JPH0883662A - Manufacture of super-micro connector - Google Patents

Abstract

PURPOSE: To provide a method for producing a super-micro connector of high connectability and reliability, allowing good connection state via the restraint of a connection defect with a semiconductor chip or a circuit board electrode. CONSTITUTION: A plurality of conductors 2 substantially arranged in parallel are fixed with an elastic insulator 3 laid in the gap thereof and a complex structure formed out of the conductors 2 and the insulator 3 is thereby prepared. Then, the structure 4 is cut along a plane F orthogonal with the conductors 2 to prepare a plurality of complex chips 5. Thereafter, the insulator 3 is dissolved and removed from at least one of cutout edges of each chip 5 by use of a chemical, thereby exposing the ends of a plurality of the conductors 2 over the prescribed length. Then, a solder bump 6 is formed on the the end of each exposed conductor 2.

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 a super micro connector which can electrically connect electrodes of a semiconductor chip and a circuit board to each other with high reliability.

[0002]

2. Description of the Related Art A large number of electrodes are formed on a semiconductor chip at a fine pitch, and the number of electrodes is increasing along with the high integration of circuits. To electrically connect the electrodes of the semiconductor chip to the outside, use a lead frame
IP (Dual Inline Package) has been the mainstream, but when the number of electrodes has increased and a large number of electrodes have been arranged in a grid pattern or a multilayer structure, conventional DIP using a lead frame cannot cope with this.

For this reason, when a large number of electrodes are used, the solder balls are reflow-soldered between the electrodes of the circuit board and the electrodes of the semiconductor chip in which the same number of electrodes as the semiconductor chips are arranged at the same pitch, and thereby the semiconductor Bare chip mounting method (Chip On Board)
Also called the Flip Chip method. ) Was used.

[0004]

However, in this bare chip mounting method, the electrodes of the semiconductor chip and the electrodes of the circuit board are directly connected by solder balls. Therefore, a circuit board on which a semiconductor chip is directly mounted by the bare chip mounting method causes thermal strain due to a thermal expansion difference between the semiconductor chip and the circuit board due to a temperature rise during use, and this thermal strain is concentrated on the solder portion. However, there is a problem that the solder portion deteriorates and causes a connection failure.

The present invention has been made in view of the above points, and has excellent connectivity and reliability that suppresses the occurrence of poor connection between the semiconductor chip and the electrodes of the circuit board and enables good connection. It is an object of the present invention to provide a method for manufacturing a high-performance super micro connector (hereinafter referred to as "SMC").

[0006]

In order to achieve this object, a method of manufacturing an SMC according to a first aspect of the present invention is directed to an elastic insulator in which a plurality of conductive wires arranged substantially in parallel are interposed therebetween. A step of producing a composite body which is fixed by a conductor and an insulator, a step of producing a plurality of composite chips by cutting the composite body at a plane orthogonal to the conductor wire, and at least one of the composite chips The insulator was dissolved and removed from the cut surface with a chemical agent, and a step of exposing the end portions of the plurality of conductive wires by a predetermined length, and a step of forming solder bumps on the exposed end portions of each conductive wire were adopted. Of.

The method of manufacturing the SMC of the present invention will be described below with reference to FIG.
It will be specifically described with reference to. First, a large number of conductive wires 2 are stretched over a square pipe 1 made of metal with high dimensional accuracy in a predetermined pattern substantially in parallel with the axis of the square pipe 1.
A liquid insulator 3 is injected into the inside and solidified. As a result, a composite body 4 in which a large number of substantially parallel conducting wires 2 are fixed by the insulator 3 is formed (FIG. 1 (a)).

Next, the composite body 4 is extracted from the square pipe 1 (FIG. 1 (b)), and the composite body 4 is cut to a predetermined thickness at a plane F orthogonal to the conducting wire 2 to form a thin plate-shaped composite body chip 5. Yes (Fig. 1
(c)). Next, the insulator 3 is dissolved and removed from the cut surfaces 5a and 5b of the composite chip 5 with a chemical agent to expose the end portions of the multiple conductive wires 2 by a predetermined length (FIG. 1 (d)).

Then, the substantially spherical solder bumps 6 are collectively formed on one end of the exposed large number of conductors 2 to manufacture the SMC 10 (FIG. 1 (e)). 1 (c) to 1 (f), a large number of conductor wires 2 are omitted to be four in order to simplify the drawing. Also, FIGS. 5, 6, 7, and 8 described later.
Also, in the above description, a large number of conducting wires 2 are omitted for the same purpose.

In the method of the first aspect, it is preferable to use an insulator whose coefficient of thermal expansion is intermediate between the semiconductor chip and the circuit board. Such an insulator prevents the solder bumps from suffering thermal strain due to the difference in coefficient of thermal expansion from the semiconductor chip or the circuit board and deteriorating the electrical connectivity. According to a second aspect of the present invention, after the step of forming solder bumps on the exposed ends of each of the conductive wires, the insulator on the side on which the solder bumps are formed is further dissolved and removed with a chemical agent to remove the solder bumps and the solder bumps. It is a manufacturing method of SMC provided with the process of exposing the above-mentioned plurality of conducting wires for a predetermined length between insulators.

According to the method of claim 2, S shown in FIG.
The insulator 3 on the side where the solder bumps 6 are formed is further removed from the MC 10 with a chemical agent, and the SMC 11 with the conductor 2 exposed is manufactured (FIG. 1 (f)). SM manufactured by the method of claim 2.
In C11, the conductor 2 is exposed between the solder bump 6 and the insulator 3 for a predetermined length. Therefore, this SMC11, when the electrodes of the semiconductor chip and the circuit board are connected by soldering,
Even if thermal strain occurs due to the difference in thermal expansion coefficient between the insulator and the semiconductor chip or the circuit board, the exposed portion of the conductor is deformed to absorb the thermal strain and the conductor is exposed. Therefore, heat dissipation is also improved.

In the method of the present invention, the reason why the elastic insulator is used as the insulator interposed between the conductors is that SMC is used.
Since the thermal stress at the time of soldering with the electrodes of the semiconductor chip and the circuit board is absorbed by the elastic deformation of the insulator, the deformation of the conductive wire due to the change in the distance between the electrodes and the thermal expansion is less likely to be hindered. This is because high connectivity is maintained during the period.

