Технология PCB - технология омеднения в процессе гальванизации платы PCB

Introduction of copper plating process technology for PCB плата цепи electroplating processing

The main feature of the electroplated hole copper plating processing technology used by the плата цепи изготовитель будет производить многослойное сопротивление плата цепи is the blind and buried vias of the micro vias formed in the "core board" of the multilayer PCB плата цепи. микропроходное отверстие необходимо осуществлять через сверление и омеднение. The most critical aspect of this blind buried hole for hole metallization and electroplating is the access and replacement of the electroplating solution.

Circuit board manufacturers manufacture multi-layer PCBs by coating or laminating a dielectric layer (or resin-coated copper foil) on the surface of the "core board" and forming micro-vias. Эти микропроходные отверстия, сформировавшиеся на слое "стержневой пластины", изготовлены, в частности, путем фотоиндукции, плазменный метод, laser method and sandblasting method (mechanical method, числовой метод бурения, сорт.) Made. These micro-vias on многослойная плата PCB для обеспечения электрической связи между слоем PCB требуется металлизация и омеднение. This section mainly introduces the characteristics and requirements of micro-vias in PCB boards during boring and electroplating.

сквозное отверстие, if it is a vertical hole plating, the PCB manufacturer can swing, vibrate, перемешивающий гальванический раствор, or spray flow in the plate making fixture (or hanger) to make the PCB on the two plates of the plate. между ними гидравлический напор. This hydraulic pressure difference will force the plating solution into the hole and drive away the gas in the hole to fill the hole. For high aspect ratio (thickness to diameter ratio: the ratio of the thickness of the dielectric layer to the micro-via hole) Small holes, наличие такого перепада давления более важно, затем перфорация или гальванизация. During pore electroplating, part of the Cu2+ ions in the plating solution in the hole must be consumed. Therefore, the Cu2+ concentration of the plating solution in the hole is getting lower and lower, а эффективность отверстия или гальванизации будет все меньше и меньше. In addition to the effect of the plating fluid in the through hole (such as a "laminar flow" phenomenon, etc.) and the uneven current density distribution (the electric current density in the hole is much lower than the current density on the plate surface), поэтому, the center of the hole The thickness of the coating is always lower than the thickness of the coating at the board surface. для уменьшения толщины покрытия, the most fundamental method is: one is to increase the flow rate of the plating solution in the hole or the number of exchanges of the plating solution in the hole per unit time (assuming that the plating solution is changed again and again, Это действительно сложно, but this assumption can explain the problem); the second is to increase the current density in the hole, Это очевидно трудно или невозможно, because increasing the current density of the plating solution in the hole is bound to be Increasing the current density of the plate surface, поэтому, it will cause a greater difference between the thickness of the plating layer in the center of the hole and the thickness of the plate surface; the third is to reduce the current density during electroplating and the concentration of Cu2+ ions in the plating solution, and at the same time Increase the flow rate of the plating solution in the hole (or the number of exchanges of the plating solution), такой, can reduce the difference of Cu2+ ion concentration in the plating solution between the plate surface and the hole (referring to the difference between partial consumption of Cu2+ and replacement of the plating solution. Cu2+ concentration difference), this measure and method can improve the difference between the thickness of the plating layer on the board and the plating layer in the hole (at the center), but it is often at the expense of PCB productivity (yield), which is again undesirable. четвёртый, the use of pulse electroplating method, микропористость по отношению к другой толщине, the corresponding pulse current electroplating method {can significantly improve the difference between the PCB board surface plating and the thickness of the plating layer in the hole, даже до такой же толщины покрытия. Are these measures applicable to the hole plating of micro-vias in многослойная плата PCB?

Как отмечалось выше, the pore plating of micro-vias in multilayer плата цепиS пройти в слепой дыре. When the hole depth of the blind holes is small or the thickness-to-diameter ratio is small, Практика показала, что все четыре вышеназванных гальванических мероприятия дают хорошие результаты.. However, когда толщина слепого отверстия выше или больше, how reliable is the plating of micro vias? Иными словами, how to control the depth of the blind hole or the appropriate degree of thickness to diameter ratio of the multilayer плата цепи?

для обработки микропористого отверстия в многослойном PCB с помощью гальванизации горизонтальных отверстий, there is no detailed report, Но мы можем себе представить отношение толщины PCB к диаметру, horizontal hole plating is used. Необходимо обеспечить надежные электрические межсоединения. For blind vias with a larger aspect ratio, слепое отверстие под многослойной оболочкой плата цепи are difficult to drive off the gas in the hole, гальваническое даже трудно попасть в отверстие, не говоря уже об обмене раствором гальванизации в отверстии., unless the plate surface is regularly turned over.

словом, according to the basic characteristics and basic principles of the holeization and electroplating processing of the above multilayer PCB board, Мы можем сделать вывод, что слепое отверстие в многослойной мембране и закопанное отверстие плата цепи are processed by horizontal hole plating (especially the Large aspect ratio, such as aspect ratio>0.8), эффект гальванизации.