JPH07235359A - Method for formation of socket electrode part for inspecting ic package - Google Patents

Abstract

PURPOSE:To provide an electrode part of a socket for use in inspection equipped with a number of edges, with which it is possible to easily crush or exfoliate an oxide film on the surface of a covering solder layer of a lead when it is to be put in pressure contact, perform connection with the lead easily and certainly, and to make proper inspection of circuit. CONSTITUTION:A socket for inspection is provided with a copper pattern or contact pins having an electrode part to be connected with a lead of an IC package so that inspection of circuit can be made upon accommodating the IC package. Only the portion 2a with electrode part is exposed by a masking means, etc., in a copper pattern or contact pin, and the electrode part 14 is formed which has edges in the portion 2a and in which a number of super-hard particles 11 are implanted by electrodeposited metal 13 by complex electric plating means to be conducted by suspending the super-hard particles 11 in a metal plating bath 10. It is further preferable to form in the electrode part 14 with the electroconductivity enhanced by laminating a gilding layer 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming an electrode portion with a lead in a socket for accommodating an IC (integrated circuit) package and performing a circuit inspection.

[0002]

2. Description of the Related Art ICs are subjected to circuit inspection by mounting probes on their terminal leads after packaging, but in recent years, integrated circuits have become smaller and higher in density, the number of leads has increased, and the lead pitch has narrowed. It tends to be difficult to do. Therefore, the circuit inspection can be performed efficiently, and the lead pitch can be enlarged to facilitate the inspection.
Inspection sockets are becoming popular.

As this inspection socket, as shown in FIG. 6, a copper pattern 2 formed inside a case body composed of a socket body 20 and a cover 21 which are hinged to each other and formed on an insulating film 1 is provided. There is the inspection socket A that was made. As shown in FIG. 7, the copper pattern 2 has electrode portions 2a aligned in the central portion on the insulating film 1 and radially extending to the peripheral portion so that the outer end portion 2b has a large mutual interval. The frame 2 formed by the pattern printing method
It is fixedly held at 2.

The copper pattern 2 is arranged at a predetermined central position of the socket body 20 and is fixed so as to be held between the elastic body 23 and the holding frame 24, and each outer end 2b penetrates the socket body 20. By means of the pin 25, it is possible to conduct electricity to the outside of the inspection socket A.

Then, as shown in FIG. 9, an IC package C having a large number of leads b protruding from the resin sealing portion a is
The lead b can be pressed by the protruding pressing portion 21a of the cover 21 by putting the socket 21 in a predetermined central position in FIG. 6 and closing the cover 21, and as shown in FIG. Through the coating solder layer c, the electrode portion 2a of the copper pattern 2 can be pressed and contacted,
The pin 25 protruding to the outside of the inspection socket A enables the circuit inspection of the IC package C.

Further, as the inspection socket, in addition to the one in which the copper pattern 2 as described above is incorporated, as shown in FIG. 8, a contact pin 26 made of an elastic copper alloy is used.
There is also an inspection socket B that has the interior. The contact pin 26 has an electrode-corresponding portion 26a having a smooth upper surface, a curved portion 26b for utilizing elasticity, and a mounting portion 26 to the socket body 27.
c and a pin portion 26d penetrating the socket body 27 and projecting the tip thereof are integrally formed, and an electrode is provided with a partition wall 27a interposed at the same interval as the lead pitch of the IC package C to be inspected. The mounting portion 26c and the pin portion 26d are press-fitted and fixed to the socket body 27 so that the corresponding portions 26a are arranged side by side. Two types of contact pins 26 are prepared in which the positions of the pin portions 26d in the mounting portion 26c are changed, and when fixing to the socket body 27, the positions of the pin portions 26d are arranged in a staggered manner. The space between the pin portions protruding to the outside can be enlarged. Then, by setting the IC package C and closing the cover 28, the lead b of the IC package C can be pressed against the electrode corresponding portion 26a of the contact pin 26 by the pressing portion 28a of the cover 28, and the pin portion 26d protruding to the outside can be used. The circuit of the IC package C can be efficiently inspected.

