In products like mobile phones, tablets, laptops, energy storage batteries, and automotive electronics, graphite sheets have long become a "standard" in thermal management solutions. However, many engineers tend to focus solely on "thermal conductivity" during selection, overlooking an equally crucial dimension—thickness and dimensions.

Choosing a thickness that's too large can lead to fit issues, warping, and interference; opting for one that's too thin may result in impressive specifications on paper, but fail to reduce actual temperatures effectively.

Based on practical applications and Jiangxi Dasen's experience in graphite thermal management projects, this article systematically clarifies:

* What do the common sizes/parameters of graphite sheets actually mean?

* What are the differences between thickness, length/width, and density?

* How to measure and inspect them?

* What thicknesses are commonly used in different application scenarios (with a table)?

* What process should be followed for selecting graphite sheets in new projects?

I. Key Dimensions of Graphite Sheets: Clarified First

In communications between engineers and suppliers, the most easily confused terms regarding graphite sheets are: thickness, length/width dimensions, areal density/grammage, and bulk density.

Here’s a brief comparison using a table, with detailed explanations to follow later in the article.

Table 1: Comparison of Common Dimension Terms for Graphite Sheets

Item	Meaning	Measurement/Inspection Method
Thickness	Z-direction height of the graphite sheet (mm or μm)	Micrometer/thickness gauge, averaging readings from multiple points
Length/Width Dimensions	X-Y dimensions when unfolded	Caliper, steel ruler, projector
Areal Density/Grammage	Mass per square meter of the material (g/m²)	Weighing + area calculation
Bulk Density	Mass per unit volume (g/cm³), related to density	Laboratory testing/supplier’s report

1. Thickness

Thickness is one of the most sensitive and frequently debated parameters. Common thickness ranges are roughly as follows:

Mobile phones, tablets: 0.015–0.03 mm

Thin and light laptops: 0.02–0.05 mm

Industrial control, automotive, power electronics: 0.05–0.3 mm or even thicker

When providing samples to customers, Jiangxi Dasen Technology Co., Ltd. first recommends 1–2 solutions based on the common thickness ranges for similar models. Then, it fine-tunes the final thickness based on the customer’s actual temperature rise and assembly feedback, rather than offering an "theoretically optimal" ultra-high-specification product upfront.

2. Length/Width Dimensions and Irregular Shapes

Graphite sheets are rarely regular rectangles; most are customized into irregular shapes (L-shaped, U-shaped, with holes, or fold lines) based on motherboards and structural components.

Key considerations during design:

Cover all hotspots: CPU/PMIC/PA/charging IC, etc.

Identify appropriate "heat diffusion paths": diffuse heat to the middle frame, back cover, or metal bracket.

Avoid structural interference from screw posts, buckles, FPC wiring, etc.

Based on the customer’s 3D structure diagram, Jiangxi Dasen Technology Co., Ltd. can first provide a preliminary unfolded drawing (including folds and allowances). After trial production, it fine-tunes the die-cut dimensions together with the customer to reduce the time spent on multiple sampling rounds.

3. Areal Density/Bulk Density

Generally, higher density indicates:

Better crystallinity and higher thermal conductivity of the graphite sheet.

Stronger heat dissipation capacity at the same thickness.

However, excessively high density can also lead to:

Reduced flexibility, making the sheet more prone to breaking or warping during assembly.

Increased material costs.

If your product is highly sensitive to weight (e.g., wearables, ultra-thin laptops), you should focus on the grammage index. Ask the supplier to provide a complete set of data including "thermal conductivity/thickness/grammage" to achieve a comprehensive balance.

II. Why Are Thickness and Dimensions So Important?

1. Thermal Performance

Too thin: In- thermal conductivity is good, but contact with devices and structural components is insufficient, resulting in relatively high actual thermal resistance.

Too thick: Although it may seem "more substantial," excessive compression or bulging can cause local suspension, leading to higher rather than lower temperatures.

When supporting projects, Dasen often recommends a "slightly conservative" thickness, then confirms whether further thickening is necessary based on actual temperature rise tests, rather than blindly increasing material usage.

2. Assembly and Reliability

Too thin: Prone to wrinkling and tearing during production line operations, resulting in unstable yield rates.

Too wide or overhanging: Easily scratched by screws or buckles, or even pinched in gaps.

Unreasonable fold design: Fold areas are prone to cracking after long-term thermal cycling.

Therefore, thickness and dimensions should not be considered in isolation, but rather in conjunction with assembly processes and structural tolerances.

3. Cost and Inventory Management

Each increase in thickness grade may lead to changes in price and inventory.Based on your expected annual usage and project positioning, Dasen recommends prioritizing selection within common thickness grades to facilitate subsequent replenishment and cost control.

III. How to Measure Graphite Sheets? Thickness, Dimensions, and Density Explained

This section corresponds to the "How to Measure Perimeter" part in the original text.

1. Thickness Measurement: Micrometer/Thickness Gauge as Standard

Common practices:

Use a calibrated micrometer or digital thickness gauge.

Select multiple points on the flat area of the graphite sheet (avoiding folds, holes, and edges).

