Hitachi AP1 Data Book page 25

stances such as temperature, humidity and dust,
and the control of submaterials,like gas, and pure
water used in a manufacturing process, are inten-
sively executed.
Dust control is essential to realize higher integra-
tion and higher reliability of devices. At Hitachi,
maintenance and improvement of cleanliness at
manufacturing sites is accomplished through
QUALITY ASSURANCE
attention to buildings, facilities, air conditioning
systems, delivered materials, clothes, work envir-
onment, and periodic inspection of floating dust
concentration.
3.3.3 Final Product Inspection and Reliability
Assurance
(1) Final Product Inspection
Lot inspection is done by the quality assurance
Process Control Point
Purpose of Control
Purchase of Material
Wafer,
I--
Surface Oxidation
Frame
Package
Inspection on Surface
Oxidation
Photo Resist
Inspection on Photo Resist
<> Pac Level Check
Diffusion
Inspection on Diffusion
<>
pac
Level Check
Evaporation
Inspection on Evaporation
<> Pac Level Check
Wafer Inspection
Inspection on Chip
Electrical Characteristics
Chip Scribe
Inspection on Chip
Appearance
<> Pac Lot Judgement
Assembling
<> Pac Level Check
Inspection after
Assembling
<>
Pac Lot Judgement
Sealing
<>
pac
Level Check
Final Electrical Inspection
<> Failure Analysis
Appearance Inspection
Sampling Inspection on
Products
Receiving
Shipment
Wafer
Oxidation
Photo
Resist
Diffusion
Evapora·
tion
Wafer
Chip
Characteristics, Appearance
Appearance, Thickness of
Oxide Film
Dimension, Appearance
Diffusion Depth, Sheet
Resistance
Gate Width
Characteristics of Oxide Film
Breakt.:own Voltage
Thickness of Vapor Film,
Scratch, Contamination
Thickness, VTH Characteris·
tics
Electrical Characteristics
Appearance of Chip
Assembling Appearance after Chip
Bonding
Sealing
Marking
Appearance after Wire
Bonding
Pull Strength, Compression
Width, Shear Strength
Appearance after Assembling
Appearance after Sealing
Outline, Dimension
Marking Strength
Analysis of Failures, Failure
Mode, Mechanism
Figure 3 Example of Inner Process Quality Control
23
Scratch, Removal of Crystal
Defect Wafer
Assurance of Resistance
Pinhole, Scratch
Dimension Level
Check of Photo Resist
Diffusion Status
Control of Basic Parameters
(VTH, etc.) Cleanness of surface,
Prior Check of VIH
Breakdown Voltage Check
Assurance of Standard
Thickness
Prevention of Crack,
Quality Assurance of Scribe
Quality Check of Chip
Bonding
Quality Check of Wire
Bonding
Prevention of Open and
Short
Guarantee of Appearance
and Dimension
Feedback of Analysis Infor·
mation