JP3381375B2 - Electrode assembly, manufacturing method thereof, and lead frame using electrode assembly - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a semiconductor chip in which electronic circuits are integrated with extremely high density (hereinafter simply referred to as "IC chip") and a large number of outer leads are led out. An electrode assembly such as a connector capable of mounting an electronic circuit element such as an integrated circuit device (hereinafter simply referred to as “IC”) on an electronic circuit wiring board, and the same
The present invention relates to a manufacturing method and a lead frame on which an electronic circuit element can be mounted.

[0002]

2. Description of the Related Art The invention disclosed in Japanese Patent Application Laid-Open No. Hei 5-36547, "Electronic Components, Their Application Devices and Their Manufacturing Methods", which was filed by the present applicant and published on February 12, 1993, and Heisei 5 In the invention filed on Dec. 15, 2015, entitled “Probe Assembly, Method for Manufacturing the Same, and Probe Card for IC Measurement Using the Same”, Japanese Patent Application No. 5-315180, for example, a connector for electronic circuit elements and a lead for IC To obtain a fine-pitch electrode assembly such as a glow bar for measuring and evaluating the characteristics of the frame and the IC or IC chip, a plurality of metal thin plates and a plurality of insulating thin plates are alternately laminated at a predetermined pitch. To form a multilayer laminate,
This is cut into an appropriate thickness, and a plurality of metal layers exposed on at least one plane of the obtained cubic laminated block are etched to form concave grooves having a uniform depth. Is processed to obtain a fine-pitch electrode assembly.

[0003]

However, in the electrode assembly such as the probe assembly of the invention of the earlier application, the metal of the thin metal plates which basically constitute the laminated block is basically subjected to the chemical etching or the like to form the concave groove. Must be formed, and the electrodes, for example, probes, which are electrodes, must be inserted and fixed in these grooves to adjust the distance between their tips, and to the metal plate exposed on the opposite surface. Although bumps have to be formed separately, it is easier to manufacture than known electrode assemblies, but this probe is still inserted, fixed,
Alternatively, troublesome work such as formation of bumps is required, which remains a problem.

[0004]

Therefore, the electrode assembly of the present invention is provided with at least a laminated block or a laminated thin plate in which a plurality of metal thin plates of a conductive material and a plurality of insulating thin plates of an insulating material are alternately laminated at a predetermined pitch. The insulating material exposed on one plane is partially removed in the thickness direction, and the metal exposed on the same exposed plane is projected to form a plurality of electrodes.

As a means for removing the insulator of the electrode assembly, a physical means such as a liquid honing method mixed with an abrasive or a chemical means such as a wet etching method is used.

[0006]

Therefore, according to the present invention, the fine pitch
It is extremely easy to use an existing assembly facility for the electrode assembly ,
It can be manufactured with high yield, and the cost can be significantly reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrode assembly of the present invention and its manufacturing method will be described below with reference to the drawings. First, an electrode assembly according to a first embodiment of the present invention and a method for manufacturing the same will be described with reference to FIGS. FIG. 1 is a perspective view showing each step of a method for manufacturing an electrode assembly according to the first embodiment of the present invention,
2 shows an electrode assembly of the present invention manufactured by the manufacturing method of FIG. 1, FIG. 2A is a perspective view thereof, and FIG.
FIG. 3 is a partial cross-sectional view taken along the line BB of FIG. 3, and FIG. 3 shows an electrode assembly of a modified example of the present invention manufactured by the manufacturing method of FIG. 1, and FIG. FIG. 3B is a plan view of the electrode assembly showing an example of parallel metal bumps.

First, a method of manufacturing an electrode assembly will be described with reference to FIG. In FIG. 1A, first, a material forming the electrode assembly is prepared. Reference numeral 1 indicates an insulating thin plate. This insulating thin plate 1 has a thickness of 0.15 mm including the thickness of the adhesive and is made of thermosetting resin such as epoxy resin or phenol resin (for example, glass epoxy resin, PET, PI) or vinyl resin (for example, , Vinyl chloride, vinyl acetate), and styrene-based thermoplastic resins. Reference numeral 2 indicates a metal thin plate, which is also 0.1 including the thickness of the adhesive.
For example, copper or beryllium copper having a plate thickness of 5 mm and the same area as the insulating thin plate 1 is used. The insulating thin plates 1 may be laminated so as to be the outermost layer.

