JP4114235B2 - Inspection jig - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection jig used for reliability tests such as continuity inspection and thermal shock of a semiconductor or a printed circuit board, and more particularly to an inspection jig compatible with a BGA (ball grid array) chip.
[0002]
[Prior art]
Conventionally, a continuity test of a semiconductor chip such as a BGA is performed by using a test jig having a frustoconical test electrode 21 as shown in FIG. A reliability test was conducted.
[0003]
In such reliability testing methods such as continuity inspection and thermal shock, the contact between the inspection electrode and the solder ball is stable when the center position of the truncated conical inspection electrode and the solder ball of the semiconductor chip such as BGA is aligned. However, even if a slight shift occurs, the contact area between the test electrode and the solder ball decreases and the electrical connection becomes unstable, and if it is shifted from the center, an oblique force is applied to the test electrode and the solder ball. There is a problem in that the deformation of the ball occurs, accumulates as strain, and causes metal fatigue, resulting in a short repeated use life of the test electrode.
[0004]
In addition, depending on the structure of the socket to which the inspection jig is attached, a lateral force is applied to the inspection jig and the semiconductor chip when attaching to the socket, resulting in poor connection or distortion in the inspection electrode and accumulation of the inspection jig. There is a problem of reducing the life.
[0005]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described problems, and a reliable electrical connection is obtained with respect to a slight (about 10 to 20 μm) positional deviation between a solder ball of a semiconductor chip such as a BGA and an inspection jig. An object of the present invention is to provide an inspection jig.
[0006]
[Means for Solving the Problems]
Therefore, in order to solve the above problems, the present invention is an inspection jig that performs continuity inspection by pressing a test electrode against a solder ball (solder ball) of a semiconductor chip such as a BGA, and the tip shape of the test electrode is an elliptic cylinder. The inspection jig is characterized by having a shape.
[0007]
By making the tip shape of the inspection electrode of the inspection jig into an elliptical cylindrical shape, even if the solder ball of the semiconductor chip and the inspection jig electrode are slightly displaced (about 10 to 20 μm), the contact area is determined from the shape. Therefore, reliable electrical contact can be made. In addition, when the chip shape of BGA or the like is rectangular, if the elliptical long axis of the elliptical cylinder is aligned with the long side direction of the rectangle, it is possible to reliably prevent slight positional deviation (about 10 to 20 μm) in the long side direction. Can make electrical contact.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 shows a partial perspective view and a partial cross-sectional view of an inspection jig of the present invention. As shown in FIG. 1, an elliptical cylindrical inspection electrode 19 is formed on one surface of a film-like insulating substrate 13, and a wiring pattern 18a and a wiring electrode 18b are formed on the other surface. 18a is electrically connected through the wiring electrode 18b. Furthermore, the wiring pattern 18 a is connected to external connection terminals formed around the insulating substrate 13.
[0009]
Hereinafter, a method for producing the inspection jig of the present invention will be described with reference to FIGS.
First, the resin layer 12 and the insulating substrate 13 are formed on the metal substrate 11 (see FIG. 2A). The metal substrate 11 can be used as long as it is a metal having conductivity. Here, a stainless steel plate is preferable in terms of the manufacturing process. The resin layer 12 is for adjusting the height of the inspection electrode 19 to be described later, and any resin having an insulating property can be used. A liquid photosensitive resist or dry film that is easy to handle is suitable.
[0010]
The insulating substrate 13 serves as a support substrate for the inspection jig, and is required to have insulation, heat resistance, dimensional stability, and mechanical strength. Polyester, epoxy, acrylic, polyimide resin, etc. can be used. Is preferred.
[0011]
Next, an elliptical opening 14 is formed by laser processing at predetermined positions of the resin layer 12 and the insulating substrate 13 (see FIG. 2B).
Specifically, a mask in which an elliptical opening pattern is formed in a laser-impermeable film (such as a metal film or a dielectric multilayer film) formed on a glass substrate is prepared, and an excimer laser is passed through this mask to a resin layer. 12 and the insulating substrate 13 are irradiated to form an elliptical opening 14.
[0012]
Next, the metal substrate 11 is used as the cathode of the plating electrode, and the conductive electrode 15 is formed in the opening 14 by electrolytic plating (see FIG. 2C). The conductor electrode 15 can be used as long as it is a metal material excellent in conductivity such as copper, nickel, and aluminum, but may be used alone or in combination in consideration of strength, hardness, and the like. Further, although it may be used in combination with a noble metal (gold, platinum, palladium, tungsten, etc.) material, nickel metal is preferable from the viewpoint of physical strength, conductivity, cost, and the like.
[0013]
Next, in order to form a wiring pattern by a semi-additive method, the thin film conductor layer 16 is formed on the insulating substrate 13 and the conductor electrode 15 by vapor deposition sputtering or electroless plating. Further, a resist pattern 17 is formed on the thin film conductor layer 16 by photolithography (see FIG. 2D).
[0014]
Next, electrolytic copper plating is performed using the thin film conductor layer 16 as a cathode (cathode) electrode for plating to form a conductor layer 18 made of copper on the thin film conductor layer 16 other than the resist pattern 17 (see FIG. 2E). .
Further, the resist pattern 17 is peeled off, and the thin film conductor layer 16 under the resist pattern 17 is soft-etched to form the wiring pattern 18a and the wiring electrode 18b.
