JP7640222B2 - Electrical property inspection tool - Google Patents

Description

This technology relates to testing jigs for the electrical characteristics of electronic components such as wafers, chips, and packages.

Currently, electrical characteristics evaluation of semiconductor devices at the wafer level is performed using a probe card, with the probe directly contacting the conductive pads and bumps formed on the front and back surfaces of the wafer (see, for example, Patent Document 1).

This method allows inspection before packaging or 3D mounting.

However, because probe testing involves scratching the surface to remove the oxide film from the pad surface of the wafer, there are cases where products that pass the test are subsequently mounted, resulting in failed products due to damage caused by the test. In addition, as pad sizes become smaller, the impact of scratches made during testing, which can cause defects during bump formation and mounting, becomes greater. In particular, in recent years, as semiconductor chips have become increasingly fine-pitched, scratches made during testing have become an increasingly big problem.

For bare chips and packages, handler tests using rubber connectors are conducted. As a rubber connector that serves as an inspection probe sheet, for example, an anisotropic conductive sheet has been proposed in which magnetically oriented conductive particles are arranged so as to penetrate the elastomer sheet in the thickness direction (see, for example, Patent Document 2).

The inspection probe sheet described in Patent Document 2 has difficulty in dealing with fine pitches because the conductive particles are linked in the in-plane direction when they are magnetically oriented in the rubber elastic elastomer resin. In addition, although a frame is attached to surround the periphery in order to improve durability, the elastomer resin inside the frame is a material that easily expands and contracts due to thermal expansion, which can lead to problems with reduced durability and inspection failures due to contact misalignment (misalignment). Misalignment during heat cycle testing is particularly fatal, and will be difficult to deal with in the future as finer pitches are developed.

In addition, rubber connectors, which generally have conductive material disposed in elastomer resin, are difficult to manufacture with fine pitch. For example, it is difficult to manufacture inspection connectors with a level of 200 μmP or less. For this reason, inspections are currently carried out on packages after assembly, which results in extremely poor yields and is also a factor in making it impossible to reduce prices.

As a method for solving these problems, Patent Document 3 describes that by using an inspection probe sheet 100 having a plurality of through electrodes 114 with recesses 112 on the first surface 111a of a flexible sheet 110 and protrusions 113 on the second surface 111b as shown in FIG. 4, and disposing a conductive elastomer 120 in the recesses 112, electrical characteristics can be inspected even when an oxide film is formed on pads or bumps formed at a fine pitch.

However, while the method described in Patent Document 3 makes it possible to inspect the electrodes formed in the fine pitch, the electrodes come into direct contact with the conductive elastomer portion, and as inspections are repeated, the conductive elastomer portion gradually deteriorates, causing the conductive particles and binder to fall off or break, and causing the resistance value to increase. Furthermore, while these inspections usually require a minimum of 10,000 repeated uses, the current situation with the method described in Patent Document 3 is that it only lasts less than 1,000 times.

JP 2009-042008 A JP 2006-024580 A JP 2018-141652 A

This technology solves the above-mentioned problems and provides an electrical characteristics inspection tool with excellent durability for testing the electrical characteristics of pads and bumps formed at fine pitch.

As a result of intensive research, the inventors of the present technology have found that by using an inspection tool including a flexible sheet in which a through electrode is half-formed in a through hole penetrating a first surface and a second surface, and a recess recessed into the first surface, and a conductive bump disposed in the recess and containing polyamide having a predetermined bending elastic modulus and a melting point of 160°C or more and 200°C or less , and conductive particles, the conductive particles being connected in the thickness direction of the flexible sheet, excellent durability can be obtained for inspection of the electrical properties of pads and bumps formed at a fine pitch.

In other words, the electrical characteristic inspection jig related to the present technology comprises a flexible sheet having a through electrode half-formed in a through hole penetrating a first surface and a second surface, the flexible sheet having a recess recessed in the first surface, and a conductive bump disposed in the recess, the conductive bump containing polyamide having a flexural modulus of elasticity of 1300 MPa or more and 1600 MPa or less and a melting point of 160°C or more and 200°C or less , and conductive particles, the conductive particles being connected in the thickness direction of the flexible sheet.

