Semiconductor Dispensing Process - Solutions for Gluing and Filling Systems

Semiconductor refers to a material whose conductivity is between the conductor and the insulator at room temperature. Semiconductors have a wide range of applications in mobile phones, automobiles, military industry, aerospace, etc., such as diodes are one of the common semiconductor devices.

The semiconductor front-end process is very complex, mainly including circuit design, coating, corrosion, slicing, placement, packaging, testing, etc. Semiconductors are mainly used in LED, MEMS, electroacoustic, PCBA and other industries. The dispensing process includes: chip fixation - red glue, electrical connection fixation - silver paste, fixed MEMS device - silicone, COB packaging protection - epoxy glue, chip solder ball protection (Underfill) - epoxy glue, etc. The role of glue in packaging is more important, and the dispensing methods are also diverse, including: time pressure type, screw type, plunger type, jet type, piezoelectric type, etc.

Common applications are:

Silver paste

Fix the chip and carrier, and play a conductive role.

IC and carrier are connected by adhesive, playing the role of fixation + conductivity, commonly used adhesives are usually formulated from metal particles, fluxes, adhesives and thinners, the most common adhesive is silver paste.

Process characteristics

silver paste application products include crystal oscillator, hard disk, chip, LED, headphone, microphone, etc.

Silver paste is used for the connection between ICs and carriers, and the key points of this process are:

1. Silver paste is evenly coated;

2. Valve body glue stability;

For silver paste dispensing processes, efficiency and consistency are particularly important.

Silver paste is used in the semiconductor industry, and the production capacity and stability of equipment are extremely important to manufacturers, and can be flexibly matched with multiple types of dispensing valves to meet the needs of different customers. There have been great breakthroughs in core technology fields such as closed-loop control of rubber volume and high wear-resistant screw feeding system.

Chip-level dot solder paste

Dot solder paste mainly plays the role of conductivity, bonding and heat dissipation.

The most commonly used method of solder paste coating in the semiconductor industry is stencil printing, and with the gradual reduction of the pad area, a new way of solder paste coating has emerged - dot solder paste.

The commonly used spot solder paste methods are divided into contact and non-contact, which has obvious advantages for non-standard products and laboratory small-batch development and testing.

Process characteristics

The most common spot solder paste process on the market is contact dispensing, and the key points are:

1. The uniformity of solder paste dotting, the progressive cavity valve controls the glue output more stably;

2. Accurate control of dispensing height, high or low will affect the dispensing effect;

Efficiency and consistency are especially important for the solder paste dispensing process.

We have accumulated many years of application experience in solder paste dispensing process applications, and have mature and stable products and solutions.

Chip-level underfill

Protect the internal structure of the chip, moisture and shockproof.

With the development of the microelectronics industry towards lightweight, thinning, miniaturization, the increase in the number of I/O terminals, and functional diversification, flip chip packaging technology has emerged, and underfill is the core process.

The chip underfill process is to fill the gap between the chip and the substrate with glue to protect and strengthen the solder balls or solder pins, which is commonly used in Flipchip packaging.

Chip-level underfilling usually uses non-contact dispensing, which requires high scatter points and glue volume.

The key points of the chip-level backfill process are as follows:

1. There are many components around, and the width of overflow needs to be strictly controlled;

2. The surface of the BGA chip is smooth, and the scatter point requirements are high, and there can be no stains on the surface;

3. The solder balls inside the BGA are not uniformly arranged, and it is easy to travel the cavity during the underfilling process;

4. The heating of the bottom of the machine will affect the viscosity of the glue, thus affecting the amount of glue.

For chip-level underfill processes, efficiency and consistency are particularly important.

The chip-level underfill process is used in the semiconductor industry, and the production capacity and stability of the equipment are extremely important to the manufacturer, and the semiconductor industry has accumulated many years of application experience, which can be flexibly matched with multiple types of dispensing valve options to meet the needs of different customers.

