A micro-coaxial radio frequency probe card

Abstract

The present invention relates to the technical field of probe cards and discloses a micro-coaxial radio frequency probe card, in which a radio frequency probe is embedded in an isolating plastic sleeve, the isolating plastic sleeve is embedded in a grounding copper sleeve, the front end portion of the probe shielding grounding head is recessed with a second through hole compatible with the radio frequency probe, the front end portion of the radio frequency probe is provided with a needle tip with a cone-shaped structure, the needle tip is extended out of the second through hole, and two sides of the front end wall of the probe shielding grounding head are respectively provided with an inwardly inclined shielding grounding pin, the needle tip is located on the inner side of the shielding grounding pin, the lower end portion of the coaxial radio frequency connector is provided with a core, the lower end portion of the pin is provided with a second plug hole compatible with the radio frequency probe, and the upper end portion of the radio frequency probe is detachably embedded in the second plug hole, thereby effectively improving the shielding effect and performance stability of the radio frequency probe, and has the advantages of simple structure, low production cost, low insertion loss, low standing wave, stable performance, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of probe cards, and in particular to a micro-coaxial radio frequency probe card. Background Art

[0002] Transmission lines used in RF applications are typically coaxial cables connected to circuit boards and microstrip lines embedded within them. RF probes are measurement devices used in electronic test equipment to measure radio frequency (RF) signals in electronic circuits within silicon wafers, die, and open microchips. RF probes are also used for narrow-pitch or high-density RF interconnects in connector assemblies. RF probes were developed in 1980. Prior to this, there was no easy way to test monolithic microwave integrated circuits (MMICs) without mounting or attaching them. This often compromised circuit integrity, causing system interference or reducing power loading. The first generation of RF probes used coplanar ceramic feeds and covered frequencies up to 18 GHz. Advances in RF probe technology have led to the use of spring-loaded inner and outer conductors in modern communications electronics. Today, RF probes remain an essential tool for testing RF switches, printed circuit board RF traces, terminal devices, and other RF components.

[0003] Measuring RF circuits is often a challenging task due to the highly sensitive and often delicate nature and composition of devices under test (DUTs). Two of the most significant challenges in high-reliability RF measurements are the inability of current test equipment to measure RF energy at high frequencies and the requirement for measurements without frequency or amplitude perturbations when the DUT is sensitive to small changes in the electrical environment. These issues can be addressed by using measurement probes that minimize energy perturbations to the DUT. The amplifiers in high-impedance probes balance the perturbed energy within the DUT. In RF circuit system testing, impedance matching between the probe and the test equipment is crucial for efficient power transfer. However, with increasing test frequencies and increasingly stringent test tolerances, this impedance matching becomes increasingly challenging.

[0004] High-frequency testing of high-frequency product components requires the use of complex test equipment, which can include a vector network analyzer (VNA), a wafer probing system, high-frequency probes, semi-rigid or flexible coaxial RF cables, and calibration substrates. The probe is the most critical part of the measurement system because it must be physically connected to the device under test.

[0005] During chip manufacturing, after wafer tape-out, the chip undergoes performance testing before entering the packaging and testing process. With the improvement of chip performance, miniaturization, and diversification of functions, the requirements for the probe card itself, which serves as the connection channel between the chip and the tester, are becoming increasingly stringent. Testing RF chips requires shielding protection of RF signals, and shielding becomes more difficult at higher frequencies. Currently, existing micro-coaxial RF probe cards have stable performance but poor shielding effectiveness, resulting in unstable test results and affecting product yield. Further improvement is needed. Summary of the Invention

[0006] The main purpose of the present invention is to provide a micro-coaxial radio frequency probe card, aiming to solve the technical problem that the existing micro-coaxial radio frequency probe card has stable performance but unsatisfactory shielding effect.

[0007] To achieve the above-mentioned purpose, the micro coaxial RF probe card proposed in the present invention includes a metal fixing bracket, a coaxial RF connector, a RF probe, an isolation plastic sleeve, a grounding copper sleeve and a probe shielding grounding head. The front end of the metal fixing bracket is inclinedly recessed with a first through hole, the coaxial RF connector can be embedded in the first through hole and can be moved up and down, the RF probe is embedded in the isolation plastic sleeve, the isolation plastic sleeve is embedded in the grounding copper sleeve, the rear end of the probe shielding grounding head is recessed with a first plug hole, the lower end of the grounding copper sleeve is detachably embedded in the first plug hole, and the probe The front end of the shielding grounding head is recessed with a second through hole that is compatible with the RF probe, and the front end of the RF probe is provided with a needle tip with a conical structure, and the needle tip is extended out of the second through hole. A shielding grounding pin inclined inward is respectively protruded on both sides of the front end wall of the probe shielding grounding head, and the needle tip is located on the inner side of the shielding grounding pin. The lower end of the coaxial RF connector is provided with a core, and the lower end of the pin is provided with a second plug hole that is compatible with the RF probe. The upper end of the RF probe is detachably embedded in the second plug hole, and the upper end of the RF probe is electrically connected to the core.