[0009] Each of these sheets is alternately laminated and vacuum-heat-molded for adhesion, and laminated in multiple layers.
The multilayer laminate 3 as shown in FIG. In this step, bonding is performed while vacuum pressing is performed so that air bubbles do not occur between the layers. Next, as shown in FIG. 1C, the multilayer laminate 3 is formed in a thickness of 5 to 6 mm in the stacking direction of the multilayer laminate 3 and along its long side in the step of FIG. 1C. It is cut and cut into strip-shaped laminated blocks 4. As a result, the structure of the cut laminated block 4 is such that the exposed surfaces 4A, 4B (the exposed surface 4B is the opposite surface of the exposed surface 4A) formed of two planes are formed, and the thin metal plate 2 has a rectangular cross section. These rectangular metal thin plates are arranged in parallel with each other at a predetermined pitch, and the space between these rectangular metal thin plates is filled with insulating resin.
(Hereafter, simply referred to as "metal foil", but rather than "foil"
2A and insulating resin 1A, and the exposed surfaces 4A, 4
B is formed.

The exposed surface 4 of the strip-shaped laminated block 4
A, 4B were washed and optionally a surface of a predetermined portion, for example, masked with silicone rubber, a resist film, as shown in FIG. 1 Da, using the technique of the liquid honing, SiO ₂ from the nozzle N The insulating resin 1A is removed by jetting a high-pressure liquid containing an abrasive such as.

When such a process is performed, FIG. 2 and FIG.
As shown in FIG. 5, the electrode assembly 110 or the electrode assembly 120 in which the plurality of recessed grooves 5 having a depth of about 0.5 mm, and thus the plurality of electrodes 6, are formed on the exposed surfaces 4A and / or 4B, respectively. Can be easily obtained. The electrode assembly 110 of FIG. 2A shows the structure when the insulating resin 1A on both exposed surfaces 4A and 4B is removed. This electrode assembly 110
To obtain the above, a glass epoxy resin is applied to the insulating thin plate 1,
This can be easily obtained by using the laminated block 4 made of copper for the thin metal plate 2 and subjecting both exposed surfaces 4A and 4B to liquid honing.

In this case, it is not necessary to mask both exposed surfaces 4A and 4B, and the glass epoxy resin having a hardness lower than that of copper is faster, and the concave groove 5 is formed by polishing and removing a large amount. become. Metal foil 2A in this case
As shown in FIG. 3B, the copper is a shape in which both side edges are polished roundly, and this shape is rather preferable, and when the electrode assembly 110 is used as a connector, the electrode 6 Can be in point or line contact with the wiring electrodes of the printed wiring board.

In the electrode assembly 120 shown in FIG. 3A, only the both ends of both exposed surfaces 4A, 4B of the laminated block 4 are masked with silicone rubber, a resist film or the like, and the other portions of the insulating resin 1A and the metal foil 2A are masked. Is removed to form a plurality of metal bumps 8. As shown in FIG. 3B, these metal bumps 8 are projected toward the ends of the exposed surfaces 4A and 4B of the electrode assembly 120 at the center thereof.
It is also possible to arrange and form the side edge portions so as to recede from their ends, and the electrode assembly 120 provided with the metal bumps 8 of such an arrangement has a space in the wiring interval of the printed wiring board. It can be designed. Due to the configurations of the multilayer laminate 1 and the multilayer block 4, the groove 5, the electrode 6, and the metal bump 8 are naturally formed at equal intervals in parallel with each other.

In the above description, the method of surface-treating the laminated block 4 by the method of liquid honing is mentioned, but the method of polishing and removing the insulating resin 1A is the chemical etching method as shown in FIG. 1Db. Can be done using. In this case, a thermoplastic resin is used for the insulating thin plate 1, and the multilayer laminate 3 laminated with the metal thin plate 2 is used as a starting base material. When a plurality of laminated blocks 4 cut out from such a multilayer laminate 3 are immersed in a bath V containing a ketone solvent such as methyl ethyl ketone, the insulating resin 1A can be removed, and an electrode assembly having substantially the same structure can be obtained. The body 110 or the like can be obtained.

