Land Pattern doesn't match chip?

I'm trying to setup a PCB footprint for a 16mHz Ceramic resonator.

I was looking at this CSTCE_V part in this Murata datasheet...

http://www.murata.com/products/catalog/pdf/p16e.pdf

The CSTCE_V chip dimensions on page 23 don't seem to match the recommended land pattern on page 25, the chip pads are wider than the PCB pads.

Is this a problem?

Am I not reading this right?

I'm working on my first PCB layout.

You should be able to decide on something simple like this yourself, I should think.

However, you have a datasheet for ceramic resonators. Those things typically have 0.5% frequency tolerance. That's potentially 300 msec of timing error every "minute". Forget that! Use a real crystal instead, having a 20-50 ppm tolerance.

Page* 22 has the land pattern. Bottom, left figure says "This Land Pattern is not common to CSTCE_V." Page* 27 has another CSTCE_V land pattern and I agree, the pads are half the size of the leads stated on page* 25.

It may be an error on their part.. But, I agree with Oric, save yourself alot of work in the future and go with a Crystal + some 22pF caps.

*My page numbers are referring to Adobe Reader's page numbers.

@Oric, what is that pic of in your avatar? Looks interesting..

Thanks for the recommendation.

However, I'm still curious....

The chip has pads 0.6, 0.4 and 0.6 wide, spaced 0.95 apart. The pattern has all three pads 0.3 wide, spaced 0.08 apart.

Doesn't seem to fit very well. Or is this OK?

Are you looking at the right one? On p25, second row, right seems to be the correct pattern, with 0.95 spacing. I would not think 0.8 spacing would be right. Nothing says the lands on the board have to be the same width as the pads on the chip. I don't see why the second one down on the right wouldn't work, depending on soldering method. OTOH, there's no reason not to design your own land pattern that's more suitable to your methods.

codlink: @Oric, what is that pic of in your avatar? Looks interesting..

If you look closely, you'll see it's just a plastic box with 4 AA cells and some blinkie lights, LOL. Without telling you specifically what it is, do a search at google images on "Blake's 7 computer". A classic from before time began. Servalan, Avon, and Soolin.

oric_dan: If you look closely, you'll see it's just a plastic box with 4 AA cells and some blinkie lights, LOL. Without telling you specifically what it is, do a search at google images on "Blake's 7 computer". A classic from before time began. Servalan, Avon, and Soolin.

Oh, lol. Still looks pretty sweet though.