WO2017069136A1 - Three-dimensional structural body manufacturing method, mold used in same, and electric contact - Google Patents

Abstract

In the present invention, using a mold having a shape in which the center portion of a prescribed region is recessed, the surface shape of a leading end of a three-dimensional structure is pressed into a resin plate to mold the same, and a metal layer is formed on the surface of the molded plate, thereby manufacturing a three-dimensional structural body.

Description

Manufacturing method of three-dimensional structure, mold and electric contactor used therefor

The present invention relates to a method for manufacturing a three-dimensional structure, a mold used for the manufacturing, and an electric contact as a three-dimensional structure to be manufactured, and in particular, a fine metal having a recess formed by an inclined surface on the surface. The present invention relates to a method of manufacturing the three-dimensional structure, a mold having an inclined surface for forming a shape of a depression on the surface of the three-dimensional structure, and an electric contact manufactured by the manufacturing method.

As a method of creating a three-dimensional structure with a metal, a method is generally employed in which a molten metal is poured into a plurality of combined molds, and after cooling, the mold is removed to create a desired three-dimensional structure. However, when the structure is a fine three-dimensional structure having a diameter of about 10 to several tens of microns and a length of about 100 microns, a different method is performed. For example, when creating an electrical contact (probe) used for electrical inspection of a semiconductor device, the three-dimensional structure to be manufactured includes an upper part (tip part), a middle part (body part), a lower part (base part), etc. A method of dividing the plurality of parts into a plurality of parts and stacking a body part and a base part in order from the tip part is performed.

When this fine three-dimensional structure is required to have a unique shape like a probe, that is, in the probe, the tip is sharpened like a pyramid or inclined obliquely in order to contact the electrode of a semiconductor device. Various shapes are required. When an inclined surface is formed at the tip, a recess having an inclined surface is formed on the substrate, a metal thin film is formed on the inner wall surface of the recess, and electroplating is performed using the metal thin film as an electrode to form a metal in the upper shape. A layer is formed.

And after forming the metal layer of the tip part, in order to form the metal layer of the body part, a resist is applied, this is exposed with a predetermined pattern, and an exposed surface corresponding to the pattern is formed by developing, Patent Document 1 proposes that a metal three-dimensional structure having a predetermined pattern is formed by stacking metal layers on an exposed surface by electroforming, and the base metal layers are sequentially formed in the same manner. Thus, after forming the metal layer of a front-end | tip part, a trunk | drum, and a base, the solid structure by a metal layer is created by removing a board | substrate, a metal thin film, and a resist. However, although the three-dimensional structure shown in Patent Document 1 has been described that a hard tool such as a diamond indenter is pressed as a means for forming the shape of the protrusion on the upper part, there is a specific explanation. In addition, since the means of realization was not shown at all, photolithography became the mainstream and was stuck.

JP 2003-121469 A

This method of manufacturing a three-dimensional structure by electroforming has no particular problem when a single structure is created. There was a problem with the production.

Conventionally, in order to form a depression having an inclined surface on a substrate, it is common to expose a portion where the depression is formed and press a hard tool such as a diamond indenter with a sharp tip or perform etching. However, if the tip has a sharp shape, you can obtain a die with the desired shape by pressing the sharp-shaped mold and forming a dent on the surface of the tip. In this case, there is a problem that there is no mold having an appropriate shape. In addition, it is conceivable to form the inclined surfaces in a stepped manner by stacking multiple layers, but there is a problem that a large number of layers are required to make the surface as smooth as possible, and the process takes a long time. Furthermore, it was unexpected to produce a three-dimensional structure having a depression with an inclined surface at the tip.

An object of the present invention is to provide a method of manufacturing a three-dimensional structure that can solve the above-described problems and can create a large number of three-dimensional structures with high accuracy in as short a time as possible.

