Probe tablet and probe card

Abstract

The invention provides a probe tablet and a probe card. Wherein the probe pressing sheet is manufactured by the following steps: providing a jig which comprises a working surface with preset flatness; a demolding layer is arranged on the working surface, a fence is arranged on the peripheral edge of the working surface, and a space defined by the working surface and the fence is a molding space of the probe pressing sheet; resin with certain fluidity is injected into the forming space, so that the forming space is filled with the resin, and the resin is subjected to flattening treatment; and after the resin is cured, demolding to obtain the probe tablet. The adopted probe pressing sheet is formed by resin injection molding, the supporting sheet made of resin has the advantages of being convenient to form, convenient to cut and form and low in cost, and the supporting sheet not only has certain hardness, but also has certain toughness, so that installation and fixation of the supporting sheet in the probe card are facilitated. Meanwhile, the thickness of the injection-molded probe tablet can be adjusted by controlling the number of the unit layers, so that probe tablets with different thickness sizes can be conveniently obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor chip testing, and in particular to a probe pressing sheet and a probe card using the probe pressing sheet. Background Art

[0002] A semiconductor chip is an integrated circuit made of a piece of semiconductor material (such as silicon, gallium arsenide, germanium, etc.). Semiconductor chips can be widely used in various electronic devices, such as mobile phones, computers, televisions, automobiles, and industrial control equipment. The production of semiconductor chips requires wafer manufacturing, wafer testing, chip packaging, and post-packaging testing.

[0003] Among them, wafer testing is located after wafer manufacturing and before chip packaging. Specifically, wafer testing is a wafer acceptance test for processed wafers, the main purpose of which is to detect the electrical characteristics of each grain (or bare die, chip) on the wafer.

[0004] During the wafer test process, the probes on the probe card are in contact with the wafer to be tested. The probes are made of gold wires and are as thin as hair. The probes are arranged according to certain rules. These probes contact the pads on the die to test its electrical characteristics such as voltage, current, and function. Through this test, unqualified die can be identified and eliminated in the subsequent wafer cutting process, avoiding unnecessary packaging and subsequent process costs.

[0005] With the development of semiconductor chip technology, there are more and more types of wafers. In order to adapt to the detection of different types of wafers, there are more and more types of probe cards. For example, the probes on some probe cards are set in multiple rows. At this time, the needle marks produced by the multiple rows of probes when contacting the test wafer have different depths, and the needle marks with shallower contact will affect the transmission of the signal, thereby affecting the accuracy of wafer detection. Therefore, it is necessary to propose further solutions to the above problems. Summary of the invention

[0006] The present invention aims to provide a probe pressing sheet and a probe card using the probe pressing sheet, so as to overcome the deficiencies in the prior art.

[0007] In order to solve the above technical problems, the technical solution of the present invention is:

[0008] A probe pressing sheet is used in a probe card and is pressed on a corresponding row of pins according to a preset position; the probe pressing sheet is made by the following steps:

[0009] Providing a jig, the jig comprising a working surface with a preset flatness;

[0010] A demoulding layer is arranged on the working surface, and enclosures are arranged around the edges of the working surface, and the space defined by the working surface and the enclosures is the molding space of the probe pressing sheet;

[0011] Injecting a resin with a certain fluidity into the molding space so that the resin fills the molding space, and performing a flattening process on the resin;

[0012] After the resin is solidified, it is demoulded to obtain the probe pressed sheet.

[0013] As an improvement of the probe pressing sheet of the present invention, the jig has a plurality of the working surfaces; the plurality of working surfaces are arranged at intervals on the jig; and the sizes of the plurality of working surfaces are the same or different.

[0014] As an improvement of the probe pressing sheet of the present invention, the demoulding layer is a demoulding tape attached to the working surface.

[0015] As an improvement of the probe pressing sheet of the present invention, the demoulding tape comprises: a substrate layer, an adhesive surface located on one side of the substrate layer and a demoulding surface located on the other side of the substrate layer; the demoulding tape is bonded to the working surface via the adhesive surface.

[0016] As an improvement of the probe pressing sheet of the present invention, the enclosure is composed of at least one unit layer; and the thickness of the injection molded probe pressing sheet is adjusted by controlling the number of the unit layers.

[0017] As an improvement of the probe pressing sheet of the present invention, the resin is a high temperature resistant epoxy resin.

[0018] As an improvement of the probe pressing sheet of the present invention, after the resin is cured, demoulding the resin to obtain the probe pressing sheet comprises:

[0019] The jig and the resin thereon are placed in a high temperature environment. After the resin is solidified, the enclosure on at least one side edge of the working surface is removed, and the solidified probe pressing sheet is taken out from the molding space.

