1. VFD Production Process & QA

2. VFD Construction Exhaust Tip Getter Filament Lead Contact Lead Anode
The VFD has a triode structure in which the front and base plate constitute a vacuum envelope, in which the filament cathode, grid and anode are arranged to form electrodes.
Figure above shows:
The Aluminium wiring pattern.
The Carbon insulation layer printed onto the base plate.
The anode pattern printed onto the carbon layer.
Grid mesh photo etched from stainless steel & placed over the anodes.
Grid & anodes are connected to the pins via the wiring on the base plate.
Filament wires (Cathodes) are stretched above the grids & anodes and anchored at each end.
The complete structure is then sealed at 500°C & evacuated to torr, to ensure free electron movement.
Anode
Insulation
Layer
Grid
Glass
Substrate
Anode
Wiring

3. Basic VFD Construction
Side Glass
Front Glass
Phosphor pattern
Filament wires
Grid
Anodes
Isolation layer
Wiring pattern etched into aluminium layer
Evacuation hole
Connection leads
Base Glass
+ Sealing cap

4. Aluminum Wiring Process
Wiring pattern is made by chemical photo etching
A thin Aluminum film is sputtered on 300×300 mm base glass plate

5. Isolation Layer Carbon pad Printing Process
The isolation layer is printed on the wiring pattern made by etching process
The carbon layer is added for el-ectrical connection improvement on the through hole made by isolation film
Terminal pad printing is added for later external lead frame connection

6. Phosphor Printing Process
Before printing the phosphor pattern, the sealing paste to be printed for final assembly　　　　
Max
Temp
12:15 AM
Phosphor pattern is printed (one color for one screen),12 different colours are available

7. Self Standing Grid
A set of grids (metal mesh) are bonded over the top of the phosphor, fixed by SSG bond paste
ＦＵＴＡＢＡ
ＶＦＤ
ＣＩＧＶＦＤ
ＦＥＧ

8. CIG and Wire Bonding
IC driver is connected to base glass by aluminium wire
Using IC driver inside VFD, the number of external lead terminals is reduced significantly

9. Final Assembly & Exhausting
Base plate, Metal frame and Front Glass are assembled
The assembled VFD is sealed in oven
Exhausting air creates vacuum tube
Getter flashing removes residual gases

10. Aging & Display inspection
Aging process to equalize phosphor luminance (e.g C, 2hrs, all segments on)
Lead cutting, brushing, soldering & bending process
Final inspection: short circuit, failure modes, double check QA

11. Manufacturing Flow Chart (1)
Cleaning 300 x 300 glass
Aluminium sputtering
Cleaning
Photo-resist printing
UV exposure
Development
Etching
Photo-resist removal
Base-plate wiring continuity test
First insulation layer printing
Curing
Drilling of exhaust hole
Cleaning & Drying
Second insulation layer printing
Base-plate inspection
Carbon printing
Drying
Terminal pad printing
Sealing paste printing
Phosphor paste printing
Grid bonding paste printing
Grid bonding assembly
Basic Flow chart – based on BH211GN

12. Manufacturing Flow Chart (2)
Substrate insulation inspection
Substrate cutting
Frame, mesh Hydrogen treatment
Terminal forming
Filament anchor welding
Filament welding
Getter welding
Mount check
Final assembly
Sealing
Exhausting
Getter flashing
Baking
Aging
Lead cutting
Lead brushing
Soldering
In-process inspection
Lead forming
Labelling
External inspection
Out going inspection
Shipping
Packaging

13. A word about Phosphor
“Phosphor” is a generic term. Chemically “Phosphor” is mainly a mixture of zinc and zinc oxides (zno:zn)
Phosphors are available in 17 different colours.
Most commonly specified is green because it has
greatest luminance (>2000 cd/sq m)
longest lifetime – 30,000 hours to ½ brightness
cost – high volume reduces cost
can be filtered to produce range of effects
wavelength of 550nm
Phosphor description.

14. Quality Management Systems
Futaba Corporation holds Certificates issued for the following systems:
ISO 9001 / ISO Quality Management
ISO Environment Management
ISO TS Extended Automotive QA Requirements

15. Our Quality Policy
It is the quality goal of Futaba Corporation to continuously improve its product acceptance in PPM level, and finally reach the ultimate goal of:
Innovation, quality and dependability will continue to be hallmarks of our growth and Futaba‘s commitment to quality in all aspects of operations is the base for our position of market leadership
Process Control
Process FMEA
Control plan
Inspection criteria
Monitoring
Test method.

16. Functional / Durability
Reliability Testing (1)
Test Item
Test Conditions
Life
Lighted for 1000 hours at room temperature, rated voltage applied.
Vibration fatigue
Lighted, 4.4G acceleration, 2000 cpm vibration, applied for 4 hours in the X plane and 2 hours each in the Y and Z planes.
High temperature operation
Lighted, for 96 hours at +85° ± 2ºC.
Temperature Cycling
Lighted subject to the specified test conditions as shown, for 5 cycles.
30 mins
15 mins
85°C -0 +3
-30°C -3 +0
25°C -5
+10
Functional / Durability
Heater Cycling
Filament voltage at 120% of the rated voltage and cycles without voltage applied to anode and grid.
10 seconds
5 seconds

17. Reliability Testing (2)
Test Item
Test Conditions
High temperature Storage
Unlighted, for 72 hours at +85° ± 2ºC.
Low temperature Storage
Unlighted, for 72 hours at -40° ± 3ºC.
Thermal Shock
Unlighted subject to the specified test conditions as shown, for 5 cycles.
30 mins
5 mins
85°C -0 +3
-55°C -3 +0
25°C -5
+10
Environmental Test
Humidity (Steady State)
Unlighted, subject to a relative humidity of 90 to 95%, at a temperature of 40° ± 2ºC, for 96 hours.

18. Physical Characteristics
Reliability Testing (3)
Test Item
Test Conditions
Vibration (1)
Shock
Solderability
Unlighted, 1.5mm total excursion, 10 – 55Hz frequency. Sweep time cycle 1 minute. Vibration applied for 2 hours in each X, Y and Z planes.
Unlighted, 100G maximum acceleration, 6 ms duration, half sine wave 3 times in each X, X’, Y, Y’ and Z, Z’ planes (18 times in total in unlighted state).
Immerse in a 230° ± 5ºC solder pot for 5 seconds.
Physical Characteristics
Vibration (2)
Unlighted, 4G acceleration, 55 – 200 Hz frequency. Sweep time cycle 10 minutes. Vibration applied for 2 hours in each X, Y and Z planes.
Resistance to Soldering Heat
Immerse in a 280° ± 5ºC solder pot for 30 ± 2 seconds.
Terminal Strength
Attach 250g weight to leads. Bend leads through 90° and then return to original position, 3 cycles.

19. Thank you for your attention!