Method for fabricating a probe card - Patents.com

Abstract

Disclosed herein is a method for fabricating a probe card, the method including the steps of preparing a carrier board, a surface of the carrier board having at least one probe guide portion, and generating a probe by performing additive manufacturing with a conductive material directly on the at least one probe guide portion to generate a probe on the probe guide portion, the additive manufacturing including depositing a conductive material directly on the probe guide portion.

Description

[Technical field]

[0001] The present invention provides methods for fabricating probe cards, probe cards obtained by such methods, and uses of the fabricated probe cards. [Background technology]

[0002] Probe card is an important component and interface used for semiconductor wafer or IC chip being tested by the test system, and the main function of the probe card includes achieving circuit continuity and space size matching.

[0003] Please refer to Fig. 1, which is a schematic structural diagram of a conventional probe card. The probe card usually includes a carrier board 90 and a probe assembly 91 (also called a probe head) mounted on the front end of the carrier board 90. The probe assembly 91 is formed by passing a plurality of probes 93 through two parallel guide plates 92. One end of the probe 93 is a connection end 931, and the other end is a testing end 932.

[0004] The carrier board 90 is provided on one side with a number of probe connection guides 94 for contacting the connection ends 931 of the above-mentioned number of probes 93. Since the arrangement of the number of probes 93 is usually very dense, the carrier board 90 is provided with a suitable space transformer. A distribution circuit 95 is used to expand the circuit configuration space so that the space-matching circuit 95 can be connected to a circuit board 96. Some manufacturers also consider the circuit board 96 to be part of the probe card or consider the circuit board 96 to be part of the test system.

[0005] Since the conventional probe 93 is manufactured by a conventional processing method, there may be dimensional errors during manufacturing, and there may be height differences between the multiple semiconductor terminals 971 of the semiconductor device 97 to be inspected. Therefore, the probe 93 is usually designed to include a curved section 933 for generating appropriate elasticity. When the inspection end 932 of the probe 93 touches the semiconductor terminals 971 of the semiconductor device to be inspected 97, an appropriate elastic deformation is generated in the curved section 933 so that the multiple probes 93 and the multiple semiconductor terminals 971 all come into contact with each other when the multiple probes 93 and the multiple semiconductor terminals 971 come into contact with each other, regardless of the difference in length of the probe 93 and the difference in height of the semiconductor terminals 971.

[0006] However, the conventional multiple probes 93 must be accurately placed and positioned, and the distance between the probes 93 must be maintained, so that the probe card 93 can perform normal operation for accurate detection. The conventional method of simultaneously positioning the multiple probes 93 is by penetrating the multiple probes 93 through two parallel guide plates 92, as described above. The assembly is relatively labor-intensive and time-consuming, and is prone to assembly problems, and misalignment often occurs. Errors occurring during the manufacture of the probes 93 can seriously affect the accuracy of the measurement. Secondly, since the probes 93 are raised, there may be a problem of poor contact between the probes 93 and the probe guide portion 94. In response to miniaturization in the semiconductor industry, the probe card needs to have a fine pitch. As an example, micro LEDs require a very small pitch, for example about 20 μm. The assembly between the needles 93 and the needle guide plate 92 is more difficult, and it is also difficult to maintain the assembly quality. All the above reasons may cause problems of poor contact, poor impedance matching of the probe card, and increased manufacturing costs of the probe card. Summary of the Invention

[0007] The main objective of the present invention is to provide a method for fabricating a probe card in a first aspect, which can be applied to fabricating a probe card, where the probe card not only eliminates the traditional needle guide plate setting, but also provides good electrical contact. To achieve the above objective, the method for fabricating a probe card according to the present invention includes the steps of preparing a carrier board or substrate, where a surface of the carrier board or substrate has at least one probe guide portion, and producing a probe by performing additive manufacturing with a conductive material directly on the at least one probe guide portion to produce a probe on the probe guide portion, where the additive manufacturing includes directly laminating a conductive material on the probe guide portion.

