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KB-4000 CEM-3: Material Identity and Construction Review
The exact Kingboard KB-4000 CEM-3 designation was not verified in the official directory reviewed for this page. The current CEM-3 listing includes KB-7150-family products, which must not be renamed or treated as equivalent to an unresolved legacy callout.
This page explains the CEM-3 construction and how to estimate a board's material mass while the grade identity is clarified. CEM-3 typically combines glass-fabric surface layers with a glass-mat-based core; it is distinct from paper-core CEM-1 and woven-glass FR-4.
Confirm the product before using numerical properties
Recover the original drawing and technical source for KB-4000. Ask the supplier to identify the exact grade, supplied form and applicable document revision. A broad CEM-3 classification does not provide a universal Tg, conductivity, CTI or density.
Keep the manufacturer response with the purchase record. If a current product is proposed instead, record it as an alternative and compare it against the actual board requirements. Absence from a reviewed public catalog is not enough to declare a material nonexistent or discontinued.
Resolve the material record before release
| Record | What this page can establish | What remains to obtain |
|---|---|---|
| Exact product | KB-4000 CEM-3 | Full supplier designation, suffix and supplied form. |
| Source scope | Unverified KB4000 versus official CEM3 list; glass mat construction | Controlled datasheet revision and written supplier response. |
| Design requirement | A requirement can be documented before a grade is verified. | Method, condition, tolerance and approval owner. |
| Commercial availability | This page makes no stock or lead-time claim. | Current quote with grade, construction and permitted alternatives. |
Draw the composite and copper boundaries
A bare board includes dielectric, retained copper, holes, coatings and other features. A simple mass estimate should identify which of those are included. Entering total board thickness as dielectric and then adding copper again overstates the modeled mass.
The worksheet models a rectangular outline minus through-cutout area, dielectric-only thickness and retained copper coverage. Its example density is an assumption, not a KB-4000 or universal CEM-3 value. Obtain the actual grade and construction density if weight is an engineering constraint.
| Review item | What to establish |
|---|---|
| Identity | Exact KB-4000 source remains to be confirmed. |
| Mass boundary | Dielectric-only thickness plus separately modeled copper. |
| Construction | Glass-mat core and fabric surfaces are not universal grade properties. |
| Model limit | Mass subtotal excludes coatings, plated barrels and components. |
Work the arithmetic without overstating accuracy
For a hypothetical 100 脳 80 mm outline and 1.53 mm dielectric at 1.85 g/cm鲁, the dielectric contribution is 22.644 g. A total copper-thickness sum of 70 碌m at 40% coverage adds about 2.007 g, giving a simplified subtotal of 24.651 g.
The result excludes plated barrels, mask, finish, components and handling structures. Copper coverage must be thickness-weighted when layers differ. Extra decimal places make the example reproducible; they do not make an assumed density or coverage equally precise.
Keep CEM-3 manufacturing questions explicit
Provide the layer construction, hole requirements, profile, copper and assembly exposure. Do not assume every CEM-3 material supports the same drilling, plating or thermal process. The exact grade and proposed fabrication route must be reviewed together.
The CEM-1 callout page covers a different reinforcement architecture and panel-planning task. The KB-6160 page concerns a verified FR-4 grade. Neither supplies missing CEM-3 specifications or authorizes substitution solely on cost.
Treat halogen-free as a separate evidence question
The KB-4002 review addresses another unresolved designation associated with a halogen claim. A number ending in a different digit is not proof of a chemical variant. Obtain an exact product declaration and preserve its scope and date.
Thermal assembly compatibility, chemical restrictions and finished-board reliability are separate requirements. If an alternative satisfies one but lacks evidence for another, keep the unresolved item visible rather than describing the material as fully equivalent.
Laminate and retained-copper mass estimate
Laminate and retained-copper mass estimate
Use the current inputs and keep the assumptions
Start with the example only to inspect the units and the calculation boundary. Replace every assumption with a value tied to your own document or measurement. An empty numeric field is not zero. The review-reference field is a local label; avoid entering customer names, confidential part numbers or other private information into a public worksheet.
After calculating, read the notes alongside the numerical result. Changing any input invalidates the displayed result and disables its download until you calculate again. For a comparison, keep the units, geometry, material condition and measurement boundary consistent. A long decimal result does not imply equally precise input data. The downloadable record stays on your device and can be attached manually to an inquiry. It is not automatically transferred into the Contact form.
