A method for rapidly forming a MEMS probe

Abstract

The present invention discloses a method for rapidly forming a MEMS probe in the field of semiconductor probe processing, comprising the following steps: selecting an alloy plate to be cut, cutting the alloy plate with a five-axis laser cutting machine, removing the waste hollowed-out portions of the alloy plate to obtain an alloy frame, removing the alloy frame, and bonding the alloy frame to a substrate by gluing. The five-axis laser cutting machine then cuts the left and right ends of each cross-shaped probe body on the alloy frame at the edges connecting the alloy frame to the alloy frame, separating the alloy frame from the substrate, leaving multiple probe bodies on the substrate. The present invention improves the efficiency of probe product production and increases the number of probes produced.

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, and the requirements for the number, quality, and accuracy of the probes also increase accordingly.

[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 detection, positioning, and identification of the object to be measured.

[0004] There are two common methods for preparing MEMS probes at present: (1) mold casting method, in which photoresist is applied to a single crystal silicon substrate. After exposure, plasma gas is used to etch several groups of probe-shaped cavities on the single crystal silicon substrate and a seed layer is deposited; 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;

[0005] (2) Deposition method: deposit a metal seed layer on the surface of the substrate; apply glue evenly on the metal seed layer to obtain a glue layer, expose the dried glue layer with a laser light source, and dissolve the corresponding glue layer with a developer, thereby photoetching multiple vertical probe patterns in the glue layer; wet the glue layer through high-frequency vibration under vacuum conditions, and electroplate the wetted glue layer multiple times to deposit the plating liquid to form probes.

[0006] Regarding the above two methods, the present invention addresses the problems of complex MEMS probe preparation process, long time consumption, low precision, etc., and has achieved a new method for quickly preparing MEMS probes after multiple tests and improvements. This method has the advantages of simple process, short time consumption, high output, good stability, etc., and effectively improves the preparation efficiency of MEMS probes. Summary of the Invention

[0007] The purpose of the present invention is to provide a preparation method for quickly forming MEMS probes. 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 steps of casting and deposition, thereby improving the efficiency of probe product preparation and increasing the output of probes.

[0008] The object of the present invention is achieved as follows: A method for rapidly forming a MEMS probe comprises the following steps:

[0009] (1) Select the 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;

[0010] (2) The alloy plate to be cut is fixed on the cutting platform of the five-axis laser cutting machine by hot melt adhesive;

[0011] (3) A five-axis laser cutting machine is used to cut the alloy plate to be cut, and each waste hollow portion of the alloy plate to be cut is cut off, so that each waste hollow portion is separated from the alloy plate to be cut, and an alloy frame is obtained. The alloy frame is provided with a plurality of groups of needle unit assemblies arranged in a rectangular array, and each group of the needle unit assemblies includes a plurality of probe bodies arranged 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;

[0012] (4) Pour hot water with a temperature of 70-80°C onto the cutting platform of the five-axis laser cutting machine to separate the alloy frame and the hollow parts of the waste materials bonded to the cutting platform from the cutting platform;

[0013] (5) Clean up the hollowed-out parts of the waste materials, then remove the alloy frame and glue the alloy frame to the substrate by gluing. The area of the substrate is larger than the outer area of the alloy frame.

[0014] (6) Then, the bottom of the substrate is 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;

[0015] (7) A five-axis laser cutting machine cuts the left and right ends of each cross-shaped probe body on the alloy frame and the connection edge of the alloy frame, so that each cross-shaped probe body is separated from the alloy frame;

[0016] (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 remain on the substrate.

[0017] The present invention formulates alloy materials of corresponding proportions according to the material used for the probe, and customizes the alloy thickness 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, a MEMS probe cutting route map is drawn using CAD drawing software, 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 removed and transferred to the next process. Compared with the existing technology, the beneficial effects of the present invention are: the probe is prepared by laser cutting and molding, which improves the preparation efficiency and output, is simple to operate, and shortens the preparation time; avoids the phenomenon of insufficient production capacity due to the cumbersome and time-consuming processing methods of casting and deposition, improves the efficiency of probe product preparation, and increases the number of probes produced.

[0018] As a further improvement of the present invention, the thickness of the alloy plate to be cut is 40-50 microns.

[0019] As a further improvement of the present invention, the five-axis laser cutting machine is a femtosecond high-precision laser cutting machine.

[0020] As a further improvement of the present invention, the alloy plate and the substrate are both rectangular.

[0021] As a further improvement of the present invention, in 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 is the same in shape and area as the waste hollow portion cut off from the alloy plate. The waste hollow groove is equal in length to 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 close to the side of the cross-shaped probe body is provided with a notch corresponding to the cross-shaped probe body. The cross-shaped probe body is provided with two left-right symmetrical insertion parts, and the two insertion parts are respectively fitted into the notches of two adjacent waste hollow grooves. The waste hollow portion on the alloy plate is cut off by laser, so that multiple 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.

[0022] 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 multiple probe structures arranged at equal intervals along the longitudinal direction.

[0023] 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

[0024] Figure 1 Schematic diagram of the distribution of needle unit components on the alloy frame of the present invention.

[0025] Figure 2 for Figure 1 Magnified view of part A.

[0026] Figure 3 for Figure 1 Enlarged view of part B.

[0027] Figure 4 This is the main view of the alloy frame bonded to the substrate.

[0028] Figure 5 This is a structural diagram of a five-axis laser cutting machine.