[0020] In order to solve the above technical problems, the technical solution of the present invention is:

[0021] A probe card, comprising: a PCB substrate, a probe card head and the probe pressing sheet as described above; the probe card head comprises: a supporting part, a fixing part and a plurality of rows of probes;

[0022] The support portion is arranged on the PCB board; the rows of probes are arranged in layers, the needle tips of each layer of probes are concentrated on the support portion through the fixing portion, and the needle tips of each layer of probes are respectively extended to different detection positions, and the needle tails of each layer of probes are respectively connected to the PCB board; the probe pressing sheets are arranged between the layers of probes to ensure that the lengths of the needle tips in each layer of probes remain consistent.

[0023] As an improvement of the probe card of the present invention, the support portion is a ceramic block or a metal block arranged on the PCB board.

[0024] As an improvement of the probe card of the present invention, the fixing portion is a resin that attaches the portion between the tip and the tail of the probe to the supporting portion.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention arranges probe pressing plates at appropriate positions between each layer of probes, and each probe pressing plate can press a row of probes below, so that the fixed position of the row of probes can be closer to the needle tip, thereby making the extended length of the needle tips in each layer of probes consistent. When the extended length of each probe is consistent, it is ensured that the needle marks produced when each layer of probes contacts the test wafer remain uniform, thereby avoiding affecting the accuracy of wafer detection.

[0027] In addition, in the probe card of the present invention, the probe pressing sheet used is injection molded by resin. The supporting sheet made of resin material has the advantages of convenient molding, easy cutting and molding, and low cost. It has both a certain hardness and a certain toughness, which is conducive to its installation and fixation in the probe card. At the same time, the thickness of the injection molded probe pressing sheet can be adjusted by controlling the number of the unit layers, so that probe pressing sheets of different thicknesses can be easily obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 is a three-dimensional schematic diagram of a probe card in one embodiment of the present invention;

[0030] Figure 2 for Figure 1 An enlarged schematic diagram of area E in the middle, where area E represents the area where each row of probe tips are located. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] An embodiment of the present disclosure provides a probe card that can be used to test the electrical characteristics of a wafer. During actual testing, the probe card is combined with a corresponding test device, and the test device controls the probe card to contact the die on the wafer to be tested to perform relevant test items.

[0033] like Figure 1 As shown, the probe card includes: a PCB substrate 100 , a probe card head 200 and a probe pressing sheet 300 .

[0034] The PCB substrate 100 has both mechanical properties and electrical properties. The mechanical properties are reflected in the fact that the PCB substrate 100 can realize the bearing and fixation of the probe card head 200 and the probe pressing sheet 300, etc., and ensure the stability of the installation of the probe card head 200 and the probe pressing sheet 300. At the same time, a circuit structure 101 is provided on the PCB substrate 100, and the circuit structure 101 is used to realize the electrical characteristics detection of the probe card.

[0035] The probe card 200 is mounted on the PCB substrate 100 , and includes a supporting portion 201 , a fixing portion 202 and a plurality of rows of probes 203 .

[0036] The main function of the support part 201 and the fixing part 202 is to assist the installation of the plurality of rows of probes 203. Specifically, the plurality of rows of probes 203 are first assembled into one with the support part 201 and the fixing part 202, and then assembled on the PCB substrate 100. In one embodiment, the support part 201 can be a ceramic block or a metal block, and the shape of the ceramic block or the metal block is adaptively designed according to the type of the probe 203 card and the application environment.

[0037] Several rows of probes 203 are combined on a ceramic block or a metal block through a fixing part 202. In one embodiment, considering that the wafer is under a high temperature environment during inspection, the fixing part 202 can be a high temperature resistant resin. At this time, the high temperature resistant resin adheres several rows of probes 203 to the surface of the ceramic block or the metal block.

[0038] The probe 203 is used to contact the die on the wafer with its needle tip to test its electrical characteristics such as voltage, current, function, etc. Through this test, unqualified die can be identified and eliminated in the subsequent wafer cutting process, avoiding unnecessary packaging and subsequent process costs.

[0039] During actual testing, the probes 203 are arranged in multiple rows as needed. At this time, the multiple rows of probes 203 are arranged in layers, and the needle tips of the multiple rows of probes 203 are concentrated on the support part 201 through the fixing part 202, and the needle tips of each layer of probes 203 are extended to different testing positions. With this arrangement, the probe 203 card can simultaneously test different areas on the wafer in one action. Here, the concept of "probe 203 needle tip extension length" should be clarified, which is the length of the needle tip from the fixed end. Therefore, the needle tips of each layer of probes 203 are extended to different testing positions, resulting in different extension lengths of the needle tips of each row of probes 203.

[0040] However, when the multi-row probes 203 arranged in layers above come into contact with corresponding areas on the wafer, the different extension lengths of the probes 203 in different rows will result in different force arms of the probes 203 in each row. Thus, the corresponding forces when in contact with the wafer are also inconsistent. As a result, the needle marks produced by the multi-row probes 203 when in contact with the test wafer are of different depths, and the needle marks with shallower contact will affect the transmission of the signal, thereby affecting the accuracy of wafer detection.

