1, PCB board select (specific equipment foreach parameter may be slightly different)

1.1 Maximum area: X x Y = 330mm × 250mm (corresponding the small workbench placementequipment) X × Y = 460mmx 460mm(corresponding to the workbench placement equipment)

1.2 Minimum area: X × Y = 80mm × 50mm

Around 1.3 PCB chamfer R 1.5mm

1.4 PCB thickness: 0.8 ~ 2.5mm

1.5 If the PCB board is too small, the needto design a puzzle, if the puzzle, it is recommended that stamps version ordouble face carved V-groove separation technology.

2, component layout rules

2.1 elements are arranged in the effectiverange of: PCB board X, Y directions are set aside the transmission side, eachside 3.5mm, suchas inevitable, extra process transmit side.

2.2 PCB board components required uniformemissions to avoid the severity uneven. 2.3 Parts discharged to the PCB, inprinciple, with the components change in the type varies, i.e., similarcomponents are arranged in the same direction as far as possible, so that theplacement of the components, welding and testing. 2.4 When wave soldering,contact with the solder wave at the same time try to ensure that the componentsof both ends of the solder joints (SOIC must be guaranteed, flaky, columnarelements to ensure as far as possible).

2.5 When the size difference between thelarger flake components arranged adjacent, and the pitch is very small, smallercomponents in the wave soldering should be arranged at the front, first enterthe solder wave, to avoid the large size of the components shieldingsubsequently size than small components, resulting in lack of weld.

2.6 panel adjacent to the differentcomponents of the minimum spacing between the pad pattern should be more than 1mm.

3, the reference mark

3.1 In order to precisely mount components, based on the need to design aset of graphics for a complete PCB optical positioning (reference mark) for thepin number, pin pitch single optical positioning device graphics ( localfiducial markers).

3.2 fiducial markers commonly usedgraphics: ■ ●▲ + size range of 0.5 ~ 2.0mm, diagonal symmetry direction positionin the PCB or a single device.

3.3 Reference signs to consider the colorof the PCB material and environmental contrast, usually set into a pad-like,copper or pewter plating. 3.4 puzzle deviations due to die stamping, may formthe board-to-board spacing inconsistencies between the best benchmarksestablished signs on every block puzzle, allowing the machine to look eachpuzzle as veneer.

4 pad graphic design

    Pad design isgenerally based on the appearance of components used in the CAD standardlibrary select the appropriate standard pad size, not large generation of smallor small-generation.

5 pads printed wire

5.1 reduces the width of the pad at printedwire communication, unless the subject to the limit of the charge capacity, andfactors such as PCB processing limit, the maximum width should be 0.4mm, or half the width of the pad (a smallpad) .

5.2 pad with larger area of the conductive region, such as, the power supply plane is connected,through a shorter length of the thin conductive wires for heat isolation.

5.3 printed wire should be avoided was acertain angle is connected with the pad, as long as possible, printed wire atthe center of the long side should pads connected thereto

6, pads and solder mask

6.1 on a printed circuit boardcorresponding to the opening size of the solder resist film of each pad, andits width and length, respectively, should be higher than the pad size 0.05 ~~ 0.25mm, depending on the padpitch, the purpose is to prevent the solder resist pollution pad, but also toavoid the solder paste printing, of welding even India and even welding.

6.2 solder mask thickness of not greaterthan the thickness of the pad

7, vias layout

7.1 to avoid the mounting pads on thesurface or less, or less from the surface mounting pads 0.635mm set of vias. If youcan not avoid, the loss of the solder resist solder channel blockers.

7.2 as the test support vias, in the designlayout, the need to fully consider the probes of different diameter, theminimum spacing for automatic online test (ATE).

8, welding PCB overall design

8.1 reflow almost suitable for all SMDcomponents soldering, wave soldering is only suitable for welded rectangularchip component, cylindrical components, SOT and smaller SOP (pin number is lessthan 28 feet spacing 1mm). Tin flow direction when wave soldering SOP feet components, the last two(each side) fillet set at burglary tin pad to prevent even welding.

8.2 In view of the the operability production PCB optimize the overalldesign as much as possible in the following order:

A. sided mount or mixed, the PCB-sidedlaying SMD components or plug-in component;

B. sided mount PCB A surface laying chipcomponents and plug-in component B surface laying suitable for wave solderingSMD components;

C. sided mixed PCB A surface laying chipcomponents and plug-in component B face cloth placed on the need to reflow SMDcomponents.