Csg Solar Ag

Pacific Solar Pty Limited

Trevor Lindsay Young

Paul Alan Basore

Rhett Evans

Neil John Barrett

Patrick Lasswell

As a step in performing a process on a structure, a hole pattern is provided in a thin layer of organic resin masking material formed over the structure to provide a process mask. A processing step is then performed through the openings in the mask, and after a processing step is completed the mask is adjusted by a re-flow process in which the structure is placed into an atmosphere of solvent vapor of a solvent of the mask material. By way of the re-flow process, the mask material softens and re-flows to reduce the size of the openings in the mask causing edges of the surface areas on which the processing step was performed to be covered by the mask for subsequent processing steps.

Adjustment of masks by re-flow

An interconnect structure is provided by applying a conductive layer (typically one or more metal layers) over the entire surface of the module () to form all of the contacts () to all of the cells in the module and then scribing the conductive layer into a series of strips using a series of straight high speed laser scribes. The strips are then divided into individual links by scribing transversely to the first scribe direction with the laser turned on and off to cut each alternate stripe. The p-type regions of the cells are contacted through holes (), n-type regions are contacted through holes (). A silicon film () is separated into cells () by isolation grooves (). In a first embodiment, every second transverse scribe is offset by one strip such that each strip is cut into links which overlap two links on either side that are offset by a distance equal to half the pitch of the links. The pitch of the links is equal to two cell widths and the transverse scribes are coincident with or close to interruptions in the underlying cell layout representing cell boundaries between adjacent cells of the module. In a second embodiment, conductive bridges extend across longitudinal interruptions separating the parallel extending strips. In this embodiment, the like type contact pads for the cells are aligned in rows extending transverse to the cell boundary with alternating rows of p type and n type contact pads.

Chain link metal interconnect structure

As a step in performing a process on a structure, a hole pattern is provided in a thin layer of organic resin masking material formed over the structure to provide a process mask. A processing step is then performed through the openings in the mask, and after a processing step is completed the mask is adjusted by a re-flow process in which the structure is placed into an atmosphere of solvent vapor of a solvent of the mask material. By way of the reflow process, the mask material softens and re-flows to reduce the size of the openings in the mask causing edges of the surface areas on which the processing step was performed to be covered by the mask for subsequent processing steps.

Adjustments of masks by re-flow

A thin film of organic resin material (), such as novolac, is used as an etch mask and openings () are formed in the mask in a predetermined pattern to allow processing in selected areas defined by the openings. The openings () are formed by applying a pattern of droplets () of caustic etchant, such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) in the areas where the openings are to be formed. The droplets () are applied using a inkjet printer () which is scanned over the surface of the organic resin as the droplets are applied. The droplets () are of a size which defines the dimension of the openings () and allows the organic resin () under the droplet () to be completely removed. After the etchant has etched through the organic resin to expose an underlying surface (), the etchant is washed from the organic resin and the openings ().

Method of forming openings in an organic resin material

Silicon () is etched through a mask () comprising a layer of organic resin material (such as novolac) through which openings () are formed in the areas to be etched. The layer of organic resin is first deposited over a free surface of the device to be etched. The openings () are then formed by depositing droplets of a caustic etchant such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) with an inkjet printer. The etchant reacts with the resin to expose the silicon surface in areas to be etched. The etching of the silicon surface is performed by applying a dilute solution of hydrofluoric acid (HF) and potassium permanganate (KMnO) to the exposed surface through the openings in the mask to etch the silicon to a desired depth ().

Method of etching silicon

A simple thin film structure is illustrated in which a substrate ( ), which may be glass or any other suitable substrate material, supports a device structure ( ), over which is formed an inert dielectric layer ( ) and a metal film ( ). A pulsed laser beam ( ) directed at the surface of the metal film layer ( ). When the laser is pulsed on, a small amount of metal is ablated directly under the beam and surface tension in the surface of molten metal surrounding the ablated region pulls the metal back from the hole causing a slight thickening of the metal ( ) around the hole, and creates a hole ( ) which is significantly larger in diameter than the ablated region.

Growing community of inventors

Botany, Australia

Trevor Lindsay Young