JOHNAN contributes to the growth of global society through Monozukuri, Japanese quality manufacturing. 

Since 1962, the JOHNAN group has been providing consistent services mainly for PCB mounting for electronic components and equipment. In particular, we have responded consistently to clients' requirements ranging from productization to production launch. Solving wide ranging challenges faced at every manufacturing phase, we have earned great trust from clients. Based on time-proven Japanese high-quality manufacturing, known as Monozukuri, we will devote ourselves to contributing to global industrial growth and the creation of a sustainable society by solving various challenges in manufacturing.


1. About us


【Introduction of Executives】
Chairman:Mitsuyo Yamamoto、President:Hiroshi Sasaki、Vice President:Tomoji Kouda

【Business Contents】
PCB ASSEMBLY & PRE-BOX ASSEMBLY Inspection and Pre-Assembly Services

【number of employees】
224 As of October 18, 2019 (including contract employees)

789/108 Moo 1, Tambol Nongkham, Amphur Sriracha, Chonburi 20230, Thailand
TEL +66-03-829-6858-59 / FAX +66-03-829-6860

<History of the Company>

2007 CELCO (THAILAND) CO.,LTD registrations
2008 Launch of printed circuit board assembly service (ISO9001: acquired in 2008)
2009 Launch of PCBA services for Plasma TV
2012 Launch of PCBA services for motors, and home appliances Commencement of PCBA services for air conditioners, ISO14001: Obtained 2004 certification
2016 Launch of business inspection services
2019 JOHNAN Corporation acquired all shares of CELCO (THAILAND) CO., LTD.
Our name has been changed "JOHNAN SIAM CORPORATION LIMITED".

2. Features and Strengths

  • ■Since 2007 company foundation, JOHNAN SIAM has been running EMS business in Thailand for last thirteen years, and we provide from low volume high mix to high volume low mix production.
  • ■It's located in Chonburi Province, close to Thailand's largest trading port Laem - Chabang Port, where the risk of flooding is low.
  • ■JOHNAN SIAM owns L size PCBA equipment in all process, from Auto Insert, SMT, AOI to dip soldering.
  • ■Wide range PCBA is available from 0402(mm) chip, majority is 0603(mm) actually, to large odd parts.
  • ■JOHNAN SIAM owns N2 reflow oven with N2 generator (High Density PCBA and BGA are capable).
  • ■3D AOI inspection machines are set in SMT line, which feedback mount failure immediately.
  • ■JOHNAN SIAM proposes solutions of manufacturing problems to improve productivity and quality, such as VA and VE proposals.
  • ■Propose inspection equipment (function tester) according to the customer's specifications.
  • ■ISO 9001/14001 was certified. JOHNAN SIAM provides same management quality/operation as our Japan side facility. We provide highly reliable products complying with customer specifications.

3. Services Summary

■PCBA Assembly & Assembly


Printed Circuit Board Assembly (PCBA) our product ranges cover varieties of consumer home appliance, electronic products, and automotive products (AC, Refrigerator, Rice Cooker, Television, Jarpot, etc.)

■Inspection and Pre-assembly services

Inspection and Pre-Assembly Services

JOHNAN SIAM provides hi-resolution inspection service (dimensions and appearance) for electronic parts and automotive parts.

■Packing / Shipping Services

Packing / Shipping service

JOHNAN SIAM handles packing design, manufacturing and shipping services, according to customer delivery styles. If you have any problems, please feel free to contact us.

4. Introdution of our services

Here are some introductions of our manufacturing related services, please feel free to contact us as we may be able to provide other services.

  • ・Service details
    Consignment manufacturing and inspection of boards for consumer electronic appliances, home appliances, vehicles, and industrial equipment
  • ・PCBA base materials capability
    Ceramic substrate, Alminium substrate, FPC, High Multilayer PCB, Large size PCB, Paper Phenol PCB..etc.
  • ・Type of solder
    Pb-free solder(with Ag) and Pb-free solder(without Ag)
  • ・SMD component capability
    Minimum pin pitch: 0.3mm
    Mounting accuracy: +/-30um(with high-producing mode off)
    Minimum chip: 0402
    Chips: BGA,SOP,QFP,LED,QFN,etc.
    Size: Maximum work size: 360 mm x 410 mm;
    Board thickness: 0.5 mm to 1.6 mm (MAX: 5.0 mm)
    • Axial insertion machine:5.0 mm to 26.0 mm pitch
    • Radial insertion machine:2.5mm, 5.0mm, 7.5mm pitch compatible
    • 3D image inspection equipment:Chip0603
    • DIP Pot, automatic soldering Machine

5. Introduction of Manufacturing facilities

JOHNAN SIAM has manufacturing equipment to correspond customers request and needs, if you have any problems, please do not hesitate to contact us.

Equipment owned

Equipment owned

Mounting machine 7 lines
Jumper Inserter 1 machine
Axial Inserter 2 machine
Radial Inserter 3 machine
DIP Insertion 5 Line
SPI Inspection 4 machine
AOI Inspection 6 machine
Pin board for ICT
Function tester machines, etc.

■Material Warehouse

Material storehouse

■SMT Process

SMT process

■AOI Processing

AOI process

■Auto-Insert (AI) Process

Auto insert (AI) process

■Dip soldering to PCB
completed assembly

Dip components finishing process

■SMT Processing Line

Printing Machine

Printing Machine

3D Solder Paste Inspection (SPI)

3D Solder Paste Inspection (SPI)

High-Accuracy Mounter

High-Accuracy Mounter

N2 Reflow Oven

N2 Reflow Oven

3D Appearance Inspection Machine (AOI)

3D Appearance Inspection Machine (AOI)


In order to provide high-value-added manufacturing to customers, we are actively engaged in various initiatives such as productivity and quality improvement at manufacturing sites, 5S activities, skill training and human development.

7. Access

【Time required】
  • ・50 minutes by car from Suvarnabhumi International Airport
  • ・20 minutes by car from Laem Chabang Port

789/108 Moo 1, Tambol Nongkham, Amphur Sriracha, Chonburi 20230, Thailand
TEL +66-03-829-6858-59 / FAX +66-03-829-6860
Email: phungpetch.ng@johnan.com