[0015]
Here, the wiring pattern 18a and the wiring electrode 18b are formed by the semi-additive method, but the present invention is not limited to this, and a wiring pattern forming process that is generally used, such as a subtractive method and a printing method. Is applicable.
[0016]
Next, by removing the metal substrate 11 and the resin layer 12, an elliptical cylindrical inspection electrode 19 is formed on one side of the insulating substrate 13 as a support substrate, and a wiring pattern 18a and a wiring electrode 18b are formed on the other side. The obtained inspection jig of the present invention can be obtained (see FIG. 2F).
[0017]
【Example】
Hereinafter, the present invention will be described in detail by way of examples.
A resin film 12 is formed by laminating a 50 μm thick dry film resist (manufactured by Hitachi Chemical Co., Ltd.) on a metal substrate 11 made of a 0.25 mm thick SUS plate, and a 25 μm thick polyimide roll is further formed thereon. An insulating substrate 13 was formed by laminating a film (manufactured by Ube Industries).
[0018]
Next, an elliptical opening 14 was formed by irradiating a KrF excimer laser using a mask having an elliptical opening pattern at predetermined positions on the resin layer 12 and the insulating substrate 13. The KrF excimer laser was processed at an energy density of 1.5 j / cm ² . Here, the opening 14 can be formed in the resin layer 12 and the insulating substrate 13 without damaging the metal substrate 11 even if the excimer laser is irradiated under the above conditions.
[0019]
Next, electrolytic nickel plating was performed using the metal plate 11 as a cathode (cathode) electrode to form a conductor electrode 15 in the opening 14.
[0020]
Next, metal chromium and copper were sputtered on the insulating substrate 13 and the conductor electrode 15 with a DC magnetron sputtering apparatus to form a thin film conductor layer 16 having a thickness of about 0.2 to 0.3 μm.
[0021]
Next, a dry film resist having a thickness of 50 μm is laminated on the thin film conductor layer 16 and baked at 70 ° C. for 30 minutes to form a photosensitive layer, and a negative mask of the wiring pattern is formed with a double-sided printer (Oak Manufacturing Co., Ltd.). The resist pattern 17 was formed by exposure at / cm ² and development with a 3% sodium carbonate solution.
[0022]
Next, using the thin film conductor layer 16 as a plating electrode, electrolytic copper plating was performed on the thin film conductor layer 16 other than the resist pattern 17 to form a conductor layer 18 having substantially the same thickness as the resist pattern 17.
[0023]
Next, the resist pattern 17 was dissolved and peeled with a 3% aqueous sodium hydroxide solution, and the thin-film conductor layer 16 under the resist pattern 17 was soft etched to form the wiring pattern 18a and the wiring electrode 18b. .
[0024]
Next, the substrate on which the conductor electrode 15, the wiring pattern 18 a and the wiring electrode 18 b are formed is dipped in a 3% aqueous sodium hydroxide solution, and the metal substrate 11 and the resin layer 12 are peeled and removed, so that the insulating substrate serving as a support substrate is obtained. An inspection electrode 19 having an elliptical cylindrical shape was formed on one side of the substrate 13, and a wiring pattern 18 a and a wiring electrode 18 b were formed on the other side to produce an inspection jig of the present invention.
[0025]
【The invention's effect】
By using the inspection jig of the present invention having an elliptical cylindrical inspection electrode, it is possible to securely connect the solder ball of a semiconductor chip such as a BGA to the inspection jig with a slight (about 10 to 20 μm) positional deviation. And improved reliability during inspection.
In addition, the distortion of the electrode with respect to the positional shift is reduced, and the life of the inspection jig is extended.
[Brief description of the drawings]
FIG. 1A is a schematic partial perspective view showing an embodiment of an inspection jig of the present invention.
(B) shows the structure sectional view of the inspection jig which cut the typical partial perspective view showing one example of the inspection jig of the present invention by the AA 'line.
FIGS. 2A to 2F are cross-sectional views showing the manufacturing steps of the inspection jig of the present invention in the order of steps.
FIG. 3 is a schematic perspective view showing an embodiment of an inspection electrode of a conventional inspection jig.
[Explanation of symbols]
11 ... Metal substrate 12 ... Resin layer 13 ... Insulating substrate 14 ... Opening 15 ... Conductor electrode 16 ... Thin film conductor layer 17 ... Resist pattern 18 ... Conductor layer 18a ... Wiring pattern 18b ... Wiring electrodes 19, 21 ... Inspection electrodes

Claims (1)

An inspection jig that performs continuity inspection by pressing an inspection electrode against a solder ball (solder ball) of a semiconductor chip such as BGA,
Forming a resin layer and an insulating substrate on a metal substrate;
Forming an elliptical opening at a predetermined position on the resin layer and the insulating substrate by laser processing;
Forming an inspection electrode in the opening by electrolytic plating using the metal substrate as a cathode;
Forming a thin film conductor layer by vapor deposition sputtering or electroless plating on the insulating substrate and the conductor electrode;
Forming a resist layer on the thin film conductor layer, and then exposing and developing a predetermined wiring pattern to form a resist pattern;
Performing electrolytic copper plating using the thin film conductor layer as a cathode, and forming a conductor layer made of copper on a thin film conductor layer without a resist pattern;
After peeling off the resist pattern, soft etching the thin film conductor layer that was under the resist pattern to form a wiring pattern and a wiring electrode,
Removing the metal substrate and the resin layer;
The inspection electrode having an elliptical cylindrical tip shape is formed on one surface of the insulating substrate, and the wiring pattern and the wiring electrode are formed on the other surface. Inspection jig characterized by that.

Images