Spring needle high-frequency test seat and method based on cluster compression threshold triggering

Abstract

The application discloses a spring needle high-frequency test seat and method based on cluster compression threshold triggering, and belongs to the technical field of semiconductor high-frequency testing. The test seat is provided with a cluster compression coupling cavity below a plurality of spring needles, the cavity comprises a cavity frame and an upper elastic film, and is internally filled with compressible composite material containing micro metal particles. When the compression stroke of any spring needle exceeds a preset threshold for the first time, the cavity is triggered to enter a compensation state: the elastic film deformation drives the rearrangement of the particles, synchronously changes the effective dielectric constant of the cavity, and thus adaptively compensates the characteristic impedance of the local channel group centered on the needle. The application solves the problem of cluster impedance deviation caused by uneven compression in high-density testing, improves the consistency and stability of high-frequency testing, and is suitable for mass production testing of high-speed servers and AI chips.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor testing, in particular to a spring needle test seat for high-frequency and high-speed chip testing and a testing method thereof. BACKGROUND

[0002] The spring needle test seat is a key component for testing high-speed digital chips, AI chips and radio frequency chips. With the chip rate moving towards tens or even hundreds of GHz and the power consumption increasing dramatically, the challenge of maintaining impedance consistency of the test seat under extreme conditions is becoming increasingly severe. The packaging warpage caused by high power consumption further amplifies this problem.

[0003] In high-density array compression, the compression amount of each spring needle differs due to factors such as packaging tolerance, assembly error and uneven pressure. This leads to uneven compression of the surrounding composite material, which in turn causes local changes in the effective dielectric constant. At high frequencies, this change directly translates into the dispersion of the characteristic impedance of the transmission line. More critically, due to the superposition effect of mechanical stress transmission and electromagnetic coupling, impedance deviation often occurs in clusters of 3-5 adjacent spring needles, i.e., "clustered impedance dispersion", which severely degrades signal integrity and affects testing accuracy and yield.

[0004] Existing solutions mostly passively suppress such problems by improving material uniformity and optimizing structural precision, but cannot dynamically eliminate the local impedance deviation that has already occurred during compression. As the frequency and density increase, the effectiveness is quickly limited. Therefore, there is an urgent need for an innovative solution that can actively sense and compensate for the local compression state in real time. SUMMARY

[0005] The present application aims to solve the problem of local "clustered impedance deviation" caused by inconsistent compression travel of each spring needle in high-density spring needle test seats, in order to improve the signal consistency and testing accuracy of high-frequency testing.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solution: a spring needle high-frequency test seat based on cluster compression threshold triggering, comprising:

[0007] a test seat body;

[0008] a plurality of spring needle modules arranged on the test seat body;

[0009] a cluster compression coupling cavity arranged below the plurality of spring needle modules, the cluster compression coupling cavity comprising a cavity frame and an elastic film mounted on the upper side thereof, the cavity being filled with a composite material, the composite material comprising an insulating matrix and micro-metal particles dispersed therein;

[0010] When the compression stroke of any one of the spring needle modules exceeds a preset threshold value for the first time during the crimping test, the cluster compression coupling cavity is triggered to enter a compensation state: the boss structure of the spring needle module pushes the elastic film to deform, and drives the micro metal particles in the composite material to rearrange in groups, so that the effective dielectric constant in the coupling cavity changes synchronously, thereby adaptively compensating the characteristic impedance of the signal transmission channel of all spring needle modules in a local area centered on the spring needle module.

[0011] Further, the number of spring needle modules covered by the cluster compression coupling cavity is 4 to 9, which is matched with the mechanical stress conduction radius of the test seat body during the crimping process and the electromagnetic coupling scale between the high-frequency signal channels, to form an effective cluster compensation unit.

[0012] Further, the elastic film is made of a polyimide film, a silicone rubber film, or a thermoplastic elastomer film.

[0013] Further, the micro metal particles are gold-plated copper particles, nickel particles, tin alloy particles, or a combination thereof, and the particle size is 1 μm to 20 μm.

