Copper Plate: Characteristics, Classification and Applications

Copper plate is a flat, non-ferrous metal material made from pure copper or copper alloys through rolling, annealing, and surface treatment. Its core advantages lie in its high electrical conductivity (resistivity of only 1.72×10⁻⁸Ω·m at 20°C), high thermal conductivity (thermal conductivity coefficient of 401W/(m·K)), good ductility, and unique metallic luster. It also offers a certain degree of corrosion resistance in non-strongly oxidizing environments. While more expensive than steel, it is irreplaceable in applications such as electrical conductivity, heat dissipation, and decoration, serving a wide range of industries, including electronics, electrical power, architectural decoration, and machinery manufacturing. This article will comprehensively analyze the technical value and practical significance of copper plate from five perspectives: definition and classification, core characteristics, typical applications, selection criteria, and future trends.

I. Definition and Classification of Copper Plate

The key criteria for copper plate are its base composition (pure copper must contain ≥99.5% copper; alloyed copper content varies depending on the grade). The addition of alloying elements such as zinc, tin, and nickel can enhance its strength, corrosion resistance, and workability. Based on material composition, processing technology, and application, copper sheets are primarily categorized into the following categories:

Classification by Material Composition (Core Differences)

Pure Copper Sheet (Red Copper Sheet): Copper content ≥99.5%, named for its purple-red surface color. Subdivided by purity:

T1 Pure Copper Sheet: Copper content ≥99.95%, extremely low impurity content, optimal electrical and thermal conductivity, used for precision electronic components (such as integrated circuit lead frames) and standard resistor materials.

T2 Pure Copper Sheet: Copper content ≥99.90%, offering the best value for money, accounting for over 80% of total pure copper sheet production. Used in general electrical and thermal applications such as wire and cable, busbars, and heat sinks.

T3 Pure Copper Sheet: Copper content ≥99.70%, slightly higher impurity content, and slightly weaker electrical conductivity. Used for industrial components with lower performance requirements (such as general gaskets and decorative nameplates). Brass Sheet: Based on a copper base with zinc added (10%-45%), it has a golden-yellow surface. Classifications by zinc content include:

H62 Brass Sheet: Contains 62% copper and 38% zinc. It offers medium strength, good plasticity, and is easy to machine. It is used for valves, pipe fittings, and hardware accessories (such as door handles).

H65 Brass Sheet: Contains 65% copper and 35% zinc. It has better plasticity than H62 and can be cold-bent and stamped. It is used for electronic connectors and musical instrument parts (such as trumpet bells).

H90 Brass Sheet: Contains 90% copper and 10% zinc. It has properties similar to pure copper and offers excellent corrosion resistance. It is used for decorative panels (such as building curtain walls and handicrafts). Bronze: Traditionally refers to copper-tin alloys, but now broadly refers to any copper alloy other than brass and cupronickel. Common types include:
Tin bronze (QSn4-3): Contains 4% tin and 3% zinc. It offers excellent wear and fatigue resistance and is used in bearing bushings, gears, and precision molds.
Aluminum bronze (QAl9-4): Contains 9% aluminum and 4% iron. It offers high strength (tensile strength ≥600 MPa) and resistance to seawater corrosion. It is used in ship propellers and chemical valves.
Phosphorus bronze (QSn6.5-0.1): Contains 6.5% tin and 0.1% phosphorus. It offers excellent elasticity and conductivity and is used in springs and relay contacts.
Cupronickel: Made from a copper base with added nickel (10%-50%), it has a silvery-white surface and offers excellent corrosion resistance.
B10 cupronickel: Contains 10% nickel. It is resistant to seawater, acids, and alkalis and is used in marine instruments and chemical pipe fittings. B30 White Copper Sheet: Contains 30% nickel, offers superior corrosion resistance to B10, and is non-magnetic. It is used for medical devices (such as surgical instruments) and precision instrument housings.

