A Plastic Leaded Chip Carrier (PLCC) is a
general-purpose SMT part used in many electronic assemblies. As the technology
and development of PCB advanced, the trend is increasingly towards more compact
and efficient chip packages, and thus the development of PLCCs.
Today, miniaturization compact solutions
with high reliability and performance are of essential importance in
electronics. One of these components is the plastic leaded chip carrier,
abbreviated as PLCC, which is an essential component in surface mount technology,
abbreviated as SMT, and is used in many electronics circuits.
With this, you will have some knowledge of
the design of PLCC packages and the different types and uses. Of particular
importance is that all this knowledge will not only improve your comprehension
of surface-mounted devices but also point to the relevant data needed to
improve PCB design in the consumer electronics industry, car manufacturing, and
other applications.
An Introduction to PLCC Packages
The PLCC is established in planar form,
often containing one or more integrated circuits to reduce the amount of space
that is occupied on the PCB. A PLCC-IC package is rectangular or square and is
provided with "J-leads" coming out from the corners of the package,
and the component can be placed directly on the surface of the PCB.
In the overall context, one of the more
assignments of a PLCC package is in Surface-Mount Device (SMD) packaging. While
through-hole components have to have the pins go through the defined holes in
the PCB, the PLCCs can be soldered directly on the surface of the PCB. This
leads to less of a requirement for making holes and thus enables the
development of more compact and high-density PCB systems.
Types and Sizes of Plastic Leaded Chip Carrier
There are various types of PLCCs depending
on their size and configuration for various applications.
1. PLCC20: A plastic lead chip
carrier with a layout of 20 pins and is most preferred in less complex or
compact circuits. Due to its promising features and small size, it is suitable
for devices with small spaces available.
2. PLCC28: This one comes with 28
pins, which offer more points of connection and are appropriate for somewhat
more complicated gadgets.
3. PLCC44: This one has 44 pins
and is widely used in intricate wiring because this option provides more
contacts for connection.
4. PLCC68: A package with 68 pins
used in even more complicated and high-performance products like
microprocessors and memory modules.
Usage by Pin Count:
The pin count plays a direct role in the
application of the PLCC. A very high pin count results in a large package size
that causes a problem in the PCB area. Such devices like PLCCs, are selected by
manufacturers based on the ultimate requirements of the circuit.
Advantages and Disadvantages of PLCC
Advantages of PLCC Packages
One of the most significant advantages of
using PLCCs is that they take up less space. Since PLCCs are affixed directly
on the surface of the printed circuit board, they do not require through-hole
drilling, thus producing more compact printed circuit boards. Some of the
common types of PLCCs include those that can be plugged into a socket.
Disadvantages of PLCC Packages
However, there are still certain
disadvantages that might be attached to the use of PLCCs. Heat dissipation is
one of the most significant drawbacks of printed circuit boards and one of the
most substantial limitations of PCBs. PLCCs are made of plastic mold, and their
heat dissipation capability is lower compared to packages such as ceramic ones.
Construction of PLCC
A PLCC package is more efficient and
well-built than other packages that are used for integrated circuits. PLCCs are
built with a lead frame configuration; the metal leads are curved at the end
with a hook-like formation or the "J" shape that enables it to make
an electrical connection to the PCB. This type of J-lead design provides a sure
electrical contact and at the same time reduces the board space occupied by the
component.
A conventional PLCC package has a square or
rectangular shape, though the leads may come out from the sides of the package.
The body of the PLCC is made of plastic, giving the outside case of the
integrated circuit a very strong but light structure for housing its interior
circuits.
The primary materials used in the
construction of PLCCs include:
• Plastic: Used for the outer body as this was the most durable and cost-effective
technique.
• Metal: Used
for the leads and internal wiring so that it is guaranteed to carry current and
signals with no problem.
These materials are selected in such a way
that they possess the right combination of characteristics, such as high
performance, low cost, and high reliability which makes the PLCCs ideal for a
multitude of applications in the electronics industry.
PLCC vs. LCC Packages
This is evident after comparing the PLCCs
against the LCC (Leadless Chip Carrier) package types, whereby one of the main
distinguishing attributes is the leads. PLCCs (Plastic Leaded Chip Carriers)
have J-shaped leads extending from the package, while LCCs are leadless, which
often makes them smaller and more compact.
Applications of PLCC Packages
There is a wide market for PLCCs since they
are utilized in various industries owing to their flexibility and small size.
Some of the most common applications include:
Consumer Electronics: With size and performance characteristics, PLCCs are used in devices
such as TVs, game consoles, and mobile phones.
Automotive Systems: Some of applications of PLCCs in car electronics which include ECUs,
airbags, and infotainment modules.
Industrial Systems: Besides the PLCCs mentioned above, they are also commonly
applied in industrial control equipment and sensors.
Conclusion
In the current electronic systems, the PLCC
is an indispensable component since it is compacted and compatible with
sockets, making it suitable for different industries. When aiming at designing
consumer electronics, automotive systems, or industrial machinery, it is
crucial to get to know the so-called PLCC package to gain some insights into
efficient PCB layouts.
