Can you wave solder this part

Without having tried it, I'll be the first to say I don't know how you could, and I would have no trouble at all telling my management absolutely not.

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Cannot be done, no way to solder the heat pad underneath center.

P.S. Rob also spells color wrong!!! must have been a real bad school!! How does the wave master do it?

Russ

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National says: [ http://www.national.com/packaging/llp/faq.html#faq_manu ] Manufacturing FAQ's Are there any precautions that need to be taken with the LLP package? It is critical to follow National�s guidelines for successful surface mount process Like BGA�s and other land grid array packages the solder joints can not be viewed from the top without X-ray

What pick and place equipment can be used for LLP? a) The standard pick and place equipment that can handle BGAs and QFPs with 0.5mm pitch can handle LLP. The LLP has been picked and placed successfully using Fuji, Panasonic & Quad, Siemens, ESEC, Sanyo, Amistar, and Universal equipment.

How do customers determine if the solder joint is reliable after re-flow? a) Using X-ray inspection of the solder joint after re-flow is the recommended method.

What is the recommended solder reflow profile? a) The recommended soldering profile is included in National�s LLP package application notes, AN-1187, and meets IPC-9502.

Can the LLP package be reworked after soldering on the PCB? a) Yes, commercially available rework equipment can be used to rework LLP .

Is LLP shipped in Tape & Reel? a) Yes. LLP is shipped in tape and reel using industry standard guidelines (ref. EIA-481-1).

Can this package be hand soldered? a) No. The contacts are on the bottom of the package and no contacts on the side.

What is the reliability of the package after rework? a) With proper rework the reliability is the same as a new part

Can this package go through wave solder? a) No. Due to specific design of LLP with contacts on the bottom wave soldering is not possible.

Is National available to assist in manufacturing? a) Yes. Please contact the LLP team in the Package Technology Group through your local National Semiconductor sales engineer.

Are voids acceptable in the solder between the PCB land and the thermal pad of the package after surface mount? a) National has done extensive modeling and studies on the impact of voids and the results are summarized in AN-1187.

What is the standoff for this package after surface mount? a) Typically about 2 mils

Can a "no" clean solder paste be used? a) Yes.

Can we use a type 1 or 2 solder paste? a) No. These are not recommended for fine pitch. Type 3 or 4 is the recommended solder paste for LLP packages.

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Nope, and, Be careful with the "grid" on your stencil for the big centre pad - I could not find the stencil recommendations. I use a similar part by Cygnal (CP2101). Next time I will reduce the apertures by 50% from their suggested layout. We had floating and bridging issues with a 0.005" stencil. Simply too much paste underneath. Yes, fillets are fun too.

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Dave, Cygnal was taken over by Silabs. I based my design on the second link that you provided. Tell me folks, are you using one large pad with only the stencil having the grid, or are you actually breaking up the large pad into grids with mask around them and a reduction for the stencil? In my original "problem" design I followed the guidelines on page 10 of the link Dave provided, i.e an array of 3 x 6 with dimensions of 0.6mm x 0.3mm. I see I have another one, (28 pin) coming up and the large pad is 2.5mm x 2.5mm. I have changed the array to 4 x 3 with dimensions of 0.45mm x 0.3mm.(I know; I didn't go 50% like I said). In line with our various educations: What say ye olde fellowe? Whadyareckon buddy/doll? Whatya thinkin' mate?

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