Doubt about PCB drill holes

Discussion in 'General Electronics Chat' started by cumesoftware, Mar 31, 2008.

  1. cumesoftware

    Thread Starter Senior Member

    Apr 27, 2007
    1,330
    10
    I have a doubt. I'm designing a PCB for the "Quatour" project. But I need to know if there are standard hole diameters.

    I'm planning to use 0.8mm and 1.2mm holes for components, but I'm not sure if this is correct.
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,535
    I have bought a set of high quality refurbished PC board drills from Dan's small parts and electronics for homemade PCB boards.

    http://www.danssmallpartsandkits.net/

    His is an odd shop, offers parts through the internet, but insists on snail mail for orders and checks. Good stuff though. I'm not sure if it is what you're asking for, but here is the section off his internet catalog. I suspect the holes are standardized, but thinking about it I have to answer I'm not sure.

    [​IMG]

    50 PIECE CARBIDE DRILL BIT KIT


    HERE IS A VERY NICE 50 PIECE CARBIDE DRILL BIT KIT..THESE ARE VERY NICE AND HAVE 1/8" SHANK..AND FIT DREMEL TOOLS..SMALL DRILL PRESS'S AND OTHER SMALL HOBBY DRILLS
    THIS KIT INCLUDES 5 PIECES EA. OF THE FOLLOWING SIZES AND 10 PIECES EA. OF NO.66 AND NO.67
    • 5 PIECES NO. 70
    • 10 PIECES NO. 66
    • 10 PIECES NO. 67
    • 5 PIECES NO. 79
    • 5 PIECES NO. 73
    • 5 PIECES NO. 76
    • 5 PIECES NO.77
    • 5 PIECES NO. 80
    THIS KIT COMES WITH A CASE TO HOLD THE BITS AND THE PIC. GIVES YOU A IDEA OF THIS AND WHAT YOU WILL GET...VERY NICE ASSORTEMENT TO HAVE AROUND THE SHOP...PRICE...$12.50
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The size of the drills available define the standard hole diameters. Sometimes, you just have to spend time with a micrometer and mechanical drawings to find out what sizes of holes you need in a PCB. Just don't make the holes too tight...
     
  4. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    Yeah, try not to dwell on standard holes, etc.. Just use the recommended footprint drawing hole size, or if it doesn't exist, make it a bit bigger than the actual pin diameter. You should get standard drill sizes from your pcb house, then account for the plating that they will apply. I second the motion 'don't make the holes too tight', it has happened to me before and it is very unpleasant.

    Steve
     
  5. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    Component drawings have the lead diameter min and max and they are sometimes even correct. ;)
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    That's why a micrometer is a real handy tool.
     
  7. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    Have a talk to your board manufacturer. Most can make the holes any size you specify but have a list of preferred sizes and charge you extra if you ask for hole sizes that are not on the preferred list.
     
  8. nanovate

    Distinguished Member

    May 7, 2007
    665
    1
    Remember that the holes get plated so the PCB Mfg will actually drill a hole larger than you specify taking into account their tolerances for drill and plating to give you a "finished through hole" size. You want to check to see what their standard tolerances are so that you do not "make them too tight" as mentioned above.
     
  9. lightingman

    Senior Member

    Apr 19, 2007
    374
    22
    Hi,

    For standard PCB work... 0.8mm for IC's, 0.95mm or 1mm for other components. Other useful sizes are 1.25mm and 1.5mm.

    Daniel.
     
  10. John Luciani

    Active Member

    Apr 3, 2007
    477
    0
    The list below is the standard **finished** hole sizes (in inches) I
    have been able to use in almost all of by PCBs. Plating decreases the
    drilled hole by apx 3-5mils. Using this set of holes is a close match
    for both AP Circuits and the PCB Express process. Allow apx 5-10mils
    for clearance.

    .020 .025 .029 .035 .046 .052 .079 .125 .150

    Using a fixed set of sizes is useful in finding mistakes. Reviewing
    the drill list gives a quick indication of a drill mistake.

    If you use components with pressfit leads you need to follow the
    manufacturers recommendation exactly.

    I have started a footprint creation document that documents the
    guidelines I use when creating footprints. It is my website at

    http://www.luciani.org/not-quite-ready/not-quite-ready-index.html

    (scroll down to "Footprint Reference Document")

    (* jcl *)
     
Loading...