JP3129655B2 - Test contact pin manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing test contact pins used as probe pins, socket pins, and the like. More specifically, the present invention relates to a method for manufacturing test contact pins for performing an electrical test by contacting each terminal of an IC chip or a liquid crystal.

[0002]

2. Description of the Related Art Conventionally, this type of test contact pin is generally a movable spring pin having a spring mechanism or a tapered cantilevered probe pin. However, it is difficult to reduce the size of the spring pin because of its mechanism, so that its application is limited to a relatively large one such as a printed board, and a probe pin is exclusively used for testing an IC chip or a liquid crystal. This probe pin is manufactured for each pin by electrolytic polishing or the like.

[0003] Such a conventional test contact pin has a process of arranging tapered probe pins in a fan shape and attaching the probe pins to a probe card, and a process of bending a contact portion at a tip in accordance with the arrangement of IC pads to make the height and pitch uniform. Is put to practical use. These processes are also commonly referred to as needlesticks, and their work requires craftsmanship. Particularly for highly integrated ICs, the demand for more pins and a narrower pitch is strict,
The number of advanced technicians who can respond to this is extremely limited, and the performance of the product tends to vary and reliability tends to decrease. Also, difficult readjustment work is often required during use. Therefore, when the conventional test contact pins are used, the productivity and performance of cards, sockets and the like cannot keep up with the progress of ICs.

[0004] In order to solve this problem, a method of forming a contact pin by etching has been proposed.
In dry etching, the productivity is too poor, and in wet etching, there are defects such as the required contact force being unable to be secured due to the poor cross-sectional shape of the pin due to the occurrence of taper etch and the like. Further, even if the cross-sectional shape is secured by using an anisotropic material, the conductivity cannot be secured because the material is limited. In addition, there is a method of giving up a pad to a wiring pattern on a resin board and pressing the wiring pattern on the resin substrate by giving up the contact portion as a pin. However, this method cannot secure a so-called overdrive, so that the contact pressure tends to fluctuate and the contact resistance is poor. Stable and unreliable. As a result, such contact pins manufactured by etching are impractical apart from experimental or limited use.

[0005] In order to solve the above problems, a method of manufacturing a test contact pin utilizing the techniques of photochemistry and plating has been proposed (JP-A-6-31377).
5). In this method, as shown in FIGS. 10A to 10H, a base metal layer 1 is formed on a supporting metal plate 6, a photoresist layer 2 is formed on the base metal layer 1, The photoresist layer 2 is exposed by applying a mask 3 having a predetermined pattern, and the photoresist layer 2 is developed to remove a portion serving as a test contact pin, thereby forming an opening 2a in the remaining photoresist layer 2, This opening 2
a, a metal layer 4 serving as a test contact pin is formed by plating, and a film 5 covering a portion other than a portion provided for the test contact pin is adhered on the metal layer 5 via an adhesive 5a. In this method, a portion composed of the film 5, the metal layer 4, and the base metal layer 1 is separated from the supporting metal plate 6 to produce the test contact pins 4 using the film 5 as a support. According to this method, I
Test contact pins suitable for testing a C chip, a liquid crystal or the like can be manufactured with high productivity.

[0006]

The test contact pin has a certain strength and elasticity so that the pin is not deformed or broken when the electrode portion to be tested is scrubbed to secure conductivity. Is required. In order to meet this demand, a test contact pin having a high aspect ratio, that is, a ratio of the width w of the pin to the thickness t of the pin (t / w) in the cross section of the contact pin 14 shown in FIG. 5 is required. . JP-A-6-31
When a test pin having a large thickness t and a high aspect ratio is to be manufactured by the method disclosed in Japanese Patent No. 3775, the resolution of the photoresist is extremely deteriorated, and the resolution shown in FIG. Thus, the bottom of the opening 2a formed in the photoresist layer 2 after exposure and development does not have a desired shape. That is, as shown in FIG. 11A, a part of the contact portion of the remaining photoresist layer 2 with the base metal layer 1 may be eroded. When the metal layer 4 is formed in the opening 2a in this state, the edge of the contact portion of the pin (the portion C in the figure) does not become sharp as shown in FIGS. 11B and 11C. For this reason, the above-mentioned method has a problem that a test contact pin having a pin cross section having a high aspect ratio and a rectangular shape cannot be obtained.

