JP2003124396A - Elastic electric contact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic electric contact in which a service life can be prolonged and an electric connection is surely enabled. SOLUTION: An elastic electric contact 1 is composed of an elastic member 2 and a conductive film 3. Concretely, the elastic member 2 is formed by forming silicon into a semi-spherical shape, and the band-like conductive film 3 is stuck from the top end face 20 of the elastic member 2 along with its side face 21. The conductive film 3 is composed of a head 30, a body 31 and an extended part 32 integrally formed from titanium and palladium. Then, the head 30 is formed from a lower layer 30a and a gold plating upper layer 30b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an elastic electric contact which can be used for a semiconductor substrate, a circuit board, an interposer, an IC socket, a bare chip inspection socket and the like.

[0002]

2. Description of the Related Art Conventionally, as a resilient electric contact of this type, there is a technique described in Japanese Patent Laid-Open No. 61-259548. FIG.
FIG. 7 is a partial cross-sectional view showing this conventional technique. In FIG. 16, reference numerals 201, 202, and 203 denote a semiconductor substrate, aluminum wiring, and an insulating layer, respectively.
The elastic electrical contact 210 is electrically connected to the aluminum wiring 202. The elastic electrical contact 210 includes a barrier layer 211 formed by vapor-depositing aluminum or nickel on the aluminum wiring 202 by a vacuum vapor deposition method, and an elastic member 212 formed by forming silicon rubber on the barrier layer 211 by screen printing in a substantially hemispherical manner. And a conductive layer 213 as a conductive film formed by plating the entire surface of the elastic member 212 with a uniform thickness of gold.

With this structure, one of the semiconductor substrate 201 and the glass substrate 220 is pressed to the other side while the semiconductor substrate 201 and the glass substrate 220 are brought close to each other and the elastic electrical contact 210 and the land 221 are in contact with each other. The elasticity of the elastic member 212 allows the elastic electrical contact 21
0 and the land 221 are ensured to be electrically connected.

[0004]

However, the above-mentioned conventional elastic electrical contact 210 has the following problems. First, since the conductive layer 213 covers the entire surface of the elastic member 212, a crack is likely to occur in the conductive layer 213 and a connection failure is likely to occur. That is, the elastic electrical contact 210 is connected to the land 2
21 when the conductive layer 213 is pressed against the elastic member 21.
By deforming following 2, the elastic electrical contact 210 and the land 221 can be reliably electrically connected. But,
The elastic modulus of the conductive layer 213 is significantly smaller than that of the elastic member 212, and moreover, the conductive layer 213 has the elastic member 212.
Since it has a structure covering the entire surface of, the conductive layer 213 does not follow the elastic member 212 and is deformed when the elastic electrical contact 210 is pressed, and a crack or the like may occur. Then, the conductive layer 213 is worn and the elastic electrical contact 210 becomes unusable in a short period of time. That is, the semiconductor substrate 201 is lowered in the vertical direction V, and the elastic electrical contact 210 is attached to the land 22.
1, but the semiconductor substrate 201 is slightly moved in the horizontal direction H after the contact between the elastic electrical contact 210 and the land 221. Therefore, the contact portion 213a, which is the tip end portion of the elastic electrical contact 210, is worn by friction with the land 221. At this time, the conductive layer 21
Since 3 is thin gold plating having a uniform thickness, repeated contact with friction causes a contact portion 213a of the conductive layer 213 in a short period of time.
Wears out. As a result, the elastic member 212 may be exposed at the contact portion 213a, and the elastic electrical contact 210 may become unusable in a short period of time.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide an elastic electrical contact capable of extending the life and ensuring reliable electrical connection.

