PLUNGER AND METHOD OF MANUFACTURING PLUNGER

A plunger comprising: a tip contactor formed by embedding a first conductive material in a recess part provided in a base; a columnar part formed by embedding a second conductive material in a first opening provided in a first resist film formed over the base, the first opening being located above the recess part; and a receiving part formed by embedding a third conductive material in a second opening provided in a second resist film formed over the first resist film, the second opening being located above the first opening.

TECHNICAL FIELD

The present invention relates to a plunger and a method of manufacturing a plunger.

BACKGROUND ART

Various inspection devices have been developed for inspecting characteristics of electronic devices such as integrated circuits (ICs). As disclosed in Patent Document 1, the inspection device includes a plunger. In Patent Document 1, the plunger includes a tip contactor and a columnar part connected to the tip contactor. The tip contactor is formed by polishing.

RELATED DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

Technical Problem

With the miniaturization of the electronic device, arrangement of minute plungers at high density is required for the inspection device in some case. For example, when the tip contactor is formed by polishing as disclosed in Patent Document 1, it may be difficult to miniaturize the plunger.

An example of an object of the present invention is to miniaturize the plunger. Other object of the present invention will be apparent from the description of the present specification.

Solution to Problem

One aspect of the present invention is a plunger including a tip contactor formed by embedding a first conductive material in a recess part provided in a base, a columnar part formed by embedding a second conductive material in a first opening provided in a first resist film formed over the base, the first opening being located above the recess part, and a receiving part formed by embedding a third conductive material in a second opening provided in a second resist film formed over the first resist film, the second opening being located above the first opening.

Another aspect of the present invention is a method of manufacturing a plunger, the method including embedding a first conductive material in a recess part provided in a base, embedding a second conductive material in a first opening provided in a first resist film formed over the base, the first opening being located above the recess part, and embedding a third conductive material in a second opening provided in a second resist film formed over the first resist film, the second opening being located above the first opening.

Advantageous Effects of Invention

According to the above aspects of the present invention, the plunger can be miniaturized.

DESCRIPTION OF EMBODIMENTS

In the following, embodiments of the present invention will be described with reference to the drawings. It should be noted that, in all drawings, similar components are designated by the same reference numerals, and the description thereof will not be repeated.

In the present specification, ordinal numbers, such as “first”, “second”, and “third”, are merely used to distinguish similarly named configurations unless otherwise noted, and do not imply any particular feature of the configuration, such as order or importance.

FIG.1is a perspective cross-sectional view showing the details of an inspection device10according to Embodiment 1.

InFIG.1, a direction indicated by an arrow indicating the vertical direction Z is the upward direction of the vertical direction Z. A direction opposite to the direction indicated by the arrow indicating the vertical direction Z is the downward direction of the vertical direction Z.

The inspection device10includes a first elastomer100, a plurality of first plungers110, a plurality of second plungers120, a first pin plate130, and a second pin plate140. Each first plunger110includes a first tip contactor112, a first columnar part114, and a first receiving part116. Each second plunger120includes a second tip contactor122, a second columnar part124, and a second receiving part126. At least a portion of the first elastomer100such as a periphery of a hole102described later in the first elastomer100, a conductive film104described later, each first plunger110, and each second plunger120function as a probe. Each first plunger110and each second plunger120are biased in the vertical direction Z by at least a portion of the first elastomer100such as the periphery of the hole102.

The first elastomer100has a sheet shape. In one example, the first elastomer100is made of a polymeric material having elasticity, for example a polymeric material such as silicone, polyimide, or styrene-butadiene rubber (SBR).

The first elastomer100defines a plurality of holes102that penetrate the first elastomer100along the vertical direction Z.

The conductive film104is formed on an inner wall of each hole102. In one example, the conductive film104includes metal such as at least one selected from the group consisting of nickel, copper, and gold. The conductive film104is, for example, a multilayer film of these metals.

Each hole102is hollow. In this case, as compared with a case in which the conductive film104is formed on the inner wall of the hole102and the hole102is solid (the hole102is filled), a material and a process for making the hole102solid are unnecessary, and a manufacturing cost of the inspection device10can be reduced.