[0008] The direct additive manufacturing of the probe onto the probe guide portion eliminates the need for tedious assembly steps such as probe mounting onto the probe guide portion, alignment steps, etc. Furthermore, additive manufacturing of the probe allows employing different materials for different sections of the probe and also allows varying the dimensions of the probe, e.g., the probe diameter, which presents the advantage of creating specific behavior, in particular mechanical and / or electrical behavior, in defined probe sections.

[0009] The carrier board or substrate may be implemented in the form of a wafer or other material, in addition to a printed circuit board (PCB), such as a multi-layer organic carrier (MLO) and a multi-layer ceramic carrier (MLC), a glass carrier (GLASS), or a silicon interposer (Silicon interposer).

[0010] The probe guide portion 11 is configured to provide an electrical connection of the probe to a respective electrical connection of the carrier board. Typically, each probe and each probe guide portion is associated with an electrical connection of the carrier board. Thus, the probe guide portion may be considered as a connection portion of the probe. In some embodiments, the probe guide portion may have a plate-like shape, particularly with a rounded contour. The probe guide portion may be made of an electrically conductive material, such as copper, silver, gold-palladium, or other suitable conductive material.

[0011] In some embodiments, the conductive material used for additive manufacturing of the probe may be copper, nickel, or a nickel alloy.

[0012] In some embodiments, the additive manufacturing is micro-electroforming printing.

[0013] In some embodiments, the probe comprises a needle body and a needle tip, and generating the probe by additive manufacturing includes generating a needle body in the probe guide portion by lamination, where the needle body includes at least one section that is not perpendicular, e.g. does not extend perpendicular, to the carrier board or substrate, and generating a needle tip in the needle body by additive manufacturing.

[0014] In some embodiments, the needle body and the needle tip are constructed from conductive materials having different hardnesses, preferably the hardness of the needle tip being greater than the hardness of the needle body.

[0015] In some embodiments, the probe manufacturing method further comprises a step of electroplating to form a surface layer, in particular for forming a layer stack on the probe, in particular on the needle body, the step of electroplating being carried out in particular on the surface of the probe, i.e. the growing probe, to form a surface layer on the surface of the probe. The surface layer may be different from the conductive material. For example, the surface layer may in some embodiments comprise or consist of gold, platinum, palladium, rhodium, graphene, beryllium, nickel, or may be made of other suitable conductors and other materials.

[0016] Additionally or alternatively, the probe manufacturing method in some embodiments further comprises one or more deposition techniques of evaporation, sputtering, atomic layer deposition, or any other physical or chemical deposition technique, in particular for forming a surface layer or layer stack on the probe, in particular the needle body. The formed surface layer may in some embodiments be an additional surface layer, i.e. another surface layer, as a surface layer produced by an electroplating step.

[0017] The layers may include or consist of gold, platinum, palladium, rhodium, graphene, beryllium, nickel, or may be made of other suitable conductors and other materials. Such layers are beneficial with respect to the mechanical performance, electrical conductivity, and electrical contact capabilities of the probe.

[0018] In some embodiments, the needle tip and the needle body are made of different materials. Alternatively, the needle tip and the needle body are made of the same material.

[0019] In some embodiments, the needle body and optionally the needle tip comprise a helical structure. The helical structure may comprise, for example, one or more coils. In some embodiments, the helical structure may be a spring. Typically, the helical structure extends from the carrier board and / or the probe guide portion.

[0020] In some embodiments, the needle body of each probe has multiple legs, preferably at least three legs, more preferably three legs. Such embodiments are beneficial because the multiple legs provide self-centering of the respective probe, particularly the needle tip, thus increasing accuracy. It is understood that the legs typically directly contact the probe guide portion and extend perpendicularly from the probe guide portion toward the needle tip.

[0021] In some embodiments, at least one section of the needle body that is not disposed perpendicular to the carrier board has elasticity, e.g., exhibits elastic behavior, and thus the probe is elastic, which allows for compensating for height differences between different probes and between the probe and the target contact pad.

