the conductive metal and selectively exposed and developed to provide a mask corresponding to the negative of the desired circuit pattern.The exposed metal that is not covered by the photoresist is removed and then the remaining photoresist is removed to thereby provide the desired circuit pattern. A conductive metal is plated on the pattern up to the desired thickness.