Electronic component packaging materials: magnesium hydroxide flame retardant solution design

——Fire safety revolution in the era of high-density integration

With the rapid development of 5G, artificial intelligence and new energy vehicles, electronic components are evolving towards miniaturization and high power, and the fire safety of their packaging materials faces severe challenges. Magnesium hydroxide (Mg(OH)₂) has become the core solution to the problem of flame retardancy of packaging materials due to its high temperature stability, halogen-free environmental protection and smoke suppression characteristics. This article provides a set of feasible technical paths from mechanism innovation, formula design to process practice.

1. Fire risk of packaging materials and the core value of magnesium hydroxide

Combustion hazards of electronic packaging

High temperature ignition: The increase in chip power density causes the local temperature to exceed 300°C, and the traditional epoxy resin package is easily pyrolyzed to generate flammable hydrocarbon gas.

Melt drop chain reaction: During combustion, the molten polymer drips and ignites the PCB board circuit, causing a secondary fire.

Toxic smoke is lethal: Brominated flame retardants release HBr and dioxins, and 80% of casualties in fires are caused by toxic smoke.

The irreplaceability of magnesium hydroxide

Thermal decomposition temperature matching: The decomposition temperature is 340–490℃, which is perfectly matched with the electronic packaging processing temperature (180–300℃) to avoid pre-decomposition failure.

Environmental protection nature: The decomposition products are only H₂O and MgO, which have passed RoHS and REACH halogen-free certification and meet the mandatory requirements for exporting electronic products to the EU.

Triple protection mechanism:

Heat absorption and cooling: 1.3 kJ/g heat absorption, reducing the surface temperature of the material by more than 150℃;

Gas phase dilution: Release 18.6% water vapor to inhibit the combustion chain reaction;

Ceramic barrier: Generate a porous MgO layer (specific surface area > 20 m²/g) to block oxygen penetration.

2. Flame retardant solution design: from single additive to systematic solution

1. Key parameters for material selection

Parameter Technical requirements Impact on packaging performance

Purity ≥99.5% Heavy metals (Pb/Cd) <100 ppm, to avoid circuit corrosion

Particle size D50=0.8–1.5μm Nanoscale filling of micropores to maintain the compactness of the package

Morphology Hexagonal flakes dominate Layered stacking enhances mechanical strength and resists thermal stress cracking

2. Design of compound synergistic system

Basic formula: 60% epoxy resin matrix + 25–35% magnesium hydroxide + 5–10% glass fiber reinforcement.

Performance doubling combination:

Zinc borate synergy: Adding 2% zinc borate promotes the formation of carbonized layer and increases the oxygen index to 38.5;

Nano clay loading: montmorillonite loaded with nano Mg(OH)₂, the addition amount is reduced to 18%, and the peak heat release rate is reduced by 62%.

3. Interface compatibility optimization

Silane coupling agent grafting: KH-570 modification reduces the surface energy of Mg(OH)₂ by 40% and increases the bonding strength with resin by 300%;

Microencapsulation technology: The polyurethane shell wraps the Mg(OH)₂ particles to isolate moisture during processing and avoid pre-curing of epoxy resin.

III. Process implementation: Key points for mass production stability control

Golden window of dispersion process

Dry mixing pretreatment: Modified Mg(OH)₂ and epoxy resin powder are pre-dispersed in a high-speed mixer (1200 rpm, 10 min);

Three-roll grinding refinement: roller gap 0.05 mm, 3 cycles, to ensure that the particle size distribution CV value is <5%.

Curing process innovation

Step temperature rise method: 80℃/1h (bubble removal) → 120℃/2h (pre-curing) → 180℃/4h (full curing) to avoid thermal decomposition of Mg(OH)₂;

Vacuum assisted molding: remove pores at -0.1 MPa and increase the dielectric strength of the package to 35 kV/mm.

IV. Performance verification and industry application benchmark

Core performance test data

Flame retardant grade: UL94 V-0 grade (1.6 mm thickness), GWIT 850℃ (glowing wire ignition temperature);

Smoke and toxicity control: NBS smoke density peak <150, hydrogen cyanide release <5 ppm;

Long-term reliability: After aging for 1000 hours at 85℃/85% RH, the insulation resistance attenuation rate is <10%.

Successful application cases

New energy vehicle IGBT module: 40% nano Mg(OH)₂ modified epoxy molding compound passed the 150℃/3000h power cycle test without carbonization cracking;

5G base station RF chip packaging: The compound system increases the heat deformation temperature to 210℃, and the dielectric constant in the millimeter wave band is stable at 3.2±0.1.

V. Common pain points and solutions

Pain point 1: High filling leads to decreased fluidity

→ Solution: Use flower ball zirconium modified Mg(OH)₂ (particle size 1.2μm), and the melt flow index is increased to 45 g/10min.

Pain point 2: Increased high-frequency signal loss

→ Solution: Deposit a nano silicon oxide layer on the surface, and the dielectric loss tangent value is reduced to 0.002 (@10 GHz).

The value of magnesium hydroxide in the field of electronic packaging has evolved from a single flame retardant to a multifunctional medium for thermal management, structural enhancement, and signal integrity. With breakthroughs in technologies such as atomic layer deposition coating and bio-based hybridization, a 15% addition amount will be required to achieve V-0 flame retardancy in the future, driving the evolution of electronic equipment towards "zero fire risk".