MG Chemicals 521, Single Sided Copper Clad Board, 1/16", 1Oz Copper, 12"X12", Case of 5
MG Chemicals 521, Single Sided Copper Clad Board, 1/16", 1Oz Copper, 12"X12", Case of 5
MG Chemicals 521 is a 12 × 12-inch single-sided copper-clad FR4 board for PCB prototyping and small production runs. Its woven glass-epoxy laminate is nominally 1/16 inch thick with 1 oz copper cladding on one face. The square blank provides a larger starting area than the 8 × 10-inch 515 for engineers, electronics workshops, students and hobbyists fabricating custom circuits. This listing supplies a case of five boards.
Best Uses / Applications
- Single-sided PCB prototypes requiring a 12 × 12-inch starting blank.
- Small production runs using an appropriate resist and copper-etching process.
- Electronics teaching, design development and hands-on circuit fabrication.
- Custom layouts where the board can be cut to the required dimensions.
This is an unpatterned copper-clad laminate, not a pre-etched circuit, pre-drilled perfboard or solderless breadboard. The manufacturer describes fabrication using an anti-etch PCB pen and copper etchant; select the complete process and handling controls appropriate to your design.
Key Features
- Continuous woven glass cloth impregnated with epoxy resin.
- FR4, described by the manufacturer as the flame-retardant version of G-10.
- Single-sided 1 oz copper, nominally 35 µm or 1.37 mil thick.
- Less copper to remove than a comparable 2 oz board, enabling quicker etching under comparable process conditions.
- DICY (dicyandiamide) cured system and UV-blocking construction.
- Manufacturer describes easy cutting without specialized equipment; use a suitable method and follow the SDS.
Technical Specifications
| Specification | Details |
|---|---|
| Manufacturer / part number | MG Chemicals / 521 |
| Family | 500 Series Copper Clad Boards |
| Construction | Single-sided copper-clad FR4 glass-epoxy laminate |
| Board dimensions | 12 × 12 in. nominal; manufacturer metric listing 304 × 304 mm |
| Laminate thickness | 1/16 in. nominal / manufacturer listing 1.6 mm |
| Copper weight | 1 oz |
| Copper thickness | 35 µm / 1.37 mil nominal |
| Sales package | Case of 5 boards |
| Cure system | DICY |
| UV blocking | Yes, per manufacturer |
| Manufacturer-reported conformance | UL file E214381 and IPC-4101C/21 |
| Flammability, typical family data | 94 V-0, UL-94 |
| Maximum operating temperature, typical | 130°C |
| Glass transition temperature, typical | 140°C |
| Moisture absorption, typical | 0.25% |
| Dielectric constant at 1 GHz, typical | 4.2 |
| Dissipation factor at 1 GHz, typical | 0.015 |
| Dielectric strength, typical | 1,200–1,400 V/mil |
| Peel strength, 1 oz copper, typical | 10–12 lb/in. as received; 9–12 lb/in. after thermal stress |
| Flexural strength, typical | 600 MPa warp; 500 MPa fill |
| Storage | 18–27°C, dry and away from sunlight; sealed airtight and protected from humidity |
Performance figures are manufacturer-published typical family values for reference, not guaranteed design limits. Consult the full TDS and qualify the laminate and fabrication process for the intended assembly.
Compare Copper-Clad Board Options
| Option | Difference | Selection consideration |
|---|---|---|
| 521: single-sided 1 oz, 12 × 12 in. | Square blank with copper on one face | Single-sided layouts needing the larger starting area |
| 515: single-sided 1 oz, 8 × 10 in. | Smaller rectangular blank in the same listed thickness | Designs fitting an 8 × 10-inch starting area |
| 540: double-sided 1 oz, 3 × 5 in. | Copper on both faces; smaller blank | Designs needing two copper faces |
| 555: double-sided 1 oz, 12 × 12 in. | Same nominal face dimensions with copper on both sides | Compare when two copper faces are needed |
| 2 oz copper-clad board | More copper than a 1 oz board | Compare circuit and etching requirements; 1 oz requires less copper removal |
The family also includes 1/2 oz copper and 1/32-inch laminate options. Those thinner family options do not describe part 521.
Fabrication and Storage Guidance
Confirm layout dimensions, copper weight and required layer count before fabrication. Apply a suitable etch resist, use a compatible copper etchant according to its instructions, and inspect the circuit before assembly. Follow the board SDS and instructions for each fabrication chemical and tool. Store unused boards in an airtight container in a dry area at 18–27°C, away from sunlight and humidity.
Frequently Asked Questions
What size is MG Chemicals 521?
Each board is nominally 12 × 12 inches. The manufacturer lists 304 × 304 mm and a 1/16-inch (1.6 mm) FR4 laminate.
Is 521 single-sided or double-sided?
It is single-sided, with copper on one face. The manufacturer's 555 is a double-sided option with the same nominal 12 × 12-inch face dimensions.
What does 1 oz copper mean?
It is the copper cladding weight designation. The manufacturer lists a nominal copper thickness of 35 µm or 1.37 mil; the finished board does not weigh only one ounce.
How many boards are included?
This listing supplies a case of five 521 boards.
How is 521 different from 515?
Both are single-sided 1 oz copper-clad FR4 in the same listed thickness. 521 is 12 × 12 inches; 515 is 8 × 10 inches.
Is it ready for components?
It is a copper-clad blank rather than a finished circuit. Your design requires an appropriate fabrication process, including resist and etching and any additional operations needed.
Why use 1 oz instead of 2 oz copper?
The manufacturer notes that 1 oz boards contain less copper and etch quicker under comparable conditions. Select copper weight for the circuit's electrical and fabrication requirements, not speed alone.
How should it be stored?
Store at 18–27°C, dry and away from sunlight, sealed in an airtight container and protected from humidity.
Technical and Safety Documents
MG Chemicals 500 Series Copper Clad Boards Technical Data Sheet
Manufacturer revision October 6, 2025, version 3.0.
MG Chemicals 500 Series Copper Clad Boards Safety Data Sheet
Manufacturer revision February 28, 2020, version 2.01; includes part 521.
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