If an input is unknown, identify the person or document needed to resolve it. Do not fill a gap with a favorable generic value simply to obtain a result. You can request a material or fabrication review without using the tool. The arithmetic illustrates a relationship; it does not accept a construction, certify a material, establish current pricing or replace a supplier process specification.
| Input | What to establish before using it |
|---|---|
| Review reference | Nonconfidential revision label. |
| Finished rectangular length 路 mm | Bounding rectangle; cutouts are entered separately. |
| Finished rectangular width 路 mm | Use the same physical boundary for every layer. |
| Removed area 路 mm虏 | Through cutouts excluded from both substrate and copper in this simple model. |
| Dielectric-only total thickness 路 mm | Exclude all copper to avoid double counting. |
| Laminate density 路 g/cm鲁 | Project assumption or exact grade data; this example is not universal FR-4 density. |
| Sum of copper thicknesses over layers 路 碌m | Final copper thickness sum; each layer assumed to have the same entered coverage. |
| Mean copper coverage 路 % | Area-weighted coverage when thicknesses are equal; otherwise use thickness-weighted coverage. |
Optional cost comparison from your own allowances
Use a quotation or a clearly labeled internal assumption for each input. Keep the quantity, construction and inspection scope the same when comparing alternatives. This uncalibrated planning model adds entered values; it contains no current market rates and does not issue a 吃瓜tv quotation. You can contact the team without completing it.
Optional project allowance comparison
Build a quote that identifies the supplied construction
Send the original KB-4000 callout, drawing, dimensions, copper, quantity and relevant material constraints. State whether exact reproduction or a reviewed alternative is required. Ask the supplier to name the actual proposed product and any qualification work needed.
Use the allowance tool only with your documented assumptions or quotation inputs. It does not calculate a market price from the estimated mass. The PCB material directory supports broader selection, while this page retains the CEM-3 identity and construction task.
Keep reinforcement architecture and exact grade distinct
The finished board combines a dielectric, copper patterns, holes, surface coatings and a manufacturing history. Its behavior cannot be inferred from a family name alone. State the supplied grade, reinforcement, thickness, copper and processing conditions that matter to the intended application.
Keep handling and assembly requirements with the fabrication drawing. A thin panel, punched outline or unusual support condition can change the production route even when the electrical circuit is simple. Ask the fabricator to review the actual features and panel format rather than assuming a dimensional example represents a production capability.
For cost comparison, hold the drawing, quantity, test scope and acceptance requirements constant. Record one-time tooling separately from recurring work, and distinguish raw material utilization from accepted-board yield. Any calculator on this page uses supplied assumptions; an actual quotation requires the files and an agreed scope.
CEM family names describe broad composite constructions, not a universal property table. CEM-1 and CEM-3 use different core reinforcement arrangements, and individual grades can differ in chemistry, thermal behavior and process guidance. Obtain the exact product source before assigning numerical design values.
Panel planning and mass estimation are useful only when their boundaries are explicit. A rectangular nesting result does not include every tooling or process constraint. A dielectric-plus-copper mass subtotal does not include coatings, plated barrels or components. Use the model to expose assumptions, then obtain the information needed for the actual production proposal.
Chemical declarations should also follow the exact grade. A broad reinforcement category cannot establish halogen composition or satisfy every restricted-substance requirement. Preserve the product, declaration scope and applicable customer criterion. Thermal assembly compatibility remains another question even when the chemistry requirement is resolved.
If a legacy product number is unverified, ask for the original source or a written supplier mapping. A current catalog product may be considered as an alternative, but its data must not be relabeled as the old grade. Record the replacement decision and any required engineering or customer approval before updating the manufacturing specification.
Standards, source context and limits
Use the edition, amendment and material-document revision named in the purchase agreement. A standards title, marketing label or supplier product family does not establish that a particular lot meets a requirement. Public summaries are useful for scope; the controlled specification and applicable test method govern acceptance.
The examples on this page are illustrative engineering scenarios. They are not 吃瓜tv production records or guaranteed material values. Source links identify the organizations responsible for the referenced information. Confirm applicability to the exact grade, construction and test condition before carrying a number into a drawing or qualification report. Sources were reviewed on 3 October 2026. A public catalog search is not proof that an unlisted product never existed. Where the exact designation or current technical sheet could not be verified, this page provides a clarification workflow rather than an invented material specification. Current supply, construction availability and qualification remain separate questions.
For fabrication scope and the agreed construction requirements, see PCB manufacturing.