[0022] In some embodiments, lamination of conductive material directly on the probe guide portion is repeated multiple times in different locations on the probe guide portion or multiple different probe guide portions of the carrier board to generate multiple probes. Such embodiments allow for the generation of multiple probes on the carrier board. Typically, one probe guide portion is connected to a single probe. Thus, for a carrier board, the number of probe guide portions may be equal to the number of probes.

[0023] In some embodiments, the distance between two directly adjacent probes, in particular between the respective needle tips of two directly adjacent probes, is between 10 μm and 1000 μm, preferably between 10 μm and 60 μm.

[0024] In some embodiments, the generated probe is coated with a coating material that is different from the conductive material that the probe is generated from. The coating material may have, for example, a different conductivity, a different hardness, and / or other different material properties as the conductive material.

[0025] In a second aspect, a probe card is provided, preferably manufactured by a method according to any of the embodiments described herein. The probe card comprises a carrier board having at least one probe guide portion and a probe made of a conductive material, the probe and the probe guide portion being directly materially bonded to each other. It is understood that the probe guide portion and the probe that are directly materially bonded to each other are directly bonded to each other, i.e., without additional adhesive. The connection is typically achieved only by material bonding.

[0026] In some embodiments, the probe comprises a needle body and a needle tip, the needle body including at least one section that is not disposed perpendicular to the carrier board.

[0027] In some embodiments, at least one section of the needle body that is not disposed perpendicular to the carrier board is resilient.

[0028] In some embodiments, the needle body and optionally the needle tip comprise a helical structure.

[0029] In some embodiments, the needle body includes multiple legs, preferably at least three legs, more preferably three legs.

[0030] In some embodiments, the carrier board comprises a plurality of probe guide portions and a plurality of probes, each of the plurality of probes being materially coupled, in particular glued, directly to one of the probe guide portions. Typically, each probe guide portion may be materially coupled, in particular glued, to only a single probe.

[0031] In some embodiments, the distance between two directly adjacent probes, in particular between the respective needle tips of two directly adjacent probes, is between 10 μm and 1000 μm, preferably between 10 μm and 60 μm.

[0032] In some embodiments, the probe comprises a coating of a coating material different from the conductive material.

[0033] A third aspect of the invention includes the use of a probe card according to any of the embodiments described herein for swing testing, in particular for semiconductor swing testing.

[0034] Compared with the prior art, the present invention uses three-dimensional printing to directly generate the probe by laminating on the probe guide part, which can eliminate the setting of the traditional needle guide plate and provide good detection results at the same time. In addition, the probe and the probe conducting part can produce good and stable electrical connection effect. Then, by three-dimensional printing, it is easy to directly build probes of various lengths, pitches, sizes, or shapes on the same carrier board / substrate, so that there are two or more probes on the same probe card to achieve various semiconductor device pads / bumps with best performance and better detection results. In addition, the technology of 3D printing or additive manufacturing can reach a thickness of less than 1000 μm each time, even 0.2 μm. Therefore, when the probe is directly layered by 3D printing, it will have high accuracy with minimized advantage of variation. In addition, in response to the problem of impedance mismatch in semiconductor high-speed inspection, the embodiment of the present invention can provide the probe with a controlled shorter distance, and a more stable structure than the prior art to improve the impedance. The improvement according to the present invention can be applied to various semiconductor industries that require high-speed inspection. [Brief description of the drawings]

