JPH09199208A - Electric connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric connector, in which a contact part of the connector can be arranged by a fine pitch, a shape of the contact part is simple, inspection and connection of an IC package can be surely stably performed without generating improper connection, and alignment to a terminal in a connected side is facilitated, relating the electric connector suited for use in the inspection and connection of the IC package of ball grid array type having a spherical protrusion electrode in an external terminal. SOLUTION: This electric connector is provided with a plurality of linear conductors 4 inserted in a thickness direction of an insulating elastomer layer. One end part of the linear conductor 4 is formed with a spherical contact part, at least partly this spherical contact part 5 is exposed from a bottom surface of a recessed part 6 provided in a surface of the insulating elastomer layer 3, when assuming L for wire size of the linear conductor 4, a spherical diameter R of the spherical contact part 5 is in an L<R<3L range, an exposed height E from a bottom surface of the spherical contact part 5 is in an R/3<E<R range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric connector suitable for use in inspection and connection of a ball grid array type IC package having a spherical projection electrode as an external terminal.

[0002]

2. Description of the Related Art Conventionally, surface mount type ICs with many input / output terminals
As the package, a quad flat package (hereinafter referred to as QFP) is used in which external terminals are taken out from four sides of the package body. In the case of QFP, in order to cope with the recent increase in the number of terminals, In order to make the mounting area as small as possible, it is necessary to keep the package size below a certain size and narrow the terminal pitch to increase the number of terminals. Therefore, recently, the terminal pitch has been reduced to about 0.4 mm. . The lead terminal of a multi-terminal QFP with such a fine pitch is thin and easily deformed. Further, since it is difficult to align the terminals, many problems occur in the manufacturing process, inspection process, mounting process, and the like.

As a countermeasure against this, recently, an area array type IC package in which terminal electrodes are arranged in a flat shape on one of the upper and lower surfaces of the IC package body, particularly a ball grid array type in which spherical terminal electrodes are attached IC package (hereinafter referred to as BGA) has been developed and is being put to practical use. For this BGA inspection, the use of a dedicated IC socket equipped with a contact corresponding to the terminal electrode of the BGA, like the conventional IC package, is being considered and is being developed.
In general, an IC socket has a socket body made by injection-molding an engineering plastic material and a large number of contacts plated with gold on a copper alloy spring material are press-fitted in the socket body. The terminal electrode of the IC package bonded to the electrode and the electrode of the inspection circuit board are electrically connected. The configuration of BGA compatible type IC sockets is basically the same.

[0004]

However, the IC socket for the BGA compatible type has the following problems.
The contact of the above-mentioned IC socket requires a predetermined contact pressure for connection with the terminal electrode of the bonded IC package,
Further, in order to absorb the height variation of each terminal electrode of the IC package, the contactor has a complicated shape with a bent portion, which is one of the causes of connection failure. It is not easy to arrange contacts with complicated shapes in this way on a plane, and it is extremely difficult to arrange contacts at minute intervals, especially for a BGA with a terminal electrode pitch of 1.0 mm or less. However, the arrangement of the contacts is not applicable, and the structure such as the positioning mechanism for the terminal electrode and the contacts and the contact pressure mechanism are complicated, resulting in high costs.

Recently, IC packages for processing high frequency signals are frequently used in mobile phones, communication devices, computers and the like. If you try to inspect such a high frequency IC package with an IC socket, the IC
Since the contactor of the socket has a complicated shape having the bent portion as described above, there is a problem that the conduction path becomes long and the output signal is delayed or the waveform is distorted. Therefore, it is an object of the present invention that the contact portions can be arranged at a fine pitch, the shape of the contact portions is simple, and the inspection and connection of the IC package can be performed reliably and stably without causing connection failure. Another object of the present invention is to provide an electric connector that can be easily aligned with the side terminal.