[0006]

In order to solve the above-mentioned problems, an elastic electrical contact according to the invention of claim 1 has a substantially hemispherical elastic member and an end portion on the tip surface of the elastic member, In addition, a strip-shaped conductive film extending from the tip surface to the base side of the elastic member along the surface of the elastic member and extending outward from the base is provided. With this configuration, in a state where the conductive film of the elastic electrical contact is connected to the electrode of the semiconductor substrate or the like,
When the base side of the elastic member is attached to the semiconductor substrate and the tip end of the elastic electric contact is brought into contact with the land of the circuit board, the end of the conductive film is brought into contact with the land to electrically connect the circuit board and the semiconductor substrate. Connection is made. When the semiconductor substrate is pressed toward the circuit board side, the elastic member of the elastic electrical contact is deformed,
Since the conductive film is formed in a strip shape and does not cover the entire surface of the elastic member, the conductive film follows the elastic member and is deformed.

Further, the invention of claim 2 is the elastic electrical contact according to claim 1, wherein the thickness of the end portion of the conductive film is set to 1 to 10 times the thickness of the other portion. is there. With such a configuration, it is possible to use for a long period of time corresponding to the film thickness of the end of the conductive film of the elastic electric contact until the end of the conductive film of the elastic electric contact is completely worn and the elastic member is exposed due to friction with the land of the circuit board. It is possible.

In particular, the invention according to claim 3 is the elastic electrical contact according to claim 1 or 2, wherein the base portion of the elastic member is thinned to form a hollow portion in the base portion. With such a configuration, flexibility is generated on the base side of the elastic member.

By the way, the materials of the elastic member and the conductive film are arbitrary, but as a good example thereof, the invention of claim 4 is the elastic electrical contact according to any one of claims 1 to 3, Is made of silicon rubber.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a perspective view showing an elastic electrical contact according to a first embodiment of the present invention, and FIG.
FIG. 9 is a sectional view taken along line AA of FIG. As shown in the figure, the elastic electrical contact 1 comprises an elastic member 2 and a conductive film 3.

The elastic member 2 is formed of silicon in a hemispherical shape, and has a band-shaped conductive film 3 attached from the tip end surface 20 to the side surface 21 thereof.

The conductive film 3 has a head portion 30 (end portion) and a body portion 3
1 and the extension 32, the lower layer 30a of the head 30, the body 31 and the extension 32 are integrally formed of titanium and palladium.

The lower layer 30a of the head portion 30 has a circular shape and is attached onto the tip surface 20 of the elastic member 2. Then, the upper layer 30b having the same shape is laminated on the lower layer 30a. The upper layer 30b is formed by gold plating and constitutes the head portion 30 together with the lower layer 30a.

The body portion 31 of the conductive film 3 has a strip shape and extends to the base portion 22 along the side surface 21 of the elastic member 2 in a state of being pulled out from the lower layer 30a. The extending portion 32 is extended from the elastic member 2 by a predetermined length while being pulled out from the body portion 31. The thickness of the head portion 30 is larger than the thicknesses of the other body portion 31 and the extension portion 32.
It is thickened by the thickness of b. In this embodiment, the thickness T of the head portion 30 is set to be twice the thickness t of the body portion 31 (extension portion 32).

Next, a method of manufacturing the elastic electrical contact 1 of this embodiment will be described. The elastic electrical contact 1 is manufactured through the following elastic member forming step, conductive film forming step, and thickness increasing step. 3, FIG. 4, and FIG. 5 are sequential process diagrams showing an elastic member forming process, a conductive film forming process, and a thickness increasing process, respectively.

First, in the elastic member forming step, as shown in FIG.
As shown in (a), a mold 100 having a hemispherical hole 100a is prepared, and as shown in (b) in the figure, a mold release agent 101 is applied to the surface of the mold 100. And the release agent 1
After 01 is dried, silicon 2'is filled in the hole 100a of the mold 100 as shown in FIG. 3C, and the insulating film 102 is filled with silicon 2'as shown in FIG. Stick to cover. After that, silicon 2 '
After forming the hemispherical elastic member 2 by hardening, the insulating film 102 to which the elastic member 2 is fixed is peeled off from the mold 100, thereby completing the elastic member forming step.

