At present, the Internet of Things, 5G, AI, deep learning, autonomous driving and other emerging fields are developing rapidly, and the generation of massive data brings the desire for faster network transmission rates, as well as higher chip performance. In order to meet the high requirements of users for chip performance, various packaging technologies are constantly updated and iterated.
In the face of increasingly complex types of chip packaging, in order to ensure the stability and reliability of the chip function, the test link has become a key step in the chip verification factory, and the test socket as a key component of the semiconductor chip packaging test process, especially in this chip size continues to shrink, the signal transmission speed continues to increase at this time, more and more attention by the major manufacturers.
Nowadays, more and more semiconductor test socket manufacturers have started to make efforts to promote the product towards more stable and reliable direction. Recently, the high-speed test socket leader Smith Inotecon launched DaVinci miniature test socket, for high-speed test socket product line to add another main force.
The hidden but critical IC Socket
IC Socket, also known as the chip test socket, is a static connector between the integrated circuit and the PCB, its main role is to meet the chip pin terminals and PCB test board connection needs, the biggest advantage is that in the chip test session can be removed and replaced at any time, will not damage the chip and PCB, so as to achieve fast and efficient testing.
Generally speaking, IC sockets are composed of three key components: first, the socket body, a metal or plastic assembly containing a precision cut chamber; second, a spring-loaded probe or shrapnel inserted into the test socket aperture, providing a mechanical electrical path to connect the chip to the test system; and third, a holding plate, a component used to hold the probe or shrapnel in place, precisely positioned to ensure that the chip and Probe can be precisely positioned to ensure that the chip and the probe can contact. In addition to the above three major components, some IC sockets are also equipped with a mechanical press-fit cover to press the chip together and provide matching pressure for the spring probe to contact the chip pin terminals and PCB Pad, etc. Depending on the application...
In the chip manufacturing process, the IC Socket has the following three main functions.
First, incoming material inspection. Due to the small size of the chip, its quality issues are often difficult to determine by the naked eye, so manufacturers generally increase the power to chip quality testing, through the IC Socket application function to determine the quality of the chip, to identify defective products.
Second, the maintenance test. The chip into the IC socket, through the test according to the chip performance performance, to find out where the problems in the chip production process.
Third, chip inspection. The repaired chip may be damaged in the disassembly process. Using IC socket can detect the bad chips, saving a lot of manpower and material resources, thus reducing various costs. BGA package chip, for example, if there is no chip inspection, after the FCT test, paste to the bad chip, if then remove the chip for baking and cleaning, may damage the relevant equipment, the use of IC Socket can greatly reduce the probability of the above problem.
Between the above three functions, IC Socket has also become a necessary special test tool for packaging and testing manufacturers. Although there are many types of IC sockets according to different chip testing requirements, but due to its own characteristics, no matter which type of IC socket must be very robust and not easily affected by changes in temperature and humidity, only in this way, to achieve a precise and repeatable connection with the device under test. In addition, the probe pins of the IC Socket must also have low contact resistance and large current-carrying capacity, and the signal path must be shielded as much as possible to minimize the impact of electromagnetic interference.
As chip updates and iterations become faster and faster, the market demand for high-speed chip testing is also rising, in this context, Smith Inotera has launched a high-speed test socket product line series, which can be widely used to test wearable device chips, AI inference chips, 5G chips, Telematics chips, data center chips and other fields.
Smith & Whitney is a leading global manufacturer of highly reliable test sockets with reliable spring probe technology, optimized design and excellent mechanical performance for test solutions that demonstrate superior quality and reliability in a variety of demanding semiconductor test applications.
Back in 2020, Smith & Nephew was the first to introduce the DaVinci56 high-speed test socket series designed for 0.70mm pitch chips, supporting reliable testing up to 67GHz RF (analog) and 56Gb/s PAM4, NRZ (digital) with fully shielded signal paths and low contact resistance below 80mΩ. The DaVinci56 series was introduced to solve the challenges of testing high-performance chips with high performance but smaller pin spacing in the market at that time.
Two years later, in the face of a new wave of demand for high-speed testing of IC packages, Smith & Nephew once again introduced the DaVinci Micro Test Socket, designed for high-speed testing at 0.35mm pitch and above, bridging the gap in its high-speed test product line for micro pitch chip testing.
Breakthrough upgrade under the challenge of high-speed IC testing
As Moore's Law continues to advance, the current chip process has come to the 3nm node, while the chip is moving toward size miniaturization, people's requirements for the chip are becoming more and more functional integration is driving the chip IC ball/pin spacing to shrink, while the mainstream coaxial structure socket on the market is mainly for ball/pin spacing ≥ 0.65mm chip test applications, can not meet the current market Technology trends.