As the elastic insulator, silicone rubber, polymer elastomer, etc. are suitable. In particular, foamed silicone rubber has a small amount of deformation due to thermal expansion. For this reason, the connector is sandwiched between the semiconductor chip and the circuit board, the electrodes of the semiconductor chip and the circuit board are aligned with the lead wires of the connector, and then the electrodes and the lead wires are misaligned when soldered by heating. It does not occur and is preferable.

The size of the solder bump is determined by the length of the conductive wire exposed from at least one cut surface of the composite chip. To form the solder bumps on the exposed ends of the conductive wires, the solder bumps are dipped in a solder bath, or the solder paste is applied with a brush. After the formation of the solder bumps, the length of the conductor wire that is further exposed between the solder bump and the insulator is such that the exposed conductor wire and the semiconductor chip or the conductor wire and the circuit board can be easily connected by soldering or the like. That is, it is variously changed depending on the material used.

Here, the length of the conductive wire exposed from the insulator is preferably 0.02 to 0.1 mm before the formation of the solder bump. If the exposed length of the conductive wire is shorter than 0.02 mm, a solder bump having a sufficient size cannot be formed. On the other hand, if the exposed length of the conductive wire exceeds 0.1 mm, it is impossible to form a substantially spherical solder bump having an appropriate shape. On the other hand, when the conductor is further exposed after the solder bump is formed, the exposed length of the conductive wire is preferably 0.2 mm or more. If the length of the exposed conductor wire is shorter than 0.2 mm, the space for using the positioning jig cannot be secured when soldering with the semiconductor chip or the circuit board, and the soldering work becomes difficult. However, the positioning accuracy with respect to the semiconductor chip or the circuit board deteriorates.

As the solder used for forming the bumps,
Other than commonly used Sn-Pb type solder, pure Sn, etc., Bi
You may use low temperature solder, such as -In type | system | group, In, or Bi-Sn type | system | group. However, when silicone rubber is used as the insulator, solder having a melting point of 320 ° C. or higher cannot be used because of the heat resistance of the silicone rubber. A commercially available drug is usually used as a drug for dissolving and removing the insulator. For example, when the insulator is a silicone rubber, a 2-methoxyethanol-based solvent is used, which has a substantially linear relationship between the amount of dissolution and the passage of time, and the amount of insulator removed can be easily controlled by time. To be done.

Any material having conductivity is applied to the conductive wire used in the method of the present invention. Specifically, phosphor bronze,
Copper alloy materials such as Cu-Be alloys, nickel silver and Corson alloy are suitable. The shape of the conducting wire is arbitrary, for example, in addition to the round wire shown in FIG. 2 (a), a square wire, a twisted wire thereof, a modified wire, or the like.
When silicone rubber is used as the insulator, the thermal expansion coefficient of the metal material that constitutes the conductor is 10 to 20 x 10-6 / ° C, whereas that of silicone rubber is 200 to 300 x 10-6 / ° C. large. Therefore, the silicone rubber thermally expands due to the temperature rise when forming the solder bumps, and is likely to be separated from the conductor. As a result, the force with which the silicone rubber grips the conducting wire is weakened, and the conducting wire is likely to come off from the silicone rubber during the production of SMC. In order to avoid such a situation, it is preferable to make the shape of the conductor wire into a shape that is difficult to separate from the insulator.

As the shape of the conductor wire which is difficult to peel off from the insulator,
There is a modified wire having a required number of recessed grooves 2a having a narrow opening and a wide inner width, such as the conducting wire 2 shown in FIG. 2B. According to this atypical wire, the insulator enters into the groove 2a and has a large contact area with the conductor wire, and when the temperature rises during use of the SMC, the insulator expands and the insulator is formed inside and outside the groove 2a. Will be tightened. By twisting this irregular wire and forming the concave groove 2a in a spiral shape, the vertical displacement of the conductor in the insulator can be suppressed.

Also, in the conductor 2 composed of the twisted wire shown in FIG. 2C, the contact area with the insulator can be made large and the twisted wire is twisted in the vertical direction, so that the conductor is also displaced in the vertical direction. It can be suppressed. Furthermore, the conductor wire 2 in which the square wires shown in FIG. 2 (d) are assembled and joined so that the surface has irregularities, has a larger contact area than the ordinary twisted wire shown in FIG. 2 (c). Becomes
The movement of the conductor wire is more strongly suppressed.

At this time, if the insulator and the conductive wire are bonded with an adhesive, the displacement of the conductive wire can be suppressed more reliably. As such an adhesive, a primer capable of strongly adhering a metal material to silicone rubber or the like is desirable, and the conductor is preliminarily coated with the primer when the insulator and the conductor are adhered. In the method of the present invention, the conductive wire 2 shown in FIG. 3 is suitable for stably forming the solder bump in a predetermined shape.
The conductor 2 is made of a material that is corroded by a predetermined corrosive liquid.
b and a composite wire composed of a non-erodible material and a coating material 2c (FIG. 3 (a)). When the end of this wire is dipped in a predetermined corrosive liquid, the core material 2b is eroded and the top is cupped. A concave portion 2d that is concave is formed (FIG. 3B). When the top is dipped in the solder bath, the solder is solidified in the cup-shaped recess 2d. The shape of the recess 2d can be arbitrarily controlled depending on the corrosion conditions.

According to an eighth aspect of the invention, a process of fixing a plurality of conducting wires arranged substantially in parallel with an elastic insulator interposed between them to produce a composite of the conducting wires and the insulator. In the method of manufacturing an SMC, a plurality of V-grooves are formed at a predetermined pitch and have different heights, and the plurality of conductors are stacked and formed in a plurality of parallel conductor rows at a predetermined interval in a tensioned state. is there.

In the manufacturing method of the eighth aspect, since the positioning of the plurality of conducting wires is performed by using the V groove, the work is easy. Positioning of the plurality of conducting wires in the arrangement direction can be performed accurately by using a V-groove piece obtained by cutting and grinding an iron block in which V-grooves are formed at a predetermined pitch at a right angle. At this time, in order to apply tension to each conductor, a method of pulling with a weight attached to the end of the conductor may be simple. Further, the stacking interval of the plurality of parallel conductor lines can be adjusted with high accuracy by a spacer interposed between the parallel conductor lines.

