JP4074297B2 - Manufacturing method of probe unit - Google Patents

Description

  The present invention relates to a method for manufacturing a probe unit that is connected to an electrode or a terminal portion of an electronic component such as a semiconductor integrated circuit or a liquid crystal panel, and is used for an energization test of the electrode.

In general, as a product inspection for a semiconductor integrated circuit, a liquid crystal panel, a printed circuit board, and the like that are becoming higher in definition, an energization inspection is performed in order to confirm whether or not these operate according to required specifications.
This energization inspection is performed by pressing the tip of the probe pin constituting the probe unit or a protrusion formed in the vicinity thereof onto an electrode arranged in parallel on a semiconductor integrated circuit, a liquid crystal panel, a printed circuit board, or the like. Is called.
By the way, the electrode layers arranged in parallel to the edge of the glass plate constituting the liquid crystal panel tend to have a finer pitch (100 μm or less). In the current-carrying inspection of such a liquid crystal panel, there is provided a probe unit that has probe pins formed at a pitch corresponding to this minute pitch electrode layer on the side of the current-carrying inspection device and can repeatedly conduct a current inspection. Necessary.
In addition, as a conventional probe unit, a cantilever type, a membrane type, a silicon whisker type, a finger lead type, and the like have been devised (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 9-148389

However, since a cantilever type probe unit made of tungsten is manufactured by machining probe pins one by one, it is very difficult to form a large number of probe pins having a width of 50 μm or less in parallel at a minute pitch of 100 μm or less. There was a problem that it was difficult and the manufacturing cost was high.
In addition, in a membrane type probe unit in which the probe holding part for holding the probe pin is a laminate of a resin film and a metal film, the expansion and contraction of the resin film is large due to changes in temperature and humidity. There was a problem that dimensional stability could not be obtained.
In addition, the silicon whisker type probe pin has a problem that its durability is low in order to repeatedly conduct an electric current inspection.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the manufacturing method of the probe unit excellent in dimensional stability and durability.

  The present invention includes a step of forming an opening in a substrate, a step of forming a sacrificial layer in the opening, a step of making the surface of the substrate and the sacrificial layer uniform, and a step of forming a base layer of a probe pin And forming a resist pattern in which an opening corresponding to the beam portion of the probe pin is formed on the sacrificial layer on the base layer, and on the base layer in a portion where the resist is not formed, A step of forming a probe pin by performing plating with a nickel content of 75 wt% or more and 84 wt% or less, a step of removing the resist and unnecessary underlayer, and a step of removing the sacrificial layer; And a step of cutting the substrate.

  According to the probe unit manufacturing method of the present invention, a step of forming an opening in a substrate, a step of forming a sacrificial layer in the opening, a step of uniforming the surface of the substrate and the sacrificial layer, and a probe Forming a pin underlayer; forming a resist pattern in which an opening corresponding to the beam portion of the probe pin is formed on the sacrificial layer on the underlayer; and the resist is not formed Forming a probe pin by performing plating with a nickel content of not less than 75% by weight and not more than 84% by weight on a portion of the foundation layer; removing the resist and unnecessary foundation layer; Since the method includes the step of removing the sacrificial layer and the step of cutting the substrate, a probe unit having excellent dimensional stability and durability can be manufactured.

The present invention will be described in detail below.
FIG. 1 is a schematic configuration diagram showing an example of a probe unit obtained by the probe unit manufacturing method of the present invention, FIG. 1 (a) is a plan view, and FIG. 1 (b) is a state cut along II-II. FIG.
The probe unit 1 in this example is generally configured by one or more probe pins 2 and a probe holding unit 3. The probe pin 2 includes a main body portion 2a, a beam portion 2b, a tapered portion 2c, and a wiring extraction portion 2d. The tip of the probe pin 2 is a beam portion 2b that is narrower than the main body portion 2a.
Further, when the probe unit 1 is attached to the energization inspection apparatus, the wiring extraction portion 2d of the probe pin 2 has solder, ACF (Anisotropic Conductive Film), NCF (Non Conductive Film, A lead wire 5 is bonded via a bonding portion 4 made of non-conductive film), gold bonding, or the like.