According to the present invention, the surface shape of the tip of the three-dimensional structure is pressed and molded on a resin flat plate by a mold having a shape in which the central portion of the predetermined region is depressed, and a metal layer is formed on the surface of the molded flat plate. This is a manufacturing method of a three-dimensional structure in which a three-dimensional structure is manufactured by forming a.

By molding the tip of the three-dimensional structure on the resin flat plate using a mold, a plurality of three-dimensional structures having the same surface shape can be repeatedly formed. The first resist layer is formed on the resin flat plate. Since the reference board is formed by forming, it is possible to obtain an effect that the accuracy of the subsequent processes from the reference board can be maintained high.

It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is explanatory drawing which shows the comparative example of a metal mold | die. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is the schematic which shows the state of the electroplating of this invention. It is the schematic which shows the state of the electroplating of this invention. It is the schematic which shows the state of the electroplating of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is the schematic which shows the state which forms a through-hole in the flat plate of this invention. It is the schematic which shows the state which forms a through-hole in the flat plate of this invention. It is process drawing which shows the manufacturing process of the three-dimensional structure of this invention. It is the schematic which shows the example of the probe of this invention. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is explanatory drawing of the metal mold | die used for the manufacturing process of this invention. It is the schematic which shows the state of the shaping | molding by the metal mold | die of this invention.

Embodiment 1
FIG. 1 is a process diagram showing molding by a mold among the processes of Embodiment 1 of the present invention. As shown in the figure, in the process of FIG. 1, molding is performed by using a mold 1 and applying pressure to a first acrylic plate 2 as a resin plate. During this molding, the first acrylic plate 2 is heated to facilitate deformation. Further, the first acrylic plate 2 is easily deformed by heating the mold 1 as well. The cross-sectional shape of the mold 1 used here is shown in FIG. 1, but the mold 1 is manufactured as shown in FIGS. First, as shown in FIG. 2, the through-hole 12 is provided in the central axis of the cylindrical main body 11 and etching is performed, thereby forming the inclined surface 13 at the opening of the through-hole 12 as shown in FIG. . In addition, this metal mold | die 1 can be produced with the material which has nickel as a main component.

As shown in FIG. 2, the mold 1 is formed with a desired inclined surface 13 formed by etching as shown in FIG. As shown in FIG. 3, the through hole 12 is provided in the central axis of the columnar body 11, which has a unique effect.

The mold 1 of the comparative example with respect to the mold 1 of the present invention has a shape without the through hole 12 as shown in FIG. When the mold 1 is pressed against the first acrylic plate 2 and the first acrylic plate 2 starts to be molded, an air pocket is formed between the recess of the central portion of the mold 1 and the surface of the first acrylic plate 2. As a result, the pressurizing force of the mold 1 is not easily transmitted to the first acrylic plate 2, and the molding is not as expected. In order to prevent this air accumulation, the mold 1 needs a through hole 12 for venting air.
The mold shown in FIGS. 2 and 3 shows a cylindrical shape on the outside. However, the shape on the outside is not limited to this, and a mold for producing a plurality of structures simultaneously. As shown in FIG. 5, as the mold 1, a plurality of regions are set on the surface of the plate-shaped main body 11, a through hole 12 is provided at the center of each region, and etching is performed with the through hole 12 as a center. The inclined surface 13 can also be provided. FIG. 5 illustrates a case where the mold 1 has a flat plate shape, and a part thereof is broken for convenience of understanding.

When the mold 1 shown in FIG. 3 is used to apply pressure to the first acrylic plate 2 and then the mold 1 is removed, the first acrylic plate 2 has a mold as shown in FIG. The same inclined surface 21 as the shape of the inclined surface 13 remains, and the portion of the through hole 12 of the mold 1 allows the first acrylic plate 2 to escape during molding, so that a slight protrusion 22 is formed. Since the figure shown in FIG. 6 is a cross-sectional view and the actual shape is difficult to understand, FIG. 7 shows the shape of the first acrylic plate 2 after molding in a perspective view. As shown in FIG. 7, the first acrylic plate 2 has an inclined surface 21 and a protruding portion 22.