Next, a lead frame using an electrode assembly according to a second embodiment of the present invention and a method for manufacturing the same will be described with reference to FIGS. FIG. 4 is a diagram for explaining each step of the lead frame manufacturing method according to the second embodiment of the present invention, and FIG. 5 is an electrode of the second embodiment of the present invention manufactured by the manufacturing method of FIG. FIG. 6 is a cross-sectional view showing a lead frame which is an assembly, and FIG. 6 shows the lead frame of FIG.
2 shows a structure in which a chip is mounted to form an IC, FIG. 2 is a perspective view thereof, FIG. 2B is a sectional view taken along the line BB of FIG. 2, and FIG. It is sectional drawing which shows the structure at the time of mounting on a printed wiring board.

First, a method of manufacturing a lead frame which is one of the electrode assemblies according to the second embodiment of the present invention will be described with reference to FIG. The process following the process in FIG. 1E is a process subsequent to the process in FIG. 1C. Therefore, in this figure, the steps in which the steps of FIGS. 2 to C of FIG. 1 are omitted are shown.

In the step of FIG. 4E, four laminated blocks 4 obtained in the step of FIG. 1C are prepared, and a pair of two sets are made to face each other in their cross sections, and the two pairs are as shown in the figure. It is supported by the support board / bottom lid 20 and is housed in a cylindrical molding die M. Laminated blocks 4 facing each other are parallel to each other at a predetermined interval, and each metal foil 2A of each laminated block 4 is parallel to each other.
It is important to arrange so that they are aligned. Further, a copper rod 30 having a square cross section is arranged at the center of each of the laminated blocks 4 and is similarly supported by the support board / bottom lid 20.

Next, when a resin, for example, an epoxy resin 35 is injected and hardened in the step of FIG. F, a molded electrode assembly cylindrical body 40 as shown in the step of G of the figure is obtained. This is perpendicular to the major axis direction, for example, 0.3 to 0.5 m
By cutting with a thickness of m, it is possible to obtain a disk-shaped electrode assembly element body 41 as shown in FIGS.

As is clear from FIG. 3H, the metal foil 2A has a width of 0.15 mm and a thickness of 0.3 to 0.
Since it is 5 mm and can no longer be said to be the metal foil 2A, this is hereinafter referred to as a square conductive wire 42. Further, a set of these rectangular conductive wires 42 is called an electrode element 43. Furthermore, the copper rod 30 in FIG. 3D has a plate shape with a thickness of 0.3 to 0.5 mm, and is called a heat dissipation plate 31 for the reason described later.

The electrode element 43 has exposed surfaces 43A, 4A and 4A where the rectangular conductive wires 42 corresponding to the number of laminated metal foils 2A are exposed.
3B, these rectangular conductive wires 42 are arranged in parallel to each other, and an insulating resin 1A such as a glass epoxy resin of the insulating thin plate 1 is filled between the rectangular conductive wires 42 so that the rectangular conductive wires 42 are It is insulated. A pair of opposing electrode elements 43, for example, reference numeral 4 in FIG.
The rectangular conductive wires 42 of 3a and 43b and 43c and 43d are arranged in a straight line. An insulating resin 36 is filled between the electrode elements 43 and between the heat dissipation plate 31 and the electrode elements 43 are firmly fixed.

As shown in FIG. 41, such an electrode assembly element body 41 has, for example, the rectangular conductive wire 42 of each electrode element 43 exposed on the exposed surface 43B among the exposed surfaces 43A and 43B.
Liquid honing is carried out in the same manner as described in the step of FIG. 1Da while masking the outer edge of the surface of the heat radiation plate 31 and the surface of the heat dissipation plate 31 with silicone rubber, a resist film, etc. and leaving the other parts exposed.