[0008] Furthermore, the front end wall of the shielding grounding needle is arranged in an inwardly inclined inclined structure, and a limit plate is protruded from the outer side of the front end wall of the shielding grounding needle, and the lower end of the needle tip extends out of the lower end wall of the limit plate.

[0009] Furthermore, it also includes a transition plate and an epoxy resin positioning block, the transition plate is arranged at the lower end of the coaxial RF connector, a third through hole is recessed in the middle of the upper end wall of the transition plate, the grounding copper sleeve is passed through the third through hole, the transition plate is arranged in the first through hole, and the outer peripheral wall of the transition plate is abutted against the inner peripheral wall of the first through hole, the epoxy resin positioning block is embedded in the lower end of the first through hole, and the upper end of the epoxy resin positioning block is abutted against the transition plate, and the RF probe is passed through the epoxy resin positioning block.

[0010] Furthermore, it also includes a limiting bolt, and a threaded hole connected to the first through hole is respectively recessed on both sides of the front end of the metal fixing bracket, and the limiting bolts are respectively screwed into the threaded holes, and the front ends of the limiting bolts can be respectively abutted against the outer peripheral wall of the coaxial RF connector.

[0011] Furthermore, the outer peripheral wall of the lower end portion of the grounding copper sleeve is in abutment and electrically connected to the probe shielding grounding head, and the upper end portion of the probe shielding grounding head is in abutment and electrically connected to the coaxial RF connector.

[0012] Furthermore, a plurality of mounting holes are recessed at the rear end portion of the metal fixing bracket.

[0013] Furthermore, the isolation plastic sleeve is made of polytetrafluoroethylene.

[0014] Furthermore, the grounding copper sleeve and the probe shielding grounding head are both made of beryllium copper.

[0015] Furthermore, the radio frequency probe is made of rhenium tungsten, tungsten or beryllium copper.

[0016] Furthermore, the distance between the needle tip and the front end wall of the shielding grounding needle ranges from 0.1 mm to 0.5 mm.

[0017] The technical solution of the present invention has the following beneficial effects: According to the technical solution of the present invention, a first through hole is obliquely recessed through the front end of the metal fixing bracket, the coaxial RF connector is embedded in the first through hole and can be moved up and down, the RF probe is embedded in the isolation plastic sleeve, the isolation plastic sleeve is embedded in the grounding copper sleeve, the rear end of the probe shielding grounding head is recessed with a first plug-in hole, the lower end of the grounding copper sleeve is detachably embedded in the first plug-in hole, the front end of the probe shielding grounding head is recessed with a second through hole adapted to the RF probe, the front end of the RF probe is provided with a needle tip with a conical structure, and the needle tip extends out of the second through hole. A shielding grounding pin inclined inward is protruded on both sides of the front end wall of the probe shielding grounding head, and the needle tip is located on the inner side of the shielding grounding pin. A plug is provided at the lower end of the coaxial RF connector, and a second plug hole is provided at the lower end of the plug that is compatible with the RF probe. The upper end of the RF probe is detachably embedded in the second plug hole, and the upper end of the RF probe is electrically connected to the plug, thereby effectively improving the shielding effect and performance stability of the RF probe. It has the advantages of simple structure, low production cost, low insertion loss, low standing wave, stable performance, etc. It can be used in electronic test equipment to measure radio frequency (RF) signals of electronic circuits in silicon wafers, tube cores and open microchips. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of the overall structure of a micro-coaxial radio frequency probe card proposed by the present invention;

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0021] Figure 3 This is a schematic diagram of the exploded structure of a micro-coaxial radio frequency probe card proposed in the present invention;

[0022] Figure 4 This is a partial structural diagram of a micro-coaxial radio frequency probe card proposed by the present invention;

[0023] Figure 5 This is a schematic diagram of a partially exploded structure of a micro-coaxial radio frequency probe card proposed by the present invention;

[0024] Figure 6This is a structural schematic diagram of a probe shielding grounding head of a micro-coaxial radio frequency probe card proposed by the present invention.