The first plunger110is located below the first elastomer100. The first plunger110overlaps with the first elastomer100in the vertical direction Z. Specifically, the first plunger110overlaps with the hole102in the vertical direction Z. Accordingly, the first plunger110can be biased in a direction away from the second plunger120, that is, downward by the first elastomer100. The first plunger110is electrically connected to the conductive film104. Accordingly, the first plunger110can be electrically connected to the second plunger120through the conductive film104. If the first plunger110does not overlap with the hole102in the vertical direction Z, an electrical path such as a conductive material embedded in the first elastomer100needs to be provided separately from the conductive film104in order to electrically connect the first plunger110to the conductive film104. When the first plunger110overlaps with the hole102in the vertical direction Z, however, the first plunger110can be directly connected to the conductive film104without through the electrical path such as the conductive material embedded in the first elastomer100. Accordingly, as compared with a case in which the electrical path is provided, a material and a process for manufacturing the electrical path itself are unnecessary, and the manufacturing cost of the inspection device10can be reduced. It should be noted that the first plunger110may be offset from the hole102in a direction orthogonal to the vertical direction Z. Even in this case, the first plunger110can be connected to the conductive film104through the electrical path such as the conductive material embedded in the first elastomer100.

The first tip contactor112includes metal such as at least one selected from the group consisting of rhodium, ruthenium, iridium, tungsten, and tantalum.

A width of the first tip contactor112is narrowed from a base end to a tip of the first tip contactor112. The first tip contactor112is a conic solid such as a cone or a pyramid, and has a tapered shape from the base end to the tip of the first tip contactor112. A tip of the first tip contactor112has a flat surface of, for example, equal to or more than 1 µm and equal to or less than 20 µm. However, the shape of the tip of the first tip contactor112is not limited to this example.

The first columnar part114includes metal such as at least one selected from the group consisting of copper and nickel.

The first columnar part114is connected to the base end of the first tip contactor112. The first tip contactor112and the first columnar part114may be integrated or separate. A height of the first columnar part114is, for example, equal to or more than 5 µm and equal to or less than 300 µm. The first columnar part114is a column such as a cylinder or a prism. When the first columnar part114is a cylinder, a diameter of the first columnar part114is, for example, equal to or more than 20 µm and equal to or less than 500 µm. However, the shape of the first columnar part114is not limited to this example.

The first receiving part116includes metal such as at least one selected from the group consisting of copper and nickel.

The first receiving part116is connected to an end portion of the first columnar part114opposite to the first tip contactor112. The first columnar part114and the first receiving part116may be integrated or separated. The first receiving part116has a width wider than a width of the first columnar part114. A thickness of the first receiving part116is, for example, equal to or more than 5 µm and equal to or less than 200 µm. An upper surface of the first receiving part116is flat. However, at least one convex part may be formed on the upper surface of the first receiving part116.

The first pin plate130is made of, for example, polyimide, liquid crystal polymer, or glass substrate.

The first pin plate130defines a plurality of first through-holes132. Each of the plurality of first plungers110is inserted into each of the plurality of first through-holes132. The plurality of first plungers110can be arranged at a minute pitch (narrow pitch) of, for example, equal to or more than 10 µm and equal to or less than 500 µm.

At least a portion of the first tip contactor112is exposed from a lower end of the first through-hole132of the first pin plate130. At least a portion of the first columnar part114penetrates the first through-hole132. The first receiving part116is located between an upper surface of the first pin plate130and a lower surface of the first elastomer100. The width of the first receiving part116in the left-right direction in the drawing is wider than a width of the first through-hole132in the left-right direction in the drawing. Accordingly, the first receiving part116is caught by a peripheral portion of an opening end of the first through-hole132on the upper surface of the first pin plate130. In this case, even if the first plunger110is biased downward by the first elastomer100, the first receiving part116can be suppressed from exiting downward the first pin plate130through the first through-hole132. Thus, as compared with a case in which the first receiving part116is not provided, even if a length of the first plunger110(a length of the first columnar part114) is shortened, the first plunger110is unlikely to exit below the first pin plate130. The length of the first plunger110can be shortened, and the first plunger110can be applied to an inspection in a high frequency band of equal to or more than 1 GHz and equal to or less than 100 GHz.