The invention of claim 11 is a method for producing an SMC, wherein condensed silicone rubber is used as an insulator having elasticity. Since silicone rubber has excellent heat resistance and flux resistance, it can sufficiently withstand the environment during soldering. Further, since the silicone rubber dissolves in the drug relatively stably, the exposed length of the conductive wire can be made constant. Among the silicone rubbers, the addition type silicone rubber having a high degree of polymerization takes a long time to dissolve, and may swell and lose its shape when dissolved. On the other hand, a condensation type silicone rubber having a low polymerization density and a relatively large amount of filler dissolves in a short time and uniformly dissolves, and is therefore suitable as an insulator.

According to a twelfth aspect of the present invention, the step of dissolving and removing the insulating material with a chemical from at least one cut surface of each composite chip to expose the end portions of a plurality of conductive wires by a predetermined length, and the exposed each In the step of forming solder bumps on the conductive wire, the ends of the plurality of conductive wires are exposed on both cut surfaces of each composite chip, and the plurality of conductive wires exposed on one cut surface are electrically connected to the metal plate for electrodes. And a solder bump is formed on the plurality of conductive wires exposed on the other cut surface by electroplating.

Solder bumps are formed on the ends of the lead wires exposed from the composite chip to connect the semiconductor chip or the circuit board. If the solder bumps are formed by the hot dip method, it is difficult to make them large. However, the solder bump can be formed in an arbitrary size and a uniform shape by using the electroplating method.

According to a thirteenth aspect of the present invention, a conductive paste including the exposed plurality of conductive wires is applied to one cut surface of the composite chip, and the paste surface is insulation-coated,
Forming solder bumps on the plurality of conductors exposed on the other cut surface by electroplating by feeding the plurality of conductors exposed on one cut surface and the conductive paste to a conductor connected to a power source to supply power. It is a manufacturing method of SMC.

As the conductive paste, for example, a resin paste in which copper powder or silver powder is dispersed is used. When the conductive paste is dried and solidified and brought into contact with the conductor, workability during power feeding is improved. It is preferable to insulate the portions where solder plating is not necessary with nail polish or the like so that the shape of the solder bumps can be formed more accurately. FIG. 8 is a cross-sectional view showing a state where the solder bumps 6 are electroplated on the plurality of conductive wires 2 of the composite chip 5. A conductive paste 20 is applied to the conductive wire 2 exposed on one cut surface of the composite chip 5, and an electrode plate 22 is electrically connected to the conductive paste 20.
The conductive paste 20 and the electrode plate 22 are insulated by the nail polish layer 21 (or an insulating film or the like).

In this way, by applying the conductive paste 20 to the conducting wire 2 on the side of supplying power and bringing the conductive paste 20 into contact with the electrode plate 22 connected to the power source, the conducting wire 2 and the electrode plate 22 are connected.
The connection with can be perfect. For this purpose, it is preferable that the exposed length of the conducting wire 2 on the power feeding side be sufficiently long to ensure contact between the paste 7 and the exposed conducting wire 2. Even if the conductive paste 20 is dried and solidified, it can be dissolved in a solvent after solder plating or can be easily removed by a chemical method.

Therefore, according to the SMC manufacturing method of the thirteenth aspect, it is possible to uniformly and easily form solder bumps of an arbitrary size at each end of several hundreds to several thousands of conductive wires. The invention of claim 14 is the method of manufacturing an SMC, wherein the plurality of conductive wires are gold wires or gold-coated conductive wires. Electrodes on a semiconductor chip or a circuit board are connected to the conductors. Therefore, the conductor is required to have good solderability. Since the surface of the gold wire or the gold-coated conductor is not easily oxidized, the environment resistance is excellent, and the contact resistance is small, the power supply is evenly performed on each exposed conductor. Therefore, solder bumps of uniform size are electroplated on each of the multiple exposed conductors.

Further, since the gold wire or the gold-coated conductive wire is non-reactive with In, a low melting point solder of In series is attached to the exposed conductive wire group on the power feeding side, and the metal plate for electrodes is directly attached to this In series solder. Power can be supplied more reliably by connecting. Further, since the gold wire or the gold-coated conductive wire has excellent acid resistance, the In-based solder can be easily melted and removed after the completion of solder plating and washed with an acid, and the conductive wire is not damaged.

A fifteenth aspect of the present invention is a method for manufacturing an SMC in which the surfaces of a plurality of conducting wires are roughened by electrolytic treatment or chemical etching. The fixing force between the conductor and the insulator in the composite chip may be due to the elastic force of the insulator or due to the shape fixing force of the conductor. However, by roughening the conductor surface, the conductor and the insulator are The contact area is increased, the fixing force is improved, and the reliability as a connector is improved.

[0032]

In the method of the present invention, (1) a plurality of conducting wires arranged substantially in parallel are fixed by an elastic insulator interposed between them to prepare a composite of the conducting wire and the insulator. ,
By cutting this composite into a plurality of composite chips by cutting the composite along a plane orthogonal to the conducting wire, it is possible to mass-produce high-precision composite chips.

(2) If the insulator is dissolved and removed with a chemical agent to expose the conductor wire from the composite chip, the exposed length of the conductor wire can be arbitrarily controlled. Therefore, solder bumps having a predetermined shape can be stably formed on each exposed conductor. (3) Since the solder bump is formed on the conductive wire exposed from the composite chip, the shape and size of the solder bump can be controlled.

(4) Since the conductive wire between the solder bump and the insulator is exposed for a predetermined length, a positioning jig can be used when soldering with the semiconductor chip, and the positioning accuracy is improved. (5) By exposing the conductive wire, soldering work with a circuit board is facilitated, and a strong connection is obtained. (6) If an insulating material having elasticity is interposed between the conductors, thermal stress during soldering is absorbed by the deformation of the insulating material, and no positional displacement occurs between the electrode and the conductor.

