Preparation method for rapidly forming MEMS probe

Abstract

The invention discloses a preparation method for quickly forming an MEMS (Micro Electro Mechanical System) probe in the field of semiconductor probe processing, which comprises the following steps: selecting a to-be-cut alloy plate, cutting the to-be-cut alloy plate by using a five-axis laser cutting machine, cutting off each waste hollow part of the to-be-cut alloy plate to obtain an alloy frame, taking down the alloy frame, and cutting off the alloy frame to obtain the MEMS probe. And the alloy frame is bonded to the base plate through glue, the five-axis laser cutting machine cuts the connecting edges of the left end and the right end of each cross-shaped probe body on the alloy frame and the alloy frame, the alloy frame is separated from the base plate, and the multiple probe bodies are reserved on the base plate. According to the invention, the preparation efficiency of probe products is improved, and the output quantity of probes is increased.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor probe processing, and in particular relates to a preparation method for rapidly forming a MEMS probe. Background Art

[0002] The probe is an indispensable component in the integrated circuit chip packaging and testing process. It contacts the chip to achieve communication and feeds back the test data to the test device for comparison to detect whether the electrical characteristics and logical functions of the wafer meet the requirements. As the chip manufacturing process precision requirements become higher and higher, the line width on the chip becomes smaller and smaller, thereby increasing the requirements for the quantity, quality, and precision of the probes.

[0003] The main principle of the MEMS probe structure is to use MEMS (micro-electromechanical system) technology to produce a micron-sized, movable probe, and through the interaction between the probe and the object to be measured, it can realize the functions of detection, positioning, and identification of the object to be measured.

[0004] At present, there are two common methods for preparing MEMS probes: (1) mold casting method, in which photoresist is applied to a single crystal silicon substrate. After exposure, plasma gas is used to etch a number of probe-shaped cavities on the single crystal silicon substrate and deposit a seed layer; different needle tip shapes are etched in the cavity using an etching liquid to form a micro-casting mold; the completely melted probe body material is cast into the micro-casting mold, and the micro-casting mold is ultrasonically immersed; the solidified probe body is taken out of the micro-casting mold; the probe body is chemically polished to form a probe; (2) Deposition method: depositing a metal seed layer on the surface of the substrate; spreading a glue on the metal seed layer to obtain a glue layer, exposing the dried glue layer with a laser light source, and dissolving the corresponding glue layer with a developer, thereby photoetching multiple vertical probe patterns in the glue layer; wetting the glue layer with high-frequency vibration under vacuum conditions, and electroplating the wetted glue layer multiple times to deposit the plating liquid to form probes.

[0005] For the above two methods, the present invention aims at the problems of complex MEMS probe preparation process, long time consumption and low precision. After multiple tests and improvements, a new method for quickly preparing MEMS probes is realized. This method has the advantages of simple process, short time consumption, high output and good stability, and effectively improves the preparation efficiency of MEMS probes. Summary of the invention

[0006] The purpose of the present invention is to provide a preparation method for quickly forming a MEMS probe. In view of the long preparation time of traditional MEMS probes, laser cutting and forming are used to avoid the problem of insufficient production capacity due to the complicated and time-consuming processing methods of casting and deposition, thereby improving the preparation efficiency of probe products and increasing the number of probe outputs.

[0007] The object of the present invention is achieved by: a method for preparing a MEMS probe for rapid formation, comprising the following steps: (1) Select an alloy plate to be cut whose thickness is equal to the length of the probe to be prepared, and ensure that the surface of the alloy plate to be cut is flat; (2) The alloy plate to be cut is fixed on the cutting platform of the five-axis laser cutting machine by hot melt adhesive; (3) A five-axis laser cutting machine is used to cut the alloy plate to be cut, and each waste hollow part of the alloy plate to be cut is cut off, so that each waste hollow part is separated from the alloy plate to be cut, and an alloy frame is obtained, wherein a plurality of groups of needle unit assemblies arranged and distributed in a rectangular array are arranged on the alloy frame, and each group of the needle unit assemblies includes a plurality of probe bodies arranged and distributed at equal intervals along the longitudinal direction, and the probe bodies are in a cross shape arranged horizontally, and the left and right ends of the cross-shaped probe body are connected to the alloy frame through a connecting edge; (4) Pour hot water at a temperature of 70-80°C onto the cutting platform of the five-axis laser cutting machine, so that the alloy frame and the hollow parts of the waste materials bonded to the cutting platform are separated from the cutting platform; (5) Clean up the hollowed-out parts of the waste materials, then remove the alloy frame, and bond the alloy frame to the substrate by gluing, where the area of ​​the substrate is larger than the outer area of ​​the alloy frame; (6) The bottom of the substrate is then horizontally bonded to the cutting platform of the five-axis laser cutting machine using hot melt adhesive so that the alloy frame is located above the substrate; (7) A five-axis laser cutting machine is used to cut the connecting edges between the left and right ends of each cross-shaped probe body on the alloy frame and the alloy frame, so that each cross-shaped probe body is separated from the alloy frame; (8) Pour hot water with a temperature of 70-80°C onto the cutting platform of the five-axis laser cutting machine to separate the substrate bonded to the cutting platform from the cutting platform. Then, use tweezers to clamp the alloy frame and lift it upward to separate it from the substrate. Multiple probe bodies are retained on the substrate.