[0007]

Some IC package leads are plated with gold. In this case, the inspection socket has its pressing force appropriately strengthened so that the leads and the inspection can be performed. Sufficient connection conduction is achieved only by crimping the electrode-equivalent portion of the power socket. However, as shown in FIG. 10 showing an example of a copper pattern, the lead b of the IC package C has a coating solder layer c. In the case where the lead is plated with gold, a thin non-conductive oxide coating (not shown) is usually formed on the surface of the coated solder layer c by air oxidation. As described above, only by crimping, the lead b and the electrode equivalent portion 2
It cannot be electrically connected to a, and it is necessary to apply a sufficiently strong compressive force and to perform a so-called wiping operation to slide the two so that the oxide film on the surface of the coating solder layer c can be destroyed. There is a problem, and if the crimping and sliding are not sufficiently performed, the performance evaluation of the product is not correctly performed, so that it often takes time to inspect the circuit.

In view of the above situation, the present invention provides an IC for products.
When the package is stored in the inspection socket, the oxide film on the surface of the solder layer of the IC package lead can be destroyed with a comparatively light pressing force, and the connection with the electrode portion of the inspection socket can be performed easily and reliably. It is an object of the present invention to provide a method for efficiently forming a surface having a large number of minute edges capable of destroying an oxide film on an electrode portion of an inspection socket so that a product can be correctly evaluated.

[0009]

In order to achieve the above object, the present invention is provided with an electrode portion connected to a lead of an IC package, and the IC package is housed so that a circuit inspection of the IC package can be performed. The method for forming a connection portion of an inspection socket according to claim 1, wherein the electrode portion of the IC package inspection socket is formed by electroplating means by implanting super-hard particles with electrodeposited metal, and the electrode. When the part is the electrode part of the copper pattern formed on the insulating film, a masking agent is applied to the copper pattern,
By the exposure means using a photomask and the developing means,
A method for forming an electrode portion of an IC package inspection socket, in which only the electrode portion of the copper pattern is exposed and, after electroplating means, super-hard particles are implanted into the electrode portion by electrodeposition metal, and then electrogold plating is performed. Further, in the case where the electrode portion is an electrode portion of a contact pin, only the electrode portion is exposed by using a masking agent, and super-hard particles are implanted in the electrode portion by electrodeposition metal by electroplating means. The present invention proposes a method for forming an electrode portion of an IC package inspection socket which is subjected to electro gold plating after the above.

[0010]

In the test socket containing the copper pattern, the copper pattern can be formed on the insulating film by a pattern printing method. Next, a masking agent with an insulative photoresist is applied on this copper pattern, and the copper pattern is exposed to light through a photomask that indicates the electrode part of each copper pattern. Only can be exposed. Next, in the plating bath of the plating bath, ultra-hard particles such as diamond particles are suspended, the copper pattern is used as a cathode, and the electrolytic metal is mixed with the ultra-hard particles by a composite electroplating means using an electrolytic metal such as nickel as an anode, Electrodeposited on the exposed portion of the copper pattern, that is, the electrode portion, a large number of super-hard particles having edges are planted by the electrodeposited metal with the head exposed on the electrode portion of the copper pattern. After that, by performing a normal electro gold plating treatment, an electrode portion having excellent conductivity can be formed by implanting ultra-hard particles and using the gold plating layer as the uppermost layer.

In an inspection socket containing a contact pin, the contact pin is covered with a masking agent to expose only the electrode portion, and this contact pin is used as a cathode.
By using a composite electroplating means for suspending ultra-hard particles such as diamond in a plating bath using an electrolytic metal such as nickel as an anode, the ultra-hard particles can be implanted on the electrode portion of the contact pin by the electrodeposited metal. After that, an ordinary electro-gold plating treatment is performed to implant ultra-hard particles and form an electrode portion by electro-deposition metal plating with the uppermost layer serving as a gold plating layer.