Further, according to the present invention, (7) a substantial parallel arrangement of a large number of fine conductor wires can be easily performed by using a piece provided with a V groove. (8) The lead wires arranged in the V-grooves of the bridge can be easily increased in alignment accuracy by weighting the lead wire ends and pulling. (9) The position in the arrangement (width) direction of the conductor wires arranged in the V-grooves of the piece is accurately determined by disposing the conductor wires in the V-grooves formed at a predetermined pitch. Further, the stacking interval of the plurality of parallel conductive wire rows can be easily adjusted by interposing a spacer between the parallel conductive wire rows.

(10) If a condensation type silicone rubber having a low polymerization density and a relatively large amount of filler is used for the elastic body, the conductive wire can be exposed to a uniform length in a short time. (11) By forming the solder bumps by the electroplating method, it is possible to form the solder bumps of any size in a uniform shape. (12) The power supply for electroplating is performed by applying a conductive paste together with the exposed plurality of conductive wires to one cut surface of the composite chip to insulate and then connecting a large number of conductive wires and this paste to a power source. This can be easily done by electrically connecting to the conductor.

(13) When a gold wire or a gold-coated conductor wire having a surface that is hard to oxidize and has good environment resistance is used as a conductor wire, solder bumps having a uniform shape can be electroplated on a large number of exposed conductor wires. (14) When the surface of the conductive wire is formed into a rough surface by electrolytic treatment or chemical etching, the contact area between the conductive wire and the insulator is increased, and the adhesion force between both is improved.

[0038]

The present invention will be described below in detail with reference to examples. Example 1 SMC10 was manufactured according to the steps shown in FIG. Phosphor bronze (Cu, 8wt% Sn, 0.13wt) is placed in a square pipe 1 made of low carbon steel with a length of 500mm and a side of 15 ± 0.01mm.
% P) of gold-plated conductor 2 (0.08 mm diameter)
1,600 pieces were stretched at a pitch of 25 mm substantially parallel to the axial direction, and liquid silicone rubber was injected into the pipe 1 as an insulator 3 and solidified to form a composite body 4 composed of a conductor 2 and an insulator 3 ( Figure 1 (a)).

Next, the composite body 4 was extracted from the square pipe 1 (FIG. 1 (b)), and the thickness of the composite body 4 on the plane F orthogonal to the conducting wire 2 was 1.5.
The composite chip 5 was cut into mm (FIG. 1 (c)). For the insulator 3, an addition type silicone rubber having a high polymerization density was used. Next, the composite chip 5 was immersed in 2-methoxyethanol to dissolve and remove the insulator 3 from the cut surfaces 5a and 5b, exposing the end portions of the multiple conductors 2 to a length of 0.02 mm (Fig. 1 (d)).

Thereafter, one end side of the exposed large number of conductors 2 is immersed in a solder bath to form solder bumps 6 on one end of each conductor 2, and the SMC 10 of 15 mm × 15 mm × 1.5 mm shown in FIG. 1 (e) is formed.
Was manufactured. For the solder bath, Sn-Pb type high temperature solder composed of 90 wt% Pb and 10 wt% Sn and having a melting point of 280 to 300 ° C. was used.

In order to stretch the above-mentioned conductive wires substantially in parallel at a pitch of 0.25 mm, a total of 1,600 holes having a diameter of 0.083 mm are provided in the vertical and horizontal directions at two pitches of 0.25 mm. It was installed at both ends of the pipe with an interval of 500 mm, and one conductor was passed through each hole of the eye plate. Example 2 An SMC 10 of 15 mm × 15 mm × 1.5 mm shown in FIG. 1 (e) was manufactured by the same method as in Example 1 except that foamed silicone rubber was used as the insulator. (Example 3) The SMC manufactured in Example 1 and shown in FIG.
The side on which the solder bumps 6 are formed is again immersed in the above chemical to dissolve and remove the insulator 3, and the conductor wire 2 is exposed between the solder bumps 6 and the insulator 3 by 0.25 mm, 15 mm × 15 mm × 1.5
mm of SMC11 shown in FIG. 1 (f) was manufactured. (Example 4) 15 mm x 15 mm x 1.5 mm in the same manner as in Examples 1 and 3 except that foamed silicone rubber was used for the insulator.
SMC11 shown in FIG. 1 (f) was manufactured. (Embodiment 5) Diameter in which the concave groove 2a shown in FIG. 2 (b) is formed
15 mm x 15 mm x in the same manner as in Examples 1 and 3 except that the conductor wire 2 having a diameter of 0.08 mm was used and the eye plate having a hole diameter of 0.083 mm was used.
A 1.5 mm SMC 11 shown in FIG. 1 (f) was manufactured. (Example 6) As the conductor 2, the twisted wire shown in FIG. 2 (c) (7 twisted wires of phosphor bronze wire, diameter 0.08 mm) was used, and the diameter of the hole was 0.
The SMC11 shown in FIG. 1 (f) having a size of 15 mm × 15 mm × 1.5 mm was manufactured by the same method as in Examples 1 and 3 except that a 083 mm eye plate was used.

1,000 SMCs 10 and 11 produced in Examples 1 to 6 were prepared, and using these, the semiconductor chip and the electrodes of the circuit board were connected by the corresponding conductors. The connection followed the procedure shown in FIGS. 5 (a) to 5 (f). Here, FIG. 5 is a diagram in the case where the electrodes of the semiconductor chip and the circuit board are connected by corresponding conductors using the SMC 11. However, since the procedure shown in FIG. 5 can be used even in the case of SMC10, the case of SMC11 will be described below, and the description of the case of SMC10 will be omitted.

Further, in the semiconductor chip 30 and the circuit board 32 shown in FIG. 5, 1,600 electrodes 30a and 32a are provided in the SMC11.
Are formed in the same pattern as the large number of conducting wires 2. First, the solder bumps 6 formed on the conductors 2 of the SMC 11 were arranged on the corresponding electrodes 30a side of the semiconductor chip 30 (FIG. 5 (a)). Next, the solder bumps 6 of the SMC 11 are connected to the corresponding electrodes of the semiconductor chip 30 by reflow soldering.
It was connected to 30a (Fig. 5 (b)).