One exposed surface 43A is not subjected to such surface treatment. Then, the insulating resin 36 exposed on the exposed surface 43B, the insulating resin 1A, and the non-masked portions of the square conductive wires 42 are polished and removed with an abrasive, and the square conductive portions of the masked portions are removed. The line 42 is not polished or removed, and this portion is a metal bump 44.
As a result, the lead frame 130, which is one of the electrode assemblies shown in FIG. 5, can be obtained. Next, the rectangular conductive wire 42, the metal bumps 44, and the heat dissipation plate 31 are subjected to surface treatment such as gold plating and solder plating.

Next, FIG. 6 shows such a lead frame 1
IC50 using 30 is shown. IC chip heat sink 3
1 as a pre-process for facilitating mounting on the printed wiring board and mounting on the lead frame 130.
Both exposed surfaces 43A and 43B are washed, and after the surface treatment such as gold plating and solder plating is performed on the heat dissipation plate 31, each rectangular conductive wire 42, the metal bump 44, etc., the IC chip 51 is mounted. The heat dissipation plate 31 at the center of the lead frame 130
Is a portion corresponding to the die pad of the conventional lead frame. The IC chip 51 is adhered to the heat dissipation plate 31 by silver paste or thermocompression bonding, and each fine-pitch electrode formed on the IC chip 51 and the square shape are formed. The QFP type IC 50 is completed by connecting each of the conductive wires 42 with a gold wire 52 and resin-molding as necessary. FIG. 2B is the same as FIG.
3 is a cross-sectional view taken along line BB of FIG.

The metal bumps 44 may be formed on the exposed surface 43A of the electrode assembly element body 41 by the same liquid honing process as described above. In addition, the rectangular conductive wire 42 to which the gold wire 52 is bonded to the metal bump 44.
It may be formed at each inner end of the. Further, instead of the copper rod 30, a 42 iron nickel alloy having the same thermal expansion as the silicon of the IC chip 51 may be used.

FIG. 7 shows a state in which the IC 50 is mounted on the printed wiring board 60. Reference numeral 61 is a terminal portion 61 of the wiring of the electronic circuit formed on the surface of the printed wiring board 60. The heat dissipation plate 31 and each metal bump 44 are arranged on the surface of the terminal portion 61 together, and, for example, a reflow furnace. When soldered through, it can be surface-mounted on the printed wiring board 60 as illustrated. After this implementation, I
The entire C50 is sealed so as to be covered with the resin R and protected.

As is clear from the above description, the metal bumps of the electrode assembly such as the lead frame 130 of the present invention can be formed at once in the same body as the rectangular conductive wire, and the manufacturing process, man-hours, etc. are greatly reduced. it can.

A third embodiment of the present invention, an electrode assembly element and a method of manufacturing the same will be described below with reference to FIGS. FIG. 8 is a view for explaining a step following the step C shown in FIG. 1, and is a perspective view of a state where the laminated block is subjected to the cutting processing, and FIG. 9 is obtained by the cutting processing of FIG. FIG. 11 is a perspective view for explaining a step of applying a resist to the entire surface of the laminated block, FIG. 10 is a perspective view for explaining an exposure step following the step of FIG. 9, and FIG.
FIG. 6 is a perspective view showing a step of performing liquid honing on the laminated block whose surface is masked in the exposure step of 0.
FIG. 12 is a perspective view of the finally obtained probe assembly of the present invention.

In FIG. 8A, the multilayer block 3 is cut to a slightly thicker thickness in the cutting step of FIG. The lower surface 4B of the laminated block 4 is cut in the thickness direction within a range indicated by a dotted line D to form a laminated block 70 having a tip portion 71 and a base portion 72 having a shape shown in FIG. In this case, a plurality of laminated blocks 70 can be mass-produced by fixing the plurality of laminated blocks 70 in a straight line on a surface plate using wax and cutting. The base 72 of the laminated block 70 has a thickness of 3 mm, and the tip 71 has a thickness of about 0.5 mm.

Next, as shown in FIG. 9, after washing the laminated block 70, a photoresist is applied to the entire surface of the laminated block 70 to form a resist film P. Then, in the next exposure step of FIG. 10, the resist film P is exposed to ultraviolet rays using, for example, a mask (not shown) for forming the insulating resin 1A portion of the tip portion 41, and each insulating resin is exposed. The resist other than the 1A portion is cured, and then the resist of each insulating resin 1A portion which has not been exposed to light by development is removed to expose only the insulating resin 1A of the tip portion 71.