In addition, a manufacturing method for an inspection jig according to the present technology includes a step of forming a half-through electrode in a through hole of a flexible sheet having a through hole penetrating a first surface and a second surface so as to have a recessed portion recessed into the first surface, a filling step of filling the recess with a conductive binder containing polyamide particles having a flexural modulus of elasticity of 1,300 MPa or more and 1,600 MPa or less and a melting point of 160°C or more and 200°C or less and conductive particles, and a heating step of melting the polyamide particles and connecting the conductive particles in the thickness direction of the flexible sheet.

In addition, a method for inspecting electrical characteristics according to the present technology includes a bonding step of bonding an inspection probe sheet having a conductive bump connected in a thickness direction of the flexible sheet to an electrode surface of an object to be inspected, the conductive bump being connected to an electrode of the object to be inspected, the inspection probe sheet including a flexible sheet having a through electrode half-formed in a through hole penetrating a first surface and a second surface and a recess recessed in the first surface, the inspection probe sheet being disposed in the recess and including a polyamide having a flexural modulus of elasticity of 1300 MPa or more and 1600 MPa or less and a melting point of 160°C or more and 200°C or less, and conductive particles, the conductive particles being connected in the thickness direction of the flexible sheet, and the conductive bump being brought into contact with an electrode of the object to be inspected; and an inspection step of pressing a probe against the through electrode from the other surface of the inspection probe sheet to inspect electrical characteristics.

This technology provides excellent durability when testing the electrical properties of pads and bumps formed at fine pitch.

FIG. 1 is a cross-sectional view showing an example of an inspection probe sheet according to the present embodiment. FIG. 2 is a cross-sectional view showing an example of a flexible sheet having a plurality of through electrodes each having a recess. FIG. 3 is a cross-sectional view that illustrates a test process for testing electrical characteristics using the test probe sheet according to the present technology. FIG. 4 is a cross-sectional view showing an example of a conventional inspection probe sheet.

Hereinafter, embodiments of the present technology will be described in detail in the following order.
1. Electrical characteristic inspection jig 2. Manufacturing method of inspection jig 3. Electrical characteristic inspection method

<1. Electrical property inspection tool>
The electrical characteristic inspection jig according to the present technology is a so-called inspection probe sheet, which includes a flexible sheet having a through-hole penetrating a first surface and a second surface, a through-electrode half-formed in the through-hole and a recessed portion recessed into the first surface , and a conductive bump disposed in the recessed portion, the conductive bump containing a thermoplastic resin having a flexural modulus of 1300 MPa or more and 2600 MPa or less and conductive particles, the conductive particles being connected in the thickness direction of the flexible sheet.

If the flexural modulus is less than the lower limit, the durability of the conductive bump may not be sufficiently improved, and if the flexural modulus is greater than the upper limit, the conductive bump may crack when subjected to an impact. In this specification, the flexural modulus of thermoplastic resin refers to the flexural modulus measured in accordance with JIS K 7071.

The inspection probe sheet of this technology makes it possible to obtain excellent durability for testing the electrical characteristics of pads and bumps formed at a fine pitch by contacting the pads or bumps with the conductive bumps and contacting the wire probes with the through electrodes.

Fig. 1 is a cross-sectional view showing an example of an inspection probe sheet according to the present embodiment, and Fig. 2 is a cross-sectional view showing an example of a flexible sheet having a plurality of through electrodes having recesses. The inspection probe sheet 1 according to the present embodiment includes a flexible sheet 10 having a plurality of through electrodes 14 formed to have recesses 12 on a first surface 11a and protrusions 13 on a second surface 11b, and conductive bumps 20 arranged in the recesses 12 , containing thermoplastic resin having a bending modulus of elasticity of 1300 MPa or more and 2600 MPa or less, and conductive particles, and the conductive particles are connected in the thickness direction of the flexible sheet.

The flexible sheet 10 is preferably made of a material that is flexible and insulating, has a low coefficient of thermal expansion, and is highly heat resistant. Examples of materials for the flexible sheet 10 include polyimide, polyamide, polyethylene naphthalate, biaxially oriented polyethylene terephthalate, and liquid crystal polymer. These materials are preferred because they have better dimensional stability than elastic elastomers, are less likely to cause electrical continuity problems due to misalignment in thermal cycle tests, and are also highly durable. Of these, it is preferred to use polyimide, which has excellent heat resistance.

