Glue filling method for vertical probe card

Abstract

The invention discloses a vertical probe card glue filling method, which comprises the following steps of: preparing a probe card assembly, inverting the probe card assembly below glue filling equipment, enabling a resin groove of a ceramic plate to face downwards, and forming an inverted cavity between a ceramic hole and an enameled wire; injecting glue into the gold-plated surface of the ceramic plate, wherein the glue fills the whole cavity from top to bottom along each ceramic hole; when the glue reaches a preset thickness in the resin groove and the varnished wire is wrapped by the overflowing resin in the ceramic hole, stopping glue pouring; and the probe card assembly is placed in a drying oven in the forward direction for curing. Reverse glue pouring is started from the back face of the ceramic plate, the capillary action is limited to the gold-plated face of the ceramic plate, pollution of glue to a conductive contact area is avoided, and the quality of a test signal and the electrical reliability of the probe card are guaranteed; the glue is prevented from climbing upwards uncontrollably, and it is guaranteed that a glue filling interface is clear, flat and controllable in height.

Description

Technical Field

[0001] This invention relates to the field of probe card technology, and in particular to a method for potting a vertical probe card. Background Technology

[0002] Vertical probe cards are key components in wafer testing. They use numerous tiny probes to contact pads on the wafer, enabling electrical connections and signal transmission. To ensure the verticality, stability, and mechanical strength of the probes, a layer of epoxy resin or other colloid is typically filled and cured in specific areas of the probe card to form a robust support structure.

[0003] Traditional potting processes such as Figure 4 As shown, the "positive potting" or "resin tank potting" method is usually used. Specifically, the probe card assembly is placed upright, and its enameled wire is inserted into the designated ceramic hole in the ceramic plate. The potting head is used to pot the probe card from the front, and epoxy resin is filled into the resin tank to ensure that the gaps in the ceramic hole are filled with enough resin. Then, it is cured.

[0004] However, during the glue pouring process, the glue, under the influence of strong capillary action, will climb upwards along the surface of the enameled wire and fill the gaps between the enameled wires, making it difficult to precisely control the glue height. In particular, it will cross the preset glue pouring resin tank area and climb upwards along the enameled wire.

[0005] When adhesive creeps uncontrollably into areas that should be kept clean, it not only contaminates the conductive contacts of the probe card, affecting the integrity of the test signal, but also alters the flexibility and elasticity of the enameled wire outside the adhesive-covered area. This affects the wire's resilience during testing and makes it prone to breakage. Furthermore, inconsistent adhesive creep heights increase the risk of wire breakage, leading to poor probe card consistency during rework, resulting in low product yield, limited maintenance and engineering modifications, and ultimately, increased susceptibility to scrapping. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a method for potting adhesive onto a vertical probe card, effectively suppressing the adhesive from climbing upwards along the enameled lines of the probe card and ensuring a smooth and controllable adhesive filling interface.

[0007] Therefore, the technical solution of the present invention is: a method for potting adhesive onto a vertical probe card, comprising the following steps: S1. Prepare the probe card assembly. The probe card assembly includes a ceramic plate. The front of the ceramic plate has a resin tank and the back has a gold-plated surface. There are multiple ceramic holes that match the enameled wire between the resin tank and the gold-plated surface. S2. Invert the probe card assembly under the glue potting equipment, with the resin tank of the ceramic plate facing down, forming an inverted cavity between the ceramic hole and the enameled wire; S3. Inject glue into the gold-plated surface of the ceramic plate, and fill the entire cavity from top to bottom along each ceramic hole. S4. Stop applying glue when the glue reaches the predetermined thickness in the resin tank and the overflow glue in the ceramic hole covers the enameled wire. S5. Place the probe card assembly face up in the oven for curing.

[0008] Based on the above scheme and as a preferred embodiment of the above scheme: In step S1, the probe card assembly is placed facing forward, the enameled wire is passed through the ceramic hole of the ceramic plate in sequence, and the excess enameled wire on the gold-plated side is cut off, leaving only the end of the enameled wire at a certain height.

[0009] Based on the above scheme and as a preferred embodiment of the above scheme: in step S4, after the glue pouring is completed, a vacuum is applied to remove air bubbles from the cavity.

[0010] Based on the above scheme and as a preferred embodiment of the above scheme: in step S4, the glue level is monitored through an observation window or sensor, and the glue pouring is stopped when the level reaches the preset filling height line.

[0011] Based on the above scheme and as a preferred embodiment of the above scheme: in step S2, a gap of less than 4~8um is formed between the ceramic hole and the enameled wire, forming an inverted cavity.

[0012] Based on the above scheme and as a preferred embodiment of the above scheme: In step S5, during the forward heating and curing process, the resin on the gold-plated surface will overflow into the resin tank through the gaps between the ceramic holes and the enameled wire, and the resin viscosity will increase and solidify.

[0013] Compared with the prior art, the beneficial effects of the present invention are: The adhesive is poured in reverse from the back of the ceramic plate, and the adhesive fills one side of the resin tank by gravity. The height of the adhesive on one side of the resin tank can be controlled by controlling the amount of adhesive poured. At the same time, capillary action is limited to the gold-plated surface of the ceramic plate, which avoids contamination of the conductive contact area by the adhesive, ensuring the quality of the test signal and the electrical reliability of the probe card. It also prevents the adhesive from climbing upwards uncontrollably, ensuring a clear, flat, and controllable adhesive filling interface.

[0014] By monitoring the liquid level with an observation window / sensor, the amount of glue poured can be precisely controlled, ensuring that the glue thickness in the resin tank consistently matches the preset standard. This eliminates product differences caused by inconsistent glue climbing height and significantly improves the production yield and performance consistency of vertical probe cards.

