Name: Red solder mask + bonding gold finger pcb
Brand: PCB Printed Circuit Board and PCBA manufacturing
Availability: InStock
Rating: 5 (1 reviews)

Description
Data Sheet

PCB bonding is a core interconnection process in semiconductor chip packaging. It mainly adopts gold wire or aluminum wire to establish electrical connection between chip internal circuits and packaging pins, as well as the gold-plated copper foil on PCB substrates before formal encapsulation.

This process relies on ultrasonic energy for metal welding: an ultrasonic generator outputs high-frequency signals ranging from 40 kHz to 140 kHz. High-frequency vibration is converted by the transducer and transmitted to the bonding capillary through a horn structure. When the capillary presses the lead wire against the bonding pad, continuous pressure and high-frequency friction destroy the surface oxide layer of the metal material and induce micro plastic deformation. Two pure metal surfaces form atomic-level close contact, realizing high-stability mechanical and electrical integration. After wire bonding interconnection is completed, the chip and internal leads are protected by black adhesive encapsulation to enhance structural reliability.

PCB bonding method

PCB Bonding Process Requirements

Complete Process Flow

PCB surface cleaning → dispensing → die attachment → wire bonding → adhesive encapsulation → comprehensive testing

1. PCB Surface Cleaning

Remove oil stains, dust and oxide layers in the bonding area by professional wiping. Auxiliary cleaning with soft brushes or air guns is required to ensure the flatness and cleanliness of welding positions and eliminate surface foreign matter interference.

2. Dispensing

Control the glue dosage to maintain uniform distribution. Four-point diagonal dispensing is adopted for balanced fixing. The bonding adhesive is strictly restricted from overflowing and contaminating bonding pads, so as to avoid damage to subsequent wire bonding quality.

3. Die Attachment (Die Bonding)

Chips are picked and placed by vacuum suction nozzles with flat contact surfaces to prevent wafer surface scratching. The chip direction and polarity must be strictly verified. During lamination with the PCB substrate, three core standards shall be met:

Flat: The wafer is parallel and closely attached to the PCB without gaps or hollow areas;
Firm: The chip maintains stable adhesion and will not fall off during subsequent processing;
Accurate: The chip is aligned with the reserved position without deflection or reverse installation.

4. Wire Bonding

Unified industrial inspection standards are implemented for bonding reliability and solder joint dimensions:

Bonding pull strength: 1.0mm wire ≥ 3.5 g; 1.25mm wire ≥ 4.5 g;
Aluminum wire tail specification: 0.3 ~ 1.5 times of the wire diameter;
Solder joint shape: standard oval structure;
Solder joint length: 1.5 ~ 5.0 times of the wire diameter;
Solder joint width: 1.2 ~ 3.0 times of the wire diameter.

Operators shall conduct microscopic real-time monitoring throughout the bonding process to identify defects such as wire breakage, winding, position deviation, cold joint, thermal welding and aluminum layer peeling. First-piece inspection is mandatory before mass production to prevent missing welding and wrong wiring. Regular sampling inspection shall be conducted every 2 hours during continuous production to stabilize process consistency.

5. Adhesive Encapsulation

Check the appearance and roundness of the plastic frame in advance to ensure no deformation or distortion. After installation, the frame bottom is closely fitted with the chip surface, and the core photosensitive area of the wafer is fully shielded from occlusion.

The black encapsulating adhesive shall completely cover bonding aluminum wires and chip interconnection structures with no exposed leads. The adhesive range is controlled within the plastic frame to avoid overflowing the PCB edge, and penetration into the chip interior is strictly prohibited. No tools or fixtures are allowed to scratch the wafer surface and bonding wires during dispensing.

Tiered temperature curing is adopted for stable adhesive forming:

Preheating: 120 ± 5℃, holding for 1.5~3.0 minutes;
Formal curing: 140 ± 5℃, holding for 40~60 minutes.

After curing, the black adhesive surface is free of pores, and the adhesive height is controlled below the top of the plastic frame.

6. Finished Product Testing

A multi-dimensional combined testing system is adopted to fully verify bonding and encapsulation quality:

Manual visual inspection for appearance defects;
Automatic welding line quality detection by bonding equipment;
AOI automatic optical imaging analysis;
X-ray internal scanning to detect hidden defects of underlying solder joints.

Model : Red solder mask + bonding gold finger pcb

Material : KB6160C

Layer : 2Layers

Color : Red/White

Finished Thickness : 1.2mm

Copper Thickness : 1OZ

Surface Treatment : immersion gold

Min Trace : 4mil(0.1mm)

Min Space : 4mil(0.1mm)

Special process : bonding pcb

Red solder mask + bonding ​gold finger pcb

Description

Data Sheet