Explanation of component packaging technology

The circuit board manufacturer will explain 9 common component packaging technologies in PCBA processing

The quality of packaging will directly affect the performance of the chip itself and the design and manufacture of PCB connected with it. Therefore, packaging technology is crucial.

An important indicator to measure whether a chip packaging technology is advanced or not is the ratio of chip area to packaging area. The closer this ratio is to 1, the better.

Main factors to be considered when packaging:

The ratio of chip area to package area shall be close to 1:1 to improve package efficiency;

The pins shall be as short as possible to reduce delay, and the distance between pins shall be as far as possible to ensure mutual interference and improve performance;

Based on the requirements of heat dissipation, the thinner the package, the better.

Packaging has roughly gone through the following development process:

Structure: TO → DIP → PLCC → QFP → BGA → CSP

Materials: metal, ceramics → ceramics, plastics → plastics

Pin shape: long lead in line → short lead or no lead mounting → spherical bump

Assembly method: through hole insertion → surface assembly → direct installation

The specific packaging forms are as follows:

1. SOP/SOIC package

SOP is the abbreviation of Small Outline Package, namely small outline package.

The SOP packaging technology was successfully developed by Philips from 1968 to 1969, and then gradually derived:

L SOJ, J-pin small outline package

L TSOP, thin package

L VSOP, very small form factor package

L SSOP, reduced SOP

L TSSOP, thin reduced SOP

L SOT, small profile transistor

L SOIC, small form factor integrated circuit

2. DIP encapsulation

DIP is the abbreviation of "Double In line Package", that is, dual in-line package.

One of the plug-in packages, the pins are led out from both sides of the package, and the packaging materials are plastic and ceramic. DIP is the most popular plug-in package, and its application range includes standard logic IC, memory LSI, microcomputer circuit, etc.

3. PLCC package

PLCC is the abbreviation of "Plastic Lead Chip Carrier" in English, namely plastic packaging J lead chip package.

The PLCC package is square in shape, 32 pin package, with pins all around. The overall dimension is much smaller than that of DIP package. PLCC package is suitable for installing and wiring on PCB with SMT surface mounting technology, and has the advantages of small size and high reliability.

4. TQFP package

TQFP is the abbreviation of "Thin Quad Flat Package" in English, that is, thin plastic encapsulated quad flat package. Four sided flatpack technology can effectively use space, thus reducing the requirements for the space size of printed circuit boards.

Due to the reduced height and volume, this packaging process is very suitable for applications requiring high space, such as PCMCIA cards and network devices. Almost all of ALTERA's CPLD/FPGA have TQFP packages.

5. PQFP package

PQFP is the abbreviation of "Plastic Quad Flat Package" in English, that is, plastic package quad flat package.

The distance between the chip pins of PQFP package is very small, and the pins are very thin. General large-scale or very large-scale integrated circuits adopt this packaging form, and the number of pins is generally more than 100.

6. TSOP package

TSOP is the abbreviation of "Thin Small Outline Package", that is, thin small size package. A typical feature of TSOP memory packaging technology is to make pins around the packaging chip. TSOP is suitable for installing wiring on PCB with SMT (surface mount) technology.

TSOP package has reduced parasitic parameters (output voltage disturbance caused by large current changes), which is suitable for high-frequency applications. It is easy to operate and has high reliability.

7. BGA package

BGA is the abbreviation of "Ball Grid Array Package", that is, ball grid array package. In the 1990s, with the progress of technology, the chip integration has been continuously improved, the number of I/O pins has increased dramatically, the power consumption has also increased, and the requirements for integrated circuit packaging have become more stringent. In order to meet the needs of development, BGA packaging has been applied to production.

The memory packaged with BGA technology can increase the memory capacity by two to three times with the same volume. Compared with TSOP, BGA has smaller volume, better heat dissipation and electrical performance. The BGA packaging technology has greatly improved the storage capacity per square inch. The memory products using BGA packaging technology are only one third of the size of TSOP packaging under the same capacity. In addition, compared with the traditional TSOP packaging, BGA packaging has a faster and more effective way of heat dissipation.

The I/O terminals of BGA package are distributed under the package in the form of circular or columnar solder joints in an array. The advantage of BGA technology is that although the number of I/O pins has increased, the pin spacing has not decreased, but has increased, thus improving the assembly yield. Although its power consumption is increased, BGA can be welded by controllable collapse chip method, which can improve its electrothermal performance. The thickness and weight are reduced compared with the previous packaging technology; The parasitic parameters are reduced, the signal transmission delay is small, and the use frequency is greatly increased; Coplanar welding is available for assembly, with high reliability.

8. TinyBGA package

When it comes to BGA packaging, it is necessary to mention Kingmax's patented TinyBGA technology. The full English name of TinyBGA is "Tiny Ball Grid", which is a branch of BGA packaging technology and was successfully developed by Kingmax in August 1998. The ratio of chip area to package area is not less than 1:1.14, which can increase the memory capacity by 2~3 times with the same volume. Compared with TSOP packaging products, it has smaller volume, better heat dissipation and electrical performance.

Memory products using TinyBGA packaging technology have only 1/3 of the volume of TSOP packaging under the same capacity. The pins of TSOP package memory are led out from around the chip, while TinyBGA is led out from the center of the chip. This method effectively shortens the transmission distance of the signal. The length of the signal transmission line is only 1/4 of that of the traditional TSOP technology, so the signal attenuation is also reduced. This not only greatly improves the anti-interference and noise resistance of the chip, but also improves the electrical performance. TinyBGA packaging chip can resist up to 300MHz external frequency, while traditional TSOP packaging technology can only resist up to 150MHz external frequency.

The memory of TinyBGA package is also thinner (package height is less than 0.8mm), and the effective heat dissipation path from the metal substrate to the radiator is only 0.36mm. Therefore, TinyBGA memory has higher heat conduction efficiency, which is very suitable for long running systems with excellent stability.

9. QFP package

QFP is the abbreviation of "Quad Flat Package", that is, small square planar package. QFP packaging is frequently used on early video cards, but few QFP packaging video memories with a speed of more than 4ns. Because of the problems of technology and performance, it has been gradually replaced by TSOP-II and BGA. QFP package has pins around the particles, which can be clearly identified. Four side pin flatpack. One of the surface mount packages, the pins lead out from four sides in a seagull wing (L) shape.

There are three kinds of substrates: ceramics, metals and plastics. In terms of quantity, plastic packaging accounts for the vast majority. When materials are not specifically indicated, plastic QFP is used in most cases. Plastic QFP is the most popular multi pin LSI package, which is not only used for microprocessor, gate display and other digital logic LSI circuits, but also used for VTR signal processing, audio signal processing and other analog LSI circuits.

There are 1.0mm, 0.8mm, 0.65mm, 0.5mm, 0.4mm, 0.3mm and other specifications for pin center distance. The maximum number of pins in 0.65mm center distance specification is 304.

These are the 9 common component packaging technologies in PCBA processing.