gEDA-user: solder masks, etc.

[David Koski <david@kosmosisland.com>]

Hello,

In the following file:

http://kosmosisland.com/island/david/test_1.pcb

I have a SOT-428_Transistor (Q1) footprint that I made. With a solder mask as
shown in the file, I cannot get the large pad closer than about 170 mils from
the edge of the board. It is as close as it can get in the above referenced
board. If I make the solder mask parameter small, the pad can be placed next to
the edge of the board. What am I missing?

Also, I have only done prototypes without solder masks so far. What is the
"right" amount of mask? I noticed that even library footprints vary as can be
seen in the file referenced above.

The transistor in the pcb file:

Element[0x00000000 "SOT-428_Transistor" "Q1" "unknown" 32000 41000 -2500 6500 0 100 0x00000000]
(
    Pad[-9000 16500 -9000 20500 6000 1000 7000 "" "1" 0x00004100]
    Pad[0 -9200 0 -9200 27500 2000 31500 "" "2" 0x00000100]
    Pad[9000 16500 9000 20500 6000 1000 7000 "" "3" 0x00004100]
    ElementLine [-15200 -24500 15200 -24500 1000]
    ElementLine [15200 -24500 15200 24500 1000]
    ElementLine [15200 24500 -15200 24500 1000]
    ElementLine [-15200 24500 -15200 -24500 1000]

    )

The footprint file:

Element(0x00000000 "SOT-428" "" "" 0 0 -25 65 0 100 0x00000000)
(
    Pad(-90 165 -90 205  60  10  70 "" "1" 0x00000100)
    Pad(  0 -92   0 -92 275  20 315 "" "2" 0x00000100)
    Pad( 90 165  90 205  60  10  70 "" "3" 0x00000100)
    ElementLine(-152 -245 152 -245 10)
    ElementLine(152 -245 152 245 10)
    ElementLine(152 245 -152 245 10)
    ElementLine(-152 245 -152 -245 10)
)



Regards,
David Koski
david.nospham@KosmosIsland.com
!.nospham