[0035] [Figure 1] 1 is a schematic diagram of a structure of a conventional probe card. [Diagram 2] 1A-1D are schematic diagrams of a probe manufacturing method according to a first embodiment of the present invention; [Diagram 3] FIG. 2 is a schematic diagram of the steps for constructing a probe in a first embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of a probe according to a first embodiment of the present invention. [Diagram 5] 1 is a schematic diagram of a probe array according to a first embodiment of the present invention; [Figure 6] FIG. 1 is a schematic diagram of a first embodiment of the present invention applied to a probe card. [Figure 7] FIG. 1 is a schematic diagram (1) of a probe shape change according to a first embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram showing a change in probe shape in the first embodiment of the present invention (2). [Figure 9] FIG. 4 is a schematic diagram of the steps for constructing a probe in a second embodiment of the invention. [Figure 10] FIG. 4 is a side view of a probe according to a second embodiment of the present invention. [Figure 11] FIG. 4 is a perspective view of a probe according to a second embodiment of the present invention. [Figure 12] FIG. 1 is a schematic diagram (1) showing a change in probe shape in the second embodiment of the present invention. [Figure 13] FIG. 13 is a schematic diagram (2) showing a change in probe shape in the second embodiment of the present invention. [Figure 14] FIG. 11 is a schematic diagram of a multi-probe implementation of a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Referring to FIGS. 1 to 3, one embodiment of a method for manufacturing a probe includes: Step S1: Prepare a carrier board or substrate 10, the surface of the carrier board or substrate 10 having at least one probe guide portion 11; Step S2: generating a probe by performing additive manufacturing with a conductive material directly on at least one probe guide portion to generate a probe on the probe guide portion, the additive manufacturing including depositing a conductive material directly on the probe guide portion; and Step S3: A step of applying electroplating to generate a surface layer 30, i.e., a conductive surface layer, includes a step in which the applying electroplating is performed on the surface of the probe 20, so that the surface layer 30 is formed on the surface of the probe 20.

[0037] Step S2 illustrates one embodiment as follows, where generating a probe by additive manufacturing includes: Step S21: Producing a needle body 21a in the probe guide part by lamination, the needle body including at least one section 21a that is not arranged perpendicular to the carrier board; Step S22: generating the needle tip 22 on the needle body 21 by additive manufacturing.

[0038] As shown in FIG. 4, the main function of the carrier board or substrate 10 is to connect the electrical path and convert the space transformer by the adapter circuit, so that the probe 20 can be indirectly connected to the inspection system. The carrier board or substrate 10 can be implemented in the form of a wafer or other material in addition to a printed circuit board (PCB), such as a multi-layer organic carrier (MLO) and a multi-layer ceramic carrier (MLC), a glass carrier (GLASS), or a silicon interposer (Silicon interposer). The probe 20 is provided to generate the required probe guide portion 11, and the probe 20 can generally be indirectly connected to the inspection system through an internal conversion adapter circuit. Since the probe 20 is a direct three-dimensional printing layer generated on the probe guide portion 11, there will be sufficient contact with the probe guide portion 11, and there will be no problem of poor contact or insufficient contact area. The three-dimensional printing can build the probe 20 layer by layer by micro-electroforming printing.

[0039] Since the technology of 3D printing can reach a thickness of 1000 μm or less, even 0.2 um, when the probe 20 is directly produced by 3D printing, it has the advantages of high precision and low variation. In addition, in response to the problem of impedance mismatch in semiconductor high-speed inspection, the embodiment of the present invention can provide a probe 20 with a controlled shorter distance and a more stable structure than the prior art. The improvement of the present invention is applicable to various semiconductor industries requiring high-speed inspection.

[0040] In implementation, the needle body 21 and the needle tip 22 can be three-dimensionally printed with conductive materials having different hardness, so that, for example, the hardness of the needle tip 22 is higher than that of the needle body. The aim is to provide a more elastic needle body 21. The elastic force provides the needle tip 22 with better wear resistance and deformation resistance. Then, the above-mentioned step S3 is used for the step of electroplating to form a material of the surface layer 30 that is better than the conductive material used in step S2 to construct the probe 20. For example, the probe 2 can be made of copper, nickel, or nickel alloy, and the difference between the needle body 21 and the tip 22 can be adjusted by the nickel content or mixed type of nickel alloy or a completely different material, and the surface layer 30 can be gold, platinum, palladium, rhodium, graphene, or can be made of other good conductors and other materials. (The surface layer 30 is disposed on the surface of the probe 20. In the following description, labeling of the surface layer 30 is omitted to avoid confusion over the reference numbers of the various components).

