Shengyi S1165 Datasheet: High-Performance Mid-Tg FR-4 for Industrial PCB Applications

In the modern landscape of industrial electronics, the move toward “Green” manufacturing is no longer a luxury—it’s a regulatory and ethical baseline. For PCB engineers, this shift often introduces a technical challenge: how to maintain high thermal reliability while using halogen-free materials that can be more brittle or difficult to process.

The Shengyi S1165 datasheet introduces a material specifically engineered to solve this dilemma. As a halogen-free, mid-to-high Tg laminate (typically rated at 170°C by DSC), S1165 serves as a high-performance alternative to standard FR-4. It is designed for applications where thermal excursions are frequent and environmental compliance is non-negotiable. Whether you are designing for high-volume consumer goods or rugged industrial controllers, understanding the nuances of S1165 is critical for maximizing your production yield.

What is Shengyi S1165? An Engineering Overview

Shengyi S1165 is a high-performance, halogen-free laminate and prepreg system based on a specialized epoxy resin. It is built to meet the IPC-4101/94 (and often /130) specification sheets. While many halogen-free materials struggle with delamination during lead-free reflow, S1165 is characterized by its superior thermal stability and lower Z-axis expansion.

The “Mid-Tg” classification (170°C) places it in a sweet spot. It offers significantly better reliability than economy-grade 140°C Tg materials, but it remains more cost-effective and easier to drill than ultra-high Tg (180°C+) specialty substrates. For the vast majority of industrial and communication designs, this provides a “Goldilocks” balance of performance and price.

Core Features at a Glance:

Halogen-Free: Complies with JPCA-ES-01-2003 standards (Cl < 0.09%, Br < 0.09%).

Lead-Free Compatible: Engineered for reflow temperatures peaking at 260°C.

UV Blocking & AOI Compatibility: Optimized for high-volume automated fabrication lines.

Low Z-Axis CTE: Reduces stress on copper-plated through-holes (PTH) during thermal cycling.

Technical Specifications: A Deep Dive into the S1165 Datasheet

From a design perspective, the datasheet isn’t just a list of numbers—it’s a set of boundary conditions. S1165 excels in areas where standard FR-4 fails, particularly regarding decomposition and expansion.

Thermal Performance Table

Parameter	Test Method	Typical Value
Glass Transition Temp (Tg)	DSC	170°C
Decomposition Temp (Td)	TGA (5% W.L.)	360°C
T260 (Time to Delamination)	TMA	> 60 Minutes
T288 (Time to Delamination)	TMA	15 Minutes
Z-Axis CTE (Before Tg)	TMA	40 ppm/°C
Z-Axis CTE (After Tg)	TMA	250 ppm/°C
Total Expansion (50-260°C)	TMA	3.2%

A Td of 360°C is a critical indicator of reliability. Most standard FR-4 materials start breaking down at 300-310°C. That extra 50°C of “thermal headroom” is what prevents pad cratering and delamination during rework or multiple reflow cycles.

Electrical and Mechanical Properties

Parameter	Test Method	Typical Value
Dielectric Constant (Dk)	1MHz (C-24/23/50)	4.8
Dissipation Factor (Df)	1MHz (C-24/23/50)	0.007
Volume Resistivity	After Moisture	2.0 x 10⁸ MΩ-cm
Surface Resistivity	After Moisture	1.0 x 10⁷ MΩ
Peel Strength (1oz Cu)	288°C, 10s	1.5 N/mm
Water Absorption	D-24/23	0.15%

For designers of communication equipment, the Df of 0.007 is particularly impressive for a conventional (non-high-speed) laminate. It allows for better signal integrity than economy grades, though it is still not a substitute for ultra-low-loss materials in 25Gbps+ applications.

Strategic Applications for S1165 PCB Material

The Shengyi S1165 datasheet identifies several high-reliability sectors where this material is the baseline specification.

Industrial Instrumentation: Precision meters and PLC modules that operate in variable temperature environments.

Communication Equipment: Routers, switches, and base station components that must meet strict halogen-free global standards.

Automotive Electronics: Interior systems and infotainment where 170°C Tg provides the necessary safety margin against thermal fatigue.

Consumer Electronics: High-end laptops, gaming machines, and smart home hubs where durability and “green” branding are prioritized.

Design and Fabrication Tips for Engineers

Choosing the material is only half the battle; designing for it requires specific considerations.

1. Impedance Matching

The Dk of S1165 (4.8 at 1MHz) is slightly higher than some low-Tg variants. If you are migrating a design from a material with a Dk of 4.4, your trace widths will need to be adjusted. Always request a stackup from your <a href=”https://www.pcbsync.com/Shengyi-pcb/“>Shengyi PCB</a> fabricator early in the CAD phase to ensure your impedance calculations are based on actual pressed-thickness values.

2. Drilling and Aspect Ratios

Halogen-free materials can be more abrasive on drill bits. S1165 is formulated to mitigate this, but it is still wise to limit your aspect ratio to 10:1 for mechanical drilling to ensure plating consistency in the holes. The lower Z-axis CTE (40 ppm/°C) provides excellent through-hole reliability even in thicker 8-12 layer boards.

3. Moisture Sensitivity

With a water absorption rate of 0.15%, S1165 is quite robust. However, as with all halogen-free laminates, a pre-bake (typically 2 hours at 120°C) before assembly is recommended if the boards have been stored in a high-humidity environment to prevent “popcorning” during reflow.

Resources and Technical Documentation

To properly integrate S1165 into your workflow, keep the following resources bookmarked:

Official S1165 Full Datasheet: Detailed breakdown of all IPC-TM-650 test results. Download PDF

Shengyi Technology USA Product List: Comprehensive comparison of the Halogen-Free line (S1165 vs. S1150G). Product Center

UL Product iQ: Search File E109769 for flammability and Maximum Operating Temperature (MOT) ratings.

Frequently Asked Questions (FAQs)

1. Is S1165 a direct replacement for S1141?

Technically, yes, but it is an upgrade. S1165 offers a higher Tg (170°C vs 140°C) and is halogen-free. You can use S1165 where S1141 is specified, but you may need to adjust your impedance traces due to the Dk difference.

2. Can S1165 be used in high-layer-count (20+) boards?

While S1165 has a low CTE, it is generally optimized for mid-layer counts (4-12 layers). For ultra-high layer counts or extreme HDI, materials like S1000-2M or S1170G might be suggested for even better dimensional stability.

3. What is the shelf life of S1165 prepreg?

When stored at room temperature (<23°C and <50% RH), the prepreg has a shelf life of three months. In cold storage (<5°C), it can last up to six months. Always allow the prepreg to normalize to room temperature for 4 hours before use.

4. Is S1165 suitable for Anti-CAF applications?

Yes, S1165 features enhanced resin chemistry that provides excellent resistance to Conductive Anodic Filament (CAF) growth, making it suitable for high-density designs with fine-pitch vias.

5. Does S1165 support lead-free “green” certifications?

Yes. It is fully RoHS and REACH compliant and meets the JPCA-ES-01-2003 “Halogen-Free” definition, making it ideal for products intended for the European and Japanese markets.