[0025] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] The present invention provides a micro-coaxial radio frequency probe card.

[0030] like Figures 1 to 6As shown, in one embodiment of the present invention, the micro coaxial RF probe card includes a metal fixing bracket 101, a coaxial RF connector 102, a RF probe 103, an isolation plastic sleeve 104, a grounding copper sleeve 105 and a probe shielding grounding head 106. The front end of the metal fixing bracket 101 is inclinedly recessed with a first through hole 1011, the coaxial RF connector 102 is embedded in the first through hole 1011 and can be moved up and down. The RF probe 103 is embedded in the isolation plastic sleeve 104, and the isolation plastic sleeve 104 is embedded in the grounding copper sleeve 105. The rear end of the probe shielding grounding head 106 is recessed with a first plug hole 1061, and the lower end of the grounding copper sleeve 105 is detachably embedded in the first plug hole 1061. The front end of the ground head 106 is recessed with a through hole 1062 that is compatible with the RF probe 103, and the front end of the RF probe 103 is provided with a needle tip 1031 with a conical structure, and the needle tip 1031 is extended out of the through hole 1062. A shielding grounding pin 1063 inclined inward is respectively protruded on both sides of the front end wall of the probe shielding grounding head 106, and the needle tip 1031 is located on the inner side of the shielding grounding pin 1063. The lower end of the coaxial RF connector 102 is provided with a core 1021, and the lower end of the pin 1021 is provided with a second plug hole (not shown) that is compatible with the RF probe 103. The upper end of the RF probe 103 is detachably embedded in the second plug hole, and the upper end of the RF probe 103 is electrically connected to the pin 1021.

[0031] Specifically, the front end wall of the shielding grounding needle 1063 is arranged in an inwardly inclined inclined structure, and a limit plate 1064 is protruded from the outer side of the front end wall of the shielding grounding needle 1063, and the lower end of the needle tip 1031 extends out of the lower end wall of the limit plate 1064.

[0032] Specifically, it also includes a transition plate 107 and an epoxy resin positioning block 108. The transition plate 107 is arranged at the lower end of the coaxial RF connector 102. A third through hole 1071 is recessed in the middle of the upper end wall of the transition plate 107. The grounding copper sleeve 105 is passed through the third through hole 1071. The transition plate 107 is arranged in the first through hole 1011, and the outer peripheral wall of the transition plate 107 is abutted against the inner peripheral wall of the first through hole 1011. The epoxy resin positioning block 108 is embedded in the lower end of the first through hole 1011, and the upper end of the epoxy resin positioning block 108 is abutted against the transition plate. The RF probe 103 is passed through the epoxy resin positioning block 108.

[0033] Specifically, it also includes a limiting bolt (not shown), and a threaded hole 1012 connected to the first through hole 1011 is respectively recessed on both sides of the front end of the metal fixing bracket 101. The limiting bolts are respectively screwed into the threaded holes 1012, and the front ends of the limiting bolts can be respectively abutted against the outer peripheral wall of the coaxial RF connector 102.

[0034] Specifically, the outer peripheral wall of the lower end portion of the grounding copper sleeve 105 is in abutment and electrically connected to the probe shielding grounding head 106 , and the upper end portion of the probe shielding grounding head 106 is in abutment and electrically connected to the coaxial RF connector 102 .

[0035] Specifically, a plurality of mounting holes 1013 are recessed at the rear end of the metal fixing bracket 101 .

[0036] Specifically, the isolation plastic sleeve is made of polytetrafluoroethylene.

[0037] Specifically, the grounding copper sleeve and the probe shielding grounding head are both made of beryllium copper.

[0038] Specifically, the radio frequency probe is made of rhenium tungsten, tungsten or beryllium copper, which has the advantages of good hardness / fatigue resistance and good stability, and is suitable for long-term testing.

[0039] Specifically, the distance between the needle tip and the front end wall of the shielding grounding needle ranges from 0.1 mm to 0.5 mm.