An object of the present invention is to solve such problems of the prior art, and to provide a method of manufacturing test contact pins suitable for testing an IC chip, a liquid crystal or the like with high productivity. It is in. It is another object of the present invention to provide a method of manufacturing a test contact pin having a rectangular cross section having a high aspect ratio and a rectangular shape.

[0008]

The invention according to claim 1 is
As shown in FIGS. 1 (a) to 1 (j), a base metal layer 1 which can be coupled to a metal layer 14 serving as a test contact pin
(1) a step of plating a base metal layer (11) on a flat and smooth supporting metal plate (10), which is peelable from the base metal layer (11), a step of forming a photoresist layer (12) on the base metal layer (11); A step of applying a mask 13 having a predetermined pattern to the photoresist layer 12 and exposing the same; and developing the exposed photoresist layer 12 to remove a portion serving as a test contact pin and to form an opening in the remaining photoresist layer 12. Forming the base metal layer 11 facing the bottom of the opening 12a;
Forming a concave portion 11a by uniformly removing the surface layer of a predetermined thickness, and an opening 12a in which the concave portion 11a is formed.
Forming a metal layer 14 serving as a test contact pin by plating, removing the remaining photoresist layer 12, and forming a film 15 on the metal layer 14 excluding a portion serving as a contact portion of the test contact pin. The step of applying the adhesive via the adhesive 15a and the step of
A test contact including a step of peeling the base metal layer 11 together with the metal layer 14 and the film 15 from the substrate, and a step of removing the base metal layer 11 to obtain a test contact pin made of the metal layer 14 supported by the film 15. This is a method for manufacturing a pin.

In the manufacturing method according to the first aspect of the present invention,
As shown in FIG. 2A, the photoresist layer 12 is formed to such an extent that the resolution of the photoresist is not extremely reduced, in other words, the photoresist layer 12 is not formed too thick. As a result, the bottom of the opening 12a formed in the photoresist layer 12 after exposure and development has a desired shape. On the other hand, base metal layer 11 is formed relatively thick, and base metal layer 11 facing the bottom of opening 12a is formed.
When the concave portion 11a is formed by uniformly removing the surface layer by a predetermined thickness, the metal layer 1 is formed as shown in FIGS. 2 (b) and 2 (c).
4 is formed at a depth t _{1 of the} opening 12a.
Depth t ₂ of the concave portion 11a is increased to join with. FIG.
As shown in (i), (j) and FIG. 2 (d), the base metal layer 11 is finally removed. As a result, a test contact pin having a rectangular cross section with a high aspect ratio and a rectangular shape is obtained. In addition, since the surface layer of a part of the base metal layer on the supporting metal plate is uniformly removed by etching to form the metal layer, the positions of the contact points of each contact pin are relatively uniform, and the surface is smooth. It is.
Therefore, sufficient overdrive and a substantially uniform and sufficient contact pressure can be ensured even for a demand for a larger number of pins and a narrower pitch, which is suitable for testing IC wafers and bare chips. Furthermore, since it can be manufactured only by a general process such as an etching process, the pin manufacturing efficiency is good.