[0014] Further, the preset threshold value is determined according to the compression stroke of the spring needle module, and the range is 20% to 60% of the maximum compression stroke.

[0015] Further, the dielectric constant of the composite material in the zero-pressure state is 2.5 to 4.0, and the dielectric constant is increased by 5% to 15% when reaching the threshold compression state.

[0016] Further, the test seat body includes a high-frequency transmission structure, which is a coplanar waveguide structure, a strip line structure, or a microstrip line structure.

[0017] A method for high-frequency testing using the spring needle high-frequency test seat, characterized in that it comprises the following steps:

[0018] Crimping the packaged chip to make the spring needle module contact the chip pin;

[0019] The preset threshold value is pre-set by the initial gap or contact relationship between the boss structure of the spring needle module and the elastic film; when the compression stroke of any one of the spring needle modules exceeds the preset threshold value for the first time, the boss structure physically contacts and pushes the elastic film, and this physical contact behavior itself is determined as a triggering event, and the corresponding cluster compression coupling cavity enters the compensation state without the aid of an independent electronic sensor or detection circuit.

[0020] In the compensation state, the boss structure of the spring needle module pushes the elastic film to deform, and drives the micro metal particles in the composite material to rearrange in groups;

[0021] The population rearrangement of the micro metal particles causes the synchronous change of the effective dielectric constant of the coupling cavity, thereby automatically adjusting the characteristic impedance of the signal transmission channel of all spring needle modules in a local area centered on the spring needle module to tend to and stabilize in a preset target impedance range, and completing the high-frequency signal test.

[0022] After the crimping is completed, the external force is removed, and the cluster compression coupling cavity exits the compensation state and resets under the restoring force of the elastic film and the action of the composite material.

[0023] Compared with the prior art, the present application has the following significant advantages:

[0024] Innovatively, the threshold determination, triggering and compensation mechanism are integrated in the physical structure (cavity, elastic film, composite material). The threshold is defined by a preset geometric gap, and the physical contact is directly triggered, so that the mechanical self-adaptive compensation without external sensors and circuits is realized, and the system is simple and reliable.

[0025] By using the "physical threshold triggering-micro-particle rearrangement" mechanism, the microstate of the composite material is directly changed through structural deformation, so that the core parameter (effective dielectric constant) affecting the impedance is macroscopically regulated and controlled, the response is rapid, and the compensation path is direct.

[0026] The local cluster impedance deviation caused by uneven compression can be actively and real-time compensated, the signal reflection and loss fluctuation is effectively reduced, and the consistency and reliability of high-frequency test are improved.

[0027] The entire compensation function is modularized, the core mechanical structure of the spring needle is not changed, no additional electronic detection unit needs to be introduced, all components can be manufactured by mature semiconductor packaging and micro-processing technology, the integration degree is high, the cost is controllable, and mass production is facilitated.

[0028] The system can automatically reset by the elasticity of the material after the crimping is completed, so as to prepare for the next test and ensure the stability and repeatability during long-term use. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The cross-sectional structure schematic diagram of the spring needle high-frequency test seat provided by the embodiment of the present application is shown.

[0030] Figure 2 The Figure 1 The enlarged cross-sectional structure schematic diagram of the cluster compression coupling cavity before the threshold triggering.

[0031] Figure 3 The cross-sectional structure schematic diagram of the spring needle module in the present application is shown.

[0032] Figure 4 The Figure 1Amplification sectional view structure diagram of cluster compression coupled cavity after threshold trigger.

[0033] Explanation of reference numerals in the drawing:

[0034] 10, spring needle module; 11, boss; 12, outer needle tube; 13, inner needle rod; 14, coil spring;

[0035] 20, coupled cavity; 21, cavity frame; 22, elastic film;

[0036] 30, composite material; 31, insulating matrix; 32, micro metal particles;

[0037] 40, printed circuit board;

[0038] 50, test seat main body. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application more clear, further explanation will be made below in combination with the drawing and examples. The following examples are used to explain the present application, but not to limit it.