[0006]

An electrical connector of the present invention is an electrical connector having a plurality of linear conductors penetrating in the thickness direction of an insulating elastomer layer, wherein one end of the linear conductor is provided. Part forms a spherical contact part, and at least a part of this spherical contact part is exposed from the bottom surface of the recess provided in the surface of the insulating elastomer layer, and the wire diameter of the linear conductor is L
Then, the spherical diameter R of the spherical contact portion is in the range of L <R <3L, and the exposure height E from the bottom surface of the spherical contact portion is R / 3.
It is characterized by being in the range of <E <R.

The electrical connector of the present invention comprises a plurality of linear conductors that are embedded in a general-purpose ball bonder so as to penetrate through the insulating elastomer layer in the thickness direction, and a spherical conductor is formed at one end of the linear conductor. A contact portion (hereinafter referred to as a spherical contact portion) and a concave portion are formed around the contact portion, and at least a part of the spherical contact portion is exposed from the bottom surface of the concave portion provided on the surface of the insulating elastomer layer. Hereinafter, the electrical connector of the present invention will be described in detail.

In the electrical connector of the present invention, the linear conductor is
Arranged through a plurality of insulating elastomer layers in the thickness direction,
It is buried. In order to have such a structure, it is preferable that the raw material of the insulating elastomer layer has fluidity before curing and forms a crosslinked structure by curing, and examples thereof include silicone rubber, polybutadiene rubber, and natural rubber. Examples thereof include rubber, polyisoprene rubber, urethane rubber, chloroprene rubber, polyester rubber, styrene-butadiene copolymer rubber, epichlorohydrin rubber, and foamed materials thereof. Of these, silicone rubber is most preferable because it has excellent electrical insulation properties, heat resistance, and compression set after curing. If the hardness is too high, the load at the time of compression connection becomes large, and if it is too low, the amount of strain at the time of compression becomes large, so that the hardness is 10 to 80 ° H, preferably 20 to 60 ° H.

The frame provided on the outer edge of the electric connector holds the sheet-shaped insulating elastomer layer, improves the convenience in handling the electric connector, and is used for positioning with the inspection board or the inspection jig. be able to. As the material of the frame, a general-purpose engineering plastic material, a ceramic material, a metal material or the like can be appropriately selected and used. Especially for engineering plastic materials having excellent heat resistance and dimensional stability, materials such as polyetherimide (PEI), polyphenylene sulfide (PPS), and polyether sulfone (PES) may be used.

The wire diameter of the linear conductor must be as small as possible to apply a load during connection, and further, it corresponds to the distance between the electrodes of the spherical terminal electrodes of the BGA arranged at a low pitch. Within the range that does not adversely affect the stability, the wire diameter of the linear conductor is preferably smaller, specifically, the wire diameter of 0.
It is selected from the range of 01-0.2mm. For the array of linear conductors, a gold wire having a wire diameter of 0.02 to 0.08 mm is preferable because it is easily available and a general-purpose ball bonder can be used. Note that the cross section of the linear conductor used in the present invention is not necessarily a perfect circle, and may be an oval, an ellipse, or a polygon represented by a quadrangle, but in any case, the aspect ratio (oblong or ellipse is The major axis / minor axis, the vertical / horizontal direction in the case of a quadrangle, the longest width / the shortest width in the case of a polygonal shape) are preferably 1 to 2. In general, the wire diameter is a term that means a diameter in a perfect circle, but in the present invention, when the cross-sectional shape of the linear conductor is other than a perfect circle, that is, when it is an ellipse, an ellipse, or a polygon. Assuming the circumscribed circles of these cross-sectional shapes, the diameter is considered to be the wire diameter. It should be noted that commercially available linear conductors such as gold wire are indicated as circles, that is, φ
Since it is displayed as 000 mm, treat it as the wire diameter. As the linear conductor, a linear conductor such as gold, gold alloy, copper, aluminum, aluminum-silicon alloy, brass, phosphor bronze, beryllium copper, nickel, molybdenum, or tungsten, or gold or gold alloy on the surface thereof. It is possible to use a linear conductor or the like that has been plated.

