Panasonic R-8705 PCB material is a double-sided paper phenolic laminate designed for cost-sensitive consumer electronics and home appliance boards. This guide covers full electrical, mechanical, and thermal specifications, application suitability, FR-4 comparison, datasheet resources, and 5 key FAQs for PCB engineers.
If you’ve spent any time sourcing laminates for low-cost consumer electronics boards, you’ve almost certainly come across the Panasonic R-8705 PCB material. It’s one of those workhorses that doesn’t get glamorous coverage the way MEGTRON 6 or Rogers does 鈥� but for the right application, nothing beats it on cost-per-performance. This guide covers everything a PCB engineer needs to know: what the material actually is, its verified specifications, where it fits in a design, and where it absolutely doesn’t belong.
What Is Panasonic R-8705 PCB Material?
The Panasonic R-8705 PCB material is a double-sided copper clad laminate built on a paper phenolic substrate. It sits within Panasonic’s R-8700 series of paper phenolic circuit board materials, which the company classifies under its broader Electronic Materials lineup. The key distinction within the series is simple: R-8700 is single-sided; R-8705 is double-sided.
Paper phenolic means the core reinforcement is cellulose-based 鈥� kraft paper fibers impregnated with a phenolic (phenol-formaldehyde) resin system. The result is a brown-toned laminate that’s been used in mass-market electronics since the early days of PCB manufacturing. It’s not exotic, but it’s reliably manufacturable at scale.
The R-8700 Series Line-Up
Panasonic offers the R-8700 family across multiple variants, each targeting a different performance tier:
| Model | Copper Cladding | Heat Resistance Class | Key Feature |
| R-8700 | Single-sided | Standard | General purpose |
| R-8700EF / R-8700EJ | Single-sided | High | Excellent heat resistance |
| R-8700SB | Single-sided | Standard | Superior tracking resistance |
| R-8705 | Double-sided | Standard | General purpose, double-sided |
| R-8705EF / R-8705EJ | Double-sided | High | Excellent heat resistance |
For most cost-sensitive double-sided board designs in home appliances or consumer electronics, R-8705 is the standard go-to. The EF and EJ variants are worth specifying when operating temperatures push toward the upper limits of the standard grade.
Panasonic R-8705 PCB Material Specifications
Panasonic does not publish a full open-access datasheet for the R-8705 in the way Rogers publishes RF substrate data, so engineers typically request the specification sheet directly through a distributor or via Panasonic’s industrial products inquiry system. That said, based on confirmed technical data across Panasonic’s paper phenolic series and aligned IPC/NEMA standards, the following parameters represent the R-8705’s profile:
Electrical Properties
| Property | Typical Value | Test Condition |
| Dielectric Constant (Dk) | 4.5 鈥� 5.0 | 1 MHz |
| Dissipation Factor (Df) | 0.030 鈥� 0.045 | 1 MHz |
| Volume Resistivity | 鈮�10鈦� M惟路cm | C-96/35/90 |
| Surface Resistivity | 鈮�10鈦� M惟 | C-96/35/90 |
| Dielectric Breakdown Voltage | 鈮�15 kV | 鈥� |
| Tracking Resistance (CTI) | Excellent | 鈥� |
The dielectric constant and dissipation factor values here tell you immediately this is not a material for anything running signals above a few hundred MHz. The relatively high Dk and Df are the trade-off you accept for the cost savings. For DC-to-low-frequency circuits 鈥� think relay boards, remote controls, motor drivers 鈥� those numbers are entirely irrelevant.
Mechanical Properties
| Property | Typical Value |
| Flexural Strength (lengthwise) | 鈮�120 N/mm虏 |
| Flexural Strength (crosswise) | 鈮�100 N/mm虏 |
| Punchability at Room Temperature | Good (FR-2 grade compatible) |
| Water Absorption (D-24/23) | 鈮�0.80% |
| Surface Hardness | Rockwell M 鈮� 100 |
The punchability characteristic is genuinely useful in high-volume manufacturing. Unlike FR-4, which must be routed or drilled, paper phenolic laminates like R-8705 can be punch-processed at or near room temperature, dramatically lowering tooling cycle times for simple board geometries.
Thermal Properties
| Property | Typical Value |
| Glass Transition Temperature (Tg) | ~105 鈥� 115掳C |
| Flammability Rating | UL 94 V-0 (standard grade) |
| Continuous Operating Temperature | 鈮�105掳颁 |
| Solder Resistance (288掳C, 10 sec) | Acceptable |
The Tg is on the lower end compared to FR-4’s typical 130鈥�170掳颁 range. This matters for your assembly process: if you’re running lead-free reflow at 260掳C peak, R-8705 is not appropriate. It’s designed primarily for wave soldering or selective soldering of through-hole components, which keeps the board exposure below its thermal limit.
Available Copper Foil Thickness
Standard copper weights for R-8705 are 1 oz (35 碌m) and 2 oz (70 碌m), with 0.5 oz available on request for specific thicknesses. Board thickness typically ranges from 0.8 mm to 2.4 mm, with 1.6 mm being the most commonly stocked.
Key Advantages of R-8705 That Actually Matter in Production
From a fabrication standpoint, a few properties of the Panasonic R-8705 PCB material stand out beyond what the spec sheet conveys.
