1, the substrate, DIE pad must be aligned with the direction of the binding line, and leads to the connection also need to and pad direction has been, for each DIE, must be placed in its diagonal position of a cross-shaped pad As the coordinates of the binding when the coordinates of the coordinates of the need to connect the network of accessories, generally have to choose (must have a network, otherwise the cross will not be able to appear), and in order to prevent the cross was copper submerged lead to accurate positioning, It is forbidden to surround the copper frame.
DIE binding to note that there is no need to use the pad that is no network connection pad need to be deleted. As shown below.
PCB circuit board substrate design principles

2, the substrate production process is special, each line must be used by the plating line plating method to cast copper material and the formation of pad and alignment, or everything else need to use copper place. It must be noted that even if there is no electrical connection that is no network of the pad, must be in the eco mode, the pad out of the frame outside the copper plating, otherwise there will be no copper pad results. And pull out the frame of the plating line must have a copper layer in the other layer to identify the location of its corrosion, where the seventh floor of the copper logo. In general, the copper sheet is located within 0.15 mm of the frame, and the edge of the copper is about 0.2 mm away from the frame.
3, plate and frame, to determine the positive and negative, it is best to all devices are placed on the same side, the surface with three XXX logo, as shown below.
PCB circuit board substrate design principles
4, the substrate used in the pad than the general pad, a special package, for the CX0201, X logo and C0201 difference. Finished as follows:
0603 pad: 1.02mmX0.92mm pad window area: 0.9mmX0.8mm, two pad in the distance of 1.5mm.
0402 pad: 0.62mmX0.62mm pad window area: 0.5mmX0.5mm, two pad in the distance of 1.0mm.
0201 pad: 0.42mmX0.42mm pad window area: 0.3mmX0.3mm, two pad in the distance of 0.55mm.
5, DIE requirements are as follows: Bonding pad (single wire) Minimum size 0.2mmX0.09mm90 degrees, the minimum spacing of the pad to do 2MILS, the inner row of the ground and the power line pad width is also required to do 0.2 Mm. The angle of the bond pad is adjusted according to the angle of the component pull line. Substrate Substrate when the tie line is not easy too long, master DIE and inner bonding pad minimum distance of 0.4mm, FLASHDIE and bonding pad distance of 0.2mm minimum. Both tied the longest should not exceed 3mm. The spacing between the two rows of bonding pads should be separated by more than 0.27 mm.
6, SMT pad and DIE bonding pad and SMT components must be maintained between 0.3mm above, a DIE binding pad and another DIE distance should be maintained at 0.2mm or more. The signal trace is a minimum of 2MILS with a spacing of 2MILS. The main power line is best to do 6-8MILS, as much as possible a large area of ​​pavement. Can not be floated place where you can shop power and other signal lines to enhance the strength of the substrate.
7, wiring should pay attention to the hole and the pad, alignment, gold finger can not be too close, the same attributes of Confucius and Goldfinger at least to maintain more than 0.12mm, different properties of the hole as far as possible away from the pad and gold finger. Through the hole to do the smallest hole 0.35mm hole to do 0.2mm. Copper should also pay attention to copper and gold finger can not be very close, some broken copper to be deleted, and not allowed to have a large area to shop Where the copper is present.
8, when the use of copper mesh, the ratio of 1: 4 that COPPERPOUR 0.1mm and COPPER 0.4mm copper angle switch to 45 degrees.