[0040] Reference Figures 1 to 4 , the embodiment provides a spring needle high-frequency test seat based on cluster compression threshold trigger.

[0041] The test seat comprises a test seat main body 50 (not completely shown in the drawing), and a high-frequency transmission structure in the form of microstrip line is integrated in the main body by using multilayer printed circuit board process. The specific structure is prior art, and thus will not be described here. A plurality of spring needle modules 10 are mounted on the upper surface of the test seat main body 50 in the form of rectangular array. As shown in Figure 3 each spring needle module 10 comprises an outer needle tube 12, an inner needle rod 13 which can slide in the inner needle tube 12, a coil spring 14 which provides elastic force, and a boss 11 which is fixed on the outer circumferential wall of the inner needle rod 13. The edge of the boss 11 extends to the outside of the outer needle tube 12, so that when the inner needle rod 13 is pressed down, the boss 11 can also move downward relative to the outer needle tube 12.

[0042] 1. Design and construction of cluster compensation unit

[0043] In view of the typical range of mechanical stress conduction and electromagnetic coupling in high-density testing, the cluster compression coupling cavity 20 is designed to cover the area directly below nine adjacent spring needle modules 10, forming an independent "cluster compensation unit". The coupling cavity 20 is made of a liquid crystal polymer (LCP) with high dimensional stability by precision injection molding to form a cavity frame 21. At the opening of the upper surface of the cavity frame 21, a piece of polyimide (PI) film with a thickness of about 0.08mm is sealed and attached as an elastic film 22 by hot pressing and epoxy bonding. The elastic film 22 has good elasticity, fatigue resistance and high temperature stability, and is the key to reversible deformation. The through holes on the elastic film 22 accommodate the up and down movement of the inner needle rods 13 of the spring needle modules 10, and the bosses 11 are located above the elastic film 22.

[0044] 2. Key material and parameter settings

[0045] The internal cavity of the coupling cavity 20 is filled with compressible composite material 30, which is wrapped around the outside of the outer needle tube 12. The composite material 30 uses low-loss liquid silicone rubber (LSR) as the insulating matrix 31, with about 10% by volume of spherical gold-plated copper micro-metal particles 32 uniformly dispersed, with a D50 particle size of about 8μm. In the initial state without pressure, the dielectric constant of the composite material at 10GHz is about 3.2. The maximum design compression stroke of the spring needle module 10 is 1.0mm. The pre-set threshold is achieved by designing the initial gap between the lower surface of the boss 11 on the spring needle module 10 and the upper surface of the elastic film 22 to be 0.30mm. Therefore, when the compression amount of the spring needle module 10 reaches 0.30mm, the boss 11 starts to contact the elastic film 22, and this physical contact is defined as the trigger event.

[0046] 3. Working principle and test process

[0047] As shown in Figure 4 , during the compression test, the chip under test is placed at the top of the spring needle module 10, the top of the spring needle module 10 is in contact with the pins of the chip under test, and the bottom of the spring needle module 10 is in contact with the printed circuit board 40 for testing. Assuming that the spring needle module 10 is compressed by 0.40mm due to package warpage. When the compression amount exceeds the threshold of 0.30mm, the boss 11 physically contacts and starts to push the elastic film 22. This contact behavior itself is directly determined as a trigger, and the coupling cavity 20 enters the compensation state without any electronic signal intervention.

[0048] In the compensation state, the elastic film 22 deforms, which converts the point-like, vertically downward mechanical pressure of the single spring needle module 10 (the boss 11) into a planar, uniform extrusion on the entire lower composite material 30, driving the rearrangement of the micro metal particle 32 group. This makes the effective dielectric constant of the cavity rise from about 3.2 to about 3.5, with a relative increase of about 9.4%. The increase falls within the effective compensation interval of 5%~15%. According to the transmission line theory, this dielectric constant increase has a synergistic compensation effect on the impedance of the nine channels in the region 9, pulling them close to the target value.