[0015] The process is simple and easy to implement; it only requires changing the direction of dispensing, without adding too many complex equipment, and is easy to modify and implement on existing production lines, resulting in low cost and high efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the glue-pouring state of the present invention; Figure 2 This is a flowchart of the method steps of the present invention; Figure 3 This is a schematic diagram of the probe card structure obtained by the present invention; Figure 4 This is a schematic diagram of the potting state of an existing probe card.

[0017] The components in the diagram are labeled as follows: 1. Printed circuit board; 2. Ceramic plate; 21. Resin tank; 22. Gold-plated surface; 23. Ceramic hole; 3. Enamelled wire; 31. Enamelled wire cut end; 4. Resin layer; 5. Dispensing machine. Detailed Implementation

[0018] In the description of this invention, it should be noted that directional terms such as "center", "lateral (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this invention, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0020] See the attached figures. The vertical probe card described in this embodiment includes a printed circuit board 1 (PCB) and a ceramic plate 2. The ceramic plate 2 has a resin tank 21 on the front and a gold-plated surface 22 on the back. A plurality of ceramic holes 23 matching the enameled wire are provided between the resin tank 21 and the gold-plated surface 22. The enameled wire 3 has a resin outer layer and a gold-plated point at its lower end to form a conductive contact.

[0021] The potting method for the vertical probe card includes the following steps: S1. Prepare the probe card assembly and the glue-drinking equipment. The glue-drinking equipment is a dispensing machine. The probe card assembly is placed upright. The enameled wire 3 is passed through the ceramic hole 23 of the ceramic plate 2 in sequence, and the excess enameled wire 3 on the gold-plated side 22 is cut off, leaving only the cut end 31 of the enameled wire at a certain height.

[0022] S2. Invert the probe card assembly under the potting equipment, with the resin tank 21 of the ceramic plate 2 facing down and the gold-plated side 22 with the enameled wire cutting end 31 facing up. At this time, a gap of less than 4~8um is formed between the ceramic hole 23 and the enameled wire 3, forming an inverted cavity.

[0023] S3. The dispensing machine 5 injects adhesive, which is a low-viscosity resin, from the gold-plated surface 22 of the ceramic plate 2 through the dispensing port. Due to gravity, the adhesive will start to accumulate from the bottom of the cavity and smoothly fill the entire cavity from top to bottom, and then slowly form a resin layer 4 in the resin tank 21.

[0024] S4. Monitor the glue level through the observation window or sensor. When the glue reaches the predetermined thickness in the resin tank 21, and it is confirmed that the overflowing resin in the ceramic hole 23 of the resin tank covers the enameled wire 3, remove the dispensing equipment to stop the glue pouring. Typically, the resin height in the ceramic plate hole is 0.5mm, and the overflow height in the resin tank is <2mm. After the glue pouring is completed, a vacuum can be selectively applied to help remove air bubbles from the cavity.

[0025] S5. Place the probe card assembly face up in the oven. The oven baking time is 3 hours and the temperature is 80℃. During the forward heating and curing process, the resin on the gold-plated surface 22 of the ceramic plate will slowly overflow into the resin tank 21 through the gap between the ceramic hole 23 and the enameled wire 3. As time changes, the resin viscosity increases and it cures.

[0026] In this embodiment, the probe card assembly is inverted, and the adhesive is poured from the back of the ceramic plate in reverse. This limits the capillary action to the gold-plated surface of the ceramic plate, avoiding contamination of the conductive contact area by the adhesive, ensuring the quality of the test signal and the electrical reliability of the probe card. It also prevents the adhesive from climbing upwards uncontrollably, ensuring a clear, flat, and highly controllable adhesive filling interface.

[0027] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for vertical probe card glue filling, characterized in that: The method comprises the following steps: S1, preparing a probe card assembly, the probe card assembly comprising a ceramic plate, the front surface of the ceramic plate being provided with a resin groove, the back surface being provided with a gold-plated surface, and a plurality of ceramic holes matched with the enameled wire being arranged between the resin groove and the gold-plated surface; S2, inverting the probe card assembly below a glue filling device, the resin groove of the ceramic plate facing downward, and an inverted cavity being formed between the ceramic holes and the enameled wire; S3, injecting glue to the gold-plated surface of the ceramic plate, the glue filling the entire cavity from top to bottom along the ceramic holes; S4, stopping the glue filling when the glue reaches a predetermined thickness in the resin groove and the ceramic hole resin overflow glue wraps the enameled wire; S5, placing the probe card assembly in a normal direction into an oven for solidification.

2. The vertical probe card glue filling method of claim 1, wherein: In the step S1, the probe card assembly is placed in a normal direction, the enameled wire is sequentially inserted into the ceramic holes of the ceramic plate, and the excess enameled wire on the side of the gold-plated surface is cut off, only leaving the enameled wire end portion of a certain height.

3. The method of claim 1, wherein: In the step S4, after the glue filling is completed, a vacuum is applied to remove the bubbles in the cavity.

4. The method of claim 1, wherein: In the step S4, the glue liquid level is monitored through an observation window or a sensor, and the glue filling is stopped when the liquid level reaches a preset filling height line.

5. The method of claim 1, wherein: In the step S2, a gap smaller than 4-8 um is formed between the ceramic holes and the enameled wire to form the inverted cavity.

6. The method of claim 1, wherein: In the step S5, during the normal heating and solidification process, the resin on the gold-plated surface will overflow into the resin groove through the gap between the ceramic holes and the enameled wire, the resin viscosity thickens and solidifies.

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