Dome Coating

Dome Coating effectively prevents chips and leads from falling off, breaking, and moisture.

Dome coating is mainly used for the protection of multiple chips and leads on the leadframe. Usually dispensing is done on the front of the leadframe, and the glue flows through the gap of the leadframe to the reverse side, and a certain glue thickness is formed on the front and back sides to protect the chip and leads, and increase the service life of components.

Process characteristics

The role of the dome coating dispensing process is to increase the stability of components and prevent falling, collision and breakage during the packaging process, and the application industries involved are mainly leadframe, chip, and lead dispensing processes in the semiconductor industry.

In the Dome Coating dispensing process, glue volume control, glue height, dispensing trajectory, and dispensing range are the key to ensuring the dispensing effect. For the dome coating process, adhesive height and consistency are particularly important.

The high degree of chip integration leads to a reduction in dispensing space and a compact chip packaging space, so how to control a smaller single point and the stability of glue dispensing is an industry trend.

It can be flexibly matched with multiple types of dispensing valves and feeding system options to meet the needs of different customers.

Dam & fill

Dam & fill is used in semiconductor chip and component packaging, which plays a role in reinforcing shock resistance, dust and water resistance.

With the continuous development of consumer electronics, dam & fill has become a necessary process for electronic products to improve service life and product quality. In the Dam & fill process, it is a double-valve process, one valve body is dammed, the glue viscosity is high, and the other valve body is filled, the glue viscosity is low.

For semiconductor packaging, wire bonding, smart card chip packaging, TP screen bonding and other processes, Dam & fill effectively encapsulates Die or Chip, thereby protecting semiconductor components and improving their service life.

Process characteristics

Dam & fill is widely used in semiconductor packaging, wire bonding packaging, smart card chip packaging, TP screen bonding and other processes.

In the Dam & fill dispensing process, glue volume control, dispensing path, and dispensing speed planning are the key points to ensure the uniformity of the dam height and fill glue coverage, no scattering, zero bubbles, etc.

With the rapid development of the electronics industry, there are higher requirements for the aesthetics, waterproofness, and drop resistance of electronic products, especially for the final thickness of the Dam & fill process, and the shape is "flat top". The requirements for the accuracy of the glue volume, the stability of the glue output, and the overflow width of the dispensing system are getting higher and higher.

Our non-contact jetting system combined with contact dispensing system is ideal for achieving Dam & Fill, which can achieve precision dispensing of the dispensing area. Moreover, we have the core product of German VERMES, piezoelectric microjet valves, with mature and stable products and solutions.

No-flow underfill

No-flow underfill adhesives act as flux in the early stages of chip packaging and are converted into adhesives for underfill in reflow.

With the continuous development of consumer electronics, the package size is gradually decreasing, and underfill has become a necessary process to improve the stability of electronic products. No-flow underfill can simplify the process flow, no need for glue capillary action, the underfill is well dotted before the solder ball patch, and the reflow soldering process completes the soldering ball welding and underfill adhesive curing at the same time, protecting semiconductor components and improving their service life.

Process characteristics

No-flow underfill is widely used in the packaging process of flip chips.

In the process of no-flow underfill dispensing, glue volume control, dispensing path, and valve parameter planning are the key points to ensure the integrity of no-flow underfill dispensing coverage, zero bubbles, dispensing thickness, etc.

With the development of the microelectronics industry towards lightweight, thin, miniaturization, the increase of the number of I/O terminals and the diversification of functions, the requirements for the simplicity of the process and the accuracy of the glue amount and the stability of the dispensing system are getting higher and higher, so the No-flow underfill technology came into being.

VERMES' non-contact jetting systems and contact dispensing systems can accurately control the amount of glue, and we have rich experience in the research of no-flow underfill processes. Moreover, it can be flexibly matched with multiple types of dispensing valves to meet the dispensing needs of different products and glues.