Precision processing of glass epoxy

This page introduces the precision processing of glass epoxy materials (glass epoxy) performed by TDC.

For more information on TDC’s precision polishing services, please also see the “Precision lapping service / ultra precision lapping service” page.

What is Glass Epoxy?

Glass epoxy refers to a resin material that is made into a laminated board (laminated bar) by soaking epoxy resin (liquid) in glass fiber and applying heat curing treatment.

Due to its combination of flame retardancy, heat resistance, strength, and excellent low conductivity, plate-shaped glass epoxy is widely used as a material for printed circuit boards.

Glass epoxy is abbreviated as glass epoxy, and is sometimes called epoxy glass or epoxy glass resin. It is sometimes written as “GFRP” on the drawing.

GFRP

GFRP stands for Glass Fiber Reinforced Plastic/Glass Fiber Reinforced Resin, and is an acronym for Glass Reinforced Resin (Plastics).

It is the cheapest FRP and is a fiber-reinforced resin used in a wide range of industries.

Characteristics of glass epoxy

Glass epoxy has the following characteristics.

• High mechanical strength and high rigidity
• Long life
• Excellent thermal conductivity, heat resistance, electrical properties, heat insulation, and insulation
• Thin but hard to warp
• No change in appearance is observed even after being left in the air at 180°C for 2 hours.
• Specific gravity is about 1.75 to 1.85
• Insulation resistance is 10(7)10(8)mΩ
• hygroscopic
• Top and bottom surfaces are glossy and smooth

Glass epoxy material properties

Item			Test method ASTM	test condition	Unit	Glass epoxy FR-4
physical properties	specific gravity		D-792	－	－	1.80
	water absorption		D-570	E-24/50＋D-24/23		0.10
electrical properties	Withstand voltage	Room temperature	D149	D-240/24	MV/m	29
		After immersion in water		Short time method		34
	Alongside withstand voltage	Room temperature	D-149	Short time method	MV/m	6.6
	volume resistance		D-257		Ω・m	1011
	surface resistance		D-257		Ω	1013
	insulation resistance	Room temperature	D-257	D-2/100	Ω	1.0×1013
		after immersion				1.0×1012
	Permittivity		D-150	3GHz	－	4.6
	Dielectric loss tangent		D-150	3GHz	－	0.050
	Arc resistance		D-495	－	sec	120
	Tracking resistance		IEC 112	－	V（CTI)	350
	Type of electrical insulation		IEC	－	－	F
thermal properties	Thermal conductivity		C-177	－	W/(m・K)	－
	coefficient of thermal expansion	vertical	D-696	25～100℃	10-5/℃	2.1
		horizontal
	Combustion quality		UL94	－	－	V-0
	Solder resistance		UTK	－	℃／ｓｅｃ	260×120
	Deflection temperature under load		D-648	1.82MPa	℃	180
mechanical nature	tensile strength	vertical	D-638	rupture	MPa	300
		horizontal				270
	tensile elongation	vertical	D-638	－	％	3.0
		horizontal				3.0
	bending strength	vertical	D-790	rupture	MPa	720
		horizontal				540
	Bending deformation rate	vertical	D-790	－	％	4.1
		horizontal				3.8
	flexural modulus	vertical	D-790	－	GPa	24.3
		horizontal				20.0
	Shear strength		D-732	－	MPa	－
	Izod impact strength		D-256	Notched	J/m	588
	Rockwell hardness		D-785	R-scale	－	120

Applications and industries of glass epoxy

In addition to being used as printed circuit boards as mentioned above, glass epoxy is used for the following purposes.

• IC printed circuit board
• Insulating and heat insulating materials for electronic parts and electrical equipment
• spacer
• honeycomb heater

Precautions for glass epoxy (glass epoxy) processing

Glass epoxy is a very hard material compared to other resin materials.

Therefore, it is necessary to use tools such as diamond cutters used for cemented carbide to process and cut.

In addition, when glass epoxy is cut, finely powdered dust scatters, and there are cases where it gets into the motor or drive part of the machine and breaks down the processing equipment, so equipment and know-how to prevent dust is indispensable.

At TDC, we are fully equipped with diamond cutters and dust collectors that are capable of processing glass epoxy.

We also accept glass epoxy processing that has been refused by other companies, so please feel free to contact TDC.

Example of precision processing of TDC’s glass epoxy (glass epoxy)

Here is an example of precision processing of glass epoxy (glass epoxy) at TDC. With our processing know-how according to the material and our accumulated polishing processing technology, we can handle any precision. Please feel free to contact TDC for glass epoxy (glass epoxy) processing projects that have been rejected by other companies.

Precision processing example 1: glass epoxy test piece thinning and polishing

• Size: 50mm x 50mm
• Specifications: Thickness polishing Thickness 0.6 mm → 0.5 mm +/- 0.01 mm
• Material: glass epoxy
• Processing details: Precision lapping reduces thickness by 100um and finishes to desired tolerance.

精Precision processing example 2: Glass epoxy dia. 530mm large substrate mirror polishing processing

• Size:dia. 530 mm x thickness 0.750 mm
• Specifications: mirror finish, finished to a thickness of +/- 0.005mm
• Material: glass epoxy
• Processing details: The processed surface is mirror-finished with precision lapping, and the thickness tolerance is within ±0.005mm.

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