What are the problems with solid state relays?

Common SSR problems include heat dissipation, off-state leakage current, on-state voltage drop, sensitivity to overvoltage, and fail-short mode. Our line mitigates these with thermal bonding, leakage measurement, and surge testing.

What are three types of solid state relays?

Zero-cross switching SSR, random-turn on SSR, and DC-to-DC SSR. Our line can assemble and test all three types.

Solid state relay · No moving parts

Solid State Relay Production Line
Up to 2,400 units/shift | 10A‑120A

Q: What is the difference between SSR and EMR?

SSR has no moving parts, faster switching, longer life but higher on-state drop and leakage. EMR uses mechanical contacts, lower resistance, fails open but wears out.

Q: What is the difference between SSR and MOSFET?

A MOSFET is a single transistor; an SSR integrates a MOSFET (or triac) with optocoupler, protection circuits, and heatsink into a complete module.

Q: What electrical tests does your SSR line perform?

Input trigger, zero-cross detection, leakage current, on-state voltage drop, load current up to 120A, blocking voltage, and optional surge current.

Q: Can you produce SSRs with overcurrent protection?

Yes, we integrate calibration and verification of built-in overcurrent protection thresholds.

The automated assembly and testing lines for solid-state relays (SSR) include a fully automated process that places PCBs, performs SMT soldering, attaches thermal pads, assembles housing, and tests electrical characteristics such as zero-cross, leakage current, and load testing. These lines are specifically engineered to address the high reliability requirements of industrial and HVAC applications.

Request a line quote → View line modules

2,400+

Units/shift

10‑120A

Current rating

±0.1mA

Leakage accuracy

0.02ms

Switching time

Core advantages

Why an automated SSR production line?

Complete assembly of solid-state relays (SSR) requires accurate PCB assembly, thermal management, and electrical verification. Our automated production line provides consistent results, minimizes the risk of electrostatic discharge (ESD) damage, and includes 100% in-line testing of all products.

Precision PCB & SMT assembly

Automated solder paste printing, component placement, and reflow soldering for power semiconductor (SCR/triac) and optocoupler circuits.

Thermal pad & heatsink bonding

Robotic application of thermal interface material and automatic heatsink screw driving – critical for SSR heat dissipation.

Comprehensive electrical test

Zero‑cross detection, leakage current (μA range), load current test, blocking voltage, and surge current verification.

MES traceability & vision QC

Each SSR’s test results (ON‑state voltage drop, leakage) linked to serial number. Vision inspection for solder joints and housing alignment.

Integrated line modules

Our solid state relay production line components

An entire assembly and testing line for industrial and HVAC solid-state relays, covering everything from loading PCBs through to the completion of the electrical performance testing.

Solid State Relay Automated Production Line
- Production Line Project
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Full line integration available – from SMT to zero‑cross test. Customizable for 10A‑120A ratings.

Field results

Real impact from automatic SSR lines

Industrial automation brand – China

Deployed full SSR line for 25A‑75A panel mount series. Output increased from 800 to 2,200 units/shift. Field return rate due to thermal issues reduced by 85%.

HVAC OEM – Europe

Integrated zero‑cross detection test and leakage current verification. Achieved 100% compliance with IEC 62314. Payback period 12 months.

Power equipment supplier – India

Custom line for 3‑phase SSRs with heatsink assembly. Reduced assembly labor by 70%, eliminated ESD damage.

Medical device manufacturer – USA

Added vision inspection for solder joints. Achieved 99.5% first‑pass yield, ISO 13485 audit pass.

Technical specs

Manual assembly vs. our fully automatic SSR line

To know how the solid state relay manufacture differ when comparing throughput, test coverage, and reliability.

Parameter	Manual / semi‑auto	Benlong fully automatic line
Output per shift (units)	600‑1,000	2,200‑2,800
SMT placement accuracy	±0.1mm (manual)	±0.02mm (vision guided)
Thermal paste application	Hand syringe, inconsistent	Robotic, ±0.01g controlled
Zero‑cross test coverage	Sample‑based (5%)	100% in‑line, ±0.1mA leakage
Load current test (10‑120A)	Manual, offline fixture	Automated, 8‑station parallel
ESD protection level	Operator dependent (risk)	Grounded workstations, ionizers, monitoring
Traceability level	Paper log, partial	Serialized barcode, MES upload (OPC UA)
Typical investment	$100k – $300k	$500k – $1.8M+

For a volume exceeding 500,000 units, a fully automated SSR line will have a payback period ranging from twelve to sixteen months. Find out your return on investment (ROI) →

Design guide

How to specify a solid state relay production line – 5 steps

Plan your SSR assembly and test line for maximum reliability and electrical performance.

Step 1: Define current rating & package type

Specify your SSR current range (10A, 25A, 50A, 75A, 120A) and form factor (PCB mount, panel mount, DIN rail). This determines load test current and fixture design.

Step 2: Select input control method

DC control (3‑32V), AC control (90‑280V), or low‑voltage logic. Our line tests both input trigger sensitivity and zero‑cross/random turn‑on types.

Step 3: Define output protection features

Overcurrent, overvoltage, short‑circuit protection, or snubber circuits. Automated verification of built‑in protection thresholds.

Step 4: Plan thermal interface assembly

Automatic thermal pad or grease application, heatsink torque control, and thermal resistance measurement.

Step 5: Specify MES & data logging

Each unit’s ON‑state voltage drop (V_DS), leakage current, zero‑cross accuracy, and load test results linked to serial number. Real‑time SPC for trending.

Do you require a complete SSR production system? Please inform us of your specifications and projected yearly output; we can provide you with a fully engineered production system. Get in touch with our production line integration engineers now.

