ACF Bonding process

2021-05-13 10:34:35

ACF bonding process

ACF bonding process ,is the process of Chip ic/COF ic/FPC bonded to the LCD(Glass)/PCB/Film/FPC/ ,use the ACF tape as the medium connecting materials,use the hot bar/bonding head as the source of the heat and pressure,use the tooling as the holder,and the silicone rubber or teflon as the Cushioning material, all the ACF bonding process finished by the ACF bonding equipments.

ACF tape has little conductive particles in the conductive lines of the tape.

acf bonding process

During ACF bonding, a combination of heat & pressure is applied on to chip (FPC/IC) for an appropriate time.

Conductive particles (each 3~30um) are compressed between IC and substrate (glass / PCB) while insulating materials pushed away.

This allows the compressed Ni-Au layer on the particles to conduct electricity between the IC and the substrates (z-axis).

The insulated particles are distributed with a minimum chance of electrical shorting in the x-axis and y-axis.

As the epoxy cures and conductive particles are trapped into permanent compressed form.

The compressed particles, by its elastic nature, are constantly pushing outwards to maintain good electrical conductivity under different environmental conditions.

This process is what produces the connection between the ACF tape and the components.  Advanced Integrated Technologies is equipped to assist you with your ACF bonding process.

ACF bonding process sorts and conditions:

acf bonding process
ACF bonding process

According to different LCD/LED/OLED and different screens, there are many ACF tapes models.  ACF tape is the important medium of the ACF bonding process.

ACF Tape/ACF Film-ACF bonding process materials

ACF TAPE

ACF Tape is normally made up of two main components, namely Adhesive & conductive particles.

-Adhesives

The adhesive composition is dependent on the materials being assembled. This means an ACF designed for use in a flex-on-glass (FOG) assembly is usually not suitable for use in a chip-on-glass (COG),chip-on-film(COF), flex-on-board(FOB),flex-on-flex(FOF) or any other configurations. It is specific to the application for which it is designed for.

-Conductive Particles

Conductive particles are used to conduct electricity from one side of the bond to the other. Depending on the application, conductive particles range from 3.5μm to 30μm in size, and can be made from Nickel-gold plated polymer spheres, gold plated nickel particles, or lead-free solder materials. Particles may be individually coated with a outer polymer to insulate them from other uncrushed particles, but which will crack open and allow electrical conduction if the particle is trapped and crushed between two pads during assembly.

ACF tape/ACF Anisotropic Conductive Film

ACF (Anisotropic conductive film) or ACF tape is an epoxy adhesive system used by electronics industry to make electrical and mechanical connections from drive electronics to substrates.

ACF are filled with conductive particles which provides electrical interconnection between pads through the film thickness (z-direction).

The conductive particles are distributed far apart thus not electrically conductive in the plane direction (X&Y) of the film.

ACF interconnect offers cost savings by substituting conventional mechanical connectors or soldering interconnect.

ACF interconnect allows low height and fine pitch which enables high density and miniaturizing of assembly.

ACF special conductive particle is made from environmental friendly material (ROHs compliance). It provides good metalic bonding.


AC-7813KM specification

ACF tape data sheet(for example:7206U/2056R)

ACF hot bar/ACF bonding head-ACF bonding process heat and pressure source

The source for heat and pressure in ACF bonding process is most often a hot bar/thermode/bonding head/bonding cutter.

Hot bar bonding systems are designed to heat the hot bar to a specific temperature using low voltage electricity, which temperature is fed back to the controller via a thermocouple.

Tooling is designed to hold the components and position the ACF tape to line up correctly with the conductive pads on the PCB or other component.

The hot bar is then brought into contact with the ACF film over the top of the bonding pad, heated to the bonding temperature, and held for a specified time.


Tell us which products you want to bonding ,then we can suggest you the right ACF bonding equipments for you ..

ACF Bonding Equipment Applications

ACF bonding equipment has been used in glass display applications for many years.  It has recently become widely used in COF, COB,COG,FOG,FOB,FOF areas.  

ACF bonding equipment

Industries that use this technology most are the mobile phone manufacturing, automotive industry, and LCD production, mobile computers, TV manufacturing, open cell panels factories, touch panel ,AD shower, Watch, Pad… factories. and  many Labs who researching in the LCD/LED/OLED/MICRO LED/MINI LED displays industries.

  • TAB Bonding (TCP-PCB / TCP-LCD)

  • COG Bonding (IC-LCD)

  • COB Bonding (IC-PCB)

  • COF Bonding (COF-LCD/PCB)

  • FOG Bonding(FPC-LCD)

  • FOB Bonding(FPC-PCB)

  • FOF Bonding(FPC-FPC)

  • Plasma Display (FPC-PDP)

  • Flip Chip Package

  • ……

ACF Bonding equipment Features

  • Heat cure

  • Fast bonding time

  • High adhesion to plastic PET,COF & FPC, substrate

  • Excellent thermal stability

  • Good contact resistance for reliability

  • Good corrosion resistance

  • Excellent chemical resistance

  • Good for wide bonding temperature range

  • Replaces solder for lead-free solution


Silicon rubber and Teflon

Teflon Tape ( Teflon cushion)

Similar to Silicone rubber, Teflon tape is often used to provide evenly distributed pressure and temperature on the ACF bonding process.

Features of Teflon Tape :

1. Superior chemical resistance – hardly affected by acids and alkalis.

2. Excellent electrical properties, including little dielectric loss, high insulation resistance and breakdown voltage.

3. Extremely high volume resistivity and remain stable over a wide range of temperature.

4. Continuous use in a wide range of temperature from -100degC to +260degC

5. Lowest friction cofficient among all solid materials and excellent self-lubricating ability.

6. Non-adhesiveness and mold releasing property

7. Excellent weather and moisture resistance

8. Superior flame resistance

Shenzhen olian is a professional ACF bonding equipment design&making factory, We know all the ACF bonding process, we also offer all the bonding machine accessories and parts. Welcome you visit us .


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