Next, the conductor 2 exposed on the other side of the SMC 11
A solder bump 7 having a melting point lower than that of the solder bump 6 was formed on the surface of the solder bump 6 (FIG. 5C). Then, the insulator 3 on the solder bump 7 side is immersed in a chemical to dissolve and remove the surface layer to expose the conductor wire 2 on the solder bump 7 side by 0.25 mm (FIG. 5).
(d)). Next, the solder bumps 7 of the corresponding conductive wire 2 are positioned on each electrode 32a of the circuit board 32 (FIG. 5 (e)), and the solder bumps 7 are reflow-soldered at a temperature at which the solder bumps 6 do not melt, The semiconductor chip 30 and the circuit board 32 were connected via the SMC 11 (FIG. 5 (f)).

Here, the solder bump 6 is Sn as described above.
-Pb-based high temperature solder, solder bump 7 is 38 wt% Pb, 62 w
A Sn-Pb-based low temperature (eutectic) solder having a melting point of 183 [deg.] C. made of t% Sn was used. And SMC10,1 by intermittent energization
A long-term deterioration test was conducted on the connection between each conductor 2 of 1 and the electrodes 30a, 32a, and each conductor 2 of SMC10, 11 and the semiconductor chip
The number (per 1,000 pieces) of the SMCs 10 and 11 that failed in conduction with the electrode 30a of 30 and the electrode 32a of the circuit board 32 was examined. The results are shown in Table 1. (Example 7) Cu-1% Cr alloy was used as the core material 2b, and Nb was used.
Using 1,600 conducting wires 2 (see FIG. 3 (a)) made of a composite wire having a diameter of 0.08 mm and a coating material 2c made of metal (0.4 μm thickness), the same procedure as in Example 1 was applied to FIG. 1 (c). The composite chip 5 shown was manufactured.

Next, the cut surfaces 5a and 5b of the composite chip 5
Then, the insulator 3 was dissolved and removed with 2-methoxyethanol to expose each conductor wire 2 by a length of 0.02 mm (FIG. 1 (d)). Then, the conductor 2 exposed on one side of the insulator 3 is immersed in a nitric acid aqueous solution to erode only the core material 2b to form a recess 2d having a maximum depth of 70 μm on the tip surface of the conductor (see FIG. 3 (b)). Was formed.

Thereafter, the solder bumps 6 as shown in FIG. 1 (e) were formed in the recess 2d by the Sn-Pb type high temperature solder used in the first embodiment. Then, in the same manner as in Example 3, the side on which the solder bumps 6 were formed was again immersed in the chemical to further dissolve and remove the insulator 3, and the conductor wire 2 was exposed between the solder bumps 6 and the insulator 3 by 0.25 mm. 15mm x 15mm x 1.5mm Figure 1
The SMC11 shown in (f) was manufactured.

In the manufactured SMC 11, the solder bumps 6 were formed in a substantially spherical shape on the tip surface of each conductor wire 2, and the shape was the same for each conductor wire. When this SMC11 was connected to a semiconductor chip, as shown in FIG.
The upper part of the covering material 2c made of the above was opened in a flower-villa shape, and the conductors 2 and the corresponding electrodes 30a of the semiconductor chip 30 were well soldered by the solder bumps 6.

Further, 1,000 manufactured SMCs 11 are prepared and the electrodes 30a and 32a of the semiconductor chip 30 and the circuit board 32 are made to correspond to each other by using the prepared SMCs 11 by the procedure shown in FIGS. 5 (a) to 5 (f). Connected with a lead wire 2. Then, a long-term deterioration test similar to the above is performed by intermittent energization, and each conductor 2 and electrode
SM with poor continuity at the connection with 30a, 32a
The number of C11 was examined. The results are also shown in Table 1. (Example 8) An SMC was manufactured using a container having a U-shaped cross section and having an open upper portion, instead of the low carbon steel pipes used in Examples 1 to 7.

First, a plurality of V-groove pieces 25 and 26 having a plurality of V-grooves formed at a predetermined pitch and having different heights apply tension to the plurality of conductor wires 2 made of phosphor bronze having a diameter of 0.08 mm used in the first embodiment. A plurality of parallel conductor lines A at predetermined intervals
40 rows were laminated on W1, AW2, AW3 .... That is, as shown in FIG. 7 (a), two V-groove pieces with 40 dimensionally high V-grooves 25a having a groove bottom height of h1 (see FIG. 7 (b)) are formed at 0.25 mm intervals. Twenty-five were placed at a predetermined interval. Then, the conductor wire 2 was placed in each corresponding V groove 25a, and tension was applied to the conductor wire 2 by the weights 27 of 200 g attached to both ends to form the parallel conductor wire row AW1.

Next, as shown in FIG. 7B, two V-groove pieces 26 each having 40 V-grooves 26a formed at 0.25 mm intervals with high dimensional accuracy were set outside the V-groove pieces 25. And each corresponding V groove
A 200 g weight attached to both ends by placing the conductor 2 inside the 26a.
At 27, tension is applied to the conductor 2 to form the parallel conductor row AW2 above the parallel conductor row AW1. At this time, in each V groove 26a, the height h2 of the groove bottom is 0.25 mm higher than the height h1 of the groove bottom of the V groove piece 25.
Since they were formed high, the stacking interval between the parallel conductive wire row AW1 and the parallel conductive wire row AW2 was 0.25 mm.

Similarly, a plurality of parallel conducting wire rows AW1,
40 rows of AW2, AW3 ......... were formed at 0.25 mm intervals.
At this time, since the plurality of conductors 2 are arranged in the V grooves 25a, 26a formed with high dimensional accuracy of the V groove pieces 25, 26, the conductor wires 2 can be accurately positioned in the arrangement direction. Also, a plurality of parallel conductor lines AW
The stacking interval of 1, AW2, AW3, ... Was adjusted by interposing a required number of spacers 28, 29 between them as shown in FIG. 7 (b). As a result, the plurality of conductive wires 2 could be arranged substantially in parallel within the error of 250 μm ± 10 μm in both the arrangement interval and the lamination interval.