The second plunger120is located above the first elastomer100. The second plunger120overlaps with the first elastomer100in the vertical direction Z. Specifically, the second plunger120overlaps with the hole102in the vertical direction Z. Accordingly, the second plunger120can be biased in a direction away from the first plunger110, that is, upward by the first elastomer100. The second plunger120is electrically connected to the conductive film104. Accordingly, the second plunger120can be electrically connected to the first plunger110through the conductive film104. If the second plunger120does not overlap with the hole102in the vertical direction Z, an electrical path such as a conductive material embedded in the first elastomer100needs to be provided separately from the conductive film104in order to electrically connect the second plunger120to the conductive film104. When the second plunger120overlaps with the hole102in the vertical direction Z, however, the second plunger120can be directly connected to the conductive film104without through the electrical path such as the conductive material embedded in the first elastomer100. Accordingly, as compared with a case in which the electrical path is provided, the material and the process for manufacturing the electrical path itself are unnecessary, and the manufacturing cost of the inspection device10can be reduced. It should be noted that the second plunger120may be offset from the hole102in a direction orthogonal to the vertical direction Z. Even in this case, the second plunger120can be connected to the conductive film104through the electrical path such as the conductive material embedded in the first elastomer100.

The second pin plate140defines a plurality of second through-holes142. Each of the plurality of second plungers120is inserted into each of the plurality of second through-holes142in the same manner as the plurality of first plungers110and the first pin plate130.

According to the present embodiment, as compared with a case in which the plunger is biased by a spring, the first elastomer100plays a role of compression and extension of the spring, and the conductive film104plays a role of conduction of the spring. If the plunger is biased by the spring, a free length of the spring needs to be short to compare the free lengths of the probe. In this case, however, it is difficult to achieve a sufficient stroke. On the other hand, in the present embodiment, there is no need to use the spring. Accordingly, as compared with a case in which the plunger is biased by the spring, a natural length of the probe can be shortened while achieving the stroke having a sufficient length.

It should be noted that, in the present embodiment, the case has been described in which the first plunger110and the second plunger120overlap with the first elastomer100in the vertical direction Z. However, the first elastomer100and the second plunger120may overlap with the first elastomer100in a direction different from the vertical direction Z.

FIGS.2to7are cross-sectional views for describing a method of manufacturing the first plunger110according to Embodiment 1.FIGS.2to7show a normal direction Z1 of a surface of a metal base600A on which a recess part602A is formed.

The method of manufacturing the first plunger110will be described with reference toFIGS.2to7. It should be noted that the second plunger120can also be manufactured in the same manner as described below.

First, as shown inFIG.2, the recess part602A is formed in the metal base600A. A width of the recess part602A is narrowed from an opening end toward a bottom end of the recess part602A. The recess part602A has a tapered shape. The metal base600A is, for example, a copper plate. The recess part602A is formed in the metal base600A by, for example, punching or pressing.

Next, as shown inFIG.3, a first resist film610is formed on the metal base600A. A first opening612is provided in the first resist film610. The first opening612overlaps with the recess part602A in the normal direction Z1. A width of the first opening612is wider than a width of the opening end of the recess part602A. That is, the width of the first columnar part114may be different from a width of the base end of the first tip contactor112due to tolerance between the width of the first opening612and the width of the opening end of the recess part602A. However, the width of the first columnar part114may be equal to the width of the base end of the first tip contactor112. That is, the width of the first opening612may be equal to the width of the opening end of the recess part602A.

Next, as shown inFIG.4, a first conductive material as the first tip contactor112is deposited by plating and the first conductive material is embedded in the recess part602A. As a result, the first tip contactor112is formed in the recess part602A. Accordingly, the first tip contactor112has a plating layer. Next, a thickness of the first resist film610is further increased. Next, a second conductive material as the first columnar part114is deposited by plating and the second conductive material is embedded in the first opening612. As a result, the first columnar part114is formed in the first opening612. Accordingly, the first columnar part114has a plating layer.