The spherical contact portion of the linear conductor is formed by irradiating the tip of the linear conductor with a general-purpose laser beam. By making the end of this linear conductor spherical, the contact part of the linear conductor repels due to the elasticity of the insulating elastomer layer when it is compression-connected to the spherical terminal electrode of BGA, and it does not sink. A good connection state can be obtained. Further, the spherical diameter R of the contact portion can be set to a predetermined size by adjusting the output of laser light and the irradiation position. The spherical diameter R of the spherical contact portion formed by this method depends on the linear diameter L of the linear conductor and is preferably in the range of L <R <3L. More specifically, assuming that the wire diameter of the linear conductor is 0.076 mm, the wire diameter is approximately 1 to 3 times, that is, the spherical diameter R is 0.08 to 0.22.
mm is preferred. If the spherical diameter R of the spherical contact portion is less than or equal to the wire diameter L of the linear conductor, the spherical contact portion does not become a spherical contact, and when the spherical terminal electrode of the BGA is compressed and connected, the spherical contact portion is depressed into the insulating elastomer layer. As a result, a connection failure occurs and it does not function as an electrical connector. On the other hand, if the wire diameter L of the linear conductor is three times or more, the fine pitch of the spherical terminal electrode of the BGA cannot be supported, and the spherical terminal electrode of the BGA is not connected on average during mounting and connection is unstable. It is not preferable because it may cause a positional shift. Therefore, it is limited to the above range, and the desired function as the electrical connector cannot be obtained outside the range.

For forming the recess, a general-purpose laser such as an excimer laser, an argon laser, a YAG laser,
A portion of the linear conductor corresponding to the spherical contact portion is irradiated with laser light in a predetermined direction, for example, from above by using a carbon dioxide gas laser or the like, and the insulating elastomer layer around the spherical contact portion is removed to form a concave portion. Provided, exposing the spherical contact from the insulating elastomer layer. At the time of forming this concave portion, a mask provided with holes having the same pattern as the arrangement pattern of the spherical contact portions,
Aligning with the spherical contacts arranged on the processed surface of the insulating elastomer layer, irradiating laser light from this mask, or irradiating the predetermined spherical contact parts with laser light passing through a similar mask. Thus, the recess can be processed efficiently and accurately. At that time, it is necessary to select a laser beam that does not affect the spherical contact portion. In general,
Since a transparent material transmits a laser beam having a long wavelength, the irradiated portion may not be removed and the concave portion may not be processed. In such a case, if an appropriately selected coloring agent or the like is added to the insulating elastomer layer to easily absorb the laser beam, the workability is improved and the surface thereof is finished nicely.

The exposure height E at which the spherical contact portion of the linear conductor is exposed from the bottom surface of the recess is in the range of R / 3 <E <R, and more preferably in the range of R / 3 <E <2/3 R. Is. When the exposure height E is R / 3 or less, the portion that can be connected to the spherical terminal electrode of the BGA is small, so that the connection becomes unstable or the insulating elastomer layer comes into contact and the connection becomes impossible, so that it does not function as an electrical connector. When the exposure height E is R or more, the spherical contact portion is buckled at the base portion during compression connection, and the reliability and stability of the connection deteriorate, which is not suitable for mounting connection. Furthermore, the spherical contact part is cut off after repeated use in BGA inspection, making it impossible to connect. In this case also, it does not function as an electrical connector, which is not preferable.

The spherical contact portion of the electrical connector of the present invention is embedded in the recess and is exposed from the surface of the insulating elastomer layer on the bottom surface of the recess. When connecting to the spherical terminal electrode of the BGA, the corresponding electrical connector connection location has a concave shape with a spherical contact embedded, so that each spherical terminal electrode of the BGA can be fitted with the concave portion of the electrical connector with one touch. ,
Alignment is easy and the connection is stable and reliable. BGA has a spherical terminal electrode pitch of 1.0 mm or less, and it can be easily and reliably connected even to extremely small electrodes with a spherical terminal electrode diameter of 0.5 or 0.3 mm.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The electric connector of the present invention is used to obtain an electrical connection with a spherical terminal electrode of a BGA or an electrode of a test board or an electronic circuit board. One aspect of the mounting using is shown in FIG. FIG. 2 shows one embodiment of the electrical connector of the present invention,
2 (a) is a plan view thereof, and FIG. 2 (b) is a vertical sectional view taken along the line AA of FIG. 2 (a). First, the electrical connector 1
A linear conductor 4 is embedded in the sheet-shaped insulating elastomer layer 3 held by the frame 2 so as to penetrate in the thickness direction thereof. Also, a spherical contact portion 5 having a large diameter is formed, and the recessed portion 6 provided on the surface of the insulating elastomer layer 3 is arranged so that a part thereof is exposed from the bottom surface.