In this state, liquid silicone rubber was poured as an insulator 3 into the container and solidified to form a composite body 4 shown in FIG. 1 (a) consisting of the conductor 2 and the insulator 3. Next, the composite 4 is extracted from the container (see FIG.
(b)), which was cut to a thickness of 1.5 mm to obtain a composite chip 5 (the same (c)). For the insulator 3, an addition type silicone rubber having a high polymerization density was used. Therefore, the composite chip 5 is
A total of 1,600 parallel conductor wires 2 are arranged at equal intervals in the thickness direction.

Next, the composite chip 5 is dipped in 2-methoxyethanol, and the insulating surfaces 3 are cut from the cut surfaces 5a and 5b.
Was removed by dissolution, and the end portions of the many conductors 2 were exposed to a length of 0.02 mm (FIG. 1 (d)). After that, one end side of the exposed large number of conductors 2 is immersed in a solder bath to form solder bumps 6 on one end of each conductor 2, and the solder bumps 6 of 15 mm × 15 mm × 1.5 mm are formed.
The SMC10 shown in (e) was manufactured.

For the solder bath, Sn-Pb type high temperature solder composed of 90 wt% Pb and 10 wt% Sn and having a melting point of 280 to 300 ° C. was used.
In addition, on both end faces of the container, comb teeth provided with gaps having the same size as the diameter of the conductor wire in the vertical direction at the same pitch as the plurality of conductor wires were installed to prevent silicone rubber from flowing off from both end faces. .

The SMC10 produced in this way is 1,000
Individually prepared, and using these, the electrode 30a of the semiconductor chip 30 and the circuit board are obtained by the procedure shown in FIGS. 5 (a) to 5 (f).
The 32 electrodes 32a were connected to each other by corresponding conductors 2. Then, the same long-term deterioration test as in Examples 1 to 7 is performed,
The number of SMCs 10 having a conduction failure at the connection between each conductor 2 and the electrodes 30a and 32a was examined. The results are also shown in Table 1. (Example 9) An SMC 10 of 15 mm x 15 mm x 1.5 mm shown in Fig. 1 (e) was manufactured by the same method as in Example 8 except that foamed silicone rubber was used as the insulator.

The SMC10 produced in this way is 1,000
5A to 5F are prepared by individually preparing semiconductor chips having the same structure as that of the eighth embodiment and electrodes of the circuit board with corresponding conductive wires.
The number of SMC10s that were connected according to the procedure shown in FIG. The results are also shown in Table 1. (Example 10) The SMC manufactured in Example 8 and shown in FIG.
The side on which the solder bumps 6 are formed of 10 is again immersed in the above chemical to further dissolve and remove the insulator 3, and the solder bumps 6 and the insulator 3 are removed.
Expose 0.25mm of conductor 2 between and, 15mm × 15mm × 1.5mm
SMC11 shown in FIG. 1 (f) was manufactured.

The SMC11 produced in this manner is used for 1,000
Individual pieces were prepared and the electrodes of the semiconductor chip and the circuit board were connected by corresponding conductors. The connection followed the procedure shown in FIGS. 5 (a) to 5 (f). Then, a long-term deterioration test is performed on the connection between each conductor 2 of the SMC 11 and the electrodes 30a, 32a due to intermittent energization, and conduction is established between each conductor 2 of the SMC 11 and the electrode 30a of the semiconductor chip 30 or the electrode 32a of the circuit board 32. The number of defective SMC11 was examined. The results are also shown in Table 1. (Example 11) 15 mm × 15 shown in FIG. 1 (f) by the same method as in Example 10 except that foamed silicone rubber was used for the insulator.
mm × 1.5 mm SMC11 was manufactured.

The SMC11 produced in this manner is used for 1,000
Individual pieces were prepared, and in the same manner as in Example 10, the semiconductor chip 30 and the electrodes 30a, 32a of the circuit board 32 were connected by corresponding conductors 2. Then, in the same manner as in Example 10, the number of SMCs 11 in which conduction failure occurred was examined, and the results are shown in Table 1. (Embodiment 12) Diameter in which the concave groove 2a shown in FIG. 2 (b) is formed
A 15 mm × 15 mm × 1.5 mm SMC 11 shown in FIG. 1 (f) was manufactured in the same manner as in Example 10 except that the conductor wire 2 of 0.08 mm was used.

The SMC11 produced in this manner is used for 1,000
Separately prepared, half as in Example 10.

[0061]

[Table 1]

The electrodes 30a of the conductor chip 30 and the electrodes 32a of the circuit board 32 were connected by corresponding conductors 2.

Then, in the same manner as in Example 10, the number of SMCs 11 in which conduction failure occurred was examined, and the results are shown in Table 1. Example 13 Example 10 was repeated except that the twisted wire shown in FIG. 2C (7 twisted wires of phosphor bronze wire, diameter 0.08 mm) was used as the conductor wire 2.
15mm × 15mm × 1.5mm SM shown in Fig. 1 (f) in the same way as
C11 was produced.

The SMC11 produced in this way is 1,000
Individual pieces were prepared, and in the same manner as in Example 10, the electrodes 30a of the semiconductor chip 30 and the electrodes 32a of the circuit board 32 were connected by corresponding conductors 2, and the number of SMCs 11 in which conduction failure occurred was examined. The results are shown in Table 1. (Example 14) The same method as in Example 10 was used except that the conducting wire 2 made of the composite wire having a diameter of 0.08 mm shown in Fig. 3 (a) was used.
The SMC11 of 15 mm × 15 mm × 1.5 mm shown in (f) was manufactured.

The SMC11 produced in this manner is 1,000
Individual pieces were prepared, and in the same manner as in Example 10, the electrodes 30a of the semiconductor chip 30 and the electrodes 32a of the circuit board 32 were connected by corresponding conductors 2, and the number of SMCs 11 in which conduction failure occurred was examined. The results are shown in Table 1. (Comparative Example 1) 1,000 semiconductor chips 30 and circuit boards 32 each having 1,600 electrodes were used and solder balls were used without using the SMC manufactured by the method of the present invention. Corresponding electrodes 30a, 32
a Directly connected to each other.