[0049] 4. Reset and test effect

[0050] After the crimping is completed, the external force is removed, and the system resets by its own elasticity: the spring needle module 10 rebounds, the boss 11 separates from the elastic film 22, the elastic film 22 restores the deformation, the micro metal particles 32 in the composite material 30 are redistributed under the elastic restoring force of the insulating matrix 31, the effective dielectric constant of the cavity is restored, and the entire system waits for the next test.

[0051] The test results show that the embodiment scheme can effectively improve the consistency of high-frequency testing, significantly suppress the fluctuation of signal integrity between channels, and has higher reliability and environmental adaptability due to its pure mechanical triggering and compensation mechanism.

[0052] The above embodiments are only preferred embodiments of the present application. Any modification, equivalent replacement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A spring needle high-frequency test seat based on cluster compression threshold triggering, characterized in that, include: Test base body; Multiple spring pin modules are installed on the main body of the test socket; A clustered compression coupling cavity is arranged below multiple spring needle modules. The clustered compression coupling cavity includes a cavity frame and an elastic membrane mounted on its upper side. The cavity is filled with a composite material, which includes an insulating matrix and micro-metal particles dispersed therein. When any of the spring pin modules exceeds a preset threshold during the crimping test, the cluster compression coupling cavity is triggered to enter a compensation state: the boss structure of the spring pin module pushes the elastic membrane to deform it, driving the micro-metal particles inside the composite material to rearrange in groups, causing the effective dielectric constant in the coupling cavity to change synchronously, thereby adaptively compensating the characteristic impedance of the signal transmission channels of all spring pin modules in a local area centered on the spring pin module.

2. The pogo pin high-frequency test socket according to claim 1, wherein, The number of spring pin modules covered by the cluster compression coupling cavity is 4 to 9. This number is set to match the mechanical stress transmission radius of the test seat body during the crimping process and the electromagnetic coupling scale between high-frequency signal channels, so as to form an effective cluster compensation unit.

3. The pogo pin high frequency test socket of claim 1, wherein, The elastic membrane is made of polyimide film, silicone rubber film or thermoplastic elastomer film.

4. The pogo pin high frequency test socket of claim 1, wherein, The micro-metal particles are gold-plated copper particles, nickel particles, tin alloy particles, or combinations thereof, with a particle size of 1 μm to 20 μm.

5. The pogo pin high frequency test socket of claim 1, wherein, The preset threshold is determined based on the compression stroke of the spring needle module, and ranges from 20% to 60% of its maximum compression stroke.

6. The pogo pin high frequency test socket of claim 1, wherein, The dielectric constant of the composite material is 2.5 to 4.0 under zero pressure, and increases by 5% to 15% when the threshold compression state is reached.

7. The pogo pin high frequency test socket of claim 1, wherein, The main body of the test stand includes a high-frequency transmission structure, which is a coplanar waveguide structure, a stripline structure, or a microstripline structure.

8. A method for high frequency testing using the spring needle high frequency test socket according to any one of claims 1 to 7, characterized in that, Includes the following steps: The packaged chip is press-fitted so that the spring pin module makes contact with the chip pins; The preset threshold is pre-set by the initial gap or contact relationship between the boss structure of the spring needle module and the elastic membrane. When the compression stroke of any spring needle module exceeds the preset threshold for the first time, its boss structure physically contacts and pushes the elastic membrane. This physical contact behavior itself is determined as a trigger event, and the corresponding cluster compression coupling cavity enters the compensation state without the need for independent electronic sensors or detection circuits. In the compensated state, the boss structure of the spring needle module pushes the elastic membrane to deform it, driving the micro-metal particles inside the composite material to undergo group rearrangement. The rearrangement of micro-metal particles causes a synchronous change in the effective dielectric constant of the coupling cavity, thereby automatically adjusting the characteristic impedance of the signal transmission channels of all spring pin modules in a local area centered on the spring pin module, so that they tend to and stabilize within the preset target impedance range, thus completing the high-frequency signal test. After the compression is completed, the external force is removed, and the cluster compression coupling cavity exits the compensation state and resets under the restoring force of the elastic membrane and the action of the composite material itself.

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