Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


SMD Adhesive Testing

#22586

SMD Adhesive Testing | 4 December, 2002

What is the typical "prove in" process for SMD adhesive?(Process Qualification)What steps would you take to qualify a new adhesive ?

Thank You

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blnorman

#22593

SMD Adhesive Testing | 4 December, 2002

What kinda adhesive? Pin Transfer, syringe dispense, screen print?

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#22640

SMD Adhesive Testing | 10 December, 2002

Sorry for the delay.

Loctite 3616 in a screen printing process.

Thanks

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#22667

SMD Adhesive Testing | 11 December, 2002

Se�or Tech

Consider the following in evaluating your adhesive: * Determine the ability to dispense/print epoxy dots over the full range of application diameters/volumes. * Assess the ability to dispense/print epoxy without undesirable characteristics [eg, spread, skip, slump, string, etc] in a 5000 - 10,000 dot experiment. * Verify the ability of the epoxy to mechanically secure the part through a full range of processes [eg, placement, handling, etc] through forming the solder connections in green and cured strength tests. * Test the hydroscopic (ie, moisture absorption) property of the epoxy that correlate well to subsequent formation of voids in cured epoxy dots.

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blnorman

#22671

SMD Adhesive Testing | 12 December, 2002

What we did: *Slump-dot diameter and height as a function of time *Print Speed-Vary speed, measure slump and missing/defects *Green Strength-We quantifiably measured tack vs time and we placed components and measure skew by SVS *Cure profile sensitivity-Use low/med/high profiles then measure break off strength *Cleaning-Clean stencils and boards with current cleaners to determine efficacy. *Under stencil wipe-Inspect bottom of stencil after "X" prints and look for bleed-out. *Compatibility-Combine with current material sets to determine any interactions. *Ionic content-Measure for ionic contamination *Moisture content

There were additional tests like CTE, Tg, for material characterization, but these were the main "process" related tests.

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Capillary Underfill process

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