DaVinci micro test socket is in this context was born. It is understood that Smith Intecon to overcome the probe spacing, and the space limitations of the probe cavity, to achieve the coaxial structure of the signal transmission line, and the resulting series of technical challenges such as the design and manufacture of ultra-fine signal pins, the processing of the probe cavity parts, etc., targeted the launch of this can effectively meet the needs of high-speed chip test applications ≥ 0.35mm microsphere / pin pitch IC Socket.
Due to the patented technology structure, taking into account signal integrity as well as the structure and processability of the components, DaVinci micro test sockets also have distinct features, specifically
Probes
Usually, the probe of IC Socket mainly provides a stable and reliable connection between the chip and the test board. The quality of the probe is mainly reflected in the structure, material, plating, spring, diameter accuracy of the sleeve and assembly manufacturing process.
DaVinci miniature test socket signal probes are designed with a double-action head, and the top shoulder ring provides preload to ensure the stable state of the probe in the cavity and the smooth performance of the test process. In addition, the signal probe is fitted with a low dielectric constant material ring, which improves assembly and ensures precise alignment of the signal probe in the cavity, ensuring the impedance characteristics of the signal transmission path.
Spring Probes
Two types of spring-loaded probes are used in DaVinci miniature test sockets, one for signal and the other for power and ground. Among them, the transmission signal application outside diameter is thin, the surface set of plastic ring signal needle, to achieve coaxial signal transmission line structure; and grounding and power use the same probe, but the application of different cavity surface and size to achieve and metal cavity parts grounding and insulation of chip test power supply needs.
In order to improve the service life of the probe, DaVinci miniature test socket can be optional chip floating positioning plate design, to provide chip test down the process of pre-positioning, reducing the possible impact on the probe impact. At the same time, Smith & Nephew's engineering team also applied a special pin height design to protect the small diameter signal probes and improve the reliability and stability of the test.
In addition, DaVinci miniature test socket metal probe cavity structure, also by a special process surface treatment of metal machined from the special material properties to help DaVinci miniature test socket compared to the traditional plastic probe cavity has better bending performance and thermal conductivity: on the one hand, in the high pin count applications, to ensure that the probe cavity parts have good strength, to ensure that all probes reliable On the other hand, the chip test process generates a large amount of heat through the metal probe cavity in a timely manner, to avoid the local concentration of heat, which helps to improve test stability and probe life.
With the unique low dielectric constant material ring structure, maximize the performance of the coaxial structure, so that DaVinci miniature test socket performance of the industry peer products unmatched performance advantages, continue to maintain the industry's leading position.
Housing
In addition to the probes, DaVinci miniature test socket housings are manufactured from Smith & Nephew's proprietary insulating metal material to house the spring-loaded probes, providing excellent signal integrity and strength.
Typically, increased system-on-a-chip performance affects pin-to-pin noise immunity requirements during testing, a problem also known as "crosstalk" in testing, and the fully shielded signal path of the DaVinci miniature test sockets effectively reduces the effects of crosstalk during testing. The above-mentioned metal probe cavity is grounded by a grounding probe, which can also shield the signal paths in the chip testing process from each other during the test, reducing crosstalk and improving the overall anti-crosstalk performance of the socket, thus significantly improving the accuracy of the test chip performance.
At the same time, the precision-machined socket housing also ensures the robust mechanical properties of the socket. It was revealed that Smith Inotecon developed and applied the new insulating metal material IM-002, which has higher strength, good thermal conductivity and processability.
Currently, DaVinci miniature test sockets have been successfully evaluated by clients and have shown the expected signal integrity performance and good batch chip test reliability for BGA, LGA, QFN, DFN and other package solutions, ideal for minimum pitch of 0.35mm, also realizing Smith & Whitney's ball/pin pitch of 0.35mm and above Full coverage of high-speed chip test applications.
Challenges don't stop, upgrades don't stop
As a new generation of Smith & Whitney high-speed test sockets, DaVinci Micro Test Sockets combine the outstanding performance of DaVinci 56 products and take full advantage of DaVinci coaxial technology for IC high-speed testing to achieve 350µm pitch and provide ideal pin-to-pin isolation, which can significantly improve the first-part test pass rate and the final chip test pass rate, and its product advantages also The advantages of the product go far beyond the above mentioned points.
DaVinci miniature test sockets have been tested to have a contact life of 500,000 cycles; can match customers' existing PCB test systems and test hardware for significant cost savings; and can be repaired in the field, replacing individual probes or entire pin arrays as needed without additional training; and have short probe contact paths and high conductivity.
It is with the DaVinci series that Smith & Whitney's test sockets are widely used in embedded devices, 5G, artificial intelligence, automotive networking, and data center high-speed computing, consolidating its leading position in the high-speed test market, with many of the world's leading chip and domestic top-tier Internet companies as its customers in the high-speed test field. In addition to various packaging test socket product lines, Smith Inotera has also developed developed wafer-level horizontal and vertical test cards to increase its market share in the chip testing field.