Next, in the liquid honing process shown in FIG. 11, the liquid containing the high-pressure abrasive is jetted from the nozzle N to the tip 71 of the laminated block 70 in the masked state as described above. The insulating resin 1A is polished and removed.

Then, as shown in FIG. 12, the insulating resin 1A of the tip portion 71 is polished and removed to form a plurality of probes 73, that is, the electrode assembly of the present invention, that is,
The probe assembly 140 is obtained. These probes 7
Since 3 is a part of each metal layer 2, it is naturally inevitably formed parallel to each other at equal intervals and on the extension of each base 72.

Thus, the probe assembly 1 of the present invention
40 can form the probe 73 all at once, and like the probe assembly of the prior art, these are also separately manufactured in those concave grooves of the electrode assembly with the concave groove manufactured in another process. There is no need to go through the process of mounting each probe individually.

13 to 15 show the probe assembly 1
We have shown some manufacturing steps that can produce 40 improved probe assemblies. 13 is a perspective view for explaining a cutting process of the laminated block in a process following the process C shown in FIG. 1, and FIG. 14 is a perspective view showing the laminated block obtained by the cutting process of FIG. FIG. 15 is a perspective view of the improved probe assembly of the present invention.

The laminated block 4 cut from the multilayer laminated body 3 in FIG. 1 is cut along a line as shown by the dotted line D in FIG. 13 to complete the laminated block 80 having the shape shown in FIG. That is, the laminated block 80 has a thin tip portion 8
1 and a thick base portion 82, and an arcuate spring portion 83 formed in the intermediate portion between them, and in this embodiment, the spring portion 83 bulges upward from the upper surface portion of the base portion 82. It has a structure in which it is connected to its base portion 82 in a curved shape, and the tip portion 8 is horizontally arranged on the extension line of this spring portion 83.
1 is connected.

The laminated block 80 is shown in FIGS.
If the resist film P as described above is applied, exposed and masked, and then liquid honing is applied to the tip portion 81, the insulating resin of the tip portion 81 and the spring portion 83 as shown in FIG. By removing 1A, it is possible to obtain the probe assembly 150 in which the spring portion 83 is formed at the center and the probe 84 is formed at the tip thereof.

Since the probe assembly 150 has the spring portion 83, the probe assembly 150 has the same I as in the conventional probe assembly.
When measuring C, the probe 84 is attached to the outer lead of the IC.
It is possible to absorb the impact that occurs when abutting against.

In the probe assembly 140 shown in FIG. 8, the laminated block 4 is cut so that the tip portion 71 and the base portion 72 can be formed, but this probe assembly does not necessarily need to form such a base portion 72. Alternatively, the entire laminated block 4 may be cut from the multilayer laminated body 3 at the thickness of the tip portion 71 to form a laminated block having a small thickness, and a probe assembly without the base portion 72 may be provided. Can be formed.

Further, the probe assemblies 140 and 150.
In the manufacturing of the above, the embodiment in which the liquid honing is used is described, but if the insulating thin plate 1 is made of the thermoplastic resin, it can be manufactured by the chemical etching as described in the first embodiment. In the probe assembly, beryllium copper may be used as the thin metal plate 2.

[0039]

As described above, according to the present invention, various electrodes of a fine-pitch electrode assembly can be extremely easily manufactured with a high yield using the existing manufacturing equipment, and the cost can be significantly reduced. You can measure down. In particular, when the electrode assembly of the present invention is applied to a connector or a lead frame, metal bumps can be automatically formed at a desired position of each of these conductors in the same step at once .

[Brief description of drawings]

FIG. 1 is a perspective view showing each step of a method for manufacturing an electrode assembly according to the first embodiment of the present invention.

2 shows an electrode assembly of the present invention manufactured by the manufacturing method of FIG. 1, FIG. 2 is a perspective view thereof, and FIG. 2B is a partial sectional view taken along line BB of FIG. is there.

