science

LCD manufacturing

LCD manufacturing is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand LCD manufacturing rather than just read about it. In short: LCD manufacturing is the process of making liquid crystal display (LCD) panels. It involves using glass and silicon substrates.

Key takeaways

LCD manufacturing belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect LCD manufacturing to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of LCD manufacturing from memory before moving on to harder problems.

Reference excerpt

LCD manufacturing is the process of making liquid crystal display (LCD) panels. It involves using glass and silicon substrates. Photolithography is used to pattern the substrates, and liquid crystal materials are added. In the case of a color TFT LCD, color filters are patterned in layers to make red, green, and blue pixels. Liquid crystal displays are manufactured in cleanrooms, borrowing techniques from semiconductor device manufacturing.

Process A class of photolithography known as display lithography is used to etch patterns into substrates. LCD manufacturing shares some of the process with OLED manufacturing. The process flow involves multiple separate components that are joined together: a process for making a thin-film transistor (TFT) backplane, a process for making color filters, and a liquid crystal cell process. Large-scale chemical vapor deposition (CVD) systems have been used in the manufacture of LCDs. Once LCD panels are manufactured, they can be measured for color quality and panel uniformity using characterization equipment.

TFT backplane process TFT backplanes are made using photolithography techniques, which involve using photomasks. The photomask(s) are used to create TFTs on a substrate, which involves formation of a gate layer, source/drain layer formation, and contact-hole formation. The TFT backplane process involves patterning of indium tin oxide (ITO), which is a transparent and electrically conductive material. Conventional LCDs use a back-channel etched (BCE) TFT display pixel structure.

Liquid crystal cell process The cell process involves layer alignment, sealant formation, and depositing liquid crystal. The panels are then bonded and cut into individual displays. A technique that can be used is one drop fill (ODF). UV photocuring equipment can be used for bonding LCD panels.

Modules An LCD module (LCM) is a ready-to-use LCD with a backlight. Thus, a factory that makes LCD modules does not necessarily make LCDs, it may only assemble them into the modules. An LCD panel is attached to a driver board using anisotropic conductive film.

Generations

LCDs are manufactured using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:

In 2004, Sharp started manufacturing panels using the 6th-generation glass size, which is 1.8 meters by 1.5 meters. Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50- and 58-inch LCDs to be made per mother glass, specially 58-inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste. The thickness of the mother glass also increases with each generation, so larger mother glass sizes are better suited for larger displays.

2019-2025

Companies Companies that have made or sold LCD panels include:

Sharp Corporation Japan Display AUO Corporation Companies that have produced FPD lithography equipment include Canon and Nikon. LCD glass substrates are made by companies such as AGC Inc., Corning Inc., and Nippon Electric Glass. Display lithography equipment include the H803T and H1003T from Canon. Display Technologies, Inc. is a defunct joint venture that manufactured LCD panels.

Materials Optically clear adhesives are used to bond display components in the manufacturing process.

Worked examples

Example 1 — a first encounter with LCD manufacturing

Start with the simplest possible case. Write down what LCD manufacturing claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to LCD manufacturing before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about LCD manufacturing ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of LCD manufacturing

In research: LCD manufacturing appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses LCD manufacturing in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: LCD manufacturing is common in secondary-school and first-year university syllabi. It links to neighbouring topics Liquid crystal displays, Manufacturing, so understanding it makes those chapters shorter.
In everyday life: Look for LCD manufacturing outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study LCD manufacturing in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what LCD manufacturing means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain LCD manufacturing out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is LCD manufacturing in simple terms?

LCD manufacturing is the process of making liquid crystal display (LCD) panels. It involves using glass and silicon substrates.

Why does LCD manufacturing matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study LCD manufacturing?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on LCD manufacturing.