The density of the ultra-hard particles in the electrode portion can be controlled by the current density in electroplating, the plating time, the amount of the ultra-hard particles added, the suspension method and the plating bath composition.

This copper pattern or contact pin is attached to a predetermined portion of the socket body of the inspection socket, and I
When the C package is housed and the cover is closed and pressed, a large number of ultra-hard particles having edges implanted in the electrode parts of the copper pattern or contact pins come into contact with the leads of the IC package, and the edges are made use of. The oxide film on the surface of the coated solder layer is crushed or peeled off, and the coated solder layer of the lead and the electrodeposited metal on the copper pattern or contact pin are connected in the state of biting of ultra-hard particles. The lead and the copper pattern or the contact pin can be easily and surely electrically connected to each other with a comparatively light pressing force without applying a strong compressive force to the layer and sliding the layer. Further, since the connection between the lead solder layer and the copper pattern or the contact pin is simply pressure contact, the IC package can be easily removed after the inspection.

As the ultra-hard particles, diamond, alumina (Al ₂ O ₃ ), boron nitride (BN), cubic boron nitride (CBN), titanium carbide (TiC),
Carborundum (SiC) or the like can be used and is not required to be a conductive substance.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for forming a copper pattern electrode portion and a contact pin electrode portion of an inspection socket of the present invention will be described below with reference to the drawings according to the embodiments. 1 and 2 are cross-sectional views of a main part of a copper pattern for explaining the steps of the method for forming a copper pattern electrode part according to the present invention, and FIG. 3 is a partially enlarged view showing an electrode part of a copper pattern formed by the forming method of FIG. FIG. 4 is a perspective view showing the connection between the copper pattern of FIG. 3 and the leads of the IC package, and FIG. 5 is the connection between the contact pin having the electrode portion formed by the method of the present invention and the IC package. FIG.

In the case of a copper pattern, the copper pattern 2 formed on the insulating film 1 as shown in FIG. The copper pattern 2 is formed as an assembly of a predetermined number of fine wires, and a copper foil is fixed on an insulating film having a large tensile strength by any means such as vapor deposition or sticking, and then a photoresist is applied. It is obtained by performing pattern printing, then removing the photosensitive resist and unnecessary copper foil portions by developing treatment and etching treatment, and peeling and removing the residual photoresist. This copper pattern is tailored to a given type of IC package. That is, as described above with reference to FIG. 7, the IC package C
Corresponding to the position of the lead b of the thin wire-shaped copper patterns 2 are juxtaposed at the electrode portion 2a at the tip with the same pitch, and are arranged so as to have an enlarged pitch at the outer end 2b on the periphery. Pin 25 (FIG. 6) on the end 2b
Are joined together.

On the copper pattern 2 thus formed on the insulating film 1, a photoresist 3 is applied as a masking agent as shown in FIG. 1B, and a photomask 4 is formed.
And is exposed to ultraviolet rays by the light source 5 to perform an exposure process. The photomask 4 is formed so as to identify the electrode portion 2a having a small area to be connected to the lead b at the tip of the copper pattern 2. Therefore, by removing the altered photoresist 3a with a developing solution after the exposure process, the electrode portion 2a of the copper pattern 2 can be exposed as shown in FIG.

Next, the copper pattern 2 is subjected to a composite electroplating process. The copper pattern 2 is connected to the power supply cathode side 6 after removing oil and grease on the surface by a predetermined pretreatment, and then connected to the power supply anode side 7 as a cathode as shown in FIG. Together with nickel, chrome in the plating tank 9,
Immerse in a metal plating bath 10 of copper or zinc. Injecting ultra-hard particles 11 such as diamond particles into the plating tank 9,
By performing the composite electroplating treatment while stirring the metal plating bath 10 with the stirrer 12, the electrode portion 2a of the exposed copper pattern 2 is electrodeposited with metal and the ultra-hard particles 1 are formed.
As shown in FIG. 2A, a large number of super-hard particles 11 having edges are exposed by the electrodeposited metal 13 to form an electrode portion 14 in which the head is exposed and fixed in an implanted state.