The length of the beam portion 2b of the probe pin 2 is preferably 10 to 5000 μm, and more preferably 100 to 1000 μm.
Further, the width of the beam portion 2b of the probe pin 2 is preferably 1 to 50 μm, more preferably 5 to 30 μm. If the width of the beam portion 2b is within this range, the width of the beam portion 2b is smaller than the width of the electrode of the object to be measured such as a semiconductor integrated circuit, a liquid crystal panel, or a printed board. Therefore, even if a slight deviation occurs between the pitch of the electrode of the object to be measured and the pitch of the beam part 2b, the beam part 2b is brought into contact with the electrode of the object to be inspected so as to correspond to 1: 1. Can do.
The thickness of the beam portion 2b of the probe pin 2 is preferably 0.2 to 2 times, more preferably 0.5 to 1.5 times the width of the beam portion 2b. If the thickness of the beam portion 2b is within this range, a probe unit having excellent dimensional stability and durability can be obtained without being deformed or damaged even when used repeatedly.

  The beam portion 2b of the probe pin 2 is made of a metal material mainly composed of a nickel-iron alloy, and the content of the nickel-iron alloy in the metal material is preferably 95% by weight of the total amount of the metal material. Or more, more preferably 99% by weight or more. When the content of the nickel-iron alloy is less than 95% by weight of the total amount of the metal material, the dimensional stability and durability of the beam portion 2b are lowered.

  The composition ratio of nickel and iron in the nickel-iron alloy contained in the metal material forming the beam portion 2b is preferably 95% by weight: 5% by weight to 45% by weight: 55% by weight, more preferably 90% by weight: 10% by weight to 70% by weight: 30% by weight. If the composition ratio of nickel and iron in the nickel-iron alloy is within this range, the beam portion 2b is hardly plastically deformed. As a result, the beam portion 2b is excellent in dimensional stability.

The lengths of the main body portion 2a and the tapered portion 2c of the probe pin 2 are appropriately set according to the size of the beam portion 2b and the probe holding portion 3 and the like.
Further, the width of the main body portion 2a of the probe pin 2 is equal to or larger than the width of the beam portion 2b. Further, as shown in FIG. 1 (a), the main body 2a and the beam 2b are joined by a taper 2c that gradually increases in width from the beam 2b toward the main body 2a. Is formed.
Moreover, it is preferable that the thickness of the main body portion 2a and the tapered portion 2c of the probe pin 2 is equal to the thickness of the beam portion 2b.

  Examples of the material for forming the main body portion 2a and the tapered portion 2c of the probe pin 2 include nickel (Ni), nickel (Ni) -cobalt (Co) alloy, nickel-based alloy, and iron (Fe) -based alloy.

The size of the probe holding portion 3 is appropriately set according to the size of the main body portion 2a of the probe pin 2, but the area of the upper surface 3a of the probe holding portion 3 is larger than the area of the upper surface 2e of the main body portion 2a. Is set to be
Further, as a material for forming the probe holding unit 3, metals such as ceramics, alumina (Al ₂ O ₃ ), silicon (Si), Ni-based alloy, and Fe-based alloy are used.

