PCB Tech - What is vippo pcb?

Short answer: vippo PCB is a hole punched in the middle of the pad of the PCB.

Long answer, all the holes on the PCB board that press on the pads can be called vippo PCB (via in pad plated over PCB). Generally speaking, the diameter of the vippo cannot be greater than 0.5mm, otherwise the solder paste will flow into the hole during placement, or the flux will flow into the hole to generate gas during heating, resulting in insufficient connection strength between the device and the pad and virtual soldering.

The most difficult thing to control for the vippo PCB plug hole is the solder ball or ink pad in the hole, which is the so-called oil explosion phenomenon. Some customers of ipcb have very strict requirements on the pad and appearance of the solder mask. Among them, the PCB fabrication There is a requirement for vippo to plug the hole, and the most difficult thing to control when we were fabricating PCB before was the problem of oil explosion after curing or spraying tin, which led to the problem of solder mask on the pad and solder ball in the hole. Curing or spraying tin is a process of the solvent volatilization of the plug hole ink and the shrinkage of the resin. Therefore, improper control is most likely to cause tin beads or oil explosion in the hole.

vippo PCB (via in pad plated over PCB)

The via hole is drilled directly on the solder joint. In order to ensure that the soldering performance of the solder joint is not affected, resin is usually used to plug the hole, and then the surface of the via hole is plated so that the hole cannot be seen on the surface, so it is called For vippo. Vippo plays two roles: first, it plays a role in the conduction between the layers; second, after plugging the hole, the surface of the hole is plated, so that it will not affect the welding performance of the solder joint.

The inner diameter of the pad of the vippo PCB, after passing through the resin plug hole, a layer of copper is deposited on the inner diameter substrate to make the surface look like a large copper surface, and the hole is buried under the pad. Vippo PCB can increase the surface pad area. For small line width and line spacing, PCB wiring, when the pad area is small, it can reduce the area and reduce the size of the PCB while completing the continuity.

Our common vippo is mainly used in the packaging area of BGA, because when its surface needs to be soldered or chip attached, its accuracy and acceptable area are high, and the flatness of the surface is also high, preventing the unevenness of the chip from causing false Welding or joints are poor, so we recommend the regular surface treatment to be chemical nickel gold.

The customer requires that the hole needs to be plugged with a certain material (conventional 0.6mm or less), and when electroplating is filled, the vippo process is used. In the BGA area, the vias are punched on the BGA solder joints, combined with the patch layer, the soldering layer, and the solder mask layer to determine whether it is a vippo PCB. The size of the vias in the BGA area is generally below 0.3mm, and the solder joints are generally 10mil. Left and right, judge whether it is a vippo PCB by the size of D code.