Directly connected semiconductor chip 30 and circuit board 32
With respect to and, a long-term deterioration test of the connection between the electrodes 30a and 32a due to intermittent energization was performed, and the number of sets of the semiconductor chip 30 and the circuit board 32 in which conduction failure occurred was examined. The results are also shown in Table 1. As is clear from Table 1, the connectors manufactured by the method of the present invention were found to have few conduction defects. In particular, the SMCs of Examples 5 and 6 and Examples 12 and 13 in which the contact area between the conductor and the insulator is large, and the solder bumps of Example 7 and 14 in which the tip end surface of the conductor is formed in a concave shape Example 2, in which foamed silicone rubber was used for the SMC and insulator,
The SMCs of 4,9,11 showed few connection failures and showed excellent connection characteristics.

On the other hand, in the semiconductor chip and the circuit board of Comparative Example 1, there were 17 in which conduction failure occurred. This is because the electrodes of the semiconductor chip and the electrodes of the circuit board are directly connected by the solder balls without the intermediary of conducting wires, so that thermal distortion is applied to the solder portions and the solder portions are deteriorated and peeled off. As for the method of laying the conducting wires, when the V-groove piece was used (Examples 8 to 14), the stacking interval could be adjusted by the spacers, so when the eye plate was used (Example 1)
~ 7), the number of defective conduction was reduced to some extent.

In Examples 1 to 14 described above, when electrically connecting the conductors of the semiconductor chip and the circuit board to each other by SMC,
Although two kinds of solders having different melting points were used and the soldering was divided into two times, the electrodes of the semiconductor chip and the circuit board were electrically connected to each other by SMC by one soldering operation using the solder having the same melting point. It is also possible. In this case, SMC is shown in FIG.
As the SMC 12 shown in FIG. 2, the conductor 3 having the solder bumps 6 formed on both ends of the conductor 2 exposed by a predetermined length (for example, 0.25 mm) from both surfaces of the insulator 3 is used. (Embodiment 15) A container having a U-shaped cross section and a V for stretching the conductor wire
An SMC was produced by the same method as in Example 3, except that a grooved piece was used and a condensation type silicone rubber having a low polymerization density and a relatively large amount of filler was used as an insulator.

The time required for laying the conductor wire is significantly shortened as compared with the case where the eye plate is used, and the time for exposing the conductor wire from the insulator is the same as that of the addition type silicone rubber used in Example 3. It was about half the time. Regarding the obtained SMC, the conductivity between the semiconductor chip and the electrodes of the circuit board was investigated in the same manner as in Example 3. as a result,
One out of every 1,000 defective connections occurs,
Good results were obtained, comparable to those of foamed silicone rubber. this is,
This is because the condensed silicone rubber was uniformly dissolved and removed. (Example 16) A container having a U-shaped cross section and a V for stretching the conductor wire
As shown in FIG. 8, a groove piece is used to expose the ends of the conductor wire 2 from both surfaces of the composite chip 5, and the conductor wire 2 exposed on one end surface is connected to the electrode plate 22 for electrodes through the conductive paste 20. SMC was manufactured by the same method as in Example 3 except that the solder bump 6 was electrically plated on the end of the conductive wire 2 exposed on the other end surface.

At this time, the exposed length of the conductor 2 on the side where the solder bumps 6 are formed is 0.1 mm, and the exposed length of the conductor 2 on the power supply side is
It was 0.25 mm. Further, a conductive paste 20 in which copper powder was dispersed in a resin paste was applied to the exposed conductive wire group on the power feeding side, and after this paste 20 was dried and solidified, each conductive wire 2 was connected to an electrode plate 22. Next, after the paste 20 and the electrode plate 22 are insulated by the nail polish layer 21, the exposed end portions of the lead wire group are immersed in a solder electrolytic bath, and a predetermined voltage is applied between the anode and the anode to electroplate the solder bumps 6. did.

The size and variation of the solder bumps 6 of the obtained SMC were investigated. All the solder bumps 6 were substantially spherical. We randomly selected 100 solder bumps and measured their diameters. As a result, the average value per 100 solder bumps was 120 μm, and the standard deviation was 0.6 μm. In addition, the same measurement was performed on 100 SMCs manufactured by the method of Example 3. As a result, the SM produced in Example 3
In C11, most of the solder bumps 6 had a substantially spherical shape, but the diameter was small at 80 to 100 μm, and the standard deviation was 2.7.
It was as large as μm. (Example 17) An In-based solder was adhered to the exposed conducting wire group (Au-plated phosphor bronze wire) on the power feeding side instead of the conductive paste, and the metal plate for electrodes was directly connected to this In-based solder. The solder bumps were electroplated by the same method as in Example 16. After the electroplating was completed, the In-based solder was heated and removed by melting, and the residual In was washed out with nitric acid.

The obtained solder bumps of SMC are substantially spherical,
The diameter was 120 μm, and the standard deviation was 0.45 μm, which was smaller than the value of Example 16. In addition, when a continuity test was conducted, no defective products were found. No damage was found in the gold plating layer of the conductor.

[0073]

As is apparent from the above description, according to the method of the present invention, the shape of the solder bump formed on the conductive wire is constant, the bonding strength between the electrode and the conductive wire is high, and the thermal strain during use is reduced. Therefore, it is possible to manufacture a highly reliable super micro connector which can be absorbed and therefore has excellent connectivity with electrodes of a semiconductor chip or a circuit board, and has an excellent industrial effect.

At this time, according to the method of claim 2, even if thermal strain occurs due to the difference in thermal expansion coefficient between the insulator and the semiconductor chip or the circuit board, the exposed portion of the conductive wire is deformed. Absorbs thermal strain, and since the conductor wire is exposed, heat dissipation is also improved. According to the method of claim 3, the amount of deformation due to thermal expansion of the insulator can be reduced, and when the electrodes of the semiconductor chip and the circuit board and the conductive wire of the super micro connector are soldered, the gap between the electrode and the conductive wire is reduced. Can be prevented from being displaced.

According to the methods of claims 4 and 5, even if the insulator thermally expands due to temperature rise during use of the supermicro connector, the insulator is less likely to be peeled off from the conductor wire. According to the method of claim 6, the solder bump can be stably formed in a predetermined shape on the conductor wire of the super micro connector. According to the method of claim 7, it is possible to more reliably suppress the displacement of the conductive wire due to the temperature rise during the use of the super micro connector.