In the molding process shown in FIG. 7, only one molding part is shown. However, in actual processing, the efficiency can be improved by performing a plurality of parts simultaneously as shown in FIG.

After the molding step of FIG. 6, as shown in FIG. 9, a sacrificial metal layer 3 is formed on the surface of the first acrylic plate 2 after molding. The sacrificial metal layer 3 serves as an electrode when the three-dimensional structure 100 is manufactured by electroplating. Next, as shown in FIG. 10, the whole is covered with the resist layer 4, and as shown in FIG. 11, the resist layer 4 is masked to expose the sacrificial metal layer 3 of the inclined surface 21. The surrounding resist layer 41 is left.

Further, as shown in FIG. 12, the main body metal layer 5 is formed on the surface of the sacrificial metal layer 3 surrounded by the inner wall surface of the resist layer 41 by electroplating.

Here, the state in which electroplating is performed using the exposed sacrificial metal layer 3 will be described with reference to FIG. The state of electroplating shown in FIG. 13 shows the case where there is a sacrificial metal layer on the bottom and central protruding portions. In this case, the plating layer is formed along the sacrificial layer, and the plating layer is formed from the bottom surface and the protruding wall surface. The state of electroplating shown in FIG. 14 shows the case where the sacrificial layer is exposed only on the bottom surface. In this case, a plating layer parallel to the inclination of the bottom surface is formed.

15 shows a comparative example in the case where the sacrificial metal layer spreads on the inner wall surface of the depression. In this case, since the plating layer is formed from the bottom surface and the side surface, in some cases, the plating solution is confined in the plating layer.

After forming the main body metal layer 5, the first acrylic plate 2, the resist layer 4, and the main body metal layer 5 are integrally formed and polished as shown in FIG. The reference board 20 is a structure in which the structure of the upper part (tip part) of the three-dimensional structure 100 to be created is embedded. Based on this part, the intermediate part (leg part) and the lower part (base part) are sequentially formed. ) By electroplating.

The reference plate 20 is composed of the first acrylic plate 2, the sacrificial metal layer 3, the resist layer 4, and the main body metal layer 5. Here, the first acrylic plate 2 is pressurized at the time of molding, but the back surface of the first acrylic plate 2 is kept flat and the mold 1 has a predetermined depth of the first acrylic plate 2. It will go in. Therefore, the main body metal layer 5 is adjusted to a reference height by polishing the resist layer 4 and the main body metal layer 5 with the back surface of the first acrylic plate 2 as a reference.

When the reference board 20 is completed, as shown in FIG. 17, the masking layer 6 is formed on the reference board 20 in order to create the intermediate part (leg part) of the three-dimensional structure 100, and the intermediate part (by the selective plating) Leg). In the first embodiment, since the probe is illustrated, a special shape is shown. However, even if other structures are used, various shapes can be realized if the reference board 20 is completed. Become.

The masking layer 6 is usually a layer obtained by superposing a resist layer on the reference plate 20 and removing a predetermined pattern from the resist layer. The intermediate portion (leg portion) of the three-dimensional structure 100 is formed by laminating a metal layer on the pattern portion from which the resist layer has been removed by electroplating.

However, when a resist layer is used as the masking layer 6, a thick layer cannot be formed at once. Therefore, the resist layer formation, the metal layer formation, and the polishing are repeated, so that the processing takes time. There is a problem of hanging.
This problem can be overcome by using the second acrylic plate 7 having a predetermined thickness.

The second acrylic plate 7 is the thickness of the dimension of the intermediate part (leg part) of the three-dimensional structure 100, and is provided with a through hole 71 at a place corresponding to the leg part. The second acrylic plate 7 can be overlaid on the reference plate 20, and a leg metal layer can be formed by electroplating using the main body metal layer 5 exposed in the through hole 71 as an electrode.

