BGA Circuit Board in PCB Reverse (PCB Structure of Ball Grid Array) and Its CAM Design
BGA in PCB Reverse engineering industry under the current hole on the PCB over the hole in the main use of technology are: ① flat front hole: for BGA plug hole at the exposed single-sided exposed or partially exposed, if the two plug hole diameter difference of 1.5mm, the (2) solder plug hole: used in the PCB Reverse BGA plug hole at both ends of the board covered with solder mask; ③ flat before and after the plug hole: for thick copper plate or other special Required board. The plug hole size: 0.25,0.30,0.35,0.40,0.45,0.50,0.55mm a total of seven species.
BGA in the CAM production should be how to deal with it?
First, PCB Reverse in the outer line of the production line BGA:
The size of the BGA, the size of the BGA via hole, the distance from the hole to the BGA pad, the copper thickness requirement is 1 ~ 1.5 ounces of PCB, in addition to the production of specific customers according to their acceptance requirements to do the corresponding compensation, the remaining customers if the production process by masking hole etching generally compensate 2mil, using the map process is to compensate 2.5mil, specifications for the 31.5mil BGA Do not use electrical processing; when the customer design BGA to the hole distance is less than 8.5mil, and BGA under the vias are not centered, you can use the following methods:
Can refer to BGA specifications, the design of the size of the corresponding BGA solder pad position to do the design of a standard BGA array, and then as the base will be required to correct the BGA and BGA under the hole is shot, after filmed with the original did not shoot before the backup Of the level of contrast check before and after the film is the effect, if the BGA pad before and after the deviation is large, can not be used, only take BGA under the hole position.
Second, PCB Reverse of the BGA solder production:
1, BGA surface mount solder resistance window: the same as the optimal value of solder mask its unilateral window range of 1.25 ~ 3mil, solder resist distance from the line (or hole pad) spacing greater than or equal 1.5mil;
2, PCB Reverse BGA plug hole template layer and the processing of the pad layer:
① make 2MM layer: BGA pad to copy the line layer for another layer of 2MM layer and deal with the scope of 2MM square, 2MM in the middle can not have gaps, gaps (if the customer requirements to BGA character box for the plug Hole range, then the BGA box for the 2MM range of characters to do the same deal), do a good job with the character layer BGA 2MM character box at the character frame, the larger of the two for the 2MM layer.
② PCB reverse in the CAM plug layer (JOB.bga): to touch the hole layer 2MM layer (with the panel Actionsàreference selection function reference 2MM layer to select), Mode Select Touch, the BGA 2MM range of holes to be copied to the plug holes Layer, and named: JOB.bga (Note, such as customer requirements BGA at the test hole for plug hole processing, you need to select the test hole, BGA test hole features: solder mask on both sides of a full window or single window) .
③ Copy the plug layer to another pad layer (JOB.sdb).
④ According to the BGA plug hole file to adjust the aperture hole layer and cushion plate layer aperture.
Third, BGA corresponding blockage layer, character layer processing:
① need to plug the hole, plugging holes are not on both sides of the block;
② character layer hole at the hole relative to allow white oil into the hole.
After the completion of the above steps, BGA CAM veneer production is completed, this is only BGA CAM veneer production situation, in fact, due to the ever-changing electronic information products, CB Reverse industry competition, BGA plug hole on the production process is often In the replacement, and continue to have new breakthroughs. This breakthrough each time, so that products on a higher level, more adapt to market changes. We look forward to more superior BGA hole on the hole or other process.