[0008] The present invention formulates the corresponding proportion of alloy materials according to the material used for the probe, and the alloy thickness is customized according to the requirements of the output probe. The probe raw material is bonded to the cutting platform to ensure that there are no bumps, scratches, etc.; according to the size and arrangement distribution of the probe to be cut, the CAD drawing software is used to draw the MEMS probe cutting route map, and the CAD map is input into the five-axis precision femtosecond laser equipment software for analysis, and the route is installed to cut the alloy plate; before, during and after the femtosecond laser cutting, the machine environment, equipment, process, and finished product after cutting need to be checked; after completion, the cut MEMS probe raw material is taken out and transferred to the next process. Compared with the prior art, the beneficial effects of the present invention are: the probe is prepared by laser cutting and molding, the preparation efficiency and output are improved, the operation is simple, and the preparation time is shortened; it avoids the phenomenon of insufficient production capacity due to the cumbersome and time-consuming processing methods of casting and deposition, improves the preparation efficiency of probe products, and increases the number of probe outputs.

[0009] As a further improvement of the present invention, the thickness of the alloy plate to be cut is 40-50 microns.

[0010] As a further improvement of the present invention, the five-axis laser cutting machine is a femtosecond high-precision laser cutting machine.

[0011] As a further improvement of the present invention, the alloy plate and the substrate are both rectangular.

[0012] As a further improvement of the present invention, in the step (3), each probe body of the cut alloy frame is provided with a waste hollow groove on both the front and rear sides in the longitudinal direction, and the waste hollow groove has the same shape and area as the waste hollow part cut off from the alloy plate, and the waste hollow groove is equal in length to the cross-shaped probe body, and the left and right sides of each waste hollow groove are respectively flush with the left and right sides of the corresponding cross-shaped probe body, and each waste hollow groove has a notch corresponding to the cross-shaped probe body on one side close to the cross-shaped probe body, and the cross-shaped probe body is provided with two left-right symmetrical insertion parts, and the two insertion parts are respectively matched and embedded in the notches of two adjacent waste hollow grooves. The waste hollow part on the alloy plate is cut off by laser, so that a plurality of waste hollow grooves are formed on the alloy frame, and then the left and right connecting edges of the cross-shaped probe body are cut off by laser to separate the probe body from the alloy frame.

[0013] As a further improvement of the present invention, the probe body on the alloy frame and the waste hollow grooves on the front and rear sides of the probe body form a probe structure, and the needle unit assembly is composed of a plurality of probe structures arranged at equal intervals in the longitudinal direction.

[0014] As a further improvement of the present invention, the pulse width of the five-axis laser cutting machine is 500-800fs, the laser frequency is 800kHz, the laser power is 0.8-1.2W, and the cutting speed is 100mm / s. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the distribution of each needle unit assembly on the alloy frame of the present invention.

[0016] Figure 2 for Figure 1 Enlarged view of part A.

[0017] Figure 3 for Figure 1 Enlarged view of part B.

[0018] Figure 4 This is the front view of the alloy frame bonded to the substrate.

[0019] Figure 5 This is a structural diagram of a five-axis laser cutting machine.

[0020] Among them, 1 is a five-axis laser cutting machine, 1a is a cutting platform, 2 is an alloy frame, 201 is a needle unit assembly, 201a is a probe body, 201a1 is an insertion part, 201b is a waste hollow part, 3 is a connecting edge, 4 is a substrate, 5 is a notch, 6 is a waste hollow groove, and 7 is a laser head. DETAILED DESCRIPTION

[0021] like Figure 1-5 As shown, a method for preparing a MEMS probe for rapid formation includes the following steps: (1) Select an alloy plate to be cut with a thickness equal to the length of the probe to be prepared, and ensure that the surface of the alloy plate to be cut is flat; the thickness of the rectangular alloy plate to be cut is 40-50 microns; (2) The alloy plate to be cut is fixed on the cutting platform 1a of the five-axis laser cutting machine 1 by hot melt adhesive; (3) The five-axis laser cutting machine 1 cuts the alloy plate to be cut, cuts off each waste hollow part 201b of the alloy plate to be cut, separates each waste hollow part 201b from the alloy plate to be cut, and obtains an alloy frame 2, on which a plurality of groups of needle unit assemblies 201 arranged in a rectangular array are provided, each group of the needle unit assemblies 201 includes a plurality of probe bodies 201a arranged at equal intervals in the longitudinal direction, the probe bodies 201a are in a cross shape arranged transversely, and the left and right ends of the cross-shaped probe body 201a are connected to the alloy frame 2 via a connecting edge 3; Each probe body 201a of the cut alloy frame 2 is provided with a waste hollow groove 6 on the front and rear sides in the longitudinal direction. The waste hollow groove 6 has the same shape and area as the waste hollow part 201b cut off on the alloy plate. The length of the waste hollow groove 6 is equal to that of the cross-shaped probe body 201a. The left and right sides of each waste hollow groove 6 are respectively flush with the left and right sides of the corresponding cross-shaped probe body 201a. A notch 5 is provided on one side of the waste hollow groove 6 close to the cross-shaped probe body 201a corresponding to the cross-shaped probe body 201a. Two left-right symmetrical insertion parts 201a1 are provided on the cross-shaped probe body 201a. The two insertion parts 201a1 are respectively embedded in the notches 5 of two adjacent waste hollow grooves 6. The waste hollow part 201b on the alloy plate is cut off by laser, so that a plurality of waste hollow grooves 6 are formed on the alloy frame 2, and then the left and right connecting edges 3 of the cross-shaped probe body 201a are cut off by laser to separate the probe body 201a from the alloy frame 2. The probe body 201a on the alloy frame 2 and the waste hollow grooves 6 on the front and rear sides of the probe body 201a form a probe structure, and the needle unit assembly 201 is composed of a plurality of probe structures arranged at equal intervals in the longitudinal direction; (4) Pour hot water at a temperature of 70-80° C. onto the cutting platform 1 a of the five-axis laser cutting machine 1 , so that the alloy frame 2 and the waste hollow portions 201 b bonded to the cutting platform 1 a are separated from the cutting platform 1 a ; (5) Cleaning up the hollowed-out parts 201b of the waste materials, then removing the alloy frame 2, and bonding the alloy frame 2 to the substrate 4 by gluing, wherein the area of ​​the substrate 4 is larger than the outer area of ​​the alloy frame 2; the alloy plate and the substrate 4 are both rectangular; (6) Then, the bottom of the substrate 4 is horizontally bonded to the cutting platform 1a of the five-axis laser cutting machine 1 by hot melt adhesive, so that the alloy frame 2 is located above the substrate 4; (7) The five-axis laser cutting machine 1 cuts the connecting edges 3 between the left and right ends of each cross-shaped probe body 201a on the alloy frame 2 and the alloy frame 2, so that each cross-shaped probe body 201a is separated from the alloy frame 2; (8) Pour hot water at a temperature of 70-80°C onto the cutting platform 1a of the five-axis laser cutting machine 1, so that the substrate 4 bonded to the cutting platform 1a is separated from the cutting platform 1a, and then the alloy frame 2 is clamped with tweezers and lifted up to separate it from the substrate 4, and a plurality of probe bodies 201a are retained on the substrate 4. The adhesiveness between the bonding substrate and the alloy frame is not strong, and the bonding substrate and the alloy frame can be separated manually.

[0022] The five-axis laser cutting machine 1 is a femtosecond high-precision laser cutting machine.

[0023] The five-axis laser cutting machine 1 has a pulse width of 500-800 fs, a laser frequency of 800 kHz, a laser power of 0.8-1.2 W, and a cutting speed of 100 mm / s.

[0024] The present invention formulates the corresponding proportion of alloy materials according to the material used for the probe, and the alloy thickness is customized according to the requirements of the output probe. The probe raw material is bonded to the cutting platform to ensure that there are no bumps, scratches, etc.; according to the size and arrangement distribution of the probe to be cut, the CAD drawing software is used to draw the MEMS probe cutting route map, and the CAD map is input into the five-axis precision femtosecond laser equipment software for analysis. The laser head 7 of the five-axis laser cutting machine emits a laser to cut the alloy plate on the cutting platform according to the route; before, during and after the femtosecond laser cutting, the machine environment, equipment, process and finished product after cutting need to be checked; after completion, the cut MEMS probe raw material is taken out and transferred to the next process. The advantages of the present invention are: the probe is prepared by laser cutting and molding, the preparation efficiency and output are improved, the operation is simple, and the preparation time is shortened; it avoids the phenomenon of insufficient production capacity due to the cumbersome and time-consuming processing methods of casting and deposition, improves the preparation efficiency of probe products, and increases the output of probes.

