Guide

IC Package Types and How IC Package Techniques Help in the Miniaturization of PCB

IC Package

Over the years, the need for electronic wearable devices has increased day by day in various industries, such as medical, military, telecommunication, mobiles, tablets, laptops, and automotive. Wearable devices are small, lightweight, slim, portable, and have custom geometry or structure.

Let’s compare both smartphones and smartwatches. We expect all the functions that a smartphone can do in a small smartwatch. So it should meet all the needs that we can expect. So the different IC package types emerge to make this expectation come true.

Comparision between smartphones and smartwatches

Let’s decode this article in more detail about IC package types and how IC package techniques contribute to the reduction of PCB dimensions.

What is IC Packaging?

Integrated circuit (IC) packaging technology refers to various methods and processes used to package and protect semiconductor chips while providing electrical connections with external circuits. There are many IC package types, and the corresponding technologies are different, so it is necessary to carry out appropriate packaging according to the requirements of the chip. The most complex electronic designs are required to operate these wearable devices and must satisfy all conditions that wearable devices have. As a result, we have to shrink the size of the PCB. We Chinese manufacturers are able to carry out relevant packaging for different  IC package types according to high standards.

A Brief Guide to IC Package Types

IC package techniques are usually used in high interconnection density PCBs. HDI PCBs use custom-based IC packages with a smaller size and minimum pitch, which helps reduce the size of the PCB. Packaging methods for different IC packaging types are shown below,

  1. Direct Chip attach (Chip on board) and Wire bonding
  2. Flip-chip packaging or C4
  3. Tape Automated Bonding

When we fit these small IC packages in the PCB, the track we can draw has a smaller width and a shorter path by using micro vias.

High-density Interconnect Technology Boards

High-density interconnect technology boards have dense tracks or more tracks in a smaller area (the size of the tracks is less than or equal to 75µ) and a connection, such as a micro-vias connection, present.

 

The Detailed Introduction of the Different IC Package Types of Techniques

1. Direct Chip Attachment (DCA):

Direct Chip Attachment (DCA) is one of the IC package types of techniques. These IC package types are called chip-on-board (COB), which is semiconductor assembly technology. Silicon die, microchip, or bare IC (package less IC) that is directly mounted on the substrate or PCB board, which we call a direct chip attachment. DCA terminal is different from traditional IC package terminal (Traditional IC package have pads and leads to make the connection on PCB). However, in this technology, electrical interconnection is achieved with the help of the wire bonding technique.

  • Direct chip attachment processDirect Chip Attachment (DCA)

 

  • Step 1: Conducting material is applied to the substrate
  • Step 2: A bare silicon IC chip is then placed on the substrate and bonded together
  • Step 3: After the placement of the Bare IC chip, the electrical or signal interconnection is done with the help of wire bonding
  • Step 4: Placement of a bare IC chip and bonded wire requires protection from air and physical damage, for that bare IC chip is protected by soft encapsulation (epoxy material), which is otherwise called a cow-dung integrated IC

Types of wire bonding are

  • Gold wire bonding ENEPIG (Electro less Nickel Electrolytic Palladium Immersion Gold)
  • Aluminium bonding ENIG (Electro less Nickel Immersion Gold)

The advantages of Cow Dung IC or Direct Chip Attach or Chip on Board

  • Create a shorter interconnection
  • Increases performance
  • Enhance the reliability of the PCB
  • Package less IC occupies less space and less weight when compared to conventional integrated chip package
  • Increasing functionality, higher density, and higher speed

 

2. Flip Chip Packaging or C4:

Flip chip packaging or C4 is also one of the common IC package types of techniques. C4 stands for Controlled-Collapse chip connection. In the chip-on-board technique, the active side of silicon IC terminals is facing the upside to make a wire bond connection for electrical conductivity. Whereas in the flipped chip technique active side of the silicon chip is “flipped over” to make a direct connection between a substrate, and chip carrier or directly mounted on a PCB board with the help of solder bump or balls.

A flip-chip package is one of the IC package types of chip-scale packages. Surface-mountable integrated circuit, and its area is not more than 1.2 times the original die area. As per IPC/JEDEC standards, the flip and chip scale package should qualify or satisfy the following two conditions: First, it should be a single die, and second, the ball pitch should not exceed more than 1 mm.

Flip Chip package process:

Step 1: Wafer solder bump

Flip Chip Packaging

Solder bumps or balls are deposited on the solder bond of the Silicon IC chip using various methods Solder bumping, Stud bumping, and adhesive bumping.

Step 2: Alignment

Alignment in Flip Chip package

After the Silicon IC is bonded with the solder bump it is then aligned with pads present on the substrate, chip carrier, or PCB board.

Step 3: Reflow

During the Reflow process, bond pads on the substrate and solder balls undergo with the heating process to get the bond together.

Step 4: Encapsulation

Encapsulation in Flip Chip Packaging

After mounting the silicon IC with the substrate there is a gap between the substrate and the IC that is filled with resin to ensure securely attached to the board.

 

3. Tape Automated Bonding

Tape Automated Bonding

Traces are routed on polyimide (flexible material) film is then attached to a targeted position of bare chip (Silicon IC) and both are mounted on PCB and then soldered. In this technique, the tape is referred to as polyimide film (Kapton). This is also called a “Tape carrier package” (TCP). After the mount of the bare chip and film, the PCB is covered or encapsulated by plastic or epoxy (Glob topping method).

When compared to the wire bond technique, Tape-automated bonding is an automated and quick process as it uses films for making connections from silicon IC and PCB board.

Can be suggested for High volume production of PCB.

As the microchip and film are thin, therefore thin package is enough, and its applications are used in sim cards, smart cards, debit cards and mobiles.

The Advantages of Tape Automated Bonding

  • The pitch of the pads becomes smaller
  • Production turnaround time is less
  • Allows PCB to be flexible
  • I/O port count increases
  • Multichip module manufacturing possibilities

 

Conclusion:

All these  IC packages shrink the size of the PCB without compromising its performance and reliability. All of these IC package types of techniques make the path to evolve smaller electronic gadgets. Through IC package types of this technique mobile smartwatches, small medical devices that can be attached to body parts, and telecommunications application purposes.

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