Разработка ионно-плазменной технологической установки для нанесения функционального покрытия на крышки масляных фильтров, страница 23

The considered cylinder at rotation has the constant area of a surface on which the sprayed covering is besieged, equals to 1/3 area of lateral surface S_ц of the considered cylinder. Then we can define the ratio between weights of sprayed and besieged covering:

.                                                         (3.12)

The area of the cylinders lateral surface:

S=π·d·h,                                                       (3.13)

where d and h – diameter and height of the cylinder accordingly.

The ratio between weight of besieged and sprayed covering:

.

The weight of sprayed and besieged covering is defined under the formula:

m=Vρ=Sδρ.                                                            (3.14)

Then the ratio (3.11) will become:

S_оδ_о=0,762·S_кδ_к ,                                                   (3.15)

where S_о and δ_о – the total area of filters covers  surface and thickness of depositing coverings, S_к and δ_к – the area of  sprayed surface and thickness of the sprayed layer.

Thickness of depositing coverings 0,5 microns, S_к=0.012 m².

From expression (3.15) we can define δ_к:

;                                                        (3.16)

m;

Time of covering deposition with thickness of 0,5 microns:

,                                                        (3.17)

h.

As in designed installation the covering is deposited simultaneously on 15 covers, and film deposition on lateral surfaces of every product is provided by two magnetrons thickness 0,5 microns will make time of covering  deposition of 0,05 h. Received time of covering  deposition less certain in section 3.1. It speaks that at the given speed of dispersion and the geometrical sizes of the chamber and sources the surface of processable products at moving from clearing compartment in the compartment of covering deposition remains clean from the adsorbed atoms of residual gases.

Thickness of the cathode decreases on 20 … 25 mm in process of its dispersion, hence δ_к increases a little. Also at reduction of target thickness there is a growth of dispersion intensity because of increase in magnetic field induction.

These factors influence rated conditions of dispersion; however it is not so ssential. The error makes no more than 10 %, and it can be considered by bringing in the correction factor depending on total time of target dispersion.

Proceeding from that in time 0,05 h is necessary to put a covering thickness 0,5 microns also on the bottoms of covers we shall calculate critical parameters of three top magnetrons.

The area of a sprayed cathode  surface of this magnetron  S_к = 0,006 m². Proceeding from (3.11) we shall define the ratio between weights of sprayed and besieged covering:

,                                                           (3.18)

where S_д = π∙R² = 0,005 m², S_п = 0,055 m².

The ratio between weight of besieged and sprayed covering:

.

Then the ratio (3.12) will become:

S_оδ_о=0,45·S_кδ_к ,                                                     (3.19)

where S_о and δ_о – the total area of a surface of the filters  cover  bottom  and thickness of depositing coverings, S_к and δ_к – the area of sprayed surface and thickness of the sprayed layer.

Thickness of depositing covering 0,5 microns, S_к=0,006 m².

From expression (3.19) it is determined δ_к:

;                                                         (3.20)

m.

From (3.18) we define dispersion speed of target  material in time 0,1 h, and from (3.10) ionic current density:

m/s

 А/sm².

Proceeding from (3.7) we define discharge current:

 А.

Using expressions (3.2-3.6) it is defined working voltage: U_р = 580 V.

Thus, time of covering deposition thickness in 0,5 microns on 3 covers simultaneously in developed installation makes 0,05 hours. So long process of drawing speaks the following:

- A total area of covers surface in 15 times more the areas of  sprayed target surface;