Next, as shown inFIG.5, a first seed layer116ais formed on the first columnar part114and the first resist film610.

Next, as shown inFIG.6, a second resist film620is formed on the first resist film610. A second opening622is provided in the second resist film620. The second opening622overlaps with the first opening612in the normal direction Z1. A width of the second opening622is wider (larger) than the width of the first opening612.

Next, as shown inFIG.7, a third conductive material as a first plating layer116bis deposited by plating and the third conductive material is embedded in the second opening622. As a result, the first receiving part116is formed in the second opening622. In this case, the first receiving part116simultaneously forms a plurality of layers including the first seed layer116aand the first plating layer116b.

Next, the first resist film610and the second resist film620are removed by, for example, chemical solution treatment. Next, the first plunger110is removed from the metal base600A. Next, as necessary, the tip of the first tip contactor112is treated by, for example, machining to form the flat surface. It should be noted that the flat surface of the tip of the first tip contactor112may be formed by adjusting a shape of the bottom end of the recess part602A of the metal base600A.

According to the present embodiment, the first tip contactor112can be formed by using the recess part602A of the metal base600A as a die. The first columnar part114can be formed by using the first opening612of the first resist film610as a die. The first receiving part116can be formed by using the second opening622of the second resist film620as a die. Accordingly, the first plunger110can be miniaturized as compared with a case in which the first tip contactor112is formed by polishing. According to the present embodiment, the first plunger110can be manufactured at a low cost as compared with a case in which the first tip contactor112is formed by polishing. Further, according to the present embodiment, a degree of freedom in a structure of the first plunger110can be increased as compared with a case in which the first tip contactor112is formed by polishing.

FIG.8is a cross-sectional view for describing a method of manufacturing the first plunger110according to Embodiment 2. The method according to Embodiment 2 is the same as the method according to Embodiment 1, except for the following points.

In the present embodiment, the first plunger110is manufactured as follows.

First, as shown inFIG.8, a recess part602B is formed in a semiconductor base600B. The semiconductor base600B is, for example, a silicon substrate. The recess part602B is formed by, for example, anisotropic etching.

The subsequent steps are the same as the steps described with reference toFIGS.3to7of Embodiment 1.

In general, the flatness of the surface of the semiconductor base600B according to Embodiment 2 is higher than the flatness of the surface of the metal base600A according to Embodiment 1. Accordingly, in Embodiment 2, the first tip contactor112can be formed by using the recess part602B provided on the surface having such high flatness as a die. Thus, as compared with Embodiment 1, Embodiment 2 may be suitable for mass production of the first plunger110.

FIG.9is a cross-sectional view for describing a method of manufacturing the first plunger110according to Embodiment 3. The method according to Embodiment 3 is the same as the method according to Embodiment 1, except for the following points.

In the present embodiment, the first plunger110is manufactured as follows.

First, as shown inFIG.9, a recess part602C is formed in a resin base600C. The resin base600C is, for example, polyimide or liquid crystal polymer. The recess part602C is formed by, for example, machining. Next, a seed layer604C is formed on an inner wall of the recess part602C. The seed layer604C is provided for depositing the first conductive material as the first tip contactor112by plating.

The subsequent steps are the same as the steps described with reference toFIGS.3to7of the embodiment.

In general, the resin base600C according to Embodiment 3 is softer than the metal base600A according to Embodiment 1. Accordingly, the recess part may be more easily formed in the resin base600C according to Embodiment 3, than in the metal base600A according to Embodiment 1.

In the above, the embodiments of the present invention have been described with reference to the drawings, but these are examples of the present invention, and various configurations other than the above can be adopted.

According to the present specification, the following aspects are provided.

Aspect 1-1 is a plunger including a tip contactor formed by embedding a first conductive material in a recess part provided in a base, a columnar part formed by embedding a second conductive material in a first opening provided in a first resist film formed over the base, the first opening being located above the recess part, and a receiving part formed by embedding a third conductive material in a second opening provided in a second resist film formed over the first resist film, the second opening being located above the first opening.