In this composite electroplating, for example, a nickel plate is used as an anode plate and nickel sulfate 250 to 500 is used.
g / l, preferably 280 g / l, nickel chloride 40-
80 g / l, preferably 45 g / l, boric acid 30-70 g / l
1 g of 20 to 150 ct / g of ultra-hard particles having a particle size of 1 to 20 μm, preferably 3 to 6 μm, using a nickel plating bath of 22 g / l, preferably 40 g / l and a brightening agent (trade name: Samolite N-11 and 22). l preferably 80 ct
/ L is added to suspend the reaction, and the treatment is preferably carried out at a current density of 1 to 5 A / dm ^2, preferably 1.5 A / dm ² for 10 to 60 minutes, preferably 20 minutes.

Further, the ultra-hard particles 1 are formed by the electrodeposited metal 13.
The copper pattern 2 in which 1 is implanted is subjected to normal gold plating in a gold cyanide bath in another plating tank, and as shown in FIG. The gold plating layer 15 is formed on the surface to improve the conductivity of the copper pattern 2.

Next, by removing the remaining photoresist 3 of the masking agent by peeling, as shown in FIGS. 2 (c) and 3, the tip of each copper pattern 2 on the insulating film 1 is electrically charged. The super-hard grain 11 can be planted in an exposed state by the deposition metal 13, and the electrodeposition metal 13 portion can form the electrode portion 14 of a small area formed by stacking the gold plating layer 15.

The copper pattern 2 formed in this manner is fitted and fixed to the inspection socket A after its periphery is held by the molded plastic frame. Then, at the time of inspection, by setting the IC package C of the compatible type at a predetermined center position (see FIG. 6), the lead b of the IC package C comes into contact with the super-hard particles 11 of the electrode portion 14.

Then, when the cover 21 of the inspection socket A is closed, the lead b of the IC package C is pressed by the pressing portion 21a of the cover 21, as shown in FIG.
The ultra-hard particles 11 of the electrode portion 14 of the copper pattern 2 crush or peel off the oxide film (not shown) on the surface of the coating solder layer c by utilizing the edge thereof, and the inside of the coating solder layer c or the lead b. Since the bite and the coated solder layer c and the gold plating layer 15 of the copper pattern 2 are brought into contact with each other, the lead b and the copper pattern 2 are electrically connected. Therefore, by using the pin 25 protruding from the socket body 20 of the inspection socket A to the I
The circuit inspection of the C package C can be performed easily and surely.

In the case of the contact pin 26, the contact pin 26 having a predetermined shape is treated, and after degreasing and cleaning, the entire surface except for the upper surface of the electrode corresponding portion 26a and the pin portion 26d connected to the plating power source is masked. Is applied to and held in an insulating jig as a cathode, and is set in a plating tank with the upper surface of the electrode corresponding portion 26a facing the anode, and then composite electroplating is performed in the same manner as in the case of the copper pattern 2. The electrode portion 1 in which a large number of ultra-hard particles 17 having edges are planted with the electrodeposited metal 16 and further gold electroplating is performed to superpose the gold plating layer 18 on the electrodeposited metal 16
9 can be formed. After the plating is completed, the masking agent can be easily removed with a solvent.

Contact pins 26 that have been plated
Is attached and fixed to the inspection socket B. At the time of inspection, the compatible type IC package C is connected to the inspection socket B.
By setting it in the center predetermined position (see FIG. 7),
The lead b of the IC package C comes into contact with the ultra-hard particles 17 of the electrode portion 19. When the cover 28 of the inspection socket B is closed in this state, as shown in FIG. 5, the lead b of the IC package C is pressed by the pressing portion 28a, and the ultra-hard particles 17 of the electrode portion 19 of the contact pin 26 have their edges. The oxide film on the surface of the coated solder layer c of the lead b is crushed or peeled off and penetrates into the coated solder layer c to the lead b, and the coated solder layer c and the contact pin 26.
Since the gold plating layer 18 is contacted, the lead b and the contact pin 26 are electrically connected. Therefore, the circuit inspection of the IC package C can be easily and surely performed by utilizing the pin portion 26d protruding from the socket body 27 of the inspection socket B to the outside.