[0041] In the following, refer to FIG. 5 and FIG. 6. 3D printing has the advantages of high precision and direct molding, so it is very suitable for miniaturization, high density, and multiple repeated build-up processing. It easily completes the generation of multiple probes 20, and directly arranges the multiple probes 20 in a required array form to correspond to the semiconductor terminals 41 of the semiconductor device 40 to be tested. Since the multiple probes 20 are directly arranged on the probe guide portion 11 of the carrier board 10, an additional step of attaching the probes 20 to the carrier board 10 is not required, thereby providing a more efficient manufacturing process and reducing manufacturing costs.

[0042] The probe 20 shown in Fig. 7 has a different shape than the probe shown in Fig. 4. A needle body 21 is placed in the probe guide part 11 by additive manufacturing, and the bottom end of the needle body 21 has a base 21b. A resilient section 21a extends vertically and diagonally above the base 21b, and a tip 22 is printed on the resilient section 21a. The tip 22 is generated at the end of the resilient section 21a to generate a better connection area between the base 21b and the probe guide part 11.

[0043] Figure 8 shows another probe 20 made according to an embodiment of the method according to the invention. The probe 20 shown in Figure 8 has a different shape than the probe shown in Figure 4. The needle body 21 is produced by additive manufacturing on the probe guide part 11, and the elastic section 21a has a helical structure and covers essentially the whole of the needle body 21. The needle tip 22 is produced by additive manufacturing on the end of the needle body 21, in order to create a better elastic effect through the helical elastic section 21a.

[0044] 9 to 11 are schematic diagrams of steps of constructing a probe according to another embodiment of the present invention. This embodiment also includes steps S1, S2, and S3. However, this embodiment differs in that the steps of generating the probe layer by layer include: Step S23: Producing a plurality of needle bodies 21 by direct additive manufacturing on the probe guide portion 11, each needle body 21 of the plurality of needle bodies 21 having at least one elastic section 21a that is not perpendicular to the carrier board 10; and 2 in that it includes the step of: step 24: generating needle tips 22 on a plurality of needle bodies 21 by additive manufacturing to generate corresponding needle tips 22.

[0045] A plurality of needle bodies are generated so that the S-shaped elastic section 21a of the needle body 21 is provided. A plurality of joint areas can be formed between the probe guide parts 11, which can enhance the structural stress. In order to improve the overall conductive effect, the needle tip 22 is formed in a plurality of needle bodies 21, and thus the plurality of needle bodies 21 are fixed to the needle tip 22. When the needle tip 22 is subjected to a force, the pressure can be evenly distributed to the needle body 21, and each needle body 21 can bring about elastic deformation, which is accompanied by the retreat of the needle tip 22. This makes the probe 20 more robust and durable, and also has a good detection effect. The structure and function of such a probe 20 cannot be manufactured by conventional methods. This embodiment can further prove that the present invention directly uses the conductive material of the probe connection part 11 to produce a probe by three-dimensional printing layers. The technology of 20 can provide a probe 20 with more complex structural modifications and more delicate designs.

[0046] Fig. 12 shows a probe 20 manufactured according to the method shown in the second embodiment, and the probe 20 shown in Fig. 12 includes a needle body 21 including three legs. Section 21a further includes a helical structure and covers the entire needle body 21.

[0047] The probe 20 shown in Figure 13 has a needle body 21 similar to the probe shown in Figure 12, also with three legs. Section 21a has a helical structure and essentially covers the entire needle body 21. The main differences are in the length of the needle body 21 and the helical shape of the elastic section 21a. The position of the needle tip 22 at the end of the multiple needle bodies 21 is changed, which results in a different overall length of the probe 20 and a different inclination angle of the section 21a, which will greatly affect the elastic behavior of the needle.

[0048] FIG. 14 shows probes 20 of various lengths, spacing, sizes or shapes directly manufactured on the same carrier board 10. Compared with the general embodiment of FIG. 1 in which multiple probes 20 of a single length, single size or single shape are combined in an array, this embodiment can overcome the problems of the prior art that arise when the semiconductor terminals 41 on the surface of the semiconductor object 40 to be inspected are arranged at different heights or different pitches. The probe card according to the present invention can include probes 20 of various lengths, spacing, sizes or shapes directly on the same carrier 10 by additive manufacturing, so that there are two or more types on the same carrier 10. Additionally or alternatively, the height difference can be accommodated by providing elastic or resilient probes.

