Here is the translated comparison of thecharacteristics of photoresist, knife coating, and electrophoresis processes indiode chip manufacturing:
I. ProcessPrinciples
Photoresist Process
Utilizes photolithography technology toform specific patterns on the chip surface through photochemical reactions ofphotoresist (photosensitive material). Followed by etching and other processes,it achieves precise patterning of the chip, enabling nanometer-level precisioncontrol for forming glass passivation layers.
Knife Coating Process
Relies on manual experience to mechanicallyscrape passivation materials onto the chip surface using tools like scrapers.The thickness of the passivation layer is controlled by adjusting the scraper'smovement and pressure.
Electrophoresis Process
Based on the effect of an electric field,charged particles (such as passivation material particles) suspended in asolution move toward and deposit on the chip surface, forming a passivationlayer—similar to a "spray painting" method for covering the chipsurface.
II. ProcessCharacteristics
Photoresist Process
l Features high precision and reliability, achieving nanometer-levelaccuracy control.
l Enables fabrication of ultra-thin chips (thickness < 100μm),facilitating device miniaturization.
l The glass passivation layer shows excellent uniformity, withwithstand voltage up to 2000V, leakage current < 1μA, and resistance to hightemperature and corrosion. Chip lifespan exceeds 10 years.
Knife Coating Process
l Simple process and low cost, but with poor film thickness controlprecision (fluctuation ±20%).
l Weak thermal cycle resistance: prone to failure after cyclingbetween -40℃ and 125℃, leading to low long-term reliability and high failurerates.
Electrophoresis Process
l Simple equipment, easy operation, and high production efficiency.
l However, the deposited film has poor uniformity (thin at edges,thick at the center), insufficient withstand voltage (typically < 1000V),and is prone to aging during long-term use.
III. CostAspects
Photoresist Process
l High unit cost due to high-precision automated equipment, longproduction (workflow), and strict requirements for cleanroom cleanliness,temperature, and humidity—resulting in high operation costs for purificationplants.
l However, its long lifespan and low failure rate may lead to lowerlife-cycle costs.
Knife Coating Process
l Low cost due to simple processes and low equipment/material costs.
l Drawback: High post-sales maintenance costs due to frequentfailures.
Electrophoresis Process
l High one-time investment and environmental protection costs, withdifficult waste disposal.
l Although single-product cost may be low, comprehensive costs cannotbe ignored.
IV. ApplicationFields
Photoresist Process
Suitable for high-reliability fields such as automotive electronics,high-end industrial control equipment, and charging piles. Meets requirementsfor high voltage resistance, low leakage current, and high stability.
Knife Coating Process
Used in cost-sensitive consumer electronics with low reliabilityrequirements, such as general lighting and simple household appliance controlcircuits.
Electrophoresis Process
Commonly applied in mid-to-low-end electronic devices with moderatecost and performance requirements, such as some portable electronics andordinary power supply circuits.