[0041] like Figure 2 As shown, taking the above problems into consideration, the probe pressing sheet 300 is arranged at the corresponding position between each layer of probes 203 and pressed on a row of probes 203 in the lower layer, so that the lengths L1 and L2 of the needle tips in each layer of probes 203 are kept consistent, that is, the length of the needle tip is kept consistent with the distance from the nearest fixed end.

[0042] The fixed end is formed by the probe pressing piece 300 pressing the probe 203, or the fixed end is formed by the above-mentioned fixing part 202 pressing the probe 203. By setting the probe pressing piece 300, the fixed end can be closer to the end of the needle tip, thereby preventing the needle tip from extending too long to achieve the effect of keeping the length of the needle tip in each layer of probes 203 consistent. In this way, the corresponding force when each row of probes 203 contacts the wafer can be kept consistent, thereby ensuring the accuracy of the signal transmitted between the wafer.

[0043] The needle tails of each layer of probe 203 are electrically connected to the PCB board respectively, and the connection method can be welding. In this way, the signal collected by the needle tip is transmitted to the PCB board during detection, and the PCB further realizes the detection of the wafer by running the detection circuit thereon. At this time, the probe 203 crosses the support part 201, and the fixing part 202 attaches the part between the needle tip and the needle tail of the probe 203 to the support part 201.

[0044] Since the probe pressing sheet 300 is located between each layer of probes 203, the thickness of the probe pressing sheet 300 is required to be at the micrometer level, and the probe pressing sheet 300 is also required to have a certain hardness and toughness, so as to facilitate its installation and fixation between each layer of probes 203. Therefore, how to manufacture the probe pressing sheet 300 that meets the above requirements is a difficult problem that needs to be solved.

[0045] In this embodiment, the above-mentioned probe pressing sheet 300 is manufactured by resin injection molding, and the resin probe pressing sheet 300 obtained thereby has the advantages of convenient molding, easy cutting and molding, and low cost, and takes into account a certain hardness and toughness. Among them, the convenience of cutting is of great significance for the application of the probe pressing sheet 300. Specifically, when the probe pressing sheet 300 is placed between the two layers of probes 203, the probe pressing sheet 300 needs to have a suitable size, and considering the diversity of the types of probe 203 cards, it is often necessary to cut the entire probe pressing sheet 300 according to the actual situation. Therefore, the probe pressing sheet 300 should not be easy to produce burrs or breakage when cutting. The resin-molded probe pressing sheet 300 can well meet the above requirements. In addition, considering that the wafer detection is carried out in a high temperature environment, the resin used for injection molding the probe pressing sheet 300 is a high temperature resistant epoxy resin.

[0046] In this example, the probe pressing sheet 300 is manufactured by the following steps:

[0047] S1. Provide a jig, wherein the jig comprises a working surface with a preset flatness.

[0048] The working surface is used as a plane for holding the resin during injection molding. In this embodiment, the jig can be made of an aluminum block. At this time, a boss that meets the preset flatness can be machined on one side of the aluminum jig as a working surface. In order to perform collaborative injection molding at multiple stations at the same time, the jig has multiple working surfaces. Multiple working surfaces are arranged at intervals on the jig; the sizes of the multiple working surfaces are the same or different.

[0049] S2. A demoulding layer is provided on the working surface, and enclosures are provided around the edges of the working surface. The space defined by the working surface and the enclosures is the molding space of the probe pressing sheet 300 .

[0050] Among them, the demoulding layer is to make the molded resin probe pressing sheet 300 better demoulding. In order to facilitate the setting of the demoulding layer, a demoulding tape can be used as the demoulding layer, one side of the demoulding tape is bonded to the working surface, and the other side is a non-sticky surface. The adhesion of the non-sticky surface is less than the adhesion of the working surface to play a demoulding role. In one embodiment, the demoulding tape can be a single-sided gray high temperature resistant tape, which includes: a substrate layer, an adhesive surface located on one side of the substrate layer, and a demoulding surface located on the other side of the substrate layer; the demoulding tape is bonded to the working surface through the adhesive surface thereon.

[0051] The enclosure is used to form the side wall of the molding space, and further limit the thickness of the injection molded probe sheet 300. In order to adjust the thickness of the injection molded probe sheet 300 to obtain a probe sheet 300 that meets actual needs, the enclosure is composed of at least one unit layer, and further the thickness of the injection molded probe sheet 300 can be adjusted by controlling the number of unit layers. In one embodiment, the enclosure can be made of high temperature resistant tape. At this time, the thickness of the enclosure is adjusted by providing a layer or superimposing multiple layers of high temperature resistant tape.

