| USER MAINTENANCE | |
| 4-1 | GENERAL |
| Maintenance on the Plasma-Prep II consists of cleaning, changing RF tubes, replacing such spare parts as "O" rings, lamps and fuses. In addition, a procedure is given for tuning the RF oscillator circuit board (see Section 4-9, 4-10). Any other repairs should be performed by SPI Supplies. The maintenance flow chart (Figure 4-2a, 2b, 2c) is a convenience to help both the user and maintenance personnel understand the relationship between symptom and cause. | |
| 4-2 | CLEANING |
| Cleaning consists of a routine procedure which should be performed periodically. This schedule will depend on frequency of use, type of materials processed and the environment in which the machine has to operate. Routine Procedure: The inner chamber will require more frequent cleaning than the outer chamber as it is more likely to "see" contamination. For light contamination, running an oxygen plasma for a few minutes should be enough to clean the chamber. For more difficult contaminants, (inorganic films and residues), use standard laboratory cleaning procedures. Remove the inner chamber and wash the chamber with a test tube brush and a good laboratory detergent. If this is not effective, it will be necessary to use an oxidizing agent. Refer to the "Handbook of Chemistry and Physics" for the proper agent. The outer chamber will also require a similar procedure, but requires cleaning about half as frequently as the inner chamber. | |
| 4-3 | REPLACING RF TUBES |
| ***WARNING*** | |
| Disconnect the Plasma-Prep II from AC power before replacing the RF tubes. | |
| If the RF tubes have to be replaced, proceed as follows: [refer to the operation and maintenance flow chart (Fig. 4-1) for RF tube failure symptoms]. | |
| a. | Remove the 4 screws that fasten on the sheet metal cover and remove the top cover. |
| b. | Unscrew the attaching hardware and remove the leads to the tube plate caps. The old tubes can then be lifted out of their sockets. CAUTION: Tubes can be hot. |
| c. | Replace with the new tubes and reattach the leads to the plate caps with the same hardware. |
| NOTE: It is good practice to avoid handling the tubes by the glass barrels. Always hold the tubes by their bases with clean hands. This will increase tube life. | |
| 4-4 | TUNING THE RF OSCILLATOR |
| To retune the RF oscillator, proceed as follows: (this procedure should be performed by a qualified electronic technician). | |
| ***WARNING*** | |
| a. | Unplug the AC connector from the power source. |
| b. | Remove the top and bottom cover and turn the Plasma-Prep II on its side. |
| c. | The AC interlock switches have to be overridden; that is, mechanically held in "closed" position. |
| d. | Connect VOM test leads between OSC and GND test points at rear of the machine. Set the VOM to the 50mA DC scale (or as close to that scale as your test instrument supplies). |
| e. | Plug in the AC cord of the Plasma-Prep II. Push AC pushbutton switch. Allow at least 1 minute for the tubes to warm up. |
| f. | On the oscillator circuit board (see Figure 4-2) adjust trim capacitor C7 for maximum reading on the VOM. |
| g. | Tune trim capacitor C11 for a maximum reading on the VOM. The reading should be at least 12-15mA and can be higher. Repeat (f) and (g) until no more can be achieved. |
| h. | The machine can be closed up again. Make sure that the interlock overriding devices are removed before the top and bottom covers are replaced. |
| Figures 4-2a to 4-2d are first level flow charts for troubleshooting. | |
| 4-5 | VACUUM SYSTEM ADJUSTMENTS |
| The process gas flow is adjusted by the internal needle valve located at the rear top of the instrument just after the connector for the gas line. This should be adjusted for the appropriate chamber pressure by attaching a vacuum gauge to the pressure monitor port. | |
| The chamber bleed to atmosphere is controlled by a bleed valve solenoid located on the left side of the chassis beside the chassis connector for the power transformer. The adjustment is a set screw. Turning it clockwise closes the valve and increases the time to bleed to ATM. | |
| 4-6 | SUCCESSFUL FUNCTIONING OF YOUR EQUIPMENT |
| Successful functioning of your equipment depends upon a proper vacuum. Your vacuum pump should be serviced on a frequent and regular schedule. Pump fluid changes should be done on a regular schedule per the pump manufacturers recommendation. | |
| 4-7 | SPARE PARTS LIST |
| SPI # | PART NUMBER DESCRIPTION |
| 11008-AB | 4" ID Inner Pyrex Chamber |
| 11009-AB | 4" ID Outer Pyrex Chamber |
| 11010-AB | 4" ID "O" Ring |
| 11011-AB | Fuse, Bus 7AMP |
| 11013-AB | Solenoid Valve, Straight thru |
| 11014-AB | Solenoid Valve, Metering |
| 11015-AB | Lamp, 12V |
| 11024-AB | "O" Ring for Outer Chamber |
| 11022-AC | RF Power Tubes (Set of 2) |
| 11022-AB | RF Power Tube (1) |
| 11026-AB | Quartz Inner Chamber |
| 11027-AB | Quartz Outer Chamber |
| 11005RF | Power Board |
| 11005M-AB | Meter |
| 11005P-AB | Photodetect Board |
| 11005T1-AB | H.V. Supply Transformer |
| 11005T2-AB | Bias/Filament Supply Transformer |
| 4-8 | CUSTOMER RETURN INFORMATION |
| If a Plasma Prep II is to be returned to SPI Supplies for whatever reason, the following procedure should be followed: | |
| 1. | From the USA, call SPI Supplies' Customer Service Department, 800-2424-SPI for a Return Authorization Number (RA#). If unit is not received with this RA number on the outside of the box, it will be rejected by the Receiving Department. From Canada, call (610) 436-5400 following the same instructions. For other countries, contact either your closest SPI Supplies agent or SPI Supplies in the USA by phone (610) 436-5400, FAX: (610) 436-5755 or e-mail SpiSupp@aol.com following the same instructions. |
| 2. | Repack the machine in its original shipping container. If this is no longer available, take special precautions to avoid damage to the glass chamber sections and other fragile components. DO NOT SHIP ANY GLASSWARE ASSEMBLED WITH THE UNIT. |
| 3. | If the machine is still under warranty, the only charges are shipping costs. If the machine is out of warranty, a purchase order will be required for approved accounts and customer can expect to be billed for all parts and service. All others will require some form of guaranteed prepayment such as a letter of credit. |
| 4-9 | |
| SUBSTRATE TO BE ETCHED | REACTIVE GAS OR GAS MIXTURE |
| Stainless Steel | CF4 CF4/O2 mixture (experiment for correct proportions) CCl4-necessary if chromium present |
| Hydrocarbons, all organics, polymers, etc. | O2 |
| Metal oxides | Ar |
| SiO2; Si3N4 (passivation layers) | CF4 or other reactive fluorine gases |
| Plastic packages | Combination of O2 and CF4, O2 to etch plastic, CF4 to etch glass filler. Typical formula: % 10 O2/% 90 CF4 |
| Aluminum and aluminum alloys | Cl2; CCl4; or mixtures of Cl2 + CCl4 |
| NOTE: Initially use small amount of Br2 in mixture to remove surface skin of Al2O3. Also useful are CF4 and CHF3 for this purpose | |
| Al2O3; all forms of anodized aluminum; oxide layers on electronic circuits | |
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