BLUE OVEN MIGP6680 STANDARD OPERATING

PROCEDURE

Version: 1.0 Mar 2013

UNIVERSITY OF TEXAS AT ARLINGTON

Nanotechnology Research and Education Center

Operating Instructions for Blue M Inert Gas Oven

1.0 Scope: The Blue M Inert Gas Oven (IGF 6680) is intended for the thermal treatment of materials

at temperatures between 50°C and 593° C. The primary function of the oven is the curing of

polyimide resin for the fabrication of MEMS devices. Other materials may be used, with the

specific permission of Nanofab management. It is imperative to obtain this permission prior to

using other materials. Failure to obtain proper permission will result in disciplinary action.

2.0 General Description: Operation of the Inert Gas Oven requires that the material be placed inside

the oven before it is turned on. The oven will then purge with nitrogen for approximately 30

minutes before power is applied. At the end of the purge cycle, one of two programs must be

started. These programs are configured by the user to specify the temperature, the rate of

temperature rise, the duration of the treatment, and the rate at which the oven cools. Up to ten

steps may be specified in a program.

Note: As there are only two programs available to users, it is not possible for any user to

assume that their program has been left unmolested. The user must check and, most likely,

reprogram the controller before each use.

3.0 Operating Instructions

3.1 Assure that the oven is not presently operating by verifying that the power switch is in the off

position and the Chamber Power Light is NOT illuminated. See Figure 1. If the Chamber Power

Light, or any other light on the oven, is illuminated, the system is in use. Do not proceed further

until establishing who is using the oven, and when the oven will be available. If it is clear that

the oven is not in use, proceed to the next step.

3.2 Open the oven door by pulling out on two large black levers located on the oven chamber door.

See Figure 2. Swing the door open. Open the stainless steel door that is behind the main door.

3.3 Place the sample, or samples, on the shelf located inside the chamber. Each user should establish

a protocol for locating their samples in order to minimize unnecessary variation in their process.

3.4 Close the stainless steel inner door, and the outer oven door. Push the large black levers on the

door so that the oven door is sealed closed.

3.5 Turn on the oven power by moving the Oven Power toggle switch (Figure 1) to the UP position.

The Chamber Power Light will illuminate. If the light fails to illuminate, contact a Nanofab staff

member.

Note: The oven will be purged with nitrogen for approximately thirty minutes. During

this time the function is controlled by a time delay relay and cannot be adjusted by

programming the controller. During this time, the Purge light and the Cooling light

(Figure 1) will be illuminated.

3.6 Verify that the flowmeter located on the black box attached to the top left side of the oven

(Figure 2), labeled “Oven Flow and Purge Adjustment” indicates approximately 100 SCFH. If

the flow is less than 90 SCFH, contact a Nanofab staff member for assistance. DO NOT

ATTEMPT TO ADUST the flow meter.

3.7 Program the PRO-350 Controller

Note: The PRO-350 Controller display is capable of a limited set of characters.

Consequently, the display will frequently display what appears to be gibberish. Some of

the characters displayed cannot be duplicated in print. Refer to the figures, as directed by

these instructions, for explanation.

3.7.1 Assure that the controller is in Local Mode by pressing the LOCAL pad (Figure 1) for at least

three seconds. The green led under the word LOCAL will illuminate when the controller is in

local mode.

3.7.2 Note the temperature present in the oven by reading the number on the PRO-350 labeled “PV”

(Process Variable). Adjust the Set Point (SP) to a number less than the PV by pressing the Down

Arrow as often as needed. Any number below 20 will be adequate. The decimal point next to the

SP number will be flashing. Press the SET/ENT button (Figure 2). The decimal point will stop

flashing. This practice will prevent the oven heating before the program is started.

3.7.3 Press SET/ENT for approximately three seconds. At this time, the oP.PA display (Figure 3)

will appear.

3.7.4 Press the SET/ENT pad again and the rST (Reset) display will appear (Figure 4).

Note: The choice of program number is arbitrary. These instructions will assume program 1

has been selected. Had program 2 been selected, the first digit of the PV display in the figures

to follow would have been 2, instead of 1.

3.7.5 Press either the Prg 1 or the 2 Prg button. The 1.Eon display will appear (Figure 5). This

display refers to the elapsed time, from the start of the program, when the cooling fan should

turn on. Generally, the cooling fan is not used. Press SET/ENT to skip this entry.

3.7.6 The display will now show 1.Eof (Figure 6). This is where the elapsed time at which the

cooling fan should turn off would be entered. Press SET/ENT to skip this entry.

