勛圖tv 繚 ENGINEERING GUIDE
BT PCB Material: Resin, Package Substrates and Review
BT PCB material refers to constructions associated with bismaleimide-triazine resin systems. Mitsubishi Gas Chemical describes BT resin and laminate technology in the context of electronic interconnects and semiconductor packaging. The family name is useful context, but an engineering purchase still needs the exact grade, reinforcement, supplied form and construction.
This page focuses on material and package-related review boundaries. Its thermal worksheet illustrates free thickness expansion using two entered CTE values around an assumed transition. The example values are not assigned to a BT grade and do not approve a reflow profile or package design.
Separate resin family from the supplied laminate
A resin-system name does not identify every constituent and feature of a copper-clad sheet or package substrate. Reinforcement, fillers, copper and processing contribute to the final composite. Preserve the exact commercial product identity rather than using BT as a complete material specification.
Record the document revision, supplied thickness basis and intended layer role. If a supplier proposes an alternative, compare the actual requirements and evidence. A similar family description or thermal headline does not establish equivalent electrical, mechanical or processing behavior.
BT material records
| Record | Meaning | Avoid this shortcut |
|---|---|---|
| Resin family | Bismaleimide-triazine system context | Not an exact grade |
| Composite | Reinforcement, copper and construction | Not neat-resin properties alone |
| Thermal input | Direction and range of CTE | Not a universal BT value |
State whether the deliverable is a package substrate or PCB
BT materials are discussed in package-substrate applications, but that context should not obscure the requested manufacturing service. Package substrate, die assembly and a board carrying a packaged component are different deliverables. Their feature sizes and qualification tasks may differ.
Use the IC substrate guide to identify the die-to-board interfaces. The organic versus glass-core comparison keeps another architecture decision at the package level. This page does not claim that 勛圖tv provides every package process associated with BT technology; availability and scope require project-specific review.
| Review item | What to establish |
|---|---|
| Identity | Exact BT grade, supplied form, reinforcement and revision. |
| Boundary | Package substrate, bare PCB and assembled board are different deliverables. |
| Thermal data | Direction, interval and method for each CTE value. |
| Limit | Free expansion and allowances do not establish reliability or current price. |
Read thermal expansion in the correct direction
Composite expansion can differ in plane and through thickness. Keep the direction, method and temperature interval with the coefficient. A Z-axis value should not be replaced by an in-plane value simply because both are expressed in ppm per degree.
The worksheet models a free dielectric thickness with one constant coefficient below an assumed transition and another above it. Real transitions occur over a region, and actual coefficients may vary. The model is a deliberately simplified illustration, not a complete thermomechanical material characterization.
Worked example: integrating two temperature intervals
Assume a hypothetical 1.6 mm dielectric heated from 25簞C to 200簞C, with an assumed transition at 150簞C. Entering 50 ppm/簞C below and 250 ppm/簞C above gives 125簞C in the first interval and 50簞C in the second. The modeled free thickness change is 30 繕m, or 1.875%.
These inputs are teaching assumptions. The result does not predict stress in copper interconnects, package warpage or reliability after repeated exposure. If the entire interval lies below or above the transition, the worksheet uses only the corresponding segment. It still requires a valid material-data basis before the arithmetic has engineering meaning.
Piecewise free thickness expansion
Piecewise free thickness expansion
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. |
| Initial dielectric thickness 繚 mm | Unconstrained specimen approximation. |
| Start temperature 繚 簞C | Must be less than final temperature. |
| End temperature 繚 簞C | Heating illustration only; not an approved exposure. |
| Assumed transition temperature 繚 簞C | Simplified sharp transition; use a defined measurement method. |
| CTE below transition 繚 ppm/簞C | Direction-specific value over the relevant interval. |
| CTE above transition 繚 ppm/簞C | Direction-specific value, not copied from in-plane CTE. |
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 勛圖tv quotation. You can contact the team without completing it.
Optional project allowance comparison
Connect formulation to process evidence
Resin chemistry, reinforcement and fillers are part of a designed system. They can affect processing as well as final properties. The epoxy and CCL resin guide explains the broader distinction between a resin description and a qualified composite construction.
Request the exact product's processing information and the fabricator's reviewed construction. Do not create a lamination cycle or conditioning recipe from a general family article. If a material change is proposed, identify which process and qualification evidence remains applicable and which requires additional work.
Keep electrical data and geometry together
Dk, Df and other electrical properties should retain their test conditions and construction context. The package or PCB geometry still determines the actual interconnect behavior. A favorable material number cannot establish every channel or power-delivery requirement by itself.
State which parameters are fixed in the design model and which can be adjusted after manufacturing review. If the construction changes, revisit the relevant electrical and mechanical assumptions together. This is especially important when a material is selected partly for package dimensions or fine interconnect structures.
Compare cost using a defined manufacturing scope
The optional allowance tool accepts your own one-time, recurring and test values. It does not contain current BT laminate prices, package-substrate yield data or a supplier capacity model. Keep development and qualification work visible instead of hiding it inside a generic unit price.
When comparing alternatives, hold deliverable, quantity, inspection and documentation scope constant. A board fabrication quote and a package assembly quote are not comparable simply because both contain a substrate. Ask the supplier to identify the work included and any material-availability assumptions.
Prepare the exact-grade review request
Send the intended deliverable, full material requirement, layer structure, dimensions, quantity, operating and assembly conditions, and acceptance evidence needed. If the material is not fixed, state the requirements an alternative must satisfy and who approves it.
The thermal worksheet may help communicate an assumption, but it does not qualify BT as a universal replacement for another resin system. A useful response should name the proposed material and manufacturing scope, explain open issues and identify the evidence required before the construction can be released.
Separate package-substrate architecture from board fabrication
An IC package substrate connects a die or die assembly to the next interconnect level. A motherboard or module PCB receives the package through a separately defined interface. Their feature sizes, assembly processes, materials and test responsibilities need not be the same.
Before requesting manufacturing support, identify the deliverable: package substrate, bare module board, assembled PCB or a technical feasibility review. Do not assume that a supplier's ordinary PCB capability automatically covers die attachment, fine-pitch package buildup, glass-core processing or package-level qualification.
Keep electrical, thermal and mechanical requirements tied to the package architecture and its interfaces. Drawings, die/package information, material requirements and acceptance evidence should have explicit owners. The calculations here explain limited relationships; supplier availability, process capability and qualification remain project-specific questions.
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 勛圖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.