[0026]

As is apparent from the above description, according to the forming method of the present invention, the electrode portion having a small area is formed at the contact position of the copper pattern or the contact pin of the inspection socket with the lead of the IC package. It was exposed, and the super-hard particles were deposited together with the electrolytic metal by the composite electroplating method at this point, and preferably, the gold plating layer was further laid on the electrodeposited metal. When set, the oxide film on the solder layer surface of the lead is easily crushed or peeled off by a relatively light pressing force by a large number of ultra-hard particles having edges implanted in the electrode part, and the solder layer and copper pattern or contact An inspection tool that can be easily brought into contact with the pins and therefore can easily, efficiently and reliably perform circuit inspection of the IC package in the inspection socket. Tsu electrode portion of the bets can be efficiently formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part of a copper pattern for explaining a treatment step of a method for forming an electrode portion of an inspection socket according to the present invention, where (a) is before treatment, (b) is during exposure treatment after photoresist coating,
(C) after development, (d) during composite electroplating,
It is a figure which respectively shows.

FIG. 2 is a cross-sectional view of a main part of a copper pattern for explaining the treatment process subsequent to FIG. 1, in which (a) is after composite electroplating, (b) is after electrogold plating, and (c) is after photoresist stripping treatment. , Respectively.

FIG. 3 is a partially enlarged perspective view showing an electrode portion of a copper pattern formed by the method of FIGS. 1 and 2.

FIG. 4 is an enlarged cross-sectional view of an essential part showing a connection state between the copper pattern of FIG. 3 and a lead of an IC package.

FIG. 5 is an enlarged sectional view of an essential part showing a connection state between a contact pin having an electrode portion formed by the method of the present invention and an IC package.

FIG. 6 is a cross-sectional view of a conventional test socket having a copper pattern and containing an IC package.

7 is a plan view of a copper pattern in the inspection socket of FIG.

FIG. 8 is a cross-sectional view of a conventional test socket including a contact pin and accommodating an IC package.

FIG. 9 is an enlarged perspective view of an IC package.

FIG. 10: Copper pattern and I in a conventional inspection socket
It is a principal part expanded sectional view which shows the connection condition with the lead of C package.

[Explanation of symbols]

 A Inspection socket B Inspection socket C IC package b Lead c Coated solder layer 1 Insulating film 2 Copper pattern 3 Photoresist 4 Photomask 5 Light source 8 Anode plate 9 Plating bath 10 Metal plating bath 11 Ultra-hard grain 13 Electrodeposited metal 14 Electrode Part 15 Gold Plating Layer 16 Electrodeposited Metal 17 Super Hard Grain 18 Gold Plating Layer 19 Electrode Part 26 Compact Pin

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H05K 3/34 501 A 8718-4E

Claims (3)

[Claims] 1. A method of forming the electrode portion in an inspection socket, which comprises an electrode portion connected to a lead of an IC package, accommodates the IC package, and enables a circuit inspection of the IC package. A method for forming an electrode portion of an IC package inspection socket, characterized in that ultra-hard particles are implanted in the electrode portion by electrodeposition by electroplating means. 2. When the electrode portion is an electrode portion of a copper pattern formed on an insulating film, a masking agent is applied to the copper pattern, and the exposing means using a photomask and the developing means 2. The electroplating treatment is performed after exposing only the electrode portion of the copper pattern and implanting super-hard particles with an electrodeposition metal in the electrode portion by electroplating means. A method for forming an electrode portion of an IC package inspection socket. 3. In the case where the electrode portion is an electrode portion of a contact pin, only the electrode portion is exposed by using a masking agent, and an ultra-hard grain is formed on the electrode portion by electrodeposition metal by electroplating means. 2. The method for forming an electrode part of an IC package inspection socket according to claim 1, wherein the plating is performed and then electrogold plating is performed.