[0029] 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 base plate, 5 is a notch, 6 is a waste hollow groove, and 7 is a laser head. DETAILED DESCRIPTION

[0030] like Figure 1-5 FIG. 1 is a method for rapidly forming a MEMS probe, comprising the following steps:

[0031] (1) Select the 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;

[0032] (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;

[0033] (3) The five-axis laser cutting machine 1 cuts the alloy plate to be cut, cuts off the waste hollow parts 201b of the alloy plate to be cut, and separates the waste hollow parts 201b from the alloy plate to be cut, thereby obtaining an alloy frame 2. The alloy frame 2 is provided with a plurality of needle unit assemblies 201 arranged in a rectangular array, and each group of the needle unit assemblies 201 includes a plurality of probe bodies 201a arranged at equal intervals along 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;

[0034] 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. Each of the waste hollow grooves 6 close to the cross-shaped probe body 201a has a notch 5 corresponding to the cross-shaped probe body 201a. Two left-right symmetrical insertion parts 201a1 are provided on the cross-shaped probe body 201a, and the two insertion parts 201a1 are respectively embedded in the notches 5 of two adjacent waste hollow grooves 6. The waste hollow portion 201b on the alloy plate is laser cut off, forming multiple waste hollow grooves 6 on the alloy frame 2. The left and right connecting edges 3 of the cross-shaped probe body 201a are then laser cut off 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 back sides of the probe body 201a form a probe structure. The needle unit assembly 201 is composed of multiple probe structures arranged at equal intervals along the longitudinal direction.

[0035] (4) 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 alloy frame 2 and the waste hollow parts 201b bonded to the cutting platform 1a are separated from the cutting platform 1a;

[0036] (5) Cleaning 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. 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;

[0037] (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;

[0038] (7) The five-axis laser cutting machine 1 cuts the left and right ends of each cross-shaped probe body 201a on the alloy frame 2 and the connecting edge 3 of the alloy frame 2, so that each cross-shaped probe body 201a is separated from the alloy frame 2;

[0039] (8) Hot water at a temperature of 70-80°C was poured onto the cutting platform 1a of the five-axis laser cutting machine 1 to separate the substrate 4 bonded to the cutting platform 1a. Then, the alloy frame 2 was grasped with tweezers and lifted upward to separate it from the substrate 4. A plurality of probe bodies 201a remained on the substrate 4. The adhesive strength between the substrate and the alloy frame was weak, and the two could be separated manually.

[0040] The five-axis laser cutting machine 1 is a femtosecond high-precision laser cutting machine.

[0041] 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.

[0042] The present invention formulates alloy materials of corresponding proportions according to the material used for the probe, and customizes the alloy thickness 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, a MEMS probe cutting route map is drawn using CAD drawing software, 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 conditions must be checked; after completion, the cut MEMS probe raw material is removed and transferred to the next process. The advantages of the present invention are: the probe is prepared by laser cutting and molding, which improves preparation efficiency and output, is simple to operate, and shortens preparation time; avoids the phenomenon of insufficient production capacity due to the cumbersome and time-consuming processing methods of casting and deposition, improves the efficiency of probe product preparation, and increases the number of probes produced.

[0043] 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, the whole piece of MEMS probe pattern with typeset is imported, and it is aligned to the main plate so that the processing pattern corresponds to the position of the plate, and after confirming that it is neatly arranged 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 cutting times 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. If there is no abnormality, click to start processing; (5) after the processing is completed, the product is taken out and transferred to the next process.

[0044] Tests have shown that compared with traditional probe processing, the present invention has a 20% increase in probe manufacturing efficiency, a 40% increase in output, and a 10% increase in process quality. Furthermore, the process flow is simple and the process is stable.

[0045] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some of the technical features therein according to the disclosed technical content without creative labor, and these substitutions and modifications are all within the protection scope of the present invention.

Claims

1. A method for rapidly forming a MEMS probe, characterized in that The steps include: (1) Select the 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; (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) The five-axis laser cutting machine cuts the alloy plate to be cut, cuts off the waste hollow parts of the alloy plate to be cut, separates the waste hollow parts from the alloy plate to be cut, and obtains an alloy frame. The alloy frame is provided with a plurality of needle unit assemblies arranged in a rectangular array. Each group of the needle unit assemblies includes a plurality of probe bodies arranged at equal intervals along the longitudinal direction. The probe bodies are in a cross shape arranged horizontally. The left and right ends of the cross-shaped probe body are connected to the alloy frame through the connecting edge. Each probe body of the cut alloy frame is longitudinally A waste hollow groove is provided on both the front and rear sides, and the waste hollow groove has the same shape and area as the waste hollow part cut off on the alloy plate. The length of the waste hollow groove is equal to that of 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. A notch is provided on one side of each waste hollow groove close to the cross probe body corresponding to the cross probe body, and two left-right symmetrical insertion parts are provided on the cross probe body, and the two insertion parts are respectively fitted into the notches of two adjacent waste hollow grooves; (4) Pour hot water with a temperature of 70-80°C onto the cutting platform of the five-axis laser cutting machine to separate the alloy frame and the hollow parts of the waste materials bonded to the cutting platform from the cutting platform; (5) Clean up the hollowed-out parts of the waste materials, then remove the alloy frame and glue the alloy frame to the substrate by gluing. The area of the substrate is larger than the outer area of the alloy frame. (6) Then, the bottom of the substrate is 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 cuts the left and right ends of each cross-shaped probe body on the alloy frame and the connection edge of 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 remain on the substrate. The thickness of the alloy plate to be cut is 40-50 microns; the five-axis laser cutting machine is a femtosecond high-precision laser cutting machine; the probe body on the alloy frame and the waste hollow grooves on the front and rear sides of the probe body constitute a probe structure, and the needle unit assembly consists of a plurality of probe structures arranged at equal intervals along the longitudinal direction; 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.

2. The method for rapidly forming a MEMS probe according to claim 1, wherein: The alloy plate and the base plate are both rectangular.

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