According to the method of claim 8, the V-grooves are used to position the plurality of conductors, so that the work is easy and the plurality of conductors can be accurately positioned. According to the method of claim 9, tension can be easily applied to each conductor. According to the method of claim 10, the stacking interval of the plurality of parallel conductor lines can be adjusted with high accuracy.

According to the method of claim 11, since the insulator is relatively stable and uniformly dissolved in the drug in a short time, the conductor wire can be exposed to a certain length from the super micro connector. According to the method of claim 12, solder bumps of arbitrary size and uniform shape can be formed on the super micro connector.

According to the method of claim 13, solder bumps of any size can be uniformly and easily formed at each end of the plurality of conductors of the supermicro connector. According to the method of claim 14, it is possible to uniformly supply power to the plurality of conductive wires of the supermicro connector. According to the method of claim 15, the contact area between the conductor and the insulator is increased, the fixing force is improved, and the reliability of the super micro connector can be enhanced.

[Brief description of drawings]

FIG. 1 is a process diagram schematically illustrating a method for manufacturing a super micro connector of the present invention.

FIG. 2 is a perspective view showing the shape of a conductive wire used in the method of the present invention.

FIG. 3 is a perspective view showing a state in which an end portion of a conductive wire used in the method of the present invention is corroded with a corrosive agent.

FIG. 4 is a vertical cross-sectional view showing a state after soldering of a super micro connector using the conductor wire shown in FIG.

FIG. 5 is a process diagram for connecting a semiconductor chip and a circuit board using a super micro connector manufactured by the method of the present invention.

FIG. 6 is a front view showing another embodiment of the super micro connector manufactured by the method of the present invention.

FIG. 7 is an explanatory diagram showing a state in which a plurality of conducting wires are stretched using a V-groove piece.

FIG. 8 is a cross-sectional view showing a situation in which solder bumps are electroplated on a plurality of conductive wires of a composite chip.

[Explanation of symbols]

1 Square pipe 2 Conductive wire 2a Groove 2b Core material 2c Covering material 2d Recess 3 Insulator 4 Composite 5 Composite chip 6,7 Solder bump 10,11,12 Super micro connector (SM
C) 20 Conductive paste 21 Manicure layer 22 Electrode plate 25,26 V-groove piece 25a, 26a V-groove 27 Weight 28,29 Spacer 30 Semiconductor chip 30a Electrode 32 Circuit board 32a Electrode AW1, AW2 Parallel conducting wire row

Claims (15)

[Claims] 1. A plurality of conductive wires arranged substantially in parallel,
A step of producing a composite body composed of a conductor and an insulator by fixing it with an elastic insulator interposed therebetween, and producing a plurality of composite chips by cutting the composite body in a plane orthogonal to the conductor wire. The step of dissolving and removing the insulator with a chemical from at least one cut surface of each of the composite chips, and exposing the end portions of the plurality of conductive wires to a predetermined length, at the exposed end portions of each conductive wire. A method for manufacturing a super micro connector, comprising a step of forming solder bumps. 2. After the step of forming solder bumps on the exposed ends of each of the conductive wires, the insulator on the side on which the solder bumps are formed is further dissolved and removed with a chemical agent to remove the solder bumps and the insulator. The method for manufacturing a super micro connector according to claim 1, further comprising the step of exposing the plurality of conductive wires for a predetermined length between the two. 3. The method for producing a super micro connector according to claim 1, wherein the elastic insulator is foamed silicone rubber. 4. A required number of recessed grooves having a narrow opening and a wide inner width are formed on the surface of the conductor wire in a linear or spiral shape.
A method for manufacturing a super micro connector according to claim 1. 5. The method for producing a super micro connector according to claim 1, wherein a twisted wire or a composite wire obtained by assembling and joining a plurality of wire rods so that unevenness is formed on the surface is used as the conductive wire. 6. The supermicro connector according to claim 1, wherein a composite wire comprising a core material that is corroded by a predetermined corrosive agent and a coating material that is non-corrosive to the corrosive agent is used as the conductive wire. Manufacturing method. 7. The method for manufacturing a super micro connector according to claim 1, wherein the conductor is adhered to an elastic insulator with an adhesive. 8. A plurality of wires arranged substantially in parallel,
In the step of producing a composite body composed of a conductor and an insulator by fixing it with an insulating material having elasticity interposed between these, the plurality of V grooves are formed at a predetermined pitch, 4. The method for manufacturing a super micro connector according to claim 1, wherein the conductor wire is laminated on a plurality of parallel conductor wire rows at a predetermined interval in a tensioned state. 9. The method for manufacturing a super micro connector according to claim 8, wherein tension is applied to each of the conductive wires by a weight attached to an end thereof. 10. The method for manufacturing a supermicro connector according to claim 8, wherein a stacking interval of the parallel conductor lines is adjusted by a spacer interposed between the parallel conductor lines. 11. The method for producing a super micro connector according to claim 1, wherein a condensation type silicone rubber is used as the elastic insulator. 12. A step of dissolving and removing the insulator with a chemical from at least one cut surface of each of the composite chips to expose end portions of the plurality of conductive wires by a predetermined length, and soldering to each of the exposed conductive wires. In the step of forming a bump, the ends of the plurality of conductive wires are exposed on both cut surfaces of each composite chip, and the plurality of conductive wires exposed on one cut surface are electrically connected to a metal plate for electrode. The method for manufacturing a super micro connector according to claim 1, wherein solder bumps are formed on the plurality of conductive wires exposed on the other cut surface by electroplating. 13. On one cut surface of the composite chip,
A conductive paste including the exposed plurality of conductive wires is applied, and the paste surface is insulation-coated, and then the conductive wires and the conductive paste exposed on one cut surface are brought into contact with a conductor connected to a power source. 13. The method for manufacturing a super micro connector according to claim 12, wherein solder bumps are formed by electroplating on the plurality of conductive wires exposed on the other cut surface by supplying electric power. 14. The method for manufacturing a super micro connector according to claim 1, wherein the plurality of conductive wires are gold wires or gold-coated conductive wires. 15. The method for manufacturing a super micro connector according to claim 1, wherein the surfaces of the plurality of conductive wires are roughened by electrolytic treatment or chemical etching.