[0040] Specifically, the present invention has a first through hole obliquely recessed at the front end of the metal fixing bracket, the coaxial RF connector is embedded in the first through hole and can be moved up and down, the RF probe is embedded in the isolating plastic sleeve, the isolating plastic sleeve is embedded in the grounding copper sleeve, the rear end of the probe shielding grounding head is recessed with a first plug hole, the lower end of the grounding copper sleeve is detachably embedded in the first plug hole, the front end of the probe shielding grounding head is recessed with a second through hole adapted to the RF probe, the front end of the RF probe is provided with a needle tip with a conical structure, the needle tip extends out of the second through hole, and the front end of the probe shielding grounding head is recessed with a second through hole adapted to the RF probe. A shielding grounding pin inclined inward is protruded from both sides of the wall, and the needle tip is located on the inner side of the shielding grounding pin. A plug core is provided at the lower end of the coaxial RF connector, and a second plug hole adapted for the RF probe is provided at the lower end of the plug pin. The upper end of the RF probe is detachably embedded in the second plug hole, and the upper end of the RF probe is electrically connected to the plug core, thereby effectively improving the shielding effect and performance stability of the RF probe. It has the advantages of simple structure, low production cost, low insertion loss, low standing wave, stable performance, etc. It can be used in electronic testing equipment to measure radio frequency (RF) signals of electronic circuits in silicon wafers, tube cores and open microchips.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A micro-coaxial radio frequency probe card, characterized in that: The invention comprises a metal fixing bracket, a coaxial RF connector, a RF probe, an isolating plastic sleeve, a grounding copper sleeve and a probe shielding grounding head, wherein the front end portion of the metal fixing bracket is obliquely recessed with a first through hole, the coaxial RF connector is embedded in the first through hole and can be moved up and down, the RF probe is embedded in the isolating plastic sleeve, the isolating plastic sleeve is embedded in the grounding copper sleeve, the rear end portion of the probe shielding grounding head is recessed with a first plug hole, the lower end portion of the grounding copper sleeve is detachably embedded in the first plug hole, and the front end portion of the probe shielding grounding head is recessed. There is a second through hole adapted to the radio frequency probe, the front end of the radio frequency probe is provided with a needle tip in a conical structure, the needle tip is extended out of the second through hole, and two sides of the front end wall of the probe shielding grounding head are respectively provided with an inwardly inclined shielding grounding pin, the needle tip is located on the inner side of the shielding grounding pin, the lower end of the coaxial radio frequency connector is provided with a ferrule, the lower end of the pin is provided with a second plug hole adapted to the radio frequency probe, the upper end of the radio frequency probe is detachably embedded in the second plug hole, and the upper end of the radio frequency probe is electrically connected to the ferrule; The front end wall of the shielding grounding pin is provided with an inwardly inclined inclined surface structure, and a limit plate is protruded from the outer side of the front end wall of the shielding grounding pin, and the lower end of the needle tip extends out of the lower end wall of the limit plate; The micro-coaxial RF probe card also includes a transition plate and an epoxy resin positioning block, the transition plate is arranged at the lower end of the coaxial RF connector, a third through hole is recessed in the middle of the upper end wall of the transition plate, the grounding copper sleeve is passed through the third through hole, the transition plate is arranged in the first through hole, and the outer peripheral wall of the transition plate is abutted against the inner peripheral wall of the first through hole, the epoxy resin positioning block is embedded in the lower end of the first through hole, and the upper end of the epoxy resin positioning block is abutted against the transition plate, and the RF probe is passed through the epoxy resin positioning block; The micro-coaxial RF probe card also includes a limiting bolt. A threaded hole connected to the first through hole is respectively recessed on both sides of the front end of the metal fixing bracket. The limiting bolts are respectively screwed into the threaded holes, and the front ends of the limiting bolts can be respectively abutted against the outer peripheral wall of the coaxial RF connector.

2. The micro-coaxial radio frequency probe card according to claim 1, characterized in that: The outer peripheral wall of the lower end portion of the grounding copper sleeve is in abutment and electrically connected to the probe shielding grounding head, and the upper end portion of the probe shielding grounding head is in abutment and electrically connected to the coaxial RF connector.

3. The micro-coaxial radio frequency probe card according to claim 1, characterized in that: The rear end portion of the metal fixing bracket is recessed with a plurality of mounting holes.

4. The micro-coaxial radio frequency probe card according to claim 1, characterized in that: The isolation plastic sleeve is made of polytetrafluoroethylene.

5. The micro-coaxial radio frequency probe card according to claim 1, characterized in that: The grounding copper sleeve and the probe shielding grounding head are both made of beryllium copper.

6. The micro-coaxial radio frequency probe card according to claim 1, characterized in that: The radio frequency probe is made of rhenium tungsten, tungsten or beryllium copper.

7. The micro-coaxial radio frequency probe card according to claim 1, characterized in that: The distance between the needle tip and the front end wall of the shielding grounding needle ranges from 0.1 mm to 0.5 mm.

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