CSP ( Chip Scale Package)

CSP ( Chip Scale Package) package, is a chip scale package . " The CSP package is the latest generation of memory chip package technology, its technical performance has a new upgrade. The CSP CSP package device can make the chip area and packaging area ratio exceeding 1: 1.14, is already quite close to 1 : 1 the ideal situation, absolute size is only 32 square mm, about ordinary BGA 1 / 3, only the equivalent of TSOP memory chip area 1 / 6. Compared with BGA package, the same space under the CSP package can be storage capacity is increased by three times.

Package form

This encapsulation form is made by Japan's Mitsubishi Corporation in 1994 put forward. For CSP, there are multiple definitions : Electronic Industries Association of Japan defines CSP to area of the chip and package area ratio greater than 80% package ; the U.S. Department of defense components supply center J-STK-012 standards define CSP as LSI package product area is less than or equal to LSI chip area of the 120% package ; Panasonic electronics companies will be defined for LSI packaging products and packaging chip length length of less than Imm products. These definitions although some differences, but pointed out that CSP product main features: package size small.

Memory of the CSP package not only has the advantages of small volume, but also more thin, the metal substrate to the radiating body is the most effective heat dissipation path of only 0.2 mm, greatly improving the memory chip in a long time after the operation reliability of the line impedance decreases obviously, chip speed can be increased greatly.

The CSP package memory chips to the center pin forms effectively shorten the signal transmission distance, the attenuation decreases, chip anti interference and anti noise performance can also be increased, which also makes the access time of CSP than BGA to improve 15%-20%. In the CSP package, memory grain is through a solder ball in the PCB board as the solder joint and the PCB board to the contact area is large, so the memory chip in operation of the heat generated can be easily transmitted to the PCB board and went out. The CSP package can be from the back side of heat, and the thermal efficiency is good, CSP thermal resistance of 35 DEG C / W, and TSOP resistance 40 C / W.

CSP technology in electronic product upgrading raised, it is intended for use in the chip ( chip more functions, better performance, more complex alternative to previous chip ) small chips when the package up printing plate area remained unchanged or even smaller. It is due to CSP product package small and thin, so its hand-held mobile electronic device for rapid access to applications. In 1996 August, the Japanese Sharp company began mass production of CSP products; in 1996 September, the Sony Corporation of Japan began with Japan's TI and NEC companies to provide CSP products assembled camera; in 1997, the United States began the production of CSP products. There are dozens of companies can provide CSP products, all kinds of CSP products up to one hundred or more varieties.

The CSP package product features

CSP is the most advanced integrated circuit package form, it has the following characteristics:

The small volume.

In a variety of packaging, CSP is the smallest, minimum thickness, which are the smallest package. At the input / output the same number of cases, it is area of less than 1/10 0.5mm space QFP, BGA ( or PGA) 1/3 to 1/10. Therefore, when in assembly it is occupied by the printed board area is small, thereby improving the printed board assembly density, thickness, and can be used for thin electronic products assembly ;

The input / output end can be many.

In the same sizes of various types of packaging, CSP input / output terminal can do more. For example, the 40mm x 40mm package, QFP input / output number up to 304, the BGA can be 600-700, but CSP is very easy to reach 1000. Although the CSP is mainly used for less input / output terminal circuit package.

The good performance.

CSP internal to the chip and package wiring interconnection line length than QFP or BGA is much shorter, and small parasitic parameter, signal transmission delay time is short and is favorable to improve the circuit high frequency performance.

The thermal performance is good.

CSP is very thin, chip generated heat can be a short passage to the outside. Through the air convection or installation of heat radiator for chip approach can effectively dissipate heat.

The CSP not only has the advantages of small size, and light weight.

It 's the same weight of lead number of QFP below 1/5, much more than BGA. For the aerospace, as well as the weight of the strict requirements of product should be extremely favourable

The CSP circuit

Like other encapsulated circuit, can test and burn-in screening, which can eliminate the early failure of the circuit, the reliability of the circuit is improved ; in addition, the CSP can also be hermetically sealed, therefore keeping the hermetic package circuit has the advantages of.

The CSP product

The package of the input / output (bump, bump or metal strip ) is encapsulated in a body at the bottom or surface, suitable for surface mounting.