摘要:
A flat ribbon cable having a controlled impedance and suitable for use at high data rates. The ribbon cable includes a plurality of conductors arranged side-by-side within an insulating material. The conductors include a first portion at each end having a generally circular cross-section, a center portion of generally rectangular cross-section in which the width is greater than the height and a transition portion at each end between the first portion and the second portion. A shield is disposed over selected ones of the plurality of conductors on at least one side of the ribbon cable. A drain wire is provided that is conductively coupled to the shield and may be disposed between the shield and insulating material. The drain wire is disposed over one of the conductors and may be conductively coupled to the conductor via use of a single contact of an insulation displacement connector that engages both the drain wire and the respective conductor. Multiple shield layers and associated drain wires may be provided to provide controlled impedance for selected conductors of the ribbon cable.
摘要:
A process for providing bond enhancement and an etch resist for a printed circuit board is provided. A sheet comprising at least a layer of copper is immerses in a first immersion tin solution comprising a tin metal and a complexing agent in an acidic medium for a time sufficient to deposit a first heavy tin deposit on the sheet. The sheet is then immersed in a second immersion tin solution comprising stannous tin ions and stannic tin ions and a complexing agent in an acidic medium for a time sufficient to deposit a second thin tin deposit on the sheet. The second thin tin deposit has a thickness less than a thickness of the first heavy tin deposit. A rough surface texture providing mechanical adhesion sites results. The board is then treated with a coupling agent, such as silane, for enhanced bonding to a subsequent epoxy or other polymer prepreg. Additionally, the first heavy tin deposit may serve as an etch resist in subsequent fabrication of the provided circuit board.
摘要:
A printed circuit board and method of manufacture thereof is disclosed. The printed circuit board includes a first substrate provided from a conductive layer having disposed on a first surface thereof a cured adhesive layer. A semi-cured adhesive layer is then disposed over the cured adhesive layer and a second substrate is disposed against the semi-cured adhesive layer.
摘要:
A printed circuit board and method of manufacture thereof is disclosed. The printed circuit board includes a first substrate provided from a conductive layer having disposed on a first surface thereof a cured adhesive layer, A semi-cured adhesive layer is then disposed over the cured adhesive layer and a second substrate is disposed against the semi-cured adhesive layer.
摘要:
A method of depositing a conductive material on a surface of a printed circuit board, includes the steps of chemically treating at least a portion of a surface of the printed circuit board, disposing a resist layer over the chemically treated surface, depositing a conductive layer in the areas which are not covered by the resist, stripping the resist from the surface of the printed circuit board, and cleaning exposed chemically treated surfaces of the printed circuit board to remove contaminants from the surface of the printed circuit board which were introduced in the chemically treating step.
摘要:
In a process for manufacturing a rigid-flex printed circuit wherein a rigid insulating layer supports one portion of the printed circuit and a flexible insulator supports another portion thereof to furnish flexible leads for connection the printed circuit to an operative device, a first assembly is provided comprising a curable prepreg insulator layer having an opening for the flexible leads. A flexible sheet spans the opening, and the assembly is pressed with one surface in contact with a smooth hard surface while the other surface is supported by a flowable curable prepreg layer. The insulator and flowable layers are a release layer which prevents bonding between the prepreg layers throughout most of the areas while permitting bonding along the edges. The assembly is maintained under heat and pressure to partially cure both prepreg layers and bond the flexible sheet to the edges of the opening and bond the edges of the prepregs together to form a flat rigid sandwich. A sheet of copper is bonded to that surface previously in contact with the hard surface. In a second pressing operation the copper is bonded to both the partially cured prepreg layer and the flexible sheet, and thereafter the bonded edges of the cured prepreg layers, are severed to permit separation of the cured prepreg layers.
摘要:
In a process for manufacturing a rigid-flex printed circuit wherein a rigid insulating layer supports one portion of the printed circuit and a flexible insulator supports another portion thereof to furnish flexible leads for connection the printed circuit to an operative device, a first assembly is provided comprising a curable prepreg insulator layer having an opening for the flexible leads. A flexible sheet spans the opening, and the assembly is pressed with one surface in contact with a smooth hard surface while the other surface is supported by a flowable curable prepreg layer. The insulator and flowable layers are a release layer which prevents bonding between the prepreg layers throughout most of the areas while permitting bonding along the edges. The assembly is maintained under heat and pressure to partially cure both prepreg layers and bond the flexible sheet to the edges of the opening and bond the edges of the prepregs together to form a flat rigid sandwich. A sheet of copper is bonded to that surface previously in contact with the hard surface. In a second pressing operation the copper is bonded to both the partially cured prepreg layer and the flexible sheet, and thereafter the bonded edges of the cured prepreg layers, are severed to permit separation of the cured prepreg layers.
摘要:
A rigid-flex printed circuit board having a rigid section and a flexible section extending from the rigid section is disclosed. The rigid-flex printed circuit board is capable of withstanding high temperatures experienced in high volume production environments utilizing infrared reflow ovens by providing spacers and covers for protecting the flexible section from high temperatures. A process for assembling components and devices on the rigid-flex printed circuit board in a high volume production environment utilizing infrared reflow ovens is also disclosed.
摘要:
According to exemplary embodiments, a controlled-depth slot extending into a circuit board is provided. The controlled depth slot may be milled, and may comprise ½ radial plated through-holes to generate a solderable “D” interconnect feature. The slot may include interconnect features on one to five sides. According to another exemplary embodiment, a circuit board having a depth-controlled interconnect slot is provided in conjunction with one or more solderable technology modules. The one or more solderable technology modules may include memory devices, power devices such as Point of Load Supplies (POLS), security devices and anti-tamper devices, capacitance devices, and other types of chips such as Field Programmable Gate Arrays (FPGAs). The solderable technology modules may be soldered into the slot to secure the modules in the slot and connect the modules to interconnects on the circuit board.
摘要:
According to exemplary embodiments, a controlled-depth slot extending into a circuit board is provided. The controlled depth slot may be milled, and may comprise ½ radial plated through-holes to generate a solderable “D” interconnect feature. The slot may include interconnect features on one to five sides. According to another exemplary embodiment, a circuit board having a depth-controlled interconnect slot is provided in conjunction with one or more solderable technology modules. The one or more solderable technology modules may include memory devices, power devices such as Point of Load Supplies (POLS), security devices and anti-tamper devices, capacitance devices, and other types of chips such as Field Programmable Gate Arrays (FPGAs). The solderable technology modules may be soldered into the slot to secure the modules in the slot and connect the modules to interconnects on the circuit board.