3 shows an electrode assembly of a modified example of the present invention manufactured by the manufacturing method of FIG. 1, FIG. 2 is a perspective view thereof, and FIG. B is an electrode assembly showing an example of parallel metal bumps. It is a top view of a body.

FIG. 4 is a diagram illustrating each step of the manufacturing method of the electrode assembly according to the second embodiment of the present invention.

5 is a second view of the present invention manufactured by the manufacturing method of FIG.
FIG. 6 is a cross-sectional view showing a lead frame that is an electrode assembly of the embodiment of

6 shows a structure in which an IC chip is mounted on the lead frame of FIG. 5 to form an IC, FIG. 2 is a perspective view thereof, and FIG. 6B is a sectional view taken along the line BB of FIG. is there.

7 is a cross-sectional view showing a structure when the IC of FIG. 6 is mounted on a printed wiring board.

FIG. 8 is a diagram for explaining a step that follows the step C shown in FIG. 1, and is a perspective view of a state where the laminated block is subjected to the cutting process.

9 is a perspective view for explaining a step of applying a resist to the entire surface of the laminated block obtained by the cutting process of FIG.

FIG. 10 is a perspective view for explaining an exposure process following the process of FIG.

11 is a perspective view showing a step of performing liquid honing on the laminated block whose surface is masked in the exposure step of FIG.

FIG. 12 is a perspective view of the finally obtained probe assembly of the present invention.

FIG. 13 is a perspective view for explaining a cutting process of the laminated block in a process following the process C shown in FIG.

14 is a perspective view showing a laminated block obtained by the cutting process of FIG.

FIG. 15 is a perspective view of an improved probe assembly of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulation thin plate 1A Insulation resin 2 Metal thin plate 2A Metal foil 3 Multilayer laminated body 4 Laminated block 4A Upper surface 4B Lower surface 5 Groove 6 Electrode 8 Metal bump 20 Support board / bottom cover 30 Steel rod 35 Resin 36 Insulation resin 40 Molded electrode assembly cylinder Body 41 Electrode Assembly Element 42 Rectangular Conductive Wire 43 Electrode Element 43A Exposed Surface 43 of Electrode Element 43 Exposed Surface of Electrode Element 43 Metal Bump 50 IC 51 IC Chip 52 Gold Wire 60 Printed Wiring Board 61 Terminal 70 Laminated Block 71 Tip Part 72 Base part 73 Probe 80 Laminated block 81 Tip part 82 Base part 83 Spring part 110 Electrode assembly 120 of the first embodiment of this invention Electrode assembly 130 of the modification of the first embodiment Second embodiment of this invention Lead frame 140 which is an electrode assembly of the present invention. Probe assembly 150 which is an electrode assembly of the third embodiment of the present invention. An electrode assembly of Example improved probe assembly M mold N nozzle P resist film R resin V tank

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Claims (4)

(57) [Claims] 1. A laminated block or a laminated thin plate in which a plurality of metal thin plates made of a conductive material and a plurality of insulating thin plates made of an insulating material are alternately laminated at a predetermined pitch, and the insulating material exposed on at least one plane is removed. An electrode assembly characterized in that an electrode is formed by protruding metal exposed on the same exposed surface. 2. An electrode bump is formed of the protruding metal of the electrode assembly according to claim 1.
The electrode assembly according to 1. 3. A plurality of electrode assemblies according to claim 2,
The exposed metal electrodes are arranged facing each other at a predetermined interval so that they are oriented in the length direction, and a mounting portion for an electronic circuit element such as a semiconductor chip is provided in the middle of the two, and the electrode assembly is provided. A lead frame for an electronic circuit element, characterized in that at least a part of the electrode of the exposed metal on the back surface side is formed with an electrode bump in a state where the part is raised. 4. A cubic laminated block in which a plurality of metal thin plates of a conductive material and a plurality of insulating thin plates of an insulating material are alternately laminated at a predetermined pitch, or the metal exposed on at least one plane of the laminated thin plate. Part or all, physically or chemically, of the entire length or a part of the insulating material exposed on the plane leaving the entire length or a part thereof and the residual metal partially or entirely in the thickness direction of the laminated block or laminated thin plate. A method of manufacturing an electrode assembly, comprising: