The latest Kingboard price increase concerns the materials used to manufacture PCBs, not an automatic increase in every finished-board quotation. An August 28, 2026 notice reproduced by financial media reports higher FR-4 and prepreg prices for newly accepted orders. For purchasing teams, the next step is to identify the material used in each board and confirm which commercial terms apply.
At EBest Circuit, we help customers review PCB material requirements alongside fabrication needs. This update explains the reported changes, where they enter a multilayer board’s material bill, and what to clarify when a supplier sends a revised quotation.
What Changed in the August 28 Notice?
Gelonghui’s August 28 report, carried by Sina Finance, reproduces a notice from Guangdong Kingboard Laminates Trading Co., Ltd. The stated adjustments are:
| Material category in the notice | Reported increase |
| FR-4, all thicknesses | 10% |
| Prepreg: 7628 and the notice’s thicker-cloth category | 10% |
| Prepreg: the notice’s thin-cloth category below 7628 | 20% |
The reproduced letter is dated August 28. We checked its wording against the report, but it was obtained through a media publication, not a direct supplier communication. Confirm the applicable grade and price with your material supplier before changing a purchase order.
When Does the New Pricing Apply?
The notice refers to new orders accepted from its issue date. It does not establish how every distributor will handle existing inventory, previously accepted orders, or an earlier quotation that remains valid.
Before approving a revised board price, ask for three specific confirmations:
- Order status: Was the material order already accepted, or does the job still require a new purchase?
- Quotation basis: Which material grade, copper weight, sheet size, quantity, currency, and tax basis are being compared?
- Validity: How long does the revised quotation remain open, and what event fixes the price?
A finished-PCB purchase order and a laminate manufacturer’s order are different transactions. Do not assume that sending a board PO earlier automatically secures an earlier material price; obtain written confirmation from the party supplying your boards.
Why Are Glass Cloth and Copper Foil Important?
The letter cites rising prices and tighter supply of glass cloth and copper foil. Both are inputs to PCB laminate production; neither is simply an optional accessory that can be removed from a drawing.
A copper-clad laminate combines a dielectric base with copper foil. Prepreg supplies resin-bearing reinforcement between layers during lamination. Their costs enter the material bill through different purchased items and constructions.
The notice alone does not tell us how much either input has risen across the entire market, how long supply pressure will last, or which next adjustment will follow. Those would require separate dated evidence. For a current order, the relevant information is the supplier’s quotation for the exact material being purchased.
PCB Prepreg vs Core: Which Material Is Affected?
The distinction in PCB prepreg vs core matters because a multilayer stackup uses cured laminate and bonding sheets differently. A core is already cured; prepreg starts as resin-impregnated reinforcement that bonds the assembly during pressing.
For background on the bonding stage, see our explanation of prepreg in PCB manufacturing. For this price review, identify the actual core and prepreg entries in the approved stackup rather than treating the entire board as a single sheet of FR-4.
When comparing prepreg PCB material, retain the manufacturer’s grade, resin system, glass style, resin content, and number of plies. Two options described simply as “FR-4 prepreg” may not have the same electrical properties or processing behavior. A purchasing description that omits these details can hide a construction change inside an apparently cheaper quotation.
Why Does Prepreg PCB Thickness Need a Construction Check?
Prepreg PCB thickness is not determined by a glass-style number alone. Resin content, the selected construction, and the pressed assembly all matter. Manufacturer data can list more than one thickness or resin-content option for the same glass style.
The notice’s wording around 7628 is a supplier pricing category. It should not be converted into a universal rule that every glass-style code with a smaller numerical value is physically thinner. Match each ordered prepreg item to the supplier’s classification.
Construction also affects PCB prepreg dielectric constant. Isola’s laminate-manufacturing guide explains that glass construction and retained resin content influence dielectric properties. Its material data illustrate why an apparently similar glass designation is not enough to prove equivalence; those Isola values should not be copied into a Kingboard design.
For an impedance-controlled board, changing dielectric spacing or material properties can require a new impedance calculation and an approved stackup revision. Keep the electrical requirement fixed while evaluating the material choice.
Does a 20% Prepreg Increase Mean a 20% PCB Price Increase?
No. A percentage applied to one purchased material does not automatically apply to the total selling price of a finished PCB. The board also includes other materials, fabrication operations, inspection, testing, handling, and commercial terms.
A useful calculation starts with the affected material lines, not the total board invoice: multiply each old material-line cost by its applicable adjustment, then add the differences. That estimates the change in those lines only, assuming the same specification, quantity, and purchasing basis.
It still does not determine the final commercial quotation. Inventory purchased at an earlier price, panel utilization, production volume, and other cost changes may affect the outcome. Our copper-clad laminate price guide provides broader background on material-price factors.
If a revised quotation cites the Kingboard price increase, ask which material lines changed and whether the board specification stayed the same. A traceable explanation is more useful than applying a headline percentage to every item.
Which Cost-Saving Changes Need Engineering Approval?
Start with options that preserve the approved design, such as reviewing order quantities or panel utilization with the fabricator. Material substitutions require a separate technical decision; a lower material price does not establish that the replacement will work.
- Changing prepreg construction: Review finished dielectric spacing, resin availability around copper features, and electrical requirements.
- Changing laminate grade: Compare the relevant thermal and electrical properties and any material restrictions on the drawing.
- Reducing copper: Recheck current handling, thermal behavior, and fabrication requirements rather than treating copper weight as a purchasing-only choice.
- Changing a qualified build: Agree on required samples, inspection, and customer approval before production release.
Keep the existing approved construction if equivalence has not been demonstrated or the customer does not permit substitutions. Requalification time and scrap risk can outweigh a small purchase-price saving.
How Can We Help You Review a Material-Cost Change?
At EBest Circuit, we provide PCB fabrication and PCBA services with technical support for material and build requirements. We can review your approved stackup and discuss which material choices are fixed, which alternatives may be evaluated, and what information is needed for a current quotation.
Send your Gerber files, stackup, specified laminate grade, copper weight, order quantity, and required delivery date to sales@bestpcbs.com. If you are comparing a revised quote, include the earlier specification and quote date so we can compare the same build. Any proposed material change should be documented and approved before manufacturing.