Next, in the conductive film forming step, as shown in FIG.
(A), the shadow mask 103 is arranged on the elastic member 2 fixed to the insulating film 102. FIG. 4B is a plan view seen from above in FIG. As shown in this figure, the shadow mask 103 is provided with a match rod-shaped hole 104 having a circular hole 104a and a band-shaped hole 104b. Therefore, through the hole 104,
By depositing titanium and palladium, (c) of FIG.
As shown in, the conductive film 3 is formed on the elastic member 2. Specifically, as shown in FIG. 4D, the lower layer 30 a of the conductive film 3 is formed on the tip surface of the elastic member 2, and the body 31 is formed on the side surface of the elastic member 2. . Then, the extending portion 32 is formed on the insulating film 102, and the conductive film forming step ends.

Finally, in the thickening step, as shown in FIG. 5A, the photoresist 105 is covered with the insulating film 10 so as to cover the elastic member 2 and the conductive film 3.
Apply on top of 2. Then, as shown in FIG.
A portion of the conductive film 3 corresponding to the lower layer 30a is etched to form the hole 105a. FIG. 5C is a plan view seen from above in FIG. 5B. As shown in this figure, the hole 105a has the same shape as the lower layer 30a. Then, as shown in (d) of the same figure and a plan view (e) viewed from above in this figure, gold plating is performed through the holes 105a of the photoresist 105 to attach the upper layer 30b onto the lower layer 30a. By doing so, the thickening step is completed.

As described above, the elastic member forming step, the conductive film forming step, and the thickening step are sequentially performed, and finally, the photoresist 105 is removed, whereby (a) and (b) of FIG. As shown in, the elastic electrical contact 1 mounted on the insulating film 102 can be obtained.

Next, an example of use of the connector 1 will be described. FIG. 7 is a sectional view showing an example in which the elastic electrical contact 1 is used for an interposer. This interposer 11
0 attaches a pair of elastic electrical contacts 1 (1-1, 1-2) to both sides of the insulating film 102, and these elastic electrical contacts 1-1 and 1-2 are connected through the through holes 102 a of the insulating film 102. It has a structure that is electrically connected.
That is, a plurality of through holes 102a having copper foils 102b attached to the inner surface thereof are provided at predetermined locations on the insulating film 102. A pair of elastic electrical contacts 1-1 and 1-2 are arranged on both sides in the vicinity of each through hole 102a, and the extending portion 32 of each elastic electrical contact 1 is electrically connected to the copper foil 102b. .

FIG. 8 is a sectional view showing an example in which an interposer 110 is used to connect an IC chip as a semiconductor substrate and a burn-in socket. In FIG. 8, reference numeral 111 is an IC chip, and reference numeral 112 is a burn-in socket. As shown in the figure, when the interposer 110 is housed in the burn-in socket 112,
The elastic electrical contact 1-2 on the lower side of the interposer 110 contacts the land 112 a of the burn-in socket 112.
When the IC chip 111 is placed on the interposer 110, the elastic electrical contact 1-1 on the upper side of the interposer 110 comes into contact with the electrode 111a of the IC chip 111. In this state, if the IC chip 111 and the burn-in socket 112 are sandwiched by a holding spring (not shown), I
The C chip 111 descends and presses the interposer 110. As a result, as shown in FIG.
Since -1, 1-2 are compressed toward the interposer 110 side, the elastic force of the elastic member 2 of each elastic electrical contact 1-1 (1-2) causes an upper part of the conductive film 3 of the elastic electrical contact 1-1. The layer 30b is in pressure contact with the electrode 111a of the IC chip 111,
The upper layer 30b of the elastic electrical contact 1-2 presses against the land 112a of the burn-in socket 112. As a result, the electrodes 111a and the lands 112a have elastic contact points 1-1, 1
-2 of the conductive film 3 and the insulating film 102 of the copper foil 102
The IC chip 111 and the burn-in socket 112 are electrically connected to each other via the interposer 110 by communicating with each other through the interposer 110.