[0025] When the present invention is implemented: (1) the probe raw material is attached to the laser cutting platform, and the product is checked for defects such as bumps, scratches, etc.; (2) the product is moved to the processing area of ​​the five-axis precision femtosecond laser cutting machine, and the layout of the MEMS probe whole piece pattern is imported, and it is aligned to the main body plate, so that the processing pattern corresponds to the position of the plate, and after confirming that it is neatly placed without tilt, the cutting platform is adsorbed; (3) the corresponding cutting process is selected, the pulse width is 500-800fs, the laser frequency is 800kHz, the laser power is 0.8-1.2W, the cutting speed is 100mm / s, and the number of cuttings is 7-12; (4) the temperature of the chiller, the indoor ambient temperature and humidity, the adsorption pressure, etc. are checked to see if they are normal, and if there is no abnormality, click to start processing; (5) after the processing is completed, take out the product and transfer it to the next process.

[0026] The test shows that compared with the traditional probe processing, the probe manufacturing efficiency of the present invention is improved by 20%, the output quantity is increased by 40%, the process quality is improved by about 10%, and the process flow is simple and the process is stable.

[0027] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A method for preparing a MEMS probe by rapid formation, characterized in that The steps include: (1) Select an alloy plate to be cut whose thickness is equal to the length of the probe to be prepared, and ensure that the surface of the alloy plate to be cut is flat; (2) The alloy plate to be cut is fixed on the cutting platform of the five-axis laser cutting machine by hot melt adhesive; (3) A five-axis laser cutting machine is used to cut the alloy plate to be cut, and each waste hollow part of the alloy plate to be cut is cut off, so that each waste hollow part is separated from the alloy plate to be cut, and an alloy frame is obtained, wherein a plurality of groups of needle unit assemblies arranged and distributed in a rectangular array are arranged on the alloy frame, and each group of the needle unit assemblies includes a plurality of probe bodies arranged and distributed at equal intervals along the longitudinal direction, and the probe bodies are in a cross shape arranged horizontally, and the left and right ends of the cross-shaped probe body are connected to the alloy frame through a connecting edge; (4) Pour hot water at a temperature of 70-80°C onto the cutting platform of the five-axis laser cutting machine, so that the alloy frame and the hollow parts of the waste materials bonded to the cutting platform are separated from the cutting platform; (5) Clean up the hollowed-out parts of the waste materials, then remove the alloy frame, and bond the alloy frame to the substrate by gluing, where the area of ​​the substrate is larger than the outer area of ​​the alloy frame; (6) The bottom of the substrate is then horizontally bonded to the cutting platform of the five-axis laser cutting machine using hot melt adhesive so that the alloy frame is located above the substrate; (7) A five-axis laser cutting machine is used to cut the connecting edges between the left and right ends of each cross-shaped probe body on the alloy frame and the alloy frame, so that each cross-shaped probe body is separated from the alloy frame; (8) Pour hot water with a temperature of 70-80°C onto the cutting platform of the five-axis laser cutting machine to separate the substrate bonded to the cutting platform from the cutting platform. Then, use tweezers to clamp the alloy frame and lift it upward to separate it from the substrate. Multiple probe bodies are retained on the substrate.

2. The method for preparing a MEMS probe for rapid formation according to claim 1, characterized in that: The thickness of the alloy plate to be cut is 40-50 microns.

3. A method for preparing a MEMS probe for rapid formation according to claim 1 or 2, characterized in that: The five-axis laser cutting machine is a femtosecond high-precision laser cutting machine.

4. A method for preparing a MEMS probe for rapid formation according to claim 1 or 2, characterized in that: The alloy plate and the base plate are both rectangular.

5. A method for preparing a MEMS probe for rapid formation according to claim 1 or 2, characterized in that: In the step (3), each probe body of the cut alloy frame is provided with a waste hollow groove on both the front and rear sides in the longitudinal direction, the waste hollow groove has the same shape and area as the waste hollow part cut off from the alloy plate, the waste hollow groove is equal to the length of the cross-shaped probe body, the left and right sides of each waste hollow groove are respectively flush with the left and right sides of the corresponding cross-shaped probe body, each waste hollow groove has a notch on one side close to the cross-shaped probe body corresponding to the cross-shaped probe body, and the cross-shaped probe body is provided with two left-right symmetrical insertion parts, which are respectively fitted into the notches of two adjacent waste hollow grooves.

6. The method for preparing a MEMS probe for rapid formation according to claim 5, characterized in that: The probe body on the alloy frame and the waste hollow grooves on the front and rear sides of the probe body form a probe structure, and the needle unit assembly is composed of a plurality of probe structures arranged at equal intervals in the longitudinal direction.

7. A method for preparing a rapidly formed MEMS probe according to claim 1 or 2, characterized in that: The five-axis laser cutting machine has a pulse width of 500-800fs, a laser frequency of 800kHz, a laser power of 0.8-1.2W, and a cutting speed of 100mm / s.

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