Method for fabrication of metallized medical devices

A method for fabricating a catheter in which a lumen is metal-coated, comprising the steps of:

• preparing an inner surface of an elongated polymer tube;
• electroless depositing a layer of a metal onto said inner surface, wherein said step of preparing said inner surface comprises the steps of:
• cleaning said inner surface with an ultrasonic cleaner in a solution of one of 2-Propanol and isopropyl alcohol CH.sub.3 CHOHCH.sub.3 ;
• drying;
• and
• etching said inner surface with a solution of sodium naphthalene in diethylene glycol dimethyl ether with a concentration of sodium naphthalene of approximately 0.7 Mol/liter;
• further comprising the steps of:
• washing said lumen a first time with one of N-butyl alcohol, methyl alcohol, and acetone;
• rinsing with deionized water following said step of washing a first time;
• following said step of rinsing, etching with sulfochromic acid solution containing about 75 g/l chromic acid, and 250 g/l sulfuric acid, at room temperature for a duration of 20 seconds;
• following said step of etching with sulfochromic acid solution, washing a second time with distilled water;
• following said step of etching with sulfochromic acid solution, cleaning in diluted hydrochloric acid;
• following said step of cleaning in diluted hydrochloric acid, rinsing a second time with deionized water;
• following said step of rinsing a second time, sensitizing with a solution containing 70 g/l stannous chloride, and 40 ml/l of hydrochloric acid, at room temperature for between 5 and 15 minutes;
• following said step of sensitizing, washing a second time with deionized water;
• following said sensitizing step, activating with a solution containing 1 g/l of palladium chloride, and 5 ml/l of hydrochloric acid, at room temperature for five to ten minutes;
• following said step of sensitizing, rinsing a third time with deionized water;
• following said step of rinsing a third time, plating by flowing a silver plating solution at room temperature through the lumen of the catheter, said silver plating solution containing 0.05 to 0.6M AgNO.sub.3,4.3.times.10.sup.-4 M dodecylbenzenesulfonic acid acid sodium salt (C.sub.12 H.sub.25 C.sub.6 H.sub.4 SO.sub.3 Na), 4.75M ammonium hydroxide (NH.sub.4 OH), and a quantity of acetic acid (CH.sub.3 CO.sub.2 H) sufficient to bring the final pH into the range from 7.5 to 10;
• and
• adding a reducer solution one of immediately prior to and concurrently with application of said plating solution, said reducer solution containing 0.15M of hydrazine (N.sub.2 H.sub.4.xH.sub.2 O).

A method for coating the interior of a dielectric tube, comprising the steps of:

• inserting a conductive target wire electrode into the lumen of said dielectric tube;
• maintaining an atmosphere of gas around said wire electrode at a pressure sufficient to allow glow discharge;
• and
• applying RF voltage between said wire electrode and an electrode exterior to said tube which is sufficient to cause said glow discharge, whereby said wire electrode produces coating atoms.

A method for coating the interior of a dielectric tube, comprising the steps of:

• inserting an electrically conductive target wire into the lumen of said dielectric tube;
• maintaining said wire spaced away from the walls of said lumen;
• maintaining an atmosphere of gas around said wire sufficiently low for efficient sublimation;
• and
• passing a current through said wire sufficient to heat said wire to sublime.