Classification by Processing Technology

Hot-Rolled Copper Sheet: Made from copper billets through high-temperature rolling at 800-900°C, with thicknesses ranging from 3-100mm. It offers excellent toughness and is suitable for thick workpiece processing. It is used for machine bases and large heat sinks.

Cold-Rolled Copper Sheet: Made from hot-rolled copper sheet, it is rolled and annealed at room temperature. It has thicknesses ranging from 0.1-5mm and features high dimensional accuracy (thickness tolerance ±0.01mm) and a smooth surface (Ra ≤ 0.8μm). It is used for electronic components and precision decorative parts.

Classification by Surface Condition

Polished Copper Sheet: The surface is mechanically polished (8K mirror finish) or chemically polished to a glossiness of ≥800 grit. It is used for architectural decoration (such as hotel lobby walls) and handicrafts. Brushed Copper: Surface treated with a brushed finish (grain size #400-#600 mesh), it resists fingerprints and is easy to clean. It's used for appliance panels (such as refrigerator door handles) and electronic device casings.
Oxidized Copper: Surface treated with an oxidation treatment to create a black or bronze-colored oxide film. It's used for antique decoration (such as door and window fittings in ancient buildings) and artwork.
II. Core Characteristics of Copper (Highlighting Differences from Steel)
Excellent Electrical and Thermal Conductivity: Pure copper has an electrical conductivity over five times that of mild steel and over ten times that of stainless steel. At 20°C, its conductivity reaches 98% IACS (International Annealed Copper Standard), making it a preferred material for wires, cables, and busbars. Its thermal conductivity is three times that of mild steel and five times that of stainless steel, making it suitable for radiators and heat exchangers (such as CPU heat sinks), achieving significantly higher heat dissipation efficiency than steel. Excellent ductility and workability: Pure copper sheet has an elongation of ≥45% and can be cold-bent 180° without cracking. Cold-rolled copper sheet can be stamped into complex shapes (such as electronic connectors). Brass and bronze sheets, after annealing, are easy to cut and weld, suitable for precision machining, and are less difficult to process than high-carbon steel.

Unique decorative and corrosion resistance: Pure copper and brass sheets have a natural metallic luster (purple-red and golden yellow), making them suitable for decorative applications without painting and boasting a service life exceeding 50 years in dry environments. Cupronickel and aluminum-bronze sheets are resistant to seawater, acid, and alkali corrosion, with a lifespan in marine environments over 10 times that of ordinary carbon steel. They approach stainless steel but offer better conductivity.

Non-magnetic and biocompatible: Pure copper and cupronickel sheets are non-magnetic and do not interfere with magnetic fields. They are used in medical devices (such as MRI equipment accessories) and precision instruments. Pure copper has an antibacterial effect (copper ions can destroy bacterial cell membranes) and excellent biocompatibility, making it suitable for medical catheters and tableware (such as copper pots). High Recycling Rate: The copper recycling rate exceeds 95%, and the performance of recycled copper sheet is within 3% of that of virgin copper. Recycled copper consumes only 1/20 the energy of virgin copper (virgin copper requires mining and smelting, while recycled copper is directly melted and rolled), aligning with the circular economy and the "dual carbon" goals.

III. Typical Applications of Copper Sheet

Electronics and Power (over 40%)

Conductive Components: T2 pure copper sheet is used for wire and cable conductors (such as high-voltage cable copper core) and substation busbars (high current carrying capacity and low heat generation); phosphor bronze sheet is used for relay contacts and connectors (excellent elasticity ensures stable contact).

Heat Dissipation Components: T2 cold-rolled copper sheet is used for CPU heat sinks and LED light radiators (fast heat conduction, reducing device temperature); aluminum bronze sheet is used for battery cooling plates in new energy vehicles (resistant to electrolyte corrosion and conductive).