[0052] S3. Inject a resin with a certain fluidity into the molding space so that the resin fills the molding space, and then smooth the resin.

[0053] Among them, having a certain fluidity is conducive to the resin being evenly distributed in the injection space during injection molding. In order to obtain a resin with a certain fluidity, the resin can be preheated. Then, the preheated resin is sent to the glue injection machine, and the pressure gauge of the glue injection machine is adjusted to the working pressure, such as 30pa. Then the injection molding machine is controlled to inject the resin evenly along one side of the injection space. After the injection is completed, the resin in the injection space can be leveled by a vibration table under a vacuum environment. The vacuum environment is conducive to sucking away the bubbles in the resin or applying a certain pressure to make the resin fit more closely on the release layer.

[0054] S4, after the resin is solidified, demoulding it to obtain the probe pressed sheet 300.

[0055] The resin is solidified by placing the jig and the resin thereon in a high temperature environment. In one embodiment, the jig and the resin thereon can be placed in an oven at 150 degrees for 2 hours for solidification. After the resin is solidified, the enclosure on at least one side edge of the working surface is removed, and the solidified probe pressing sheet 300 is taken out from the molding space.

[0056] In summary, in this embodiment, probe pressing plates are arranged at appropriate positions between each layer of probes, and each probe pressing plate can press a row of probes below, so that the fixed position of the row of probes can be closer to the needle tip, so that the length of the needle tips in each layer of probes remains consistent. When the length of each probe is consistent, it is ensured that the needle marks produced when each layer of probes contacts the test wafer remain uniform, avoiding affecting the accuracy of wafer detection. In addition, in the probe card of this embodiment, the probe pressing plate used is injection molded by resin. The support plate made of resin material has the advantages of easy molding, easy cutting and molding, and low cost. It has both a certain hardness and a certain toughness, which is conducive to its installation and fixation in the probe card. At the same time, the thickness of the injection molded probe pressing plate can be adjusted by controlling the number of unit layers, so that probe pressing plates of different thicknesses can be easily obtained.

[0057] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0058] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A probe pressing sheet, characterized in that: The probe pressing sheet is used in the probe card and is pressed on the corresponding pin row according to the preset position; the probe pressing sheet is manufactured by the following steps: Providing a jig, the jig comprising a working surface with a preset flatness; A demoulding layer is arranged on the working surface, and enclosures are arranged around the edges of the working surface, and the space defined by the working surface and the enclosures is the molding space of the probe pressing sheet; Injecting a resin with a certain fluidity into the molding space so that the resin fills the molding space, and performing a flattening process on the resin; After the resin is solidified, it is demoulded to obtain the probe pressed sheet.

2. The probe pressing sheet according to claim 1, characterized in that: The jig has a plurality of working surfaces; the plurality of working surfaces are arranged at intervals on the jig; and the sizes of the plurality of working surfaces are the same or different.

3. The probe pressing sheet according to claim 1, characterized in that: The demoulding layer is a demoulding tape attached to the working surface.

4. The probe pressing sheet according to claim 3, characterized in that: The demoulding tape comprises: a substrate layer, an adhesive surface located on one side of the substrate layer, and a demoulding surface located on the other side of the substrate layer; the demoulding tape is bonded to the working surface via the adhesive surface.

5. The probe pressing sheet according to claim 1, characterized in that: The enclosure is composed of at least one unit layer; the thickness of the injection molded probe pressing sheet is adjusted by controlling the number of the unit layers.

6. The probe pressing sheet according to claim 1 or 5, characterized in that: The resin is a high temperature resistant epoxy resin.

7. The probe pressing sheet according to claim 1, characterized in that: After the resin is solidified, demoulding the resin to obtain the probe pressed sheet comprises: The jig and the resin thereon are placed in a high temperature environment. After the resin is solidified, the enclosure on at least one side edge of the working surface is removed, and the solidified probe pressing sheet is taken out from the molding space.

8. A probe card, characterized in that: The probe card comprises: a PCB substrate, a probe card head and a probe pressing sheet as claimed in any one of claims 1 to 7; the probe card head comprises: a supporting part, a fixing part and a plurality of rows of probes; The support portion is arranged on the PCB board; the rows of probes are arranged in layers, the needle tips of each layer of probes are concentrated on the support portion through the fixing portion, and the needle tips of each layer of probes are respectively extended to different detection positions, and the needle tails of each layer of probes are respectively connected to the PCB board; the probe pressing sheets are arranged between the layers of probes to ensure that the lengths of the needle tips in each layer of probes remain consistent.

9. The probe card according to claim 8, characterized in that: The support portion is a ceramic block or a metal block arranged on the PCB board.

10. The probe card according to claim 8, wherein: The fixing part is a resin that attaches the portion between the needle tip and the needle tail of the probe to the supporting part.

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