Chip-On-Board-PCB

COB MCPCB, known as "Chip-On-Board" Metal Core PCB, is a type of MCPCB used in thermoelectric separation application. By using COB MCPCB, the micro-chip (also known as "die") directly touch the metal core where the heat dissipate, and electrically interconnect the trace of circuit board (wire-bonding) so that power supply can be provided.

In normal MCPCB, there's a dielectric layer between trace copper and metal core, and the thermal conductivity is limited by that dielectric layers, so value can only be 1~3 W/m.K. But using COB MCPCB, there's no such dielectric layer because chip (die) direct touch the metal core, so thermal conductivity value of COB MCPCB will be almost the same one of metal core material itself. The normal material of metal core is aluminum, so thermal conduviity of COB MCPCB is more than 200W/m.K.

COB process consists of three main categories to perform when manufacturing the Chip-on-Board:

1st: 'die mount or die attach';
2nd: 'wire bonding';
3rd: 'the encapsulation of die wires'.

By using wire bonding & epoxy packaging then directly embedded on MCPCB, this practice can extend the lifespan of LED and unified light emission.

According to process and material, COB MCPCB applications can be categorized into two types: Mirror Aluminum and silver or gold platting aluminum, or silver plating mirror aluminum PCB.


Advantage of utilizing COB MCPCB
•Excellent heat dissipation
•High thermal conductivity: 137W/m.K
•Higher reliability with better heat dispatch and small number of solder joint.
•Provide enhanced reliability and lifespan of LED
• Easy assembly for high powers LEDs
• High quality material and production process allows easy assembly and substantial reduce the error percentage in assembly process
•Substantially reduced space and cost
•With better security protection(difficult to hack using reverse engineering)
•Shorter time to the market



Application of COB MCPCB
•High Power LED (up to 200W)
• LED Backlight for LED TV
•LED Front Light for E-Book
•Agriculture & Horticulture Lighting
•Street & Parking Lot Lighting
•Automotive
•Power Supply
•ustomer Electronics Lighting
•Other products that require thermal solutions

Baggio WANG

-----------------------------------------------------------

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

Fax:86-755-82596922/82596923

SKYPE: BAGGIOWANG0214
baggio.wang@funsunpcb.com

baggio@jaapson-pcb.com 

www.jaapsonpcb.com

JAAPSON, the special-tech PCB manufacture

What is OSP

What are the advantages using OSP surface finish?

What precautions should we take when using circuit boards supplied with OSP finish?

The biggest advantage of an OSP finished board is the price. OSP boards tend to be cheaper than those fabricated with other surfaces such as HASL, Immersion Tin, Immersion Silver or ENIG. Another advantage that OSP has, particularly as compared to HASL finished boards, is the flatness of the pads.

The primary drawbacks are related to solderability, shelf life, re-use of misprinted boards, and multiple heating cycles. The solderability/shelf life issues are connected; if the OSP degrades through shelf life (typically less than 1 year), the Copper underneath oxidizes fairly easily and prevents the board from being generally easy to solder.

The re-use of misprinted boards can also be an issue with OSP since alcohol and other solvents used to clean misprinted boards will also remove the OSP, leaving the Copper surface very easy to oxidize. Misprinted boards that are cleaned need to be sent back through the print/place/reflow processes quickly to avoid this issue.

Finally, OSP boards can be susceptible to solderability problems when subjected to multiple heating cycles; this occurs as a result of the OSP itself being degraded by the heating processes.

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

Fax:86-755-82596922/82596923

baggio@jaapson-pcb.com 

www.jaapsonpcb.com

What is Immersion Silver

IAg or Immersion Silver Plating is a surface plating technology used for Printed Circuit Boards. It consists of a thin immersion silver plating over the copper traces.

Advantages of immersion silver:
Excellent surface planarity (compared to e.g. HASL)
Low High Frequency Signal loss due to skin effect

Disadvantages of immersion silver:
Rapid degradation of surface due to oxidation or contamination (with e.g. sulfur or chlorine)
Silver "whiskers" form across electrical potentials and short out components.

Baggio WANG

-----------------------------------------------------------

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

15017916507

Skype: baggiowang0214

Fax:86-755-82596922/82596923

baggio@jaapsonpcb.com 

www.jaapsonpcb.com

HDI multi-layer PCB factory

 

 

Since 2010, We have been introducing advanced production and test equipment from overseas, professional engineering& management personnel and state-of-art technique to make sure we provide our customers with HDI multi layer PCBs of high quality, reasonable price, fast delivery time and timely after-sales.

Jaapson technology capability
4-16 layer PCB
impedance control
blind via, buried via
mixed FR-4+Rogers technology
3mil trace width and space
thick gold PCB

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

Fax:86-755-82596922/82596923

baggio@jaapsonpcb.com 

www.jaapsonpcb.com

JAAPSON, the special-tech PCB manufacture

What is ENEPIG pcb

ENEPIG is suitable for soldering, gold wire bonding, aluminum wire bonding and contact resistance. It is formed by the sequential deposition of electroless Ni (120 to 240 micro inches) followed by 2 to 10 micro inches of electroless Palladium with an immersion gold flash of 2 to 6 micro inches on the top.

What is ENEPIG?

ENEPIG or Electroless Nickel - Electroless Palladium - Immersion Gold is a surface finish for Printed Circuit Boards that has been around for a decade but is only recently coming back into vogue. The high price of palladium had kept it out of reach for most businesses. With the price of palladium now less than the price of gold, this surface finish becomes the best choice for wire bonding, ROHS assembly and just all boards overall. ENEPIG works well with lead free and conventional eutectic solder alloys (Eutectic means its 63% tin and 37% lead.) ENEPIG is called the "Universal" surface finish as it can be used for all assembly processes.