Precision Components: T1 pure copper sheet is used for integrated circuit lead frames (high purity, reducing impurities from interfering with circuits); brass sheet is used for electronic connectors (easy to process and lower cost than pure copper).​
Architecture and Decoration (approximately 25%)
Decorative Sheets: H90 brass sheet (polished/brushed) is used for hotel lobby walls and elevator car panels (golden luster, high-end aesthetic); pure copper sheet is used for roofs of historic buildings (such as some roofs of the Forbidden City, corrosion-resistant and with a historical quality).
Doors and Windows and Accessories: Brass sheet is used for high-end door and window handles and hinges (moderate strength, easy to form, and rust-free); white copper sheet is used for curtain walls of coastal buildings (seawater corrosion resistance, silvery-white appearance suits modern styles).
Art Decoration: Oxidized copper sheet (bronze color) is used for sculptures and murals (long-lasting color, maintenance-free); thin-gauge pure copper sheet is used for interior ceilings (lightweight, with a strong metallic texture).

Machinery and Transportation (approximately 20%)
Wear-Resistant Parts: Tin bronze sheet is used for machine tool bearings, bushings, and gears (excellent wear resistance, reducing lubrication requirements); aluminum bronze sheet is used for ship propellers (seawater corrosion resistance, high strength, and impact resistance).
Fluid Components: H62 brass plate is used for water valves and oil pipe fittings (easy to cut, seals well, and resists tap water corrosion); cupronickel plate is used for chemical pipe fittings (acid and alkali resistant, non-magnetic, and won't interfere with instruments).

Automotive Components: Pure copper plate is used for automotive wiring harness conductors (excellent conductivity, ensuring circuit stability); brass plate is used for automotive radiator cores (fast thermal conductivity, lightweight, and lower cost than pure copper).

Medical and Consumer Sector (approximately 15%)

Medical Equipment: B30 cupronickel plate is used for surgical instruments (resistant to disinfectant corrosion, non-magnetic, and won't interfere with MRI scans); pure copper plate is used for medical catheters (excellent biocompatibility, inhibits bacterial growth).

Consumer Goods: Brass plate is used for tableware (such as copper pots, for even heat conduction, and the copper ions are beneficial to health); pure copper plate is used for musical instruments (such as trumpet and trombone bells, for excellent sound transmission). Anti-counterfeiting and logo applications: Brass plates are used for commemorative coins and medals (moderate hardness, easy engraving, and resistant to rust); pure copper plates are used for nameplates on high-end products (metallic luster and high recognition).

IV. Key Points for Copper Plate Selection
Matching Material Types to Applications

For electrical/thermal conductivity: Prefer T1/T2 pure copper plates (conductivity ≥95% IACS), such as for wires and heat sinks. For budgetary reasons, consider H65 brass plates (conductivity approximately 70% IACS, 30% lower cost).

For corrosion resistance (seawater/acid/alkali exposure): Choose white copper plates (B10/B30) or aluminum bronze plates (QAl9-4), avoiding pure copper (which is easily oxidized by highly corrosive media).

For wear resistance/high strength: Choose tin bronze plates (QSn4-3) or aluminum bronze plates (tensile strength ≥600 MPa) as an alternative to easily abrasive steel. For decorative applications: Choose H90 brass (golden) or pure copper (purple-red) for high-end applications; choose white copper (silver-white, corrosion-resistant) for seaside applications; and choose oxidized copper for antique-style applications.

Key Technical Parameters

Purity and Composition: For conductive pure copper, confirm the copper content (T2 ≥ 99.90%). For alloy copper, verify the alloying element content (e.g., H62 copper content 62% ± 1%) to avoid impurities affecting performance.

Dimensional Accuracy: For precision electronics, choose cold-rolled copper (thickness tolerance ±0.01mm, flatness ≤0.5mm/m); for thick structural components, choose hot-rolled copper (tolerance ±0.1mm, toughness preferred).