By the way, when the IC chip 111 descends, the head portion 30 of the conductive film 3 of the elastic electric contact 1-1 is pressed downward by the electrode 111a, and at the same time, the conductive film 3 of the elastic electric contact 1-2 is pressed. The head 30 is pressed upward by the land 112a. At this time, since the conductive film 3 of the elastic electrical contact 1 does not cover the entire surface of the elastic member 2, the elastic member 2 bends following the deformation of the elastic member 2. That is,
For example, if the conductive film 3 covers the entire surface of the elastic member 2, the cross section of the conductive film 3 has a shape like an arch-shaped both-ends supporting beam as shown in FIG. Therefore, when a large downward force F acts, the conductive film 3 may avoid and be cracked by the pulling force of the component forces Fθ and Fθ ′ in the tangential direction. On the other hand, in the conductive film 3 of this embodiment, the cross section thereof is shaped like a semi-arched cantilever as shown in FIG. 11, so that a large downward force F acts. The tensile force due to the component force Fθ in the tangential direction does not work, and the conductive film 3 only bends downward.
Thus, according to the elastic electrical contact 1 of this embodiment,
Since the conductive film 3 is not cracked when the elastic electric contact 1 is pressed, reliable electric connection by the elastic electric contact 1 is possible.

When the IC chip 111 is repeatedly attached to and detached from the burn-in socket 112, the head 3 of the conductive film 3 is removed.
0 wears due to the friction of the electrodes 111a and the lands 112a, but as described above, the thickness T of the head portion 30 is
Since it is set to twice the thickness t of the (extended portion 32),
It is necessary to repeat attachment and detachment a considerable number of times until most of the head 30 is worn and the tip of the elastic member 2 is exposed. Therefore, it can be said that the life of the elastic electrical contact 1 is extremely longer than that of the conventional elastic electrical contact 210 described above.

(Second Embodiment) FIG. 12 is a perspective view showing an elastic electrical contact according to a second embodiment of the present invention, and FIG. 13 is a sectional view taken along the line BB of FIG. As shown in the figure, the elastic electrical contact 1'of this embodiment has a hollow portion 2 formed by thinning out approximately half of the base portion 22 of the elastic member 2.
The difference from the first embodiment is that it has 2a.
Specifically, as is clear from FIG. 14 showing the back surface of the elastic electrical contact 1 ′, approximately half of the bottom surface of the base portion 22 of the elastic member 2 corresponds to approximately half of the elastic member 2 as shown in FIG. The hollow portion 22a is formed by cutting out to the height. As described above, according to the elastic electrical contact 1 ′ of this embodiment, since the base 22 of the elastic member 2 has the hollow portion 22a, the elastic member 2 is flexible depending on the size of the hollow portion 22a. Will increase.

Finally, the elastic electrical contact 1'of this embodiment
An example of the manufacturing method regarding will be described. The elastic electrical contact 1 ′ of this embodiment is also manufactured through the elastic member forming step, the conductive film forming step, and the thickening step shown in FIGS. 3 to 5, but the device is highly devised in the elastic member forming step. ing. That is, as shown in FIG.
While filling the hole 100a of the mold 100 with the hollow portion 2
An insulating film 102 having a photoresist 102c having the same shape as 2a is attached. At this time, the photoresist 10
The insulating film 102 is attached to the mold 100 so that 2c enters into the hole 100a of the mold 100. Thereafter, through a conductive film forming step and a thickening step, as shown in FIG. 15B, an elastic electrical contact 1 ′ having the elastic member 2, the conductive film 3 and the photoresist 102c is manufactured. However, in this state, since the photoresist 102c remains, the photoresist 102c is removed to manufacture the elastic electrical contact 1'having the hollow portion 22a as shown in FIG. 15C. be able to. Other configurations, functions and effects are the same as those of the first embodiment, and therefore the description thereof is omitted.