The invention according to a second aspect is shown in FIGS.
As shown in (j), a base metal layer 11 that can be combined with a metal layer 14 serving as a test contact pin is formed on a flat and smooth supporting metal plate 10 that is peelable from the base metal layer 11 by plating. Performing, a step of forming a photoresist layer 12 on the base metal layer 11, a step of applying a mask 13 having a predetermined pattern to the photoresist layer 12, and exposing the photoresist layer 12 to light. Forming an opening 12a in the remaining photoresist layer 12 by removing a portion to be a contact pin for testing,
forming a concave portion 11a by uniformly removing a surface layer of the base metal layer 11 facing the bottom of the base metal layer 11 by a predetermined thickness, and forming a metal coating 16 made of the same metal as the base metal layer 11 on the concave portion 11a. A step of forming by plating, a step of forming a metal layer 14 serving as a test contact pin in the opening 12a in which the metal film 16 is formed, a step of removing the remaining photoresist layer 12, and a step of removing the test contact pin. A step of applying a film 15 via an adhesive 15a on the metal layer 14 excluding a part to be a contact part of the above, and forming a base metal layer 11 from the supporting metal plate 10 with a metal coating 16, a metal layer 14, and a film 15;
And the metal layer 1 supported by the film 15 by removing the base metal layer 11 and the metal coating 16.
And a step of obtaining a test contact pin comprising:

In the manufacturing method according to the second aspect of the present invention,
As shown in FIG. 4A, the photoresist layer 12 is formed to such an extent that the resolution of the photoresist is extremely reduced.
In other words, the photoresist layer 12 is formed relatively thick. As a result, the bottom of the opening 12a formed in the photoresist layer 12 after exposure and development is partially eroded without having a desired shape. As shown in FIG.
After the surface layer of the base metal layer 11 facing the bottom of 2a is uniformly removed by a predetermined thickness to form the recess 11a, FIG.
As shown in FIG. 1C, a metal film 16 is formed on the base metal layer 11 so as to fill the eroded portion of the concave portion 11a and the bottom of the opening 12a. 3 (i), (j) and FIG.
This metal film 16 is finally removed together with the base metal layer 11 as shown in FIG. Accordingly, it is possible to prevent the pin from having an undesired tapered cross-sectional shape or to prevent the pin contact portion from being deformed, and to manufacture a contact pin having a rectangular, high-aspect ratio and preferable cross-sectional shape. Also, since the plating is performed on the supporting metal plate and then separated, the positions of the contact points of the respective contact pins are relatively uniform, and the surface is smooth. Therefore, as in the case of the first aspect of the present invention, sufficient overdrive and almost uniform and sufficient contact pressure can be ensured even for a demand for a higher pin count and a narrower pitch. Suitable for testing. Further, since it can be manufactured only by a general process such as a plating process, the pin manufacturing efficiency is good.

As shown in FIG. 6 and FIG.
4 is covered with the film 15 except the portion provided for the test contact pins. Thereby, the film 1
5 serves as a support, and a large number of contact pins 14 are formed integrally with the film.
A plurality of contact pins can be handled collectively when assembled into a socket or the like. Therefore, it is easy to assemble without a craftsmanship such as a needle stand. That is, by using the test contact pins, it is possible to improve the productivity of a product incorporating a pin such as a card or a socket.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the first embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view of each step of the embodiment. 6 and 7 are schematic diagrams of the test contact pin 14d, the lead-out wiring pattern 14e connected thereto, and the film 15 on which these are formed. This is for explanation, and in practice, the number of test contact pins is generally several tens to several hundreds, and the pitch is not always constant. Hereinafter, the test contact pins are simply referred to as pins, the lead-out wiring patterns are referred to as patterns, and the pins 14d and the patterns 14e are collectively referred to as pins 14. The entirety of the pin 14 and the like and the film 15 are referred to as a test contact pin 22 with a film. The manufacturing process of the pin according to the first embodiment mainly includes a base metal layer forming process, a resist pattern forming process which is the first process of the plating process, and a base metal layer forming process which is an intermediate process of the plating process. A step of etching part of the surface layer, an electrolytic plating step of forming a metal layer which is the final step of the plating process, a film attaching step, a peeling step which is the first half of the separation step, and a second half of the separation step And a removing step. The material of the pin 14 is N from the viewpoint of strength and toughness.
i is good. Further, Pd or the like may be included. When importance is placed on conductivity, gold is preferably coated to increase conductivity. Alternatively, a copper alloy may be used instead of Ni.

