tag:blogger.com,1999:blog-777163971497499699.post715911259105948597..comments2023-04-28T19:03:47.293+01:00Comments on Considering CADSTAR.: Having trouble with components with thermal vias in heatsink pads?Unknownnoreply@blogger.comBlogger2125tag:blogger.com,1999:blog-777163971497499699.post-73992217758308765242014-03-24T11:07:06.944+00:002014-03-24T11:07:06.944+00:00Another comment on this - for the large pad to be ...Another comment on this - for the large pad to be on both the top and the bottom - this is easily achieved when adding the large pad , Add Pad as "Through hole" rather than on "Min" and you get a pad both sides.Anonymoushttps://www.blogger.com/profile/16943066981453001805noreply@blogger.comtag:blogger.com,1999:blog-777163971497499699.post-61071798035223781312014-02-21T15:17:28.319+00:002014-02-21T15:17:28.319+00:00A few comments on the above:
The holes should rea...A few comments on the above:<br /><br />The holes should really be approx 0.3mm-0.4mm PTH and the land only needs to be enough for plating - which if you have a larger pad either side is catered for so minimum pad size is adequate.<br /><br />The holes should ideally be "filled" at board manufacture, this leaves a solid surface of the larger tab pad so there is no need of the holes in the solder resist shape.<br /><br />The Solder paste pads can then be a more reasonable matrix and larger than squeezing them between holes.<br /><br />When you flood copper, if you have thermal relief on pads enabled then the copper will not flood to the pad fully - so simply let it flood then place a copper shape larger than the pad+gap over the pad and connect it to the pad.<br />(There is another way but it involves attributes)<br /><br />And all the above if a suggestion, not a definite how to as every situation is different so think about it carefully.MattyLadhttps://www.blogger.com/profile/08767276057547892145noreply@blogger.com