Stencil Technology. Agenda: Laser Technology Stencil Materials Processes Post Process

Transcription

1 Stencil Technology Agenda: Laser Technology Stencil Materials Processes Post Process

2 Laser s YAG LASER Conventional Laser Pulses Laser beam diameter is 2.3mil Ridges in the inside walls of the apertures Clogged apertures Aperture corners rounded reducing area which in turn reduces paste deposit. Potato chip affect can occur on areas of highly dense apertures egbga s Electropolishing required FIBRE DIODE LASER Laser beam diameter is 0.8mil Clean smooth walls compared to the ridge in the walls Clogging is reduced Aperture corners sharper allowing more paste deposit Potato chip affect is eliminated no heat stress on foil on BGA parts No electropolishing required

3 Stencil Material 304 Stainless Steel Grain size 10 microns Standard Rolling Method to achieve required thickness A canning/potato chip affect occurs on boards that have BGA s or are highly populated in a small area Material thickness tolerance plus/minus 5% material thickness PHD (Material most stencil vendors currently use) PHD is the name of this product, not an acronym PHD base material is 304 with proprietary rolling method This method reduces the relief tension of the material The relief tension eliminates the canning/potato chip effect on BGA s or highly populated boards Grain size is 5 microns The small grain size creates a smoother aperture wall when cutting and increases paste deposit Material thickness tolerance plus/minus 1% material thickness

4 Stencil Material FG FG stands for Fine Grain FG base material is 301 with proprietary rolling method This method reduces the relief tension of the material The relief tension eliminates the canning/potato chip effect on BGA s or highly populated boards Grain size is 2 microns The small grain size creates a smoother aperture wall when cutting and increases paste deposit Material thickness tolerance plus/minus 1% material thickness Nickel Blanks Grain size Nano microns Grown blanks using Electroform process Control thicknesses allows for increments of.1 mil therefore sheet thicknesses can be 3, 3.1, 3.2 up to 7 mil Durable

5 Stencil Process Laser Cut Our highly repeatable, accurate printing performance you require for laser stencil manufacturing technology is: Positional accuracy Aperture tolerance Maximized paste transfer efficiency for optimum paste deposit repeatability and minimal under stencil wiping Ultra fine pitch capability Laser cut apertures have proven to exhibit minimal to no burring which improves solder paste release In a fiber diode laser, the laser beam has been reduced from.0023 in. to.0008 in., which also improves solder paste release..

6 ChemStep/Recess Stencil Technology Used for complex PCBs with various sizes of components that require different solder paste volumes in specific locations. Using various foil thicknesses on the same stencil allows the ability to control solder pasted volume in fine pitch areas while printing sufficient volume on coarse pitch areas. Step stencils are manufactured in both single process and dual process. Single Process using Photo Chemical matching (PCM) allows different areas to be etched to lower the thickness of the foil, which in turn decreases the paste deposit in these same areas. Dual Process engineered by a combination of PCM and Fibre Diode laser cutting. First, the foil is chemically etched in the areas requiring less paste (for fine pitch components), and then the foil is placed into the Fibre Diode laser machine to cut the apertures, offering greater accuracy and more precise apertures.

7 Stencil Technology LaserSTEP LaserSTEP formed by bonding one thickness metal into another No rough surface therefore paste will have a consistent roll Step or recess areas are bonded first, then the entire stencil is cut Tolerance between edge and component as low as 20 mil Electroform (EForm) Grown atom by atom the Electroform can be manufactured to custom thicknesses in increments of.0001 The smooth trapezoidal sidewalls The hardness of the electroform stencil results in longer stencil life EForm stencils require less under side wiping resulting in increased production EForm stencils ship within 24 hours after customer approval

8 Stencil Technology Advanced Nano Coating Our Advanced Nano stencil is a highly unique and patented coating that is applied to the bottom side of the stencil and inside the apertures, the squeegee remains uncoated. This advanced coating provides the stencil with antiadhesion properties. Stentech s Advanced Nano stencil utilizes a specialized 1 2 µm hardened nano coating inside every aperture and on the bottom side surface of the stencil. This permanent hydrophobic coating repels solder paste, resulting in: Higher volume of paste release More uniform shape on solder deposits Higher transfer efficiency and print yields Greater yields on low area ratio/miniaturized applications Higher screen printer thru put and lower residual materials costs due to reduced underside wiping Reduced surface energy of the paste contact area Better contour definition and lower failure. The unique easy to clean surface of the Advanced Nano Coating stencil reduces significantly the adhesion of the solder paste on the bottom side of the stencil and inside the apertures. Therefore the contour definition of the solder paste deposit is improved and constant transferred solder paste volumes are realized. Solder paste bridging is minimized as well, which leads to a higher process stability and lower failure rates.

9 Other considerations: EDITS TENSION Thank you for your time.