Sheet comprising a flexible support and a coating at least partially covering at least one face of the support, the support being made of a support material exhibiting dielectric properties, the coating being made of a coating material different from the support material and exhibiting magneto-dielectric properties or dielectric properties.

A screen printing form (1, 1′) for use in screen printing, in particular for producing a metallic contact structure of a photovoltaic solar cell, having a woven screen printing fabric (1b) with a plurality of elongate woven fabric elements, which are arranged in a first element direction and a second element direction perpendicular thereto, and a stencil (1c), arranged on the woven screen printing fabric (1b) that has at least one opening formed as straight channel with a channel width BK. The woven fabric elements have a spacing AF in the first element direction and a spacing which deviates by less than 5% from AF in the second element direction, and the woven fabric elements have a diameter DG in the first element direction and a diameter which deviates by less than 5% from DG in the second element direction. A screen printing device and screen printing form are also provided.

A light-emitting module includes (i) a board provided with: a circuit pattern and a plurality of bottomed holes in each of a set of wiring pads continuous with the circuit pattern on a first surface; electrically conductive paste extending over two or more of the bottomed holes; and an insulating resin covering the electrically conductive paste at a side close to the first surface, and (ii) a plurality of light-emitting segments connected to a second surface of the board with an adhesive sheet interposed therebetween. The light-emitting segments each include a plurality of light-emitting devices that are aligned. The electrically conductive paste includes a portion disposed on a portion of a surface of the wiring pad extending over two or more of the bottomed holes.

A stencil printer for printing an assembly material on an electronic substrate includes a frame, a stencil coupled to the frame, the stencil having apertures formed therein, a support assembly coupled to the frame, the support assembly being configured to support the electronic substrate, a print head gantry coupled to the frame, and a print head assembly supported by the print head gantry in such a manner that the print head assembly is configured to traverse the stencil during print strokes. The stencil printer further comprises a verification system to determine whether an item placed within the stencil printer is properly installed within the stencil printer.

A method for printing conductive solder paste on a base substrate to establish an electrical connection is provided. The method includes applying conductive solder paste over a stencil, and within an opening of the stencil to contact the base substrate therebeneath. In embodiments, a squeegee can be used to scrape some of the conductive solder paste off of the stencil, leaving behind some of the conductive solder paste within the opening. Subsequently, the stencil can be removed at a speed of more than 200 millimeters per second to help reduce the end-of-track bump ultimately formed at the end of the conductive solder paste that remains after the stencil is removed.

A stencil for use in stencil printing is disclosed. The stencil is configured to removably attach or rest on an upper surface of an underlying base. The stencil has an opening through which the conductive paste is deposited by spreading the conductive paste across an upper surface of the stencil and forcing the paste into the opening and onto an upper surface of the underlying base. The stencil has a stepped edge at a boundary of the opening. The stepped edge includes a ledge or floor that is configured to hold some of the paste even after a squeegee has removed the paste from an upper surface of the stencil. As the stencil is removed from the base, the ledge or floor can carry the paste that it holds away from the base in an effort to reduce an end-of-track bump on the underlying base.

A stencil printing system for printing solder paste on a base substrate to establish an electrical connection is provided. The system includes a stencil configured to removably attach or rest on an upper surface of the base. The stencil has an opening that provides access to the upper surface of the base. A squeegee spreads conductive paste across the stencil, whereupon the paste can be forced onto the upper surface of the base via the opening. In embodiments, the stencil has a stepped edge at the boundary of the opening. The stepped edge may include a platform or floor that sits lower than the upper surface of the stencil to collect the paste and reduce the amount of paste that falls back to the base as the stencil is removed. The squeegee may have a lower surface that extends oblique relative to the squeegee's leading surface and trailing surface.

A screen printer comprising: a conveyance device configured to convey a board; a board holding device configured to position a conveyed board at a printing position; a stencil holding device configured to attach a stencil above the held board; a squeegee device configured to fill pattern holes of the stencil with solder paste; a board raising and lowering device configured to raise and lower the board positioned by the board holding device; and a control device configured to perform drive control of each the above devices, the control device including a standby printing processing section configured to raise the board from below with respect to the stencil such that the board contacts the stencil, stand by in a state with solder paste filled in the pattern holes, and lower the board to separate the board from the stencil in accordance with a board conveyance signal.

Aspects of the invention include receiving a printed circuit board (PCB) having one or more of mounting pads thereon, determining a stencil for applying a solder paste to the one or more mounting pads, the stencil having a smallest aperture for a component requiring a standoff, determining a maximum threshold size for standoff particles based on the smallest aperture, determining a first concentration of the standoff particles based on the smallest aperture, determining a minimum threshold size for standoff particles to create the standoff for the component, determining a second concentration of the standoff particles to create a three-standoff seating plane for the component, introducing the standoff particles to the solder paste, the standoff particles in the solder paste having a concentration between the first concentration and the second concentration, and a size between the maximum threshold size and the minimum threshold size.

The present disclosure relates to surface modification of solder paste stencils to provide improved adhesion of a functional coating. The disclosed surface modifications include laser structuring, plasma treatments, and primers. Methods of using the solder paste stencils are further disclosed.