Sven-Eric,

It is not a misprint. It was developed that way because the SM-782 
committee had reports that the large chip capacitors were having problems 
with cracking. The land pattern was reduced so that the solder would not 
act like nails, but more like a pair of hands (with a little more flex).

At the January meeting of the committee, it was reported that the 
manufacturers now have the cracking problem under control. And the 
committee has since changed the recommended x-dimension of the land 
patterns to be:

component              recommended x
1210                        2.70
1812                        3.40
1825                        6.80

This should bring them in-line with their respective chip resistors.

The amendment is in final editing and typesetting. It should be available 
in a couple of months.

****************************************
Lisa M. Williams
Technical Staff
IPC
2215 Sanders Road
Northbrook, IL 60062
phone: (847) 509-9700 x 379
fax:   (847) 509-9798
email: [log in to unmask]
****************************************



On Wed, 27 Mar 1996, SVEBA wrote:

> A question about IPC-SM-782,Rev A,Aug 93.
> 
> In subsection 8.2 is a table for Land 
> Pattern Dimensions, figure 3.
> We have noticed that the dimension X is 
> not increasing for all increased 
> sizes.For Component Identifier 1210 and 
> 1812, the dimension seems to be too 
> small. Is that OK or is it a wrong 
> printing? The original publication from 
> March 87 has a different table, fig. 6-5, 
> which has increasing values on above.
> 
> Can anyone help?
> 
> Sven-Eric Backstrom, Saab Dynamics, 
> Sweden
> 
>