According to Aspect 1-1, the tip contactor can be formed by using the recess part of the base as a die. The columnar part can be formed by using the first opening of the first resist film as a die. The receiving part can be formed by using the second opening of the second resist film as a die. Accordingly, the plunger can be miniaturized as compared with a case in which the tip contactor is formed by polishing.

Aspect 1-2 is the plunger according to Aspect 1-1, in which a width of the columnar part is different from a width of a base end of the tip contactor.

According to Aspect 1-2, the width of the columnar part is different from the width of the base end of the tip contactor due to tolerance between the width of the opening end of the recess part of the base for forming the tip contactor and the width of the opening of the resist for forming the columnar part. The width of the columnar part being different from the width of the base end of the tip contactor can prevent the plunger from dropping out from the inspection device.

Aspect 1-3 is the plunger according to Aspect 1-1 or 1-2, in which the receiving part has a plurality of layers.

According to Aspect 3, the receiving part is formed by forming the plating layer on the seed layer. As a result, the receiving part has the plurality of layers including the seed layer and the plating layer.

Aspect 2-1 is a method of manufacturing a plunger, the method including embedding a first conductive material in a recess part provided in a base, embedding a second conductive material in a first opening provided in a first resist film formed over the base, the first opening being located above the recess part, and embedding a third conductive material in a second opening provided in a second resist film formed over the first resist film, the second opening being located above the first opening.

According to Aspect 2-1, the tip contactor can be formed of the first conductive material by using the recess part of the base as a die. The columnar part can be formed of the second conductive material by using the first opening of the first resist film as a die. The receiving part can be formed of the third conductive material by using the second opening of the second resist film as a die. Accordingly, the plunger can be miniaturized as compared with a case in which the tip contactor is formed by polishing.

Aspect 2-2 is the method of manufacturing a plunger according to Aspect 2-1, in which a width of the first opening is different from a width of an opening end of the recess part.

According to Aspect 2-2, the width of the columnar part can be different from the width of the base end of the tip contactor. The width of the columnar part being different from the width of the base end of the tip contactor can prevent the plunger from dropping out from the inspection device.

Aspect 2-3 is the method of manufacturing a plunger according to Aspect 2-1 or 2-2, in which the third conductive material is formed over a seed layer.

According to Aspect 2-3, the receiving part can be formed by forming the plating layer on the seed layer.

Aspect 3-1 is a plunger including a tip contactor including a first plating layer of which a width is narrowed from a base end toward a tip, a columnar part including a second plating layer connected to the base end of the tip contactor, and a receiving part connected to an end portion of the columnar part opposite to the tip contactor, the receiving part including a third plating layer having a width wider than a width of the columnar part.

According to Aspect 3-1, the tip contactor can be formed by using the recess part of the base as a die. The columnar part can be formed by using the first opening of the first resist film as a die. The receiving part can be formed by using the second opening of the second resist film as a die. Accordingly, the plunger can be miniaturized as compared with a case in which the tip contactor is formed by polishing.

Aspect 3-2 is the plunger according to Aspect 3-1, in which a width of the columnar part is different from a width of a base end of the tip contactor.

According to Aspect 3-2, the width of the columnar part is different from the width of the base end of the tip contactor due to tolerance between the width of the opening end of the recess part of the base for forming the tip contactor and the width of the opening of the resist for forming the columnar part. The width of the columnar part being different from the width of the base end of the tip contactor can prevent the plunger from dropping out from the inspection device.

Aspect 3-3 is the plunger according to Aspect 3-1 or 3-2, in which the receiving part has a plurality of layers.

According to Aspect 3-3, the receiving part is formed by forming the third plating layer on the seed layer. As a result, the receiving part has the plurality of layers including the seed layer and the third plating layer.

This application claims priority based on Japanese Patent Application No. 2020-106766 filed on Jun. 22, 2020, the entire disclosure of which is incorporated herein by reference.