Record the reading at each point and calculate the average value and maximum deviation.

For ultra-thin graphite sheets (around 0.02 mm), it is recommended:

Ask the supplier to provide a standard thickness measurement method.

For critical projects, sample and send to a third-party institution for re-testing.

"A difference of a few micrometers in the thickness of ultra-thin graphite sheets can result in a temperature rise difference of 1–2℃. Measurement must be standardized."

2. Length/Width Dimensions and Irregular Tolerances

Regular shapes: Directly measure side lengths with a caliper/steel ruler.

Irregular shapes: Use a projector to inspect the contour against the die-cut drawing.

Large rolls: Focus on width deviation and roll flatness.

In mass production projects at Jiangxi Dasen, the company typically provides:

Incoming inspection report (including key dimension tolerances, thickness, and statistical data on appearance defects).

Batch sampling inspection records to ensure that the actual supplied dimensions stably meet the requirements of the drawing.

IV. Common Applications of Graphite Sheets by Thickness (Core Table)

Table 2: Correlation Between Graphite Sheet Thickness and Typical Application Scenarios

Thickness Range (mm)	Typical Applications	Characteristics/Recommendations
0.015–0.02	Ultra-thin devices such as mobile phones, tablets, and smart watches	Ultra-thin and flexible, but difficult to process. Suitable for products with extreme thickness sensitivity but limited power consumption.
0.02–0.035	Mainstream smartphones and thin/light laptops	Balances thermal performance and assemblability; the most common thickness range in consumer electronics currently.
0.035–0.06	Laptops, tablets + keyboard docks, routers	Slightly more structural space and medium power consumption. Suitable for large-area laying to improve overall temperature distribution uniformity.
0.06–0.1	Automotive electronics, industrial control boards	Requires higher mechanical strength and durability; can be used in conjunction with metal heat sinks.
0.1–0.3	Energy storage systems, power electronic modules	High power density and relatively abundant space. Often forms a combined solution with heat sinks and liquid cooling plates.

V. How to "Quickly, Accurately, and Steadily" Select Graphite Sheets for Projects?

You can refer to the following simple process:

Collect Basic Data

Power consumption, hotspot locations, and maximum allowable temperature.

3D structure diagram and reserved thickness space.

Determine the approximate thickness range of the graphite sheet.

Communicate Initial Solutions with Suppliers

Provide the structure diagram and temperature rise target to the supplier.

Ask the supplier to provide a combined proposal of "thickness + thermal conductivity + unfolded drawing."

This step is ideally suited for Jiangxi Dasen Technology Co., Ltd., where its engineers can assist with preliminary thermal path planning.

Small-Batch Trial Production + Temperature Rise Testing

Check if the location of the highest temperature point changes.

Inspect for assembly interference and fitting conditions.

Lock in Thickness and Specifications for Mass Production

Finally confirm parameters such as thickness, tolerances, die-cut shape, and packaging method.

Negotiate with the supplier on lead time and annual usage.

VI. Why Do Many Cutomers Choose Graphite Sheet Suppliers Like Jiangxi Dasen?

In the field of graphite thermal management materials, Jiangxi Dasen Technology Co., Ltd. has several key advantages:

Customizable Thickness and Density: Can fine-tune thickness grades and thermal conductivity according to project requirements, not limited to "standard products."

Integrated Die-Cutting: Equipped with stamping, lamination, and composite production lines, directly providing ready-to-use die-cut graphite sheets (with protective film/adhesive, etc.).

Engineering Support: Can provide initial solutions based on your structure diagram and power consumption parameters, reducing the time spent exploring thermal management materials.

Delivery and Quality System: Provides incoming inspection reports and batch sampling records, facilitating quality audits by end-brand customers.

If you are currently:

Evaluating thermal management solutions for new models or projects.

Looking to replace existing materials with more cost-effective graphite sheets.

Facing issues such as local overheating, graphite sheet warping, or assembly interference.

You can organize your requirements and communicate with professional suppliers like Jiangxi Dasen. They will first provide 1–2 feasible solutions, then optimize them based on your test results.

VII. Frequently Asked Questions (FAQ)

Q1: Is thicker graphite sheet always better for heat dissipation?

Not necessarily. Increasing thickness changes thermal resistance and assembly status. In some cases, a thicker sheet may cause local suspension or bulging, resulting in higher actual temperatures. Thickness should be comprehensively evaluated based on space, tolerances, and fitting pressure.

Q2: Is there a significant difference between graphite sheets of the same thickness from different suppliers?

Differences mainly lie in the authenticity of thermal conductivity, batch stability, roll flatness, and die-cut yield rate. It is recommended to choose suppliers with test reports and mass production experience, such as Jiangxi Dasen Technology Co., Ltd., which has long specialized in graphite materials.

Q3: Can suppliers assist with selection if I only have approximate power consumption and partial structural information?

Yes. As long as you provide the approximate power consumption range, locations of main heat-generating components, and allowable case temperature range, professional suppliers can first offer a "slightly conservative" solution, then gradually optimize it through sample testing.