The present invention is not limited to the above embodiment, but various modifications and changes can be made within the scope of the invention. For example, in the above embodiment,
Although silicon is used as the elastic member 2, the elastic member 2 may be formed using elastic urethane or rubber.
Further, in the above embodiment, the material of the lower layer 30a of the conductive film 3 and the like is formed of titanium and palladium, but it may be formed of nickel or aluminum. Further, although the material of the upper layer 30b is gold plated in the above embodiment, the material is not limited to this, and any material may be used as long as it is a highly conductive metal. Further, in the above-described embodiment, the head portion 30 of the conductive film 3 is set to have a circular shape, but the present invention is not limited to this. The shape of the head 30 includes a polygon such as a hexagon.
Further, in the above embodiment, the thickness T of the head portion 30 is set to the body portion 31.
Although the thickness t of the (extended portion 32) is set to be twice, the thickness T of the head portion 30 is not limited to this, and the thickness T of the body portion 31 is 1 to 10 times the thickness t. Can be set to a value.
In addition, in the first embodiment, in the conductive film forming step, titanium and palladium are vapor-deposited through the holes 104 of the shadow mask 103, so that the conductive film 3 is attached to the elastic member 2.
Although formed on the elastic member 2, the conductive film 3 may be formed on the elastic member 2 by sputtering titanium and palladium. Further, in the second embodiment described above, the hollow portion 22a is formed by notching the elastic member 2 up to the height of approximately half thereof.
The size and shape of the hollow portion 22a are arbitrary. Various sizes and shapes can be set according to the degree of flexibility desired for the elastic member 2.

[0027]

As described in detail above, according to the present invention, the conductive film of the elastic electrical contact is deformed following the deformation of the elastic member, so that the conductive film is not cracked. There is an excellent effect that the reliability of electrical connection is improved.

Further, by setting the conductive film thickness at the end of the elastic electrical contact to be 1 to 10 times the film thickness of other portions,
It is possible to extend the life of the elastic electrical contact.

Further, by thinning the base of the elastic member, the flexibility of the elastic electric contact as a whole can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an elastic electrical contact according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a process step diagram showing an elastic member forming step.

FIG. 4 is a sequential process diagram showing a conductive film forming process.

FIG. 5 is a flow chart showing a thickening step.

FIG. 6 is a cross-sectional view showing an elastic electrical contact mounted on an insulating film.

FIG. 7 is a cross-sectional view showing an example in which elastic electric contacts are used for an interposer.

FIG. 8 is a cross-sectional view showing a usage example of the interposer.

FIG. 9 is a cross-sectional view showing a state in which an IC chip and a burn-in socket are electrically connected via an interposer.

FIG. 10 is a schematic diagram for explaining a crack phenomenon of a conductive film.

FIG. 11 is a schematic view showing the action of the conductive film of the present embodiment.

FIG. 12 is a perspective view showing an elastic electrical contact according to a second embodiment of the present invention.

13 is a sectional view taken along the line BB of FIG.

FIG. 14 is a plan view showing the back surface of the electrical contact.

FIG. 15 is a process drawing showing the method of manufacturing the elastic electrical contact according to the second embodiment.

FIG. 16 is a partial cross-sectional view showing a conventional technique.

[Explanation of symbols]

1 ... Elastic electrical contact, 2 ... Elastic member, 3 ... Conductive film,
20 ... Tip surface, 21 ... Side surface, 22 ... Base portion, 22
a ... hollow part, 30 ... head part, 30a ... lower layer, 30
b ... upper layer, 31 ... trunk, 32 ... extension part.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01R 11/01 501 H01L 21/92 603A 12/16 H01R 23/68 303E F term (reference) 2G003 AA07 AD09 AG01 AG03 AG08 AG12 AG20 AH05 2G011 AA03 AA15 AA21 AB06 AB08 AC14 AE01 AE03 AF02 AF07 5E023 AA05 AA16 BB18 BB21 CC22 DD26 EE18 EE32 HH05

Claims (4)

[Claims] 1. An elastic member having a substantially hemispherical shape, and an end portion on the tip end surface of the elastic member, and extending from the tip end surface to the base portion side of the elastic member along the surface of the elastic member and outward from the base portion. An elastic electrical contact, comprising: a strip-shaped conductive film extending to the. 2. The elastic electrical contact according to claim 1, wherein the thickness of the end portion of the conductive film is 1 to 1 times the thickness of the other portion.
An elastic electrical contact characterized by being set to 0 times. 3. The elastic electrical contact according to claim 1, wherein the base of the elastic member is thinned to form a hollow portion in the base. 4. The elastic electrical contact according to claim 1, wherein the elastic member is made of silicon rubber.