The electrical connector 1 having such a structure is
It is mounted on the connection between the BGA 7 and the inspection board 8. BGA7
The spherical terminal electrode 9 is fitted in a recess 6 having an inner surface of a cylindrical shape provided on the surface of the electric connector 1, the spherical contact portion 5 exposed from the bottom of the recess 6 and an insulating elastomer around the recess 6. The elasticity of the layer 3 ensures a connection without damage.
Further, by connecting the terminal electrode 10 on the opposite side of the spherical contact portion 5 of the electric connector 1 and the electrode 11 of the inspection board 8, the spherical terminal electrode 9 of the BGA 7 is connected via the electric connector 1.
Stable and reliable conduction can be obtained between the electrode 11 and the electrode 11 of the inspection substrate 8.

The shapes of the recesses formed on the surface of the insulating elastomer layer are shown in FIGS. 3 (a), 3 (b) and 4. FIG.
(A) is a plan view showing a recess, (b) is a vertical cross-sectional view taken along the line BB of (a), and FIG. 4 is a plan view showing another example of the recess. The inner surface of the recess 6 shown in FIG. 3 has a cylindrical shape, and the spherical contact portion 5 of the linear conductor 4 is exposed from the bottom surface thereof. In FIG. 3, C is the inner diameter of the concave portion 6, D is the depth of the concave portion 6, R is the spherical diameter of the spherical contact portion 5, and E is
Is the height at which the spherical contact portion 5 is exposed from the bottom surface of the concave portion 6,
L is the wire diameter of the linear conductor 4. S in FIG. 4 is the length of one side when the recess 6 is rectangular in a plan view. The inner diameter C of the recess may be set corresponding to the spherical diameter of the spherical terminal electrode 9 of the BGA 7 with some clearance taken into consideration. BG
The spherical diameter of the spherical terminal electrode 9 of A7 is generally 1.0 mm, but it tends to be smaller and finer, and spherical terminal electrodes 9 having a spherical diameter of 0.3 mm or 0.5 mm have also been developed. To connect these spherical terminal electrodes 9 and the electrical connector 1 smoothly and with good workability and without positional deviation, use the BGA7
In consideration of the variation in pitch of the spherical terminal electrodes 9, the inner diameter C of the cylindrical shape formed by the recess 6 is 0.5 to 1.2 mm.
Is optimal.

Further, the depth D of the recess 6 is 0.2 to 0 because the diameter of the spherical terminal electrode 9 of the BGA 7 is 0.3 to 1.0 mm.
By setting the thickness to 7 mm, even if the BGA 7 is compressed and connected to the electrical connector 1, the BGA 7 is connected without coming into contact with the surface of the insulating elastomer layer 3 forming the recess 6 (see FIG. 1).
reference). Further, FIG. 4 shows a case where the inner surface shape of the concave portion 6 is a quadrangular prism, and in this case as well, the side S is 0.4 to 0.4
It is preferable that the depth D is 1.2 mm and the depth D is 0.2 to 0.7 mm. The inner surface shape of the recess 6 may be a columnar shape as shown in FIGS. 3 (a) and 3 (b) or a square columnar shape as shown in FIG. 4, but since the terminal electrode 9 of the BGA 7 is spherical, The columnar shape is most preferable in consideration of displacement prevention, ease of alignment at the time of connection, and the like.