Hereinafter, each step will be described in this order. In the step of forming the base metal layer, a thin copper layer 11 as a base metal layer is formed on a stainless steel plate 10 as a supporting metal plate by electrolytic plating. The use of copper for the base metal layer is excellent in that the adherence to the Ni pins 14 and the like is excellent and that the adherence to the stainless steel plate 10 is weaker than the adherence of the film 15 to the Ni pins 14 and the like. This is because it is a conductor. Since copper is more conductive than stainless steel, electrolytic plating is performed quickly and uniformly. The stainless plate 10 is mirror-finished, and its surface is flat and smooth. In the step of forming a resist pattern, a photoresist 12 is formed on the copper layer 11.
(See FIG. 1 (a)), and a mask 1
Exposure is carried out through the substrate 3 (see FIG. 1B). This allows
The pattern corresponding to the mask 13 is transferred to the resist 12. Further, this is developed to form a resist 12 having a pattern corresponding to the mask 13, and a resist mask is applied on the copper layer 11 (see FIG. 1C).

In the step of etching a part of the surface layer of the copper layer, the surface layer of the copper layer 11 appearing in the portion where the resist mask is not formed is uniformly removed by a predetermined depth by wet etching to form the concave portion 11a. (Refer to the enlarged view of FIG. 1D and FIG. 2B). This depth t ₂ is 6 to 40% of the copper layer 11. For example, the thickness of the copper layer is 20 to 50 μm
Then, the depth t ₂ is 2 to 20 μm. It is desirable that the depth t ₂ be as large as possible in order to make the final cross-sectional shape of the pin a high aspect ratio. Next, Ni is attached to the concave portion 11a by electrolytic plating, and
2a to form a Ni layer 14 (FIG. 1 (e)).
reference). After the completion of the Ni plating, the resist 12 is removed (see FIGS. 1F and 2C). The Ni layer 14 thus formed is provided for pins.

In the film deposition step, a polyimide film 15 covering the pattern 14e and the like other than the portions 14d provided for the pins shown in FIG. 7 is deposited on the Ni layer 14. Specifically, adhesive (plastic for bonding) 1
Thermocompression bonding is performed from above the film 15 with a jig having a flat pressing surface with the film 5a interposed therebetween (see FIG. 1 (g)). As a result, the plastic side is partially deformed in accordance with the pins 14, so that N
Fine irregularities and thickness irregularities existing on the upper surface of the i-layer 14 are absorbed. As a result, the thickness of the test contact pin 22 with a film shown in FIG. 5 can be made uniform. The film 15 has a window hole 15b (see FIG. 7). The film 15 is bonded to the pin (Ni layer) 14 with the portion 14d of the pin 14 facing the window hole 15b. As a result, the pin portion 14d is supported by the film 15 in a cantilever state, and the film 15 is used as a support for integrally supporting the pins 14d and the like.

In the peeling step, the portion consisting of the copper layer 11, the Ni layer 14, and the film 15 is
1 and separated from the stainless steel plate 10. As described in the description of the base metal layer forming process, the Ni 14
Since they are weaker than the adhesive force of the film 15 corresponding to the above, they can be easily separated without damaging the film 15 and the like (see FIG. 1 (h)). In the removing step, the copper layer 11 is removed from the Ni layer 14 by wet etching. Copper layer 1
Since 1 is extremely thin, the copper layer 11 is removed without damaging the Ni layer 14 using an etching solution having a high selectivity (see FIGS. 1 (i), (j) and 2 (d)). .

The test contact pin 14 thus manufactured has a substantially rectangular cross section and a high aspect ratio. Usually, w shown in FIG.
t is 50 μm. By setting t ₂ to about 20 μm, a test contact pin 14 having a cross section of t of about 70 μm and w of 50 μm is obtained.

