Practicing How To Love Brexit

What is the best way to write an essay

Often apply special kratsevalny installation to bilateral mechanical cleaning of a surface of folgirovanny dielectric. Processing of a surface is made by the rotating brass brushes in a stream of technological solution. Installation can process preparations with a maximum size of 500500 mm at their thickness of 0,1-3,0 mm, the frequency of rotation of brushes of 1200 rpm, effort of preload of payments to brushes of 147 N.

At a varnish choice for a sheeting it is also necessary to consider properties of the materials used for production of the basis of the printed-circuit board and for gluing of conductors that at polymerization of a covering there was no change of properties of these materials.

Also odnoshpindelny semiautomatic device which can work both with a projector, and with the probe is widely applied. On the machine it is possible to process preparations of payments with a maximum size of 520420 mm at a thickness of package of 12 mm. Frequency of rotation of a spindle of 15 000-30 000 rpm (changes in steps). The maximum diameter of drilling is 2,5 mm.

Now use some types of machines for drilling of printed-circuit boards. Generally it is mnogoshpindelny high-speed machines with program control on which besides drillings of openings in printed-circuit boards also chamfering or drilling of openings in a package without chamfering is at the same time made.

Drilling does not exclude possibility of receiving openings and stamping if it is allowed by conditions of quality or is defined by a form of openings. So, stamping it is expedient to make openings in unilateral payments under conclusions of elements and in layers of MPP made by method of open contact areas where punched windows have a rectangular shape.

The positive combined way is the basic at production of two-sided printed-circuit boards. Advantage of the positive combined method in comparison with negative is good adhesion of the conductor, the increased reliability of assembly and transitional openings, high electroinsulating properties. The last is explained by that at long processing in chemically aggressive solutions (solutions of a chemical medneniye, electrolytes, etc.) the dielectric basis is protected by a foil.

The listed above data on elements will give the chance to the designer of the printed-circuit board to develop topology of the printed-circuit board, to determine its geometrical sizes and coordinates of fixing openings, optimum to place electroradioelements on a payment. This drawing is a basis for all subsequent design works.

In this technological process of preparation we will drill in a package on the S-10 boring machine the Speed of rotation of a drill thus has to be within 15 000-20 000 rpm, and the axial speed of giving of a drill - 5-10 mm/min. of Preparation gather in the conductor, are fixed and on the boring machine basic openings are bored through.

Preparation, installation (including on glue), the soldering of integrated chips, microassemblies and other electroradioelements on the printed-circuit board, and also moisture protection as a part of printing knots needs to be made them taking into account requirements of specifications of electroradioelements, OST 107063-81, OST 107011-79, OST 1 33900-79, OST 107069-8

High quality of cleaning is received at a combination of hydroabrasive processing to use of water suspension and a kratsevaniye. Installations for cleaning of lateral surfaces of preparations and openings of printed-circuit boards as nylon brushes and pumiceous suspension work at this principle.

For increase of protective properties of liquid photoresist after exhibiting and manifestation carry out its thermal tanning. For this purpose use cases with an electroheater. At a temperature of heating of a chamber to 150 0 C the cycle of a tanning lasts 4-4,5 h. More effective is application of installations of a tanning of photoresist in fusion of salts.

Widely use chemical and mechanical ways of preparation of a surface or their combination. The preserving coverings easily are removed organic solvent, with the subsequent washing in water and drying. Oxide films, dust and organic pollution are removed consecutive washing in organic solvents (a xylol, benzene, freon and water solutions of phosphates, soda, a caustic natr.