If the flexible sheet 10 is too thin, its durability will be poor, so the thickness is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. If the flexible sheet 11 is too thick, it will be difficult to form the through electrodes, so the thickness is preferably 500 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less.

The through electrodes 14 exist independently and are insulated from adjacent through electrodes, and may be formed in advance to match the positions of the pads or bumps of the object to be inspected, or may be formed at a predetermined interval.

The through electrodes 14 are formed in the thickness direction of the flexible sheet 10 and have recesses 12 recessed into the first surface 11a of the flexible sheet 10. The lower limit of the depth of the recesses 12 is preferably 20% or more of the thickness of the flexible sheet 10, more preferably 40% or more, and even more preferably 60% or more. The upper limit of the depth of the recesses 12 is preferably 90% or less of the thickness of the flexible sheet 10, more preferably 80% or less, and even more preferably 70% or less. This allows the thickness of the conductive bumps 20 to be increased, and therefore the amount of movement when the inspection probe sheet 1 is pressed down can be increased, allowing it to follow variations in the height of the pads and bumps.

The surface of the recess 12 of the through electrode 14 is preferably plated with Ni/Au plating, Ni/Pd plating, Ni/Pd/Au plating, or the like, and is covered with a metal plating film. This improves adhesion to the conductive bump 20 due to the anchor effect of the recess 12, thereby improving durability and improving conductivity with the conductive bump 20.

The through electrode 14 also has a protrusion 13 that protrudes from the second surface 11b of the flexible sheet 10. The lower limit of the height of the protrusion 13 is preferably 10% or more of the thickness of the flexible sheet 10, more preferably 20% or more, and even more preferably 30% or more. The upper limit of the height of the protrusion 13 is preferably 60% or less of the thickness of the flexible sheet 10, more preferably 50% or less, and even more preferably 40% or less. The surface of the protrusion 13 of the through electrode 14 is preferably plated with Ni/Au plating, Ni/Pd plating, Ni/Pd/Au plating, or the like, and is preferably covered with a metal plating film. This allows for excellent durability to be obtained against the tip of the wire probe and the pads and bumps of the test object.

The through electrode 14 is made of a conductive metal or alloy, and is preferably made of a metal or alloy such as copper or nickel. The through electrode 14 also preferably has a so-called "tapered shape" in which the diameter increases from the first surface 11a to the second surface 11b of the flexible sheet 10. This makes it possible to make the diameter of the tip of the wire probe larger than the size of the pad or bump of the test object.

The conductive bumps 20 protrude from the first surface 11a of the flexible sheet 10. If the protruding height of the conductive bumps 20 is too low, the amount of movement when the inspection probe sheet 1 is pressed down will be small, making it difficult to follow the variations in height of the pads and bumps. For this reason, the protruding height of the conductive bumps 20 is preferably 50% or more of the average particle diameter of the conductive particles, more preferably 100% or more, and even more preferably 150% or more. In addition, if the protruding height of the conductive bumps 20 is too high, the protruding portion will break, so it is preferably 400% or less of the average particle diameter of the conductive particles, more preferably 300% or more, and even more preferably 250% or less.

The conductive bump 20 is formed from a conductive binder containing a thermoplastic resin and conductive particles. The thermoplastic resin has a flexural modulus of elasticity of 1300 MPa or more and 2600 MPa or less, preferably 1300 MPa or more and 1600 MPa or less . The lower limit of the melting point of the thermoplastic resin is preferably 150°C or more, more preferably 160°C or more, and the upper limit of the melting point of the thermoplastic resin is preferably 220°C or less, more preferably 200°C or less. As a result, the thermoplastic resin softens at high temperatures and has excellent moldability, so that the conductive bump can be formed with a fine pitch. Examples of such thermoplastic resins include polyamide (polyamide 12, polyamide 66, polyamide 6, etc.), polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyester, PMMA, etc.

The total content of thermoplastic resin and conductive particles in the conductive bump 20 is preferably 85 wt% or more, more preferably 90 wt% or more, and even more preferably 95 wt% or more. This allows the conductive bump 20 to have the excellent durability of the thermoplastic resin.

The conductive particles are chained from the recessed portion 12 of the through electrode 14, with their ends exposed from the outermost surface of the thermoplastic resin, and the ends of the conductive bumps 20 are electrically connected to the protruding portions 13 of the through electrode 14.

The conductive particles may be any conductive material, and are preferably made of magnetic metal particles such as nickel, cobalt, or iron, or particles in which a magnetic metal is plated on a resin core or inorganic core particle. The conductive particles may be plated with Ni/Au plating, Ni/Pd plating, Ni/Pd/Au plating, or the like, and may be coated with a metal plating film. When the conductive particles contain a magnetic metal, applying a magnetic field when filling the recess 12 of the through electrode 14 with the conductive binder can easily chain the conductive particles together, linking the through electrode 14 to the conductive particles on the resin surface, and establishing electrical continuity.

The smaller the average particle diameter of the conductive particles, the smaller the size of the pads and bumps they can be used for. Therefore, the upper limit of the average particle diameter of the conductive particles is preferably 15 μm or less, more preferably 8 μm or less, and even more preferably 4 μm or less, and the lower limit of the average particle diameter of the conductive particles is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more.

The conductive particles may be spherical, polygonal, or spike-shaped. If the conductive particles are polygonal or spike-shaped, they can more easily break through the oxide film on the pads or bumps of the object being inspected.

In the above-described inspection probe sheet, the through electrode 14 has a protrusion 13 protruding from the second surface 11b of the flexible sheet 10, but this is not limited thereto, and the through electrode 14 may have a recessed portion recessed into the second surface 11b of the flexible sheet 10. By making the through electrode 14 have a recess on the second surface 11b of the flexible sheet 10, the tip of the wire probe fits into the recess, preventing the wire probe from falling off the through electrode.

2. Manufacturing method of inspection jig
The manufacturing method of the inspection tool according to the present technology includes a step of forming a through electrode in a through hole of a flexible sheet penetrating a first surface and a second surface so as to have a recessed portion recessed in the first surface, a step of filling the recess with a conductive binder containing thermoplastic resin particles made of a thermoplastic resin having a flexural modulus of 1300 MPa to 2600 MPa and conductive particles, and a heating step of melting the thermoplastic resin particles and connecting the conductive particles in the thickness direction of the flexible sheet. This makes it possible to obtain an inspection probe sheet that has excellent durability for inspection of electrical properties of pads and bumps formed at a fine pitch.

Next, a more specific method for manufacturing the inspection probe sheet will be described with reference to Figs. 1 and 2. First, a through hole is formed in the flexible sheet by laser processing, and a through electrode is half-formed in the through hole by electrolytic plating to form a recess. It is also preferable to plate the through electrode and the side surface of the recess with Ni/Au plating, Ni/Pd plating, Ni/Pd/Au plating, or the like, and cover them with a metal plating film.

Next, a screen printer is used to evenly print the conductive binder in which thermoplastic resin particles and conductive particles are dispersed, into the recesses 12. Alternatively, the conductive binder may be evenly applied into the recesses 12 using a micro-dispenser.

The lower limit of the average particle size of the thermoplastic resin particles is preferably 1 μm or more, more preferably 3 μm or more, and the upper limit of the average particle size is preferably 10 μm or less, more preferably 5 μm or less. This allows for excellent filling properties into the recesses 12.

It is preferable to adjust the viscosity of the conductive binder using a solvent. The viscosity of the solvent is preferably 1000 mPa·s to 10000 mPa·s. If the viscosity of the solvent is too low or too high, printing may become difficult.

The lower limit of the viscosity of the conductive binder at 25°C is preferably 35 Pa·s or more, more preferably 40 Pa·s or more, and the upper limit of the viscosity of the conductive binder at 25°C is preferably 60 Pa·s or less, more preferably 50 Pa·s or less. This allows the conductive binder to be printed so as to protrude from the first surface 11a of the flexible sheet 10.

Next, a magnetic field is applied from the protruding portion 13 side of the through electrode 14 of the flexible sheet. As a result, if the conductive particles contain a magnetic metal, the conductive particles are easily chained together to connect the through electrode to the conductive particles on the surface of the thermoplastic resin, thereby achieving electrical continuity.

Next, a magnetic field is applied to fix the conductive particles in place, and the sheet is heated in an oven at 100-200°C for 0.5-3 hours, and then further heated at 150-250°C for 1-4 hours. This produces a test probe sheet in which conductive bumps 20 are formed, with the conductive binder filling the recesses 12 of the through electrodes 14.

<3. Electrical characteristics inspection method>
The method for testing electrical characteristics to which the present technology is applied includes a step (A) of attaching a test probe sheet to an electrode surface of an object to be tested, the test probe sheet including a flexible sheet having a recess on the first surface , a thermoplastic resin having a flexural modulus of 1300 MPa or more and 2600 MPa or less, and conductive particles, the thermoplastic resin being disposed in the recess , and conductive bumps in which the conductive particles are connected in the thickness direction of the flexible sheet, and bringing the conductive bumps into contact with the electrodes of the object to be tested, and a step (B) of pressing a probe against the through electrode from the other surface of the test probe sheet to test the electrical characteristics. This allows the test probe sheet to exhibit excellent durability in testing the electrical characteristics of pads and bumps formed at fine pitches.

One example of an object to be inspected is a semiconductor device. The semiconductor device may be at the wafer level formed on a wafer, at the individual chip level, or at the package level after packaging. Below, a method for inspecting electrical characteristics at the chip level of a semiconductor device will be described, including an attachment process (A), an inspection process (B), and a peeling process (C) for peeling the inspection probe sheet from the semiconductor device after the inspection process. Note that the inspection probe sheet is the same as the inspection probe sheet described above, so a description thereof will be omitted here.

[Attachment step (A)]
In the attachment step (A), the inspection probe sheet is attached to the electrode surface of the semiconductor device, and the conductive bumps are brought into contact with the bumps of the semiconductor device. In addition, in the attachment step (A), it is preferable to press the inspection probe sheet. As a result, even if an oxide film is formed on the bumps of the semiconductor device, the conductive particles in the conductive bumps break through the oxide film, so that the electrical characteristics can be inspected.

[Inspection process (B)]
FIG. 3 is a cross-sectional view that illustrates a test process for testing electrical characteristics using the test probe sheet according to the present technology.

As shown in FIG. 3, in the inspection process (B), a wire probe 40 is pressed against the convex portion 13 of the through electrode 14 of the flexible sheet 10, and the bump 31 of the semiconductor device 30 is brought into contact with the conductive bump 20 arranged in the concave portion 12 of the through electrode 14 to inspect the electrical characteristics. When the wire probe 40 is pressed, it is believed that the conductive particles of the conductive bump 30 break through the oxide film of the bump 31 of the semiconductor device 30.

The wire probe 40 is a probe for testing electrical characteristics, and is preferably erected perpendicular to the electrode surface of the through-hole electrode as shown in FIG. 3. The wire probe 40 may have multiple pins arranged thereon. The tip shape of the wire probe 40 is not particularly limited, and may be spherical, flat, concave, sawtooth, or the like. The tip diameter of the wire probe 40 is preferably smaller than the width of the electrode when the through-hole electrode does not protrude, but when the electrode of the through-hole electrode protrudes, it may be larger than the width of the electrode as long as it does not short to an adjacent electrode.

Electrical characteristics are tested by measuring the characteristics of, for example, transistors, resistors (electrical resistance), capacitors, etc.

[Peeling step (C)]
In the peeling step (C), the inspection probe sheet is peeled off from the semiconductor device. The semiconductor device may be washed after the peeling of the inspection probe sheet. The peeled inspection probe sheet can be used multiple times.
3. Examples

Below, examples of the present technology are described. In these examples, an electrical property inspection tool was created and used to perform a continuity test on a bare chip. After the continuity test, the pads were evaluated for damage and durability. Note that the present technology is not limited to these examples.

[Measurement of viscosity of conductive binder]
The initial viscosity of the conductive binder at 25° C. was measured using a rheometer (manufactured by HAAKE Corporation).

[Evaluation of Pad Scratches]
After the continuity test, the solder bumps were visually inspected for damage.

[Evaluation of durability]
As a durability test, a continuity test was repeated 10,000 times, and the initial test resistance value and the test resistance value after the durability test were measured.
Example 1

[Preparation of Flexible Sheet Having Through Electrodes]
A sheet (product name: Esperflex, copper thickness 8 μm, polyimide thickness 25 μm, manufactured by Sumitomo Metal Mining Co., Ltd.) in which copper was laminated on both sides of a polyimide sheet was laser processed to form through holes with a diameter of 30 μm at a grid interval of 60 μmP, and through electrodes were formed in the through holes by electrolytic plating with copper. The through electrodes were half-formed in which a recess with a groove of 15 μm was formed from the surface of the sheet in the thickness direction. Next, after plating with nickel and gold, the copper layers on the front and back were removed by etching to create a flexible sheet. Nickel and gold plating was also formed on the polyimide surface on the side of the recess.

[Preparation of Conductive Binder]
Conductive particles were prepared by applying a gold plating layer by electroless displacement plating to the surface of Ni/Ag-plated resin core particles (manufactured by Sekisui Chemical Co., Ltd.) with an average particle size of 3 μm. In addition, nylon 12 fine particles (SP-500, manufactured by Toray Industries, Inc., bending modulus of elasticity of about 1.4 GPa , melting point 165° C.) with an average particle size of 5 μm were prepared as thermoplastic resin particles. Then, 200 parts by mass of conductive particles were mixed with 100 parts by mass of thermoplastic resin particles, and diethyl pentanediol (boiling point 264° C., viscosity 1000 mPa·s) was further added as a solvent and mixed uniformly with a planetary stirring frame mixer to prepare a conductive binder. The viscosity of the conductive binder was 43 Pa·s. In addition, the conductive binder was in a state in which nylon fine particles and conductive particles were dispersed in the solvent.

[Creating an inspection probe sheet]
Using a screen printer (manufactured by Newlong Precision Industry Co., Ltd.), the conductive elastomer dispersion was evenly printed on the recesses of the through electrodes of the flexible sheet so that the conductive elastomer protruded 10 μm from the sheet surface. Next, the flexible sheet was placed on a permanent magnet and left in an open at a temperature of 200° C. for 1 hour to dry the solvent and prepare a probe sheet for inspection. The conductive bumps formed from the conductive elastomer dispersion were in a state in which the nylon 12 fine particles were melted and the conductive particles were bonded together to form an integrated structure.

[Continuity check]
A 6 mm square bare chip (Dexerials evaluation substrate) with 20 μm high, 30 μm diameter solder-capped copper pillar bumps (hereinafter, solder bumps) arranged at 60 μm diameter was used as the evaluation bare chip, and a 30 μm diameter wire probe (manufactured by Tespro) was used to perform a continuity resistance test. More specifically, as shown in FIG. 3, the circuit surface of the evaluation pair chip and one electrode surface of the inspection probe sheet were aligned and pressed, and the wire probe was brought into contact with the opposite electrode surface of the inspection probe sheet with a load of 5 g/pin to perform a continuity test. Table 1 shows the presence or absence of scratches on the solder bumps after the continuity test, and the continuity resistance values before and after the durability test.

Example 2
A conductive binder was prepared in the same manner as in Example 1, except that the solvent was changed to "Nika MHDJ (dihydroterpineol type, boiling point 220°C, viscosity 3000 mPa·s, manufactured by Nikko Fragrance Pharmaceutical Co., Ltd.) The viscosity of the conductive binder was 49 Pa·s. The conductive binder was in a state in which nylon fine particles and conductive particles were dispersed in the solvent.

A probe sheet was also produced in the same manner as in Example 1. The conductive bumps formed from the conductive binder were in a state in which the nylon 12 fine particles had melted and the conductive particles had bonded together to form an integrated structure. A continuity test was then carried out in the same manner as in Example 1. Table 1 shows the presence or absence of damage to the solder bumps after the continuity test, and the continuity resistance values before and after the durability test.

<Comparative Example 1>
A conductive binder was prepared in the same manner as in Example 1, except that the solvent was changed to "YS200" (hydrocarbon-based, boiling point 232°C, viscosity 50 mPa·s, manufactured by Yamaichi Chemical Industry Co., Ltd.). The viscosity of the conductive binder was 30 Pa·s. The conductive binder was in a state in which nylon fine particles and conductive particles were dispersed in the solvent. An attempt was made to prepare a probe sheet in the same manner as in Example 1, but it was not possible to form conductive bumps on the FPC by screen printing, and it was not possible to prepare a probe sheet.

<Comparative Example 2>
A conductive binder was prepared in the same manner as in Example 1, except that an SEBS polymer (Tuftec M1913, manufactured by Asahi Kasei Corporation) was prepared as a binder, "YS200" was prepared as a solvent, and the SEBS was dissolved in the solvent before the conductive particles were added. The conductive binder was in a state in which the conductive particles were dispersed in the solvent in which the polymer was dissolved. A probe sheet was also produced in the same manner as in Example 1. The viscosity of the conductive binder was 30 Pa·s. The conductive bump formed from the conductive binder was in a state in which the conductive particles were dispersed in the SEBS polymer while being partially in contact with each other.

Then, a continuity test was performed in the same manner as in Example 1. Table 1 shows the presence or absence of damage to the solder bumps after the continuity test, and the continuity resistance values before and after the durability test.

<Comparative Example 3>
As the elastomer, two-part liquid silicone (TSE3032A/B, manufactured by Momentive) was mixed in a ratio of 10:1 with part A and part B, and 100 parts by mass of this silicone resin was mixed with 200 parts by mass of conductive particles to prepare a conductive binder. The viscosity of the conductive binder was 40 Pa·s. The conductive binder was in a state where conductive particles were dispersed in the liquid silicone rubber.

Using this conductive binder, a probe sheet was produced in the same manner as in Example 1. The conductive bumps formed from the conductive binder were in a state in which conductive particles were dispersed in silicone rubber with some contact. A continuity test was then carried out in the same manner as in Example 1. Table 1 shows the presence or absence of damage to the solder bumps after the continuity test, and the continuity resistance values before and after the durability test.

In Comparative Example 1, it was not possible to form conductive bumps on the FPC by screen printing. This is thought to be because the dispersion only contained a low-viscosity solvent as a liquid component, making it impossible to transfer the material to the FPC.

In Comparative Examples 2 and 3, the binder component became a uniform liquid with an appropriate viscosity, making it possible to form conductive bumps on FPCs by screen printing. However, the conductive bumps formed by this method failed the durability test because the binder component was a relatively weak material such as elastomers such as SEBS or silicone rubber.

In Examples 1 and 2, a high-viscosity type (viscosity of 1000 mPa·s or more) was used as the solvent for the conductive binder, so even when fine-particle nylon was used as the binder component, it was possible to form bumps on the FPC by screen printing. Good results were also obtained in tests using the formed conductive bumps. In addition, because high-strength nylon was used as the binder component, good resistance values were obtained even after durability tests.

REFERENCE SIGNS LIST 1 inspection probe sheet, 10 flexible sheet, 11a first surface, 11b second surface, 12 recess, 13 protrusion, 14 through electrode, 20 conductive bump, 30 semiconductor device, 31 bump, 40 wire probe

Claims (5)

a flexible sheet having a through hole penetrating a first surface and a second surface, the through electrode being half-formed in the through hole, the flexible sheet having a recess recessed in the first surface;
and a conductive bump disposed in the recess and containing polyamide having a flexural modulus of elasticity of 1,300 MPa or more and 1,600 MPa or less and a melting point of 160°C or more and 200°C or less, and conductive particles, the conductive particles being connected in the thickness direction of the flexible sheet. 2. The electrical characteristic inspection jig according to claim 1, wherein the total content of the polyamide and the conductive particles in the conductive bump is 85 wt % or more. a step of forming a through electrode in a flexible sheet having a through hole penetrating a first surface and a second surface, the through hole having a recess recessed in the first surface;
a filling step of filling the recess with a conductive binder including polyamide particles having a flexural modulus of 1300 MPa or more and 1600 MPa or less and a melting point of 160° C. or more and 200° C. or less and conductive particles;
and a heating step of melting the polyamide particles and connecting the conductive particles in a thickness direction of the flexible sheet. The method for manufacturing an inspection jig according to claim 3, wherein the viscosity of the conductive binder at 25°C is 35 Pa·s or more and 60 Pa·s or less. a bonding process for bonding an inspection probe sheet to an electrode surface of an object to be tested, the inspection probe sheet comprising a flexible sheet having a through-hole penetrating a first surface and a second surface, the through-hole having a half-formed through-electrode in the through-hole penetrating the first surface and a recessed portion recessed into the first surface, the inspection probe sheet being disposed in the recessed portion and including polyamide having a flexural modulus of elasticity of 1300 MPa or more and 1600 MPa or less and a melting point of 160°C or more and 200°C or less, and conductive particles, the conductive particles being connected in the thickness direction of the flexible sheet, and the conductive bump being brought into contact with the electrode of the object to be tested;
and an inspection step of pressing a probe against a through electrode from the other surface of the inspection probe sheet to inspect electrical characteristics.

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