Excellent tracking resistance is the headline claim Panasonic makes for this series, and it holds up. Tracking resistance refers to the material’s ability to resist the formation of a conductive carbon path across its surface under high-voltage stress. For appliance boards operating near line voltage, this is not a theoretical concern 鈥� it’s a UL/IEC compliance requirement, and R-8705 delivers in that area.
Dimensional stability for punching is the other practical win. In high-volume remote control PCB production or simple motor-driver boards, punching rather than routing can cut unit costs meaningfully. The paper fiber structure of R-8705 absorbs mechanical shock during the punch cycle rather than cracking or delaminating.
Long shelf life is another underrated benefit. The phenolic resin system is less hygroscopic than some alternatives when stored properly, and Panasonic’s paper phenolic boards have a well-established record of stable shelf performance.
Typical Applications for Panasonic R-8705
Given its properties, the R-8705 fits cleanly into a defined set of application categories:
| Application Category | Specific Products |
| 吃瓜tv Appliances | Air conditioners, washing machine controllers, microwave ovens |
| Consumer Electronics | Remote controls, DVD players, LCD TVs, audio equipment |
| Automotive Interior | In-vehicle instrument panels (non-safety-critical), motor controls |
| IT Peripherals | Keyboards, LCD backlighting control boards |
| Industrial / Motor Control | Small relay driver boards, fan control PCBs |
What’s absent from that list is equally instructive. You won’t find R-8705 in RF front-ends, high-speed data paths, power amplifiers, or anything that runs above ~50 MHz with performance-critical signals. The material simply doesn’t have the electrical stability for those uses.
R-8705 vs FR-4: Choosing the Right Material
Engineers frequently face the R-8705 vs FR-4 decision for double-sided consumer boards. Here’s a direct comparison:
| Parameter | Panasonic R-8705 | Standard FR-4 |
| Material Base | Paper phenolic | Woven glass epoxy |
| Tg | 词110掳颁 | 130鈥�170掳颁 |
| Dielectric Constant | 4.5鈥�5.0 | 4.2鈥�4.8 |
| Dissipation Factor | 0.030鈥�0.045 | 0.015鈥�0.025 |
| Punchability | Yes (room temp) | No (must drill/route) |
| Moisture Absorption | Moderate (~0.8%) | Low (~0.15%) |
| Material Cost | Lower | Higher |
| Lead-Free Reflow Compatibility | Limited | Yes |
| Suitable for High Frequency | No | Limited |
The cost advantage of R-8705 over FR-4 is real and consistent. For a remote control board or a simple household appliance controller where there’s no lead-free reflow requirement and signal frequencies are below 10 MHz, R-8705 is the rational choice.
Where to Source and Download the Datasheet
The R-8705 is not universally stocked by every distributor, but it’s accessible through the following channels:
| Resource | Link / Contact |
| Panasonic Industrial (Official Product Page) | |
| Panasonic Product Inquiry / Quote Request | Via Panasonic Industrial contact portal (region-specific) |
| PCB Directory | 鈥� search R-8705 |
| IPC Laminate Standards Reference | IPC-4101 (Specification for Base Materials for Rigid and Multilayer Printed Boards) |
| NEMA Standards (Laminate Grades FR-1, FR-2, XPC) | Available via NEMA.org |
For fabricators working with Panasonic PCB materials, it’s worth requesting the full technical data sheet directly from the manufacturer, as some specific lot-to-lot property ranges are only disclosed in the document package sent upon formal inquiry.
Frequently Asked Questions About Panasonic R-8705 PCB Material
Q1: What is the difference between R-8700 and R-8705? R-8700 is single-sided copper clad, meaning copper foil is bonded to only one face of the laminate. R-8705 is double-sided, with copper on both surfaces, enabling routing of circuitry on both layers. For designs requiring any signal crossover or ground plane on the back side, R-8705 is the correct choice.
Q2: Can R-8705 handle lead-free (ROHS-compliant) assembly processes? Generally, no. Standard R-8705 has a Tg in the 105鈥�115掳C range, which is insufficient for lead-free reflow peak temperatures of around 260掳C. If your design requires lead-free processing, specify the R-8705EF or R-8705EJ variant with enhanced heat resistance, or reconsider FR-4.
Q3: What NEMA or IPC grade does R-8705 correspond to? The R-8700 series aligns most closely with FR-2 under IPC-4101 鈥� a flame-retardant paper phenolic grade with good electrical properties. It is distinct from XPC (which lacks the flame-retardant system) and from FR-1 (which has slightly lower electrical performance).
Q4: Is punching the only way to process R-8705, or can it be routed? You can route R-8705 using standard PCB routing equipment. Punching is a cost-efficient option for high-volume simple geometries, not a fabrication requirement. For prototypes or complex outlines, CNC routing works perfectly well.
Q5: Where does R-8705 fit in Panasonic’s overall PCB material portfolio? R-8705 occupies the entry-level, high-volume tier of Panasonic’s circuit board material lineup. Above it sit the glass epoxy grades (standard FR-4 class), then the glass composite CEM-3 series, and at the top end, the MEGTRON family for high-speed/high-frequency applications. R-8705 is intentionally positioned for cost-sensitive, low-frequency designs 鈥� it’s not a compromise, it’s the right tool for the right job.
For engineering inquiries, sample requests, and regional pricing on Panasonic R-8705 PCB material, contact Panasonic Industry directly through their regional industrial products portal.