The several matters CAM engineers should pay attention to

- May 12, 2016-

According to the situation of different equipment, this article only applies to some PCB manufacturers

Welding disk overlap

Pads (except for surface mount assembly and welding disc) overlap, which means the hole overlapped, when drilling will because in a drilling result in broken bits, wire damage.

Two. Graphic layer abuse

1 in violation of the conventional design, such as the component surface design in the BOTTOM layer, welding surface design in TOP, resulting in the file editor Shi Zheng negative errors lead to product rejection.

2 PCB board if there is a need to milling groove, to use the LAYER BOARD or LAYER KEEPOUT layer painting, not the use of other layers or pad filling, to avoid the misuse of milling or milling

3 double side panels, such as there is no need for a metal hole, should be another note.

Three. Shaped hole

If the plate has shaped holes, with the KEEPOUT layer to draw a hole with the same size of the fill area can be. Special-shaped hole length / width ratio should be greater than or equal to 2:3:1, width should be >1mm. Otherwise, drilling in the processing of the special-shaped hole Shiji easily broken knife, resulting in the difficulties to process.

Four. Character placement

1 character to cover the welding disk SMD, to the printed circuit board test and the component of the welding inconvenience.

2 character design is too small, resulting in the difficulty of screen printing, so that the character is not clear enough. The character height is larger than 30mil, the width is more than 6mil.

Five. Set the size of one side pad

1 one side pads are generally not drilling, if the drilling need to be marked, the aperture should be designed to zero. If the design of the numerical, so in borehole data, the bit will be drilled hole, light will affect the surface appearance, weight scrapped the board.

2 one side pads if you want to drill to make a special mark.

Six. Use filling block to draw pads

Filled with a piece of painting pad in the design of the line to the DRC, but for processing is not good, so welding plate is not directly generated resistance welding data, on the solder resist, the filling block area will be solder resist coverage, causes the device difficult to weld.

Seven. The design of the filling block is too much or fill with a very fine line

1 produce the phenomenon that the data is lost, the data is not complete, and the deformation is drawn.

2 because of the filling block in the light of the data processing is to use a line to draw a line, so the amount of light generated by the large amount of data, increased the difficulty of data processing.

Eight. Surface mount device pad is too short

This is for on-off test, for too dense surface mount devices, the spacing between the feet is quite small, pad quite as fine, installation and testing should be (left and right) of the staggered position, such as the pad design is too short, although does not affect the device mount, but will make the wrong pin test on a.

Nine. Large area grid spacing is too small

A large area of the grid lines between the edges of the line is too small (less than 0.30mm), in the printing process will cause a short circuit.

Ten. A large area of copper from the frame too close

Large area of copper foil frame should ensure at least more than 0.20mm spacing, because in milling shape such as milling to copper foil is easy to cause copper foil Alice and the induced flux loss.

Eleven. The shape of the design of the frame is not clear

Some customers in the LAYER BOARD, LAYER TOP, OVER LAYER KEEP and so on are designed to shape the line and these lines do not coincide, resulting in a difficult to judge which is the shape of the shape of the line.

Twelve. The placement of lines

Two welding disc between connections, not intermittent painting, if you want to bold lines do not use lines to the repetitive placement, line width can be, such words in modifying the lines can be modified.

Thirteen make-up.

The track system of the automatic welding equipment has a size range of PCB board, and the clamping range of the general production line is: 50mm*50mm-460mm*460mm. PCB in small 50mm*50mm need to be designed into the form of imposition.

A.PCB must have their own reference point (Mark) is conducive to the automatic welding equipment.

B. if the V cutting processing the imposition spacing should be maintained at 0.3mm, the technology for single 5mm.

C. for the complex shape of the PCB, a good PCB should be as far as possible to ensure that the shape of the rules in order to track the clip.

D. the same PCB can be put together in a piece, different PCB can also be put together in a piece of.

E. panel can be used flat row, row of Yuanyang, in the form of.

Previous:Development of diversified PCB needs Next:The Changeable PCB Quotation