FIG. 3 is a schematic sectional view showing each step of the second embodiment of the present invention. The manufacturing process of this pin mainly includes a base metal layer forming process, a resist pattern forming process which is the first process of the plating process, and an electrolytic plating process of forming a metal film which is an intermediate process of the plating process, It comprises an electroplating step for forming a metal layer, which is the final step of the plating process, a film applying step, a peeling step which is the first half of the separation step, and a removing step which is the second half of the separation step. The material of the pin 14 is the same as that of the first embodiment.

In this embodiment, the base metal layer forming step, the resist pattern forming step, the film attaching step, the peeling step which is the first half of the separation step, and the removing step which is the second half of the separation step are the first step. This is substantially the same as the embodiment. The feature of this embodiment is that FIG.
, That is, the steps of FIGS. 4B and 4C. That is, as shown in FIG. 4 (b), the surface layer of the copper layer 11 appearing in the portion where the resist mask is not formed is uniformly removed by a predetermined depth by wet etching to form the recess 11
a is formed. Next, as shown in FIG. 4C, the same Cu as the base metal layer is formed in the concave portion 11a by electrolytic plating.
To form It is desirable that the amount of the plating adhered is as small as possible in order to make the final cross-sectional shape of the pin a high aspect ratio. That is, the thickness of the metal film 16 is the minimum amount that can flatten the irregular bottom of the opening 12a as shown in FIG. 4C. Next, Ni is deposited and grown on the metal film 16 by electrolytic plating (see FIG. 1E).
After the Ni plating, the resist 12 is removed (FIG. 1).
(F) and FIG. 2 (d)). The Ni layer 14 thus formed is shaped by the metal coating 16 even if the bottom of the opening 12a is irregular. This Ni layer 14 is provided for pins.

The test contact pins 14 obtained in the above-described first and second embodiments are bent in a cantilever shape and come into contact with an IC chip, a liquid crystal, or the like. A larger contact pressure and an overdrive ability than the pin can be exhibited. In addition, the bending rigidity in the oblique direction is large, so that it is unlikely to bend obliquely. Therefore, there is no inconvenience (about 50 μm) even if the pitch is reduced.
In addition, contact portions 14a that come into contact with an IC chip or a liquid crystal,
In FIGS. 14b and 14c (FIGS. 1 (j) and 3 (j)), the heights of the stainless steel plates 10 are uniform, corresponding to the flat surface. Therefore, there is no need to adjust the height of the pin tip. Further, contact portions 14a, 1 to which a tensile stress is applied when they come into contact with an IC chip or a liquid crystal.
4b and 14c have a smooth surface state corresponding to the smooth surface of the stainless steel plate 10. Therefore, the fatigue strength affected by the surface smoothness increases, and the number of times of repeated use increases.

FIGS. 8 and 9 show an example in which the test contact pin 22 with a film manufactured in this manner is applied to a bare chip 3 of an IC to be tested.
This shows a so-called chip carrier that holds 0 inside.
8 and 9, reference numeral 20 denotes a chip carrier main body;
1 is a jig for fixing a pin with a film, 23 is a jig for holding a pin with a film, 24 is a spring metal for pressing a pin against a chip, and 25 is a support for positioning.
Although not shown, the test contact pins 22 with a film are also applied to a probe card.

[0023]

As described above, according to the method for manufacturing a test contact pin of the present invention, a test contact pin suitable for testing an IC chip, a liquid crystal, or the like is formed by using photochemical and plating techniques. It has the advantage that it can be manufactured with high productivity, and its pin cross-section has a high aspect ratio and can be rectangular. Thus, there is an effect that a method of manufacturing a test contact pin with high productivity suitable for testing an IC chip, a liquid crystal, or the like can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a manufacturing process of a test contact pin according to a first embodiment of the present invention in the order of steps.

FIG. 2 is a sectional view showing a process of a main part thereof.