Further, a coating layer 6 having a thickness of about 0.1 to 10 μm may be formed on all or part of the surface of the probe pin.
For example, the entire upper surface of the probe pin 2 as shown in FIG. 2A, the entire surface of the beam portion 2b as shown in FIG. 2B, and the probe holding portion of the probe pin 2 as shown in FIG. The coating layer 6 is formed on the entire surface of the portion that is not joined to the surface 3. In this case, it is preferable to form a coating layer on the beam portion of the probe pin 2 that is in contact with the object to be inspected. On the other hand, as shown in FIG. 2D, a low resistance coating layer 6 such as copper, gold, silver or the like may be formed in addition to the beam portion 2b. In this case, the resistance of the probe pin 2 can be lowered, and the energization inspection can be performed with high accuracy.
In order to form the coating layer 6, methods such as sputtering, vacuum deposition, ion plating, and electrolytic plating are used.
Further, as a material for forming the covering layer 6, metals such as gold, silver, copper, palladium, platinum, tungsten, nickel-titanium alloy are used.
Thus, by forming the coating layer 6 on all or part of the surface of the probe pin 2, the probe pin 2 is worn or damaged due to contact between the probe pin 2 and the object to be inspected. Can be prevented. As a result, the dimensional stability and durability of the probe pin 2 are improved.

As shown in FIG. 3, one or two or more spire-shaped or knife-edge-shaped protrusions 7 may be formed at the tip of the beam portion 2 b of the probe pin 2.
In order to form the protrusion 7, a resist film having an opening in the shape of the protrusion 7 is formed in the probe unit manufacturing method described later, and the resist film is removed after the opening is plated and grown by electrolytic plating or the like. The method to do is used.
Further, as a material for forming the protruding portion 7, a metal such as tungsten (W), titanium nitride (TiN), nickel-iron alloy, titanium, or the like is used.
In this way, by forming the protrusion 7 at the tip of the beam portion 2b of the probe pin 2, it is possible to conduct a current test of a minute object to be inspected with high accuracy.

  In the probe unit 1, normally, as shown in FIG. 1A, the wiring extraction portion 2 d is provided on the upper surface of the probe unit 1 at the rear end portion of the probe pin 2. Further, in the probe unit of the present invention, as shown in FIG. 4, the wiring takeout part 2 d may be provided on the lower surface of the probe unit 1 by extending the probe pin 2 from the upper surface of the probe unit 1. Good.

5 and 6 are cross-sectional schematic views showing an embodiment of the probe unit manufacturing method of the present invention.
In the probe unit manufacturing method of this embodiment, first, as shown in FIG. 5A, a flat substrate 11 made of ceramics, alumina, silicon, various metals, or the like to be a probe holding portion is prepared.
Next, a mask is applied to the surface of the substrate 11, and an opening 11a as shown in FIG. 5B is formed in the substrate 11 by sandblasting or dicing.
Next, a copper sputtered film having a thickness of about 0.2 to 1 mm is formed as a sacrificial plating seed layer in the opening 11a, and then electrolytic copper plating is performed in a copper sulfate plating bath. The sacrificial layer 12 is formed by plating. In this step, plating is grown so as to overflow from the opening 11a, and an excess portion is polished and removed by using a surface grinder or the like, so that the surface of the substrate 11 and the surface of the sacrificial layer 12 are made uniform.

Next, as shown in FIG. 5D, a plating seed layer (underlayer) 13 that forms the underlayer of the probe pin is formed on the entire surface of the substrate 11 and the sacrificial layer 12 by sputtering.
The plating seed layer 13 is preferably a titanium (Ti) / NiFe alloy thin film having a thickness of about 0.02 to 0.5 μm. When a Ti / NiFe alloy thin film is formed as the plating seed layer 13, first, titanium is formed by a sputtering method as an adhesion layer, and a NiFe alloy is formed thereon by a sputtering method. In this case, the thickness of the titanium thin film is, for example, 0.02 μm, and the thickness of the NiFe alloy thin film is, for example, about 0.20 μm.
When the substrate 11 is made of a conductive material, an insulating film made of silica (SiO ₂ ) or the like is formed on the entire surface of the substrate 11 and the sacrificial layer 12 before the plating seed layer 13 is formed.

  Next, as shown in FIG. 5E, a photoresist having an arbitrary thickness is applied on the surface of the plating seed layer 13, and a mask having an arbitrary shape is disposed on the surface of the photoresist, followed by baking. Then, development processing is performed to remove unnecessary photoresist, and a resist film 14 having an opening of an arbitrary probe pin pattern is formed. The thickness of the resist film 14 is appropriately set according to the thickness of a predetermined probe pin.

  Next, as shown in FIG. 6A, electrolytic plating is performed on the surface of the plating seed layer 13 where the resist film 14 is not formed using a plating solution containing iron, nickel, etc. based on sulfuric acid. Thus, the metal layer 15 forming the probe pin is formed by plating. At this time, the plating forming the metal layer 15 includes nickel in an amount of 75 wt% to 84 wt%. The thickness of the metal layer 15 is appropriately set according to the thickness of a predetermined probe pin.

  Next, as shown in FIG. 6B, the resist film 14 is removed. In order to remove the resist film 14, the interface between the resist film 14, the plating seed layer 13, and the metal layer 15 is washed with an organic solvent, an alkaline aqueous solution, or the like. At this time, if ultrasonic cleaning is performed while heating, the resist film 14 can be efficiently removed.

Next, as shown in FIG. 6C, the plating seed layer 13 that protrudes below the metal layer 15 below the metal layer 15 is removed by ion milling, and the plating seed layer 13 is removed from the metal layer 15. And the same shape.
Next, as shown in FIG. 6D, the sacrificial layer 12 is dissolved with an etchant that preferentially dissolves copper, and the opening 11a is formed again.

  Next, as shown in FIG. 6E, the external dimensions of a predetermined probe holding portion are determined, and the substrate 11 is formed into a predetermined size by dicing, and the substrate 11, the plating seed layer 13, the metal layer is formed. A probe unit 15 is stacked in this order. At this time, for example, the length of the probe holding portion is set to l.

  Next, in order to allow the probe unit to be mounted on the current-inspection inspection device, a lead wire is connected to a probe pin wiring extraction portion 15d made of a metal layer 15 via a joint portion 16 made of solder, ACF, gold bonding or the like. 17 is joined.

Hereinafter, specific experimental examples will be shown using FIG. 7 to clarify the effects of the present invention.
(Experimental example)
A probe unit including a probe pin 21 made of a nickel-iron alloy and a probe holding portion 22 made of Al ₂ O ₃ was manufactured. The length of the beam portion 21b of the obtained probe pin 21 was 1000 μm, the width was 35 μm, and the thickness was 20 μm.
Next, the lead wire 24 was joined to the wiring extraction part 21d of the probe pin 21 of the obtained probe unit via the joining part 23.
Next, this probe unit was evaluated later.

(1) Plastic deformation amount Using a probe pin 21 formed by changing the composition of a nickel-iron alloy, the probe pin 21 is 5 μm at a speed of about 10 μm / second in a direction of 75 ° with respect to its longitudinal direction. A stepwise displacement of 10 μm, 15 μm,... Was applied, and the bending test was performed by returning to 0 point, and the deformation amount (μm) until the beam portion 21b of the probe pin 21 was plastically deformed was examined.
The results are shown in Table 1 and FIG.

(2) Durability The probe unit was attached to an electrical current inspection apparatus, and the tip of the beam portion 21b of the probe pin 21 was repeatedly brought into contact with the electrode 32 of the test substrate 30 to evaluate the durability of the beam portion 21a. At this time, the angle formed by the substrate 31 of the test substrate 30 and the probe pin 21 was kept constant at 15 °, and the probe unit was moved in the direction perpendicular to the substrate 31. The number of repetitions of bringing the tip of the beam portion 21b into contact with the electrode 32 was 100,000. Further, the amount of deformation of the probe pin 21 in the direction perpendicular to the longitudinal direction was 100 μm and 150 μm. The evaluation criteria were as follows.
A: The amount of plastic deformation after a durability test of 100,000 times is within 2 μm. Judgment = pass.
○: The amount of plastic deformation after 100,000 durability tests is within 5 μm. Judgment = pass.
(Triangle | delta): The amount of plastic deformation after a 100,000 times endurance test is less than 10 micrometers. Judgment = pass.
X: The amount of plastic deformation after 100,000 durability tests exceeds 10 μm. Judgment = Failure.
NG: Damaged during the durability test.
The results are shown in Table 1.

From the results of Table 1 and FIG. 8, the composition ratio of nickel and iron in the nickel-iron alloy is 95% by weight: 5% by weight to 45% by weight: 55% by weight, particularly 90% by weight: 10% by weight to 70% by weight. : It was confirmed that the amount of plastic deformation of the beam portion 21b is small at 30% by weight. Therefore, if the composition ratio of nickel and iron in the nickel-iron alloy is within this range, the beam portion 21b is hardly plastically deformed. As a result, the beam portion 21b is excellent in dimensional stability.
Further, it was confirmed that the beam portion 21b is excellent in durability if the composition ratio of nickel and iron in the nickel-iron alloy is within the above range.

It is a schematic block diagram which shows an example of the probe unit obtained by the manufacturing method of the probe unit of this invention, Fig.1 (a) is a top view, FIG.1 (b) is sectional drawing which shows the state cut | disconnected by II-II It is. It is a schematic block diagram which shows the other example of the probe unit obtained by the manufacturing method of the probe unit of this invention, Fig.2 (a) is sectional drawing which shows the state in which the coating layer was formed in the upper surface whole surface of the probe pin. FIG. 2B is a cross-sectional view showing a state in which a coating layer is formed on the entire surface of the beam portion, and FIG. 2C shows the entire surface of the portion of the probe pin not joined to the probe holding portion. FIG. 2D is a cross-sectional view showing a state in which the coating layer is formed on the entire surface of the portion other than the beam portion of the probe pin. It is a schematic block diagram which shows the other example of the probe unit obtained by the manufacturing method of the probe unit of this invention, and is sectional drawing which shows the state in which the projection part was formed in the front-end | tip of the beam part of a probe pin. It is a schematic block diagram which shows the other example of the probe unit obtained by the manufacturing method of the probe unit of this invention, and is sectional drawing which shows the state in which the wiring extraction part of the probe pin was provided in the lower surface of the probe unit. It is a cross-sectional schematic diagram which shows one Embodiment of the manufacturing method of the probe unit of this invention. It is a cross-sectional schematic diagram which shows one Embodiment of the manufacturing method of the probe unit of this invention. It is a schematic sectional drawing explaining the durability test of a probe unit. It is a graph which shows the relationship between the ratio of the nickel contained in the nickel-iron alloy which forms the beam part of a probe pin, and the plastic deformation amount of the beam part in a bending test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Probe unit, 2 ... Probe pin, 2a ... Main body part, 2b ... Beam part, 2c ... Tapered part, 2d, 15d ... Wiring extraction part, 2e ... Main body Upper surface of portion 2a, 3 ... probe holding portion, 3a ... upper surface of probe holding portion 3, 4,16 ... joining portion, 5,17 ... lead wire, 6 ... covering layer, 7 ... Projection, 11 ... Substrate, 11a ... Opening, 12 ... Sacrificial layer, 13 ... Plating seed layer, 14 ... Resist film, 15 ... Metal layer.

Claims (2)

Forming an opening in the substrate;
Forming a sacrificial layer in the opening;
Making the surface of the substrate and the sacrificial layer uniform;
Forming a probe pin base layer;
Forming a resist pattern in which an opening corresponding to a beam portion of the probe pin is formed on the base layer formed on the sacrificial layer;
Forming a probe pin by plating a metal material on the foundation layer in a portion where the resist is not formed;
Removing the resist and unnecessary underlayer;
Removing the sacrificial layer;
Cutting the substrate in the region where the sacrificial layer has been removed;
A method of manufacturing a probe unit comprising: The probe pin is formed by nickel alloy plating.
The manufacturing method of the probe unit of Claim 1.

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