[0049] The above is merely an example for illustrating the preferred embodiment of the present invention, and is not intended to limit the scope of implementation. All simple substitutions and equivalent modifications are made according to the scope of the patent application of the present invention and the contents of the patent specification. All of them belong to the scope of the patent application of the present invention. [Explanation of symbols]

[0050] 10 Carrier Board 11 Probe guide part 20 Probe 21 Needle body 21a Needle Body Section 21b Base of needle body 22 Needle Tip 30 surface 90 Carrier Board 91 Probe Assembly 92 Guide plate 93 Probe 931 Connection end 932 Inspection side 933 Curved Section 94 Probe Connector 95 Spatial adaptation circuit 96 Circuit Board 97 Semiconductor device to be inspected 971 Semiconductor terminals

Claims

1. 1. A method for fabricating a probe card, comprising: providing a carrier board having at least one probe guide portion on a surface thereof; generating a probe by additive manufacturing the at least one probe guide portion, the additive manufacturing comprising depositing a conductive material directly onto the probe guide portion; electroplating a surface of the probe to create a surface layer on the surface of the probe; A method comprising:

2. The method of claim 1 , wherein the additive manufacturing is micro-electroforming printing.

3. the probe comprises a needle body and a needle tip, and the step of producing the probe by additive manufacturing comprises: a) creating the needle body on the probe guide portion by lamination, such that the needle body includes at least one section that is not oriented perpendicular to the carrier board; b. generating the needle tip on the needle body by additive manufacturing; 3. The method of claim 1 or 2, comprising:

4. The method of claim 3 , wherein the needle body and the needle tip are made of conductive materials with different hardnesses.

5. The method described in claim 4, wherein the hardness of the needle tip is higher than the hardness of the needle body.

6. The method of any one of claims 3 to 5, further comprising forming an additional surface layer or layer stack by evaporation, sputtering and / or atomic layer deposition.

7. The method of any one of claims 3 to 6, wherein the needle body comprises a helical structure.

8. The method of any one of claims 3 to 7, wherein the needle body comprises multiple legs.

9. The method according to any one of claims 3 to 8, wherein the at least one section that is not arranged perpendicular to the carrier board is elastic.

10. A method according to any one of claims 1 to 9, wherein the direct lamination of the conductive material onto the probe guide portion is repeated multiple times at different locations on the probe guide portion or on multiple different probe guide portions of the carrier board to generate multiple probes.

11. The method of claim 10, wherein the distance between two directly adjacent probes is between 10 μm and 1000 μm.

12. A probe card comprising: a carrier board (10) having at least one probe guide portion (11); and a probe (20) including a conductive material laminated directly on the probe guide portion, wherein the probe (20) and the probe guide portion (11) are directly material-bonded to each other, and the probe has an electroplated surface layer on the surface of the probe.

13. The probe card of claim 12, wherein the probe (20) comprises a needle body (21) and a needle tip (22), and the needle body (21) includes at least one section (21a) that is not positioned perpendicular to the carrier board (10).

14. The probe card of claim 13, wherein the at least one section (21a) of the needle body that is not disposed perpendicular to the carrier board is elastic.

15. The probe card of claim 13 or 14, wherein the needle body (21) comprises a spiral structure.

16. The probe card of any one of claims 13 to 15, wherein the needle body (21) comprises a plurality of legs.

17. A probe card as described in any one of claims 12 to 16, wherein the carrier board (10) comprises a plurality of probe guide portions (11) and a plurality of probes (20), each of the plurality of probes (20) being material-bonded directly to one of the probe guide portions (11).

18. The probe card of claim 17, wherein the distance between two directly adjacent probes (20) is between 10 μm and 1000 μm.

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