COMPANY PROFILE

Automation System Integration at the Core

Benlong Automation Technology Co., Ltd., a National High-Tech Enterprise, has been a leader in the development of digital intelligent manufacturing equipment since its inception in 2008, when it was based out of Wenzhou, China. The company creates custom production lines, assembly equipment, and testing solutions for manufacturers of solid state relays, as well as those who manufacture HVAC products, all around the world.

We have designed our fully automatic SSR assembly lines for durable use through the integration of SMT placement, thermal management, electrical parameter testing (zero-cross, leakage, load current), and connectivity to the manufacturing execution systems (MES). We work with manufacturers producing power electronics who are making the shift to Industry 4.0.

National High-Tech EnterpriseSSR Assembly & Test

2008Founded

50.88MRegistered Capital RMB

160+National Patents

26Software Copyrights

300+Qualification Records

1200+Customers Served

ENGINEERING & INTEGRATION

From PCB to finished SSR – full automation

Benlong develops and assembles complete solid-state relay production systems, combining all key production processes together: 1) SMT placement; 2) Reflow soldering; 3) Thermal pad attachment; 4) Heatsink assembly; 5) Zero-cross detection; 6) Leakage current testing; 7) Load current verification; 8) Laser marking. Benlong provides complete installation, programming of PLC’s, and M.E.S. handshake.

Solid state relay automated production line – 2,400 units/shift, 10‑120A

Precision SMT placement & reflow – ±0.02mm, vision‑guided

Automatic thermal pad bonding – controlled application, torque monitoring

100% electrical parameter test – zero‑cross, leakage, load, surge

Request a custom SSR line quote

FACTORY ENVIRONMENT

Built for reliable SSR production

We assemble, wire, and pre‑commission every automatic SSR line in our ESD‑safe facility before shipment. Full FAT with your product samples.

GLOBAL INSTALLATIONS

Trusted by SSR manufacturers worldwide

From China to Europe and North America, our automatic production lines are improving reliability for solid state relays.

Algeria plant

Azerbaijan facility

Ethiopia plant

India facility

Iran factory

Russia site

Saudi Arabia line

CERTIFICATES & HONORS

Technology, Patents and Quality Recognition

Benlong has obtained national high-tech enterprise certification, multiple patents, software copyrights and industry honors, reflecting continuous investment in technology development and intelligent manufacturing innovation.

ISO9001 Certificate

ISO14001 Certificate

ISO9001 Certificate

ISO 45001 Certificate

TUV Certificate

Questions?

Solid State Relay Production Line FAQs

What are Solid State Relay Problems?

Common issues for SSRs include: inability to dissipate heat (proper heatsinking), leakage current while not being energized (μA range, critical to some loads), voltage drop while energized (Usually 1-1.5V, loss of power), susceptible to overvoltage (snubber circuits required), failure to short-circuit mode (unlike EMRs, which fail to open circuit). We employ thermal pad bonding, leakage testing, and surge testing in our production line to alleviate all of these problems.

What are the three types of Solid State Relays?

There are three primary types of SSRs: 1) SSRs that switch at zero crossing (turns on when the AC load voltage crosses zero, reducing EMI); 2) SSRs that are switched randomly (instantaneously) (turn ON at any point in the AC cycle for phase control); and 3) DC to DC SSRs (use MOSFET for switching loads). Our production line can assemble and test all three types, including specialized test stations for zero-cross detection or phase-angle verification.

What is the difference between SSR and EMR?

The major difference between an SSR (Solid State Relay) and an EMR (Electromechanical Relay) lies in their operational mechanisms. SSRs use semiconductors for switching and offer advantages such as faster switching (<0.02ms), no contact bounce, silent operation, longer life, and resistance to vibration/shock. However, SSRs also have disadvantages including higher on-state voltage drop (heat), leakage current, and sensitivity to overvoltage.

On the other hand, EMRs use an electromagnet to move contacts and provide advantages such as very low on-resistance (μΩ), no leakage, and failing open. However, they are slower, subject to mechanical wear, and exhibit contact bounce and audible noise. Our SSR production line addresses SSR thermal and leakage limitations through precise assembly and testing.

What is the difference between SSR and MOSFET?

A MOSFET is a single power semiconductor device (transistor) used in DC switching applications. In contrast, an SSR is a complete module comprising MOSFETs (for DC output) or SCRs/triacs (for AC output), along with an optocoupler, snubber circuit, and heat transfer substrate. Essentially, an SSR packages a MOSFET (or triac) along with control and protection circuitry into a ready-to-use module.

Our production line specializes in the assembly of complete SSR modules instead of individual components, ensuring quality and reliability in operation.

What electrical tests does your SSR line perform?

We perform 100% in-line testing including trigger input voltage/current (3-32V DC or 90-280V AC), zero-cross detection accuracy (for zero-cross switching types), output leakage current (μA range), on-state voltage drop (V_DS for MOSFET, V_T for triac), load current capacity (up to 120A), off-state blocking voltage, and surge current capability (optional). Each test procedure is serialized for traceability.

Can you produce SSRs with overcurrent protection?

Yes, we can produce SSRs with integrated overcurrent protection. As part of the production process, we can include an automated station to calibrate and verify overcurrent protection thresholds (e.g., 2× rated current for 10ms). Additionally, the production line will test and record the trip characteristics of each unit for quality assurance.

Start Your Project

Need a Turnkey Solid State Relay Production Line?

Tell us your current rating (10A‑120A), input control type (DC/AC), and annual volume. Our engineers will design a custom assembly line with SMT, thermal management, and 100% electrical testing.

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