In a PCB patch, the optical mounting point must be placed in the four corners of the PCB, usually three to find the PCB.
Common benchmarks consist mainly of three types: table benchmark, unit benchmark and local benchmark.
Shape / size: 40 mm in diameter.
FS technology supplier mask window: center the reference point and cross the reference point twice the diameter.
Requires a soft or octagonal copper wire like a 2mm diameter edge protection ring.
The inside of the optical mount on the same plate must be the same, i.e. there must be a copper cover under the three reference marks.
(II) local data points.
QFP and step sections ≤0.4mm such as BGA, CSP, FC require local data points.
Size / shape: solid circle, diameter 40 mm.
Carrier mask opening: the size is handled according to the usual board, the outer ring is not made of copper ring.
2. Set the data point:
Data points must be placed on the player to operate SMT devices.
The number of unilateral access points is greater than or equal to 3.
Place reliable components on the component surface for one-way layout.
.. When the A5I5 ^ 0L-z1m + PPCB was developed bilaterally, reference points were placed on both sides.
(1) The reference point of the FS technology of the puzzle layout.
The board must be reliable and the hive reliable.
The three boards are reliable and the unit is reliable.
The edges of the board are L-shaped and as long as possible.
The image below shows the area requirements of the image table.
When using glass symmetrical frames, the reference point on the side must meet the repeat requirement after sliding, as shown in Figure B below.
The number of reference points is three and the table is distributed in L format and the distance between each reference point should be as small as possible.
It should not exceed 5 mm from the reference point.