JP3129641B2 - 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. 8A to 8H, 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, A metal layer 4 serving as a test contact pin is formed in the opening 2a 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 4 via an adhesive 5a. After that, 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, and the test contact pins 4 using the film 5 as a support are manufactured. According to this method, test contact pins suitable for testing IC chips, liquid crystals, and the like can be manufactured with high productivity.

[0006]

The test contact pin has an integral strength and elasticity so that the pin is not deformed or broken when the electrode portion to be tested is scrubbed to ensure conductivity. Is required. To meet this demand, a test contact pin having a high aspect ratio, that is, a ratio (t / w) of the pin width w to the pin thickness t in the cross section of the contact pin 14 shown in FIG. 3 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 reduced. 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, when the remaining photoresist layer 2 rises from the base metal layer 1 as shown by C in FIG. 9A, when the metal layer 4 is formed in the opening 2a, FIGS. 9B and 9C As shown in D), adjacent metal layers 4 and 4 are connected and short-circuited. FIG.
If a part of the remaining photoresist layer 2 in contact with the base metal layer 1 erodes as shown at E in FIG.
(B) and contactors bets portion of the edge of the pin, as shown in F of (c) (G portion in the figure) is not a sharp shape. 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. A step of forming a metal film 16 made of the same metal as the base metal layer 11 at the bottom of the opening 12a by plating; and a step of forming a test contact in the opening 12a where the metal film 16 is formed. Forming a metal layer 14 serving as a pin by plating, removing the remaining photoresist layer 12, Process and the supporting metal plate metal coating 16 and the metal layer of the base metal layer 11 to 10, the film 15 on the metal layer 14 excluding the portion serving contactor bets of use contact pins deposited with an adhesive 15a Peeling together with the film 14 and the film 15, and the base metal layer 1
1 and a step of removing the metal coating 16 to obtain a test contact pin composed of the metal layer 14 supported on the film 15.

In the manufacturing method according to the first aspect of the present invention,
Instead of forming contact pins directly by etching, contact pins are formed by plating on unmasked portions. In an attempt to manufacture a test contact pin having a high aspect ratio, the resolution of the photoresist is extremely reduced. As shown in FIG. 2A, the bottom of the opening 12a formed in the photoresist layer 12 after exposure and development is reduced. Even if the desired shape is not obtained, FIG.
As shown in FIG. 2D and FIG. 2B, by forming the metal film 16 on the base metal layer 11, the eroded portion of the remaining photoresist layer 12 is supplemented by the metal film 16.
This metal film 16 is finally removed together with the base metal layer 11, as shown in FIGS. 1 (i) and 1 (j) and FIGS. 2 (c) and 2 (d). Accordingly, or become cross-sectional shape of the pin and the undesired tapered, to prevent the Pinkontaku isolation portion becomes irregular, it is possible to manufacture the contact pins of the preferred cross-sectional shape of the high aspect ratio substantially rectangular 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, 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. 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 FIGS. 4 and 5, the metal layer 1
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.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view of each step, and FIGS. 4 and 5 show test contact pins 14d and lead-out wiring patterns 1 connected thereto.
4e and the like, and the overall schematic diagram of the film 15 on which these are formed are shown. 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 14
e is referred to as a pin 14 together. 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 pin manufacturing process mainly includes a base metal layer forming process, a resist pattern forming process which is the first process of the plating process, an electrolytic plating process for forming a metal film which is an intermediate process of the plating process, and a plating process. Electroplating step of forming a metal layer, which is the final step of the process, film deposition step, and peeling step which is the first half of the separation step,
And a removal step, which is the latter half of the separation step. The material of the pin 14 is preferably Ni from the viewpoint of strength and toughness. Further, Pd or the like may be included. When importance is placed on conductivity, gold is preferably coated to increase conductivity. Alternatively, beryllium copper 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 to ultraviolet light is carried out through the substrate 3 (see FIG. 1B). As a result, a pattern corresponding to the mask 13 is
Transfer to 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 electrolytic plating step, an opening 12a above the copper layer 11 which appears in a portion where the resist mask is not
First, the same Cu as the base metal layer is formed by electrolytic plating (see FIGS. 1D and 2B). 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, as shown in FIG.
The minimum amount that can flatten the irregularly shaped bottom of a. Next, Ni is deposited and grown on the metal film 16 by electrolytic plating (see FIG. 1E). After the end of the Ni plating, the resist 12 is removed (FIG. 1F and FIG.
(C)). 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.

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. 5 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. 5). 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, a portion composed 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)). The removal process is performed using the metal coating 1
6 and the copper layer 11 are removed from the Ni layer 14 by wet etching. Since the metal coating 16 and the copper layer 11 are extremely thin,
The metal film 16 and the copper layer 11 are 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 manufactured in this manner has a substantially rectangular cross section (typically 50 μm).
× 50 μm) and a high aspect ratio. Therefore, when it is bent into a cantilever shape and comes into contact with an IC chip or liquid crystal,
The contact pressure and the overdrive capability can be exerted higher than those of pins having a triangular cross section or a circular cross section. In addition, the bending rigidity in the oblique direction is large, so that it is unlikely to bend obliquely. Therefore, there is no inconvenience even if the pitch is reduced (about 80 μm).
m). In addition, a contact portion 1 that comes into contact with an IC chip or liquid crystal.
4a, 14b, and 14c (see FIG. 1 (j)) have the same height corresponding to the flat surface of the stainless steel plate 10. Therefore, there is no need to adjust the height of the pin tip. Further, the contact portions 14a, 14 to which a tensile stress is applied when the contact portions 14a, 14
b 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. 6 and 7 show a bare chip 3 of an IC to be tested as an example of applying the test contact pin 22 with a film manufactured in this manner.
This shows a so-called chip carrier that holds 0 inside.
6 and 7, reference numeral 20 denotes a chip carrier main body, 2
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.

[0018]

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 step of a test contact pin 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 perspective view of a relevant part of the test contact pin.

FIG. 4 is a sectional view taken along line AA of FIG. 5, showing the test contact pin with a film.

FIG. 5 is a plan view of the test contact pin with a film.

FIG. 6 is a perspective view of a chip carrier using the test contact pins with a film.

FIG. 7 is an enlarged sectional view taken along the line BB of FIG. 6;

FIG. 8 is a cross-sectional view showing the steps of manufacturing a conventional test contact pin in the order of steps.

FIG. 9 is a sectional view showing a step of a main part thereof.

[Explanation of symbols]

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

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-334006 (JP, A) JP-A-6-3244081 (JP, A) JP-A-6-313788 (JP, A) JP-A-6-313788 331655 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01R 1/06-1/073 H01L 21/66

Claims (1)

(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 a metal coating (16) made of the same metal as the base metal layer (11) on the bottom of the opening (12a) by plating; and forming the metal coating (16). step and a step of removing the photoresist layer (12) to the remaining contactors preparative portion of the test contact pin is formed by metal layer serving as the test contact pin into the opening (12a) (14) plated A film (15) is applied on the metal layer (14) except for the portion to be
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.