FIGS. 5, 6 and 7 show examples of arrangement of the linear conductors 4 embedded in the recesses 6. In order to ensure a stable connection regardless of the diameter of the spherical terminal electrode 9 of the BGA 7, the number of the linear conductors 4 embedded in one recess 6 is 3 to 4 as shown in FIGS. 6 and 7. Although books are preferred, manufacturing costs increase as the number of spherical terminal electrodes of the corresponding BGA7 increases. Therefore, in a normal case, it is preferable to deal with 1 to 4. Considering stable connectivity and manufacturing cost, the three shown in FIG. 6 are most preferable. Furthermore, the electrical connector of the present invention will be described in detail based on examples.

[0020]

EXAMPLE An electrical connector of the present invention was manufactured as follows. [Example 1] Bonding of a linear conductor: a general-purpose ball bonder was used to form a diameter on a copper bonding substrate having a thickness of 0.5 mm and a length of 35 mm which was plated with gold having a thickness of 1.0 μm.
Gold wires of 76 μm were vertically arranged at a pitch of 0.5 mm on the central portion of the bonding substrate in a matrix of 17 rows and 17 columns (total number of electrodes: 289), and three gold wires were bonded and arranged per electrode. Three gold wires corresponding to one electrode were bonded to each vertex of an equilateral triangle having a side of 0.27 mm. The tips of all the arranged gold wires were irradiated with an argon laser beam to form spherical contact portions with a diameter of 150 μm at each tip, and the height from the bonding substrate was 1.0 mm so that the height was uniform.
Furthermore, along the outer edge on this board, each 30 mm in length and width,
A frame made of polyphenylene sulfide having a height of 1.2 mm and a thickness of 5 mm was arranged.

Molding of the insulating elastomer layer: Silicon rubber is used as the insulating elastomer layer in the frame of this frame.
For 100 parts by weight of KE-106 (Shin-Etsu Chemical Co., Ltd., trade name)
Curing agent Cat-RG (manufactured by Shin-Etsu Chemical Co., Ltd.) 10 parts by weight, coloring agent for silicone rubber K-Color-BK-02 (manufactured by Shin-Etsu Chemical Co., Ltd.,
Add 10 parts by weight of (commercial name) and mix well, inject until the level after curing becomes the same level as the frame,
While keeping the copper bonding board horizontal,
It was cured by heat treatment for 60 minutes. Then, the copper bonding substrate was removed by etching with a ferric chloride solution, thoroughly washed, and then post-cured at 200 ° C. for 60 minutes.

Formation of concave portion: Further, a 0.5 mm thick mask having a hole with a diameter of 0.4 mm provided at the same position as the spherical terminal electrode of the BGA is aligned and fixed on the frame, and the YAG laser beam is applied from above. The silicone rubber exposed in the hole of the mask is removed to a depth of 0.2 mm to form a recess, and a spherical contact is made from the silicone rubber surface on the bottom of each recess to each vertex of the triangle. Part is 100μ
An electrical connector of the present invention having a protruding m was obtained.

Mounting: As shown in FIG. 1 above, the electrical connector produced in this manner was used to have a diameter of 0.3 mm and a height of 0.2 mm.
mm soldered spherical terminal electrodes with 0.5 mm pitch in 17 columns,
When 0.1 mm was compressed and connected between the BGA arranged in a matrix of 17 rows and the inspection board, stable conduction was obtained, and there was no problem in conducting the conduction test. The frame used to mold the insulating elastomer layer is
The product was used without being removed from the electrical connector produced as a protective frame for the product.

[Examples 2 to 5 and Comparative Examples 1 to 4] The spherical diameter (R) of the spherical contact portion formed at the tip of the gold wire, the depth (H) of the concave portion formed on the surface of the silicone rubber, and the concave portion. An electrical connector was produced in the same manner as in Example 1 except that the exposed height (E) of the spherical contact portion protruding from the bottom surface of the silicone rubber was changed. The results are summarized in Table 1.