3.7.7 The display will now show 1.Al 1. (Figure 7). This is for setting an alarm condition. It is not

used. Press SET/ENT to skip this entry.

3.7.8 The display will now show 1.SSP (Figure 8). This is the starting set point. It will be used by the

controller for calculating ramp rates. 25° C is recommended; you may change this value by

pressing the up (↑) or down (↓) pad. When the desired value is displayed, press SET/ENT to set

the value.

3.7.9 The display will show 1.StC (Figure 9). This sets the controller to “gradient priority.” The SP

value should always be set to 1. If necessary, use the up (↑) or down (↓) pad to set SP to 1. If it

was necessary to change the value, press SET/ENT twice. Otherwise, press SET/ENT once.

3.7.10 The display will show 1.SP1 (Figure 10). This allows the first temperature to be set. If, for

example, the desired temperature is 250° C, use the up (↑) or down (↓) pad to set SP to 250. If it

was necessary to change the value, press SET/ENT twice. Otherwise, press SET/ENT once.

3.7.11 The display will show 1.Tm1 (Figure 11). The actual symbol used for “m” is different, and is

shown in Figure 11. The SP value will be the time period over which the temperature will be

raised. If, for example, the SP value were set to 1.00, then it would take 1 hour to ramp from the

SSP value to the 1.SP1 value. In this case:

mindeg/75.3min6025250=°−°=rate

The equation given above may be recast, and used to calculate the time needed to produce a

desired rate. For example, if a 5° C per minute rate is desired: min45min525250=°°−°=time

Adjust the time, using the up (↑) or down (↓) pad, and press SET/ENT. Press SET/ENT a

second time to move to the next step.

3.7.12 The display will show 1.SP2. This allows the second temperature to be set. If, for example, it

is desired to have the temperature stay at 250° C, use the up (↑) or down (↓) pad to set SP to 250.

On the other hand, if it is desired to ramp to another temperature, use the (↑) or down (↓) pad to

set SP to that temperature If it was necessary to change the value, press SET/ENT twice.

Otherwise, press SET/ENT once.

3.7.13 The display will show 1.Tm2 . If it is desired to have the oven stay at the temperature used for

the ramp in the first step, enter the desired dwell time. If it is

desired to ramp to a new temperature, enter the ramp time, calculated as shown in 3.7.11.

3.7.14 The eight remaining program steps may be used, as needed to establish the desired

temperature-time profile. The last program step should be a controlled cool-down. At the

program step where cool-down is desired, the display will show 1.SP X (X= 2 – 10). Use the (↑)

or down(↑) or down (↓) pad to set SP to that to set SP to the desired temperature e.g., 25°C. Press

SET/ENT to set the input. Press SET/ENT again to move to 1.TmX. Enter the rate, as a positive

number, as calculated in 3.7.11. Press SET/ENT to set the entry, and then press SET/ENT again

to move to the next step.

3.7.15 After entering all steps of the desired temperature profile, if fewer than ten steps have been

entered, set the following step, 1.SP(X+1), to 0 using the down (↓) pad . Press SET/ENT to

register the set point, then press SET/ENT again to move to the next step.

3.7.16 Verify that the 1.Tm(X+1) is “OFF.”

3.7.17 Press SET/ENT for three seconds. This will cause the program edit mode to close.

3.7.18 Verify the program by repeating 3.7.3 through 3.7.17, without changing any steps unless

parameters were incorrectly entered.

3.7.19 Repeat 3.7.18 until no errors are found.

3.8 Wait until the purge period expires; the “cooling” light and the “purge” light will extinguish. The

“heat” light will illuminate.

3.9 Verify that the flowmeter located on the black box attached to the top left side of the oven

(Figure 2), labeled “Oven Flow and Purge Adjustment” indicates between 20 and 25 SCFH. If

the flow is outside this range, contact Nanofab personnel for assistance. Do not attempt to adjust

the flow.

3.10 Verify that the flowmeter located on the black box attached to the top left side of the oven

(Figure 2), labeled “Throat Flow” is between 5 and 10 SCFH. If the flow is outside this range,

contact Nanofab personnel for assistance. Do not attempt to adjust the flow.

3.11 Press the appropriate program number button for three seconds to start the program.

3.12 After the run is complete, press the “Local” pad for three seconds to return the controller to

local mode.

3.13 When the oven temperature, as indicated by the PV display on the controller, is approximately

50° C, or lower, it is safe to open the oven. Remove the sample, and close the door as described

in 3.4.

3.14 Turn off the oven by setting the Oven Power toggle switch (Figure 1) to the Down position. Figures