Chip Encapsulation Process details: 7 types of mainstream Encapsulation and its derivatives

Issuing time:2023-10-28 09:58

In the final analysis, the core of the chip is the wafer, but the actual finished chip is another form, the process from the wafer to the finished chip, we call chip Encapsulation.

wafer

The actual role of the chip packaging is to protect the wafer, because the wafer working environment requirements are very strict, but the actual chip application environment is more changeable, the temperature, climate, humidity and other conditions of the use of different scenarios are also very different, so a shell is needed to isolate these changes to ensure the normal working state of the wafer; Secondly, the package also makes it easy to assemble the wafer onto the current plate while not being damaged by external forces; Thirdly, the connection is convenient, as we all know, the wafer pad is particularly small, in addition to the test when using the precision connection of Hongyi electronic probe card to test, when the normal chip is used, there is no way to use such a small PCB spacing design. Only after the wafer is bonded with gold wire, the pin can be transferred to the package external pin or pad pin with a larger spacing; Finally, the reliability and stability of the package under the premise of considering the actual use and functional integrity of the chip are beyond doubt, which will be proved by reliability testing after the package, including functional testing, aging testing and so on.

Chip core

After understanding the role of chip packaging, let's look at the types of these packages, at present, there are many types of chip packaging, but the mainstream package form (using pin division) is 7, that is, DIP, SOP, QFP, QFN, BGA, LGA, PGA.

From these packages also derived a lot of new packages such as TSOP, VSOP, TSSOP, MLF, FCQFN and so on. Let's talk about it in detail:


1. DIP, it is a general term for Dual In-line Package.


This chip package we generally see more is the kind of 51 single-chip microcomputer style, of course, there are some power chips will use this package, the pin of this package is the need to weld to the PCB through the hole, contact stability; Testing is generally done using a locking seat or a DIP special test seat. This type of package existed in relatively early chip design packages.


Derivative Package types, such as SDIP (shrink Dual In-Line Package);


2. SOP, which is a general term for Small out-of-line Package.


SOP belongs to the SMT patch component packaging type, which is useful in various types of chips and has a wide range of uses. At present, the known SOP package is generally under 44 pins (pitch 1.27mm), due to the emergence of new derivative packages, such as the emergence of TSSOP and TSOP packages, the pin spacing is reduced to 0.5mm, 0.65mm and 0.635mm, and the small spacing makes more pins of the same volume chip size.


Its derived package types include: SSOP, SOIC, VSOP, TSSOP, TSOP, VSOP, MSOP, etc. Its application scenarios include Nor Flash (SOP8/SOIC8, etc.), SDRAM (old-fashioned) (TSOP66, etc.), NAND Flash (TSOP48), Driver, Power IC, and so on. From the point of view of the aging test seat of the corresponding package on the market, the main application of its package is still in the SOP8 chip, which is small in packaging difficulty, the chip design is relatively simple, and the application is very wide.

3. QFP, it is a Quad Flat Package.


QFP is SOP qualitative package form, with the rapid development of chips, because the chip size is required to be smaller and smaller, the function is required more and more, the original two-sided pin package form can not meet the needs of The Times, so QFP chip came into being. The package will be on the chip 4 sides of the pin, so that the chip I/O more, at the same time with the level of packaging technology to provide, the minimum pin spacing can be 0.4mm spacing, making its size can be smaller, currently known QFP package pin number can be QFP176, this can be from the existing QFP176 test seat products on the market can be open. From the reliability test environment to some test seat products, its chips must have a large market and potential demand. QFP package chip is generally used in MCU, PMIC, Audio IC, logic IC and other needs, but also belongs to an application of the official IC package form.


Its derivative package types include: VQFP, CQFP (MCM package, ceramic military use IC), LQFP, SQFP, BQFP, GQFP, TPQFP and so on;


4. QFN, which is a Quad Flat No-Leads Package


It is a package form relative to QFP, on the basis of QFP, the pin is cancelled and turned into the bottom of the pad form, so that the pin spacing of the chip can be further small, as low as 0.25mm spacing, making the chip smaller, the number of pins can be more. The definition of QFN comes from the Japan Electronic Machinery Industry Association, and this packaging has become one of the mainstream packaging.

Its chip application scenarios include: MCU, Nor Flash, RF chip, Bluetooth chip, audio chip, PMIC, power amplifier chip and so on

Derivative packages include DFN, WSON, USON, UDFN, VQFN, MLF, VFQFN, etc.

Similar packaging forms: LCC, PLCC, such as;


5. BGA, which is the Ball Grid Array Package;


It is a more advanced form of packaging relative to the previous several packages, because the silicon chip process is getting smaller and smaller, the market requires more I/O pins, the frequency is getting higher and higher, and the power consumption is increasing, making the corresponding signal attenuation of the chip smaller, the heat dissipation capacity is stronger, and the bottom position can be well placed more pads to meet more I/O needs. Expand more features.


The general application scenarios of BGA are: CPU, VLSI chip, MCU, FPGA, DDR particle, Nor Flash, NAND Flash, ESSD (solid state drive chip, hard disk integration into a chip) and so on.


Its derivative packages include: PBGA, CBGA, FCBGA, TBGA, CDPBGA and so on.



6. LGA, which is a Land Grid Array package;


It is a larger pad form than the BGA package, mainly in the form of metal contact package. This chip is common in the current Intel CPU series, which is similar to BGA, with more pins, higher operating frequency, greater power consumption and other characteristics, requiring its package form.


This package has no derivative package, mainly because its application scenario is relatively simple, generally appearing in CPU or MCU;


7. PGA, which is a Pin Grid Array Package;


It is the type of chip that the pin array is placed, and its function is similar to that of BGA and LGA, generally CPU, MCU and other functional chips. This chip packaging form makes the installation of the chip need to be connected with a special Slot socket, which is typical of AMD CPU form. Its corresponding computer motherboard generally needs a special card pin Slot to use.


This PGA chip does not have any derivative package form, for reasons similar to LGA.



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