In any of the electrical connectors of Examples 1 to 5,
Even after a continuous test of mounting continuity for one year, the spherical contact portion maintained a good connection continuity state without being depressed in the silicone rubber. On the other hand, the electrical connector of Comparative Example 1
Since the spherical diameter of the spherical contact portion is too large to accommodate the fine pitch of the spherical terminal electrodes of the BGA, a positional deviation occurs, and the electrical connector of Comparative Example 2 has a small exposed height of the spherical contact portion. Since there are few parts that can be connected to the spherical terminal electrode and the connection is unstable and it does not function as an electrical connector, the electrical connector of Comparative Example 3 has a spherical contact part made of silicone rubber when compressedly connected to the spherical terminal electrode of BGA. And the connection was poor. Further, in the electrical connector of Comparative Example 4, the spherical contact portion was buckled at its base during compression connection, and the reliability and stability of the connection deteriorated, which was not suitable for mounting connection.

[0026]

[Table 1]

[0027]

According to the electrical connector of the present invention, the conventional IC socket has a predetermined contact pressure by providing the spherical contact portion at one end of the linear conductor penetrating in the thickness direction of the insulating elastomer layer. In order to obtain a long contact of a bent conduction path to obtain, the linear conductor is as short as possible,
It can be arranged in a plane with a fine pitch, and the terminal electrode pitch that is difficult for IC sockets is 1.0 mm or less, especially 0.5 mm.
Even for the following BGAs, signal delays and waveform distortions do not occur during inspection and processing when processing high-frequency signals, and at the same location as the spherical protruding electrodes of the BGA at all times. Stable inspection and connection are possible due to contact.
Further, by making the contact portion a spherical contact portion having a diameter larger than the wire diameter of the linear conductor, and at least a part of the contact portion being exposed, when the contact side electrode is pressure-welded, electric contact is made. The contact part of the connector is in the insulating elastomer layer,
It is possible to prevent a connection failure due to depression at the time of mounting or during mounting, and the connection is surely made. Furthermore, by providing this spherical contact part in the concave part of the insulating elastomer layer with elastic periphery, BGA inspection and connection at the time of BGA
The spherical projection electrode of (1) is securely aligned with the spherical contact portion of the electric connector side without being damaged by being guided by the concave portion and without any positional deviation without using the positioning guide mechanism.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a state in which an electric connector of the present invention is used for connecting a BGA and a test board.

FIG. 2 relates to an embodiment of an electrical connector of the present invention,
(A) is the top view, (b) is a vertical cross-sectional view taken along the line AA.

FIG. 3 (a) is a top view showing a recess of the electrical connector of the present invention, and FIG. 3 (b) is a longitudinal sectional view showing the inner surface of the recess having a cylindrical shape.

FIG. 4 is a top view showing an inner surface of a concave portion of the electric connector of the present invention having a square pillar shape.

5A is a top view of a recess showing a case where the number of linear conductors embedded in one recess of the electrical connector of the present invention is two, and FIG. 5B is a longitudinal sectional view thereof. Is.

FIG. 6 (a) is a top view of a recess showing a case where the electric connector of the present invention has three linear conductors, and FIG. 6 (b) is a longitudinal sectional view thereof.

FIG. 7A is a top view of a recess showing a case where the electric connector of the present invention has four linear conductors, and FIG. 7B is a vertical cross-sectional view thereof.

[Explanation of symbols]

 1. Electrical connector, 2. Frame, 3. Insulating elastomer layer, 4. 4. Linear conductor, Spherical contact point, 6. Recess, 7. BGA, 8. Inspection board, 9. Spherical terminal electrode, 10.Terminal electrode, 11.Electrode,

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01R 33/94 9462-5B H01R 33/94

Claims (1)

[Claims] 1. An electrical connector provided with a plurality of linear conductors penetrating in a thickness direction of an insulating elastomer layer, wherein one end of the linear conductor forms a spherical contact portion. At least a part of the spherical contact portion is exposed from the bottom surface of the recess provided in the surface of the insulating elastomer layer, and when the wire diameter of the linear conductor is L, the spherical diameter R of the spherical contact portion is L <R <
Exposed height E from the bottom of the spherical contact point in the range of 3L
Is an electrical connector in the range of R / 3 <E <R.