Surface Quality: For decorative applications, choose polished copper (gloss ≥ 800 grit, scratch-free); for industrial applications, choose brushed copper (Ra ≤ 1.6μm, fingerprint-resistant) to avoid surface pinholes and oxidation spots. Confirm Standards and Performance Indicators

Domestic Applications: Acceptance must comply with GB/T 2040 (pure copper plate), GB/T 2041 (brass plate), and GB/T 2042 (bronze plate). A composition analysis report and mechanical property report (e.g., T2 pure copper plate: tensile strength ≥ 205 MPa, elongation ≥ 45%) are required.

Export Applications: Comply with ASTM B152 (US) and EN 1652 (EU) standards. For example, ASTM B152-T2 corresponds to domestic T2 pure copper plate. Conductivity and corrosion resistance test data must be confirmed.

Special Requirements: Biocompatibility certification (e.g., ISO 10993) is required for medical applications; RoHS certification (to ensure the absence of hazardous substances such as lead and cadmium) is required for electronic applications.

Balancing Cost and Usage Requirements

High-end Applications (precision conductivity/decorative applications): Choose T1 pure copper plate or H90 brass plate (excellent performance, long life, and suitable for long-term use). Mid-range applications (general machinery/decoration): Choose T2 pure copper plate or H65 brass plate (high cost-effective, suitable for over 80% of general needs).
Low-cost applications (non-critical components): Choose H62 brass plate or QSn4-3 bronze plate (40% lower cost, performance meets basic requirements).
V. Future Development Trends of Copper Plates
High Precision and Ultra-Thinness: Develop ultra-thin cold-rolled pure copper plate (thickness ≤ 0.05mm) for flexible electronic devices (such as foldable screen mobile phone circuits); improve dimensional accuracy (thickness tolerance ±0.005mm) for microelectronic components (such as chip packaging).
Functional Composites
Conductive + Heat Dissipation Composite Copper Plate: Graphene coating applied to pure copper plate increases thermal conductivity by 30%. Suitable for heat dissipation in high-end CPUs and new energy vehicle batteries.
Corrosion-Resistant + Decorative Composite Copper Plate: Nano-ceramic coating applied to brass plate increases salt spray resistance by 5 times while retaining its metallic luster. Suitable for high-end coastal decoration. Antibacterial + Public Welfare Composite Copper Plate: A silver ion coating is applied to the surface of pure copper plates, achieving an antibacterial rate of ≥99.9%. Suitable for use in medical devices and food contact components.
Green Production and Recycling Upgrade
Short-Process Smelting: Promoting the "scrap copper - direct melting - rolling" process, carbon emissions are reduced by over 80% compared to the traditional "copper ore - blister copper - refined copper" process.
High-Value Recycling: Precision sorting (such as eddy current separation) removes impurities from scrap copper, resulting in recycled pure copper plates with a purity of up to 99.95%, with performance deviation of ≤2% from virgin copper.
Clean Processing: An acid-free polishing process is used to treat the copper plate surface, reducing acid mist emissions and meeting environmental requirements.
Customization and Application Expansion
Customized Performance: Adjust alloy composition based on demand, such as high-elasticity phosphor bronze plates (for 5G base station antenna springs) and high-thermal conductivity aluminum bronze plates (for aerospace heat sinks). New Application Scenarios: Developing composite sheets of copper and composite materials (such as carbon fiber) for aerospace structural components (lightweight + high conductivity); thin-gauge copper sheets for the conductive layer of photovoltaic modules (replacing silver paste and reducing costs).

Conclusion
As a "functional non-ferrous metal sheet" that complements the properties of steel, copper sheet, with its core advantages of high electrical and thermal conductivity and unique decorative properties, holds an irreplaceable position in electronics, high-end decoration, and precision machinery, where steel struggles to adapt. From chip heat sinks to brass hotel curtain walls, from ship propellers to non-magnetic surgical instruments, it permeates both high-end manufacturing and consumer applications. In the future, with the advancement of high precision, multifunctionality, and green production, copper sheet will further push the boundaries of performance and expand its applications in flexible electronics, new energy, aerospace, and other fields, providing higher-quality material solutions for industrial upgrading and sustainable development.