So why is ENEPIG the "universal" finish?
Excellent ROHS lead free and leaded solderability

• Because palladium completely dissolves into the solder leaving an oxide free nickel surface which allows a reliable tin nickel inter metallic.

High wire bond pull strengths (aluminum wire: up to 10g; gold wire: up to 8g). .

• After numerous tests, it holds high pull weights.
• Good for aluminum wedge and gold ball bonding

Low contact resistance

• Due to the controlled deposition of precious metals the electrical resistance is more uniform so it's easier to predict amperage.

Suitable for conductive adhesives

• You can connect components without the use of solder.

Finish is corrosion resistant and pore-free

• Multiple layers of metal provide a higher corrosion resistant coating.

Unlimited shelf life

• Doesn't tarnish

Nickel acts a barrier layer to further reduce copper dissolution during wave solder, thus ensuring good solderability.

• Nickel prevents the mixing of copper and solder.

ENEPIG delivers great solder joint strength with various alloys during multiple reflow soldering, especially SAC305. The middle palladium layer helps to stabilize and control the inner metallic layer. Because of the mixture, ENEPIG after testing showed amazing wire bonding, both with aluminum and gold.

Mr. Baggio Wang

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

Fax:86-755-82596922/82596923
baggio.wang@funsunpcb.com

baggio@jaapson-pcb.com 

www.jaapsonpcb.com

JAAPSON, the special-tech PCB manufacture

What is ENIG(immersion gold)?

Electroless nickel immersion gold (ENIG) is a type of surface plating used for printed circuit boards. It consists of an electroless nickel plating covered with a thin layer of immersion gold, which protects the nickel from oxidation.

ENIG has several advantages over more conventional (and cheaper) surface platings such as HASL (solder), including excellent surface planarity (particularly helpful for PCBs with large BGA packages), good oxidation resistance, and usability for untreated contact surfaces such as membrane switches and contact points.

Early ENIG processes suffered from reliability issues which caused the ENIG finish to separate from the copper pads, taking the parts with them. ENIG also does not wet as evenly or easily as HASL. In addition, a "black-pad" of nickel oxide would form during the immersion gold plating step, greatly reducing solder joint reliability. To remedy this, a layer of electroless palladium can be plated onto the nickel to create ENEPIG surface finish.
ENIG is a costlier finish, but offers the best characteristics for printed circuit boards. The process requires the most steps compared to other common finishing types.

The electroless nickel step is an auto-catalytic process that involves depositing nickel on the palladium-catalyzed copper surface. The reducing agent containing nickel ions must be replenished in order to provide proper concentration, temperature and pH levels necessary to create a consistent coating. During the immersion gold step, the gold adheres to the nickel plated areas through molecular exchange, which will protect the nickel until the soldering process. The gold thickness needs to meet certain tolerances to ensure that the nickel maintains its solderability.

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

Fax:86-755-82596922/82596923

sales@funsunpcb.com 

sales@jaapsonpcb.com 

www.jaapsonpcb.com 

COB PCB technology

COB (known as Chip-on-Board) is semi-conductor assembly technology where micro-chip also known as die is electrically interconnected instead of using traditional assembly process or individual IC packaging on the final product board. The general term meaning of this technology is direct chip attachment also refereeing to DCA. In DCA many kinds are available as substrate in form of ceramic glass or ceramic substrate which has substances of excellent dielectric and thermal property. It is also available in form of flex substrate, which exhibits bendable ability. Other names are known as COG (chip-on-glass) or COF (chip-on-flex).

COB process consists of three main categories to perform when manufacturing the Chip-on-Board. The first process is 'die mount or die attach', the second is 'wire bonding' and lastly 'the encapsulation of die wires'. In many COB assembly technology, FCOB(flip-chip-on-board) have chips facing downward on the board and does not require wire bonding which employees chip which the bond pads are pop up and it connects directly to pads on the board. It is necessary to underfill flip-chip on active surface to protect bumps from chemical and thermo-mechanical damage.

In context of COB manufacturing process, 1) 'die attach' consists of applying die attach holding to board or substrate mounting chip or die over die attach materials. 2) For wire bonding, thermosonic (Au or Cu) ball bending and ultrasonic (Al) wedge bending are used to connect wires between die and substrate. Last part the encapsulation is done dispensing chemical liquid (usually epoxy) over die and wires. Die and bond wires are encapsulated to protect chemical and mechanical damage.

The advantages of COB include better performance due to deceased interconnection between length and resistance. And better protection against reverse engineering; Reduced space and cost; Shorter time to the market. Higher reliability with better heat dispatch and small number of solder joint.

Applications
LED Backlight for LCD TV
LED Front light for E-Book
Agriculture & Horticulture Lighting
Street & Parking Lot Lighting

Invention
Reflective Pocket in PCB for LED Die Attachment (COB)
Patent pending

Advantages
Improved output efficiency of LED lighting
Avoid photonic absorption and scattering over the pocket wall

SHENZHEN JAAPSON TECHNOLOGY CO LTD

Building 2, Tongfuyu Industrial Park,Shenzhen, China, 518104

Tel: 86-755-82596922

Fax:86-755-82596922/82596923

sales@funsunpcb.com 

sales@jaapsonpcb.com 

www.jaapsonpcb.com