FIG. 3 is a cross-sectional view showing a manufacturing process of a test contact pin according to a second embodiment of the present invention in the order of steps.

FIG. 4 is a sectional view showing a step of a main part thereof.

FIG. 5 is a perspective view of a main part of the test contact pin.

FIG. 6 is a cross-sectional view taken along the line AA of FIG. 7 showing the test contact pin with the film.

FIG. 7 is a plan view of the test contact pin with the film.

FIG. 8 is a perspective view of a chip carrier using the test contact pins with a film.

FIG. 9 is an enlarged sectional view taken along line BB of FIG. 8;

FIG. 10 is a cross-sectional view showing the steps of manufacturing a conventional test contact pin in the order of steps.

FIG. 11 is a sectional view showing a step of a main part thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Support metal plate 11 Base metal layer 11a Depression 12 Photoresist layer 12a Opening 13 Mask 14 Ni layer (metal layer), pin 15 Film 15a Adhesive 16 Metal coating

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hideaki Yoshida 12-12, Techno Park, Mita City, Hyogo Prefecture Mitsubishi Materials Corporation Mita Plant (72) Inventor Akihiro Masuda 1-297, Kitabukurocho, Omiya City, Saitama Prefecture Materials Research Institute (56) References JP-A-6-334006 (JP, A) JP-A-6-3244081 (JP, A) JP-A-6-313788 (JP, A) JP-A-6-331655 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 1/06-1/073 H01L 21/66

Claims (2)

(57) [Claims] A metal layer (1) serving as a test contact pin
4) forming a base metal layer (11) that can be combined with the base metal layer (11) by plating on a flat and smooth supporting metal plate (10) that is peelable from the base metal layer (11); A step of forming a photoresist layer (12) on the layer (11), and a mask (1) having a predetermined pattern on the photoresist layer (12).
3) applying and exposing, and developing the exposed photoresist layer (12) to remove a portion to be a test contact pin and form an opening (12a) in the remaining photoresist layer (12). Forming the base metal layer (11) facing the bottom of the opening (12a).
Forming a recess (11a) by uniformly removing the surface layer by a predetermined thickness, and plating a metal layer (14) serving as the test contact pin on the opening (12a) in which the recess (11a) is formed. A step of removing the remaining photoresist layer (12); and bonding a film (15) on the metal layer (14) except for a portion serving as a contact portion of the test contact pin. (15
a) interposing the base metal layer (11) together with the metal layer (14) and the film (15) from the supporting metal plate (10); and Removing the (11) to obtain a test contact pin made of the metal layer (14) supported by the film (15). 2. A metal layer (1) serving as a test contact pin.
4) forming a base metal layer (11) that can be combined with the base metal layer (11) by plating on a flat and smooth supporting metal plate (10) that is peelable from the base metal layer (11); A step of forming a photoresist layer (12) on the layer (11), and a mask (1) having a predetermined pattern on the photoresist layer (12).
3) applying and exposing, and developing the exposed photoresist layer (12) to remove a portion to be a test contact pin and form an opening (12a) in the remaining photoresist layer (12). Forming the base metal layer (11) facing the bottom of the opening (12a).
Forming a recess (11a) by uniformly removing the surface layer by a predetermined thickness, and plating the recess (11a) with a metal coating (16) made of the same metal as the metal of the base metal layer (11). Forming a metal layer (14) serving as the test contact pin by plating in the opening (12a) in which the metal film (16) is formed, and forming the remaining photoresist layer (12). Removing a film (15) on the metal layer (14) except for a portion to be a contact portion of the test contact pin with an adhesive (15).
a) attaching the base metal layer (11) together with the metal coating (16), the metal layer (14), and the film (15) from the supporting metal plate (10). A test contact comprising the steps of: removing the base metal layer (11) and the metal coating (16) to obtain a test contact pin comprising a metal layer (14) supported on the film (15). Pin manufacturing method.