The second acrylic plate 7 used here has a very fine through hole 71, and therefore a special method is required to provide the through hole 71.
A method of providing the through hole 71 in the second acrylic plate 7 will be described. As shown in FIG. 18, a plate 70 thicker than the acrylic plate 7 to be used is prepared, and a hole 73 is formed by a through-hole mold 72 from the surface side of the thick plate 70. After forming the hole 73, as shown in FIG. 19, it grind | polishes until it becomes a predetermined thickness from the back surface side of a thick board. The polishing is repeated until the hole 73 becomes the through hole 71. The second acrylic plate 7 created in this way is adjusted on the reference board 20 with an alignment mark or the like, and then superimposed on a predetermined place.

The preparation of the second acrylic plate 7 is performed in parallel with the production of the reference board 20, and the process can be shortened by combining them when both structures are ready.
Similar to the creation of the intermediate part (leg part) of the three-dimensional structure 100, the lower part (base part) is overlaid with the third acrylic plate 8 in which the through holes 81 having a predetermined pattern are formed, and electroplating is performed. The lower part (base part) of the three-dimensional structure 100 can be created.

When the lower part (base part) of the three-dimensional structure 100 is manufactured, the first acrylic plate 2, the sacrificial metal layer 3, the resist layer 41, the second acrylic plate 7, and the third acrylic plate 8 are removed, and FIG. As shown in FIG. 2, a three-dimensional structure 100 having a predetermined shape in which the upper (tip) structure, the intermediate (leg) structure, and the lower (base) structure are integrated can be obtained.

This manufacturing method of the three-dimensional structure 100 makes it possible to create a three-dimensional structure having a special shape at the tip.
Next, a probe 101 having a special shape at the tip will be described as an example of a three-dimensional structure.
The probe 101 is in contact with the electrode of the semiconductor device and detects an electrical signal accompanying the operation of the semiconductor device, and needs to be surely in contact with the electrode of the semiconductor device. For this reason, various probe shapes have been considered. However, when the electrode of the semiconductor device has a ball shape, none has been configured to enclose the electrode.

That is, the specially-shaped probe 101 is configured such that a plurality of vertically extending fingers 1011 are in contact with one electrode, as shown in FIG. Moreover, an inclined surface 1012 is provided at the tip of the finger so as to guide the ball-shaped electrode to the center of the tip positions of the plurality of fingers. That is, three or more fingers 1011 are provided, and the inclined surface 1012 is provided so as to go to the center of the tips of the plurality of fingers 1011. Each finger 1011 has flexibility, and is configured to flexibly come into contact with the electrodes of the semiconductor device.

In other words, the overall shape of the probe 101 is similar to the wrist shape. The pedestal portion 1013 is connected like a palm, and has a configuration in which the finger 1011 extends toward the contact target, and the tip of the finger 1011 is in contact with the electrode of the semiconductor device.

By adopting such a configuration, the shape of the probe 101 that comes in contact so as to envelop the electrode of the semiconductor device can be obtained.

Also, this special shape can be used for structures other than probes. For example, it can be used as a structure for electrical connection as an electrical contact. In other words, when the electrodes of the semiconductor device are ball-shaped, the structure is effective as a connection means to replace the lead frame and to make electrical connection with a plurality of fingers.

In addition, as a three-dimensional structure for electrical connection, FIG. 21 shows a structure in which four fingers 1011 make contact. However, assuming electrical connection, contact with three fingers is more stable. There is an effect of doing. In other words, when four fingers are used, all fingers need to bend in order for all fingers to contact evenly. If not, one of the four fingers does not touch. There is. If the contact becomes unstable, it becomes an electronically minute discharge phenomenon, and a disturbance occurs in the electric signal to be handled. For this reason, it is meaningful to use three fingers for stable contact.

Also, since the three fingers are formed by electroplating, the material is the same. Here, the flexibility or the elastic force can be changed by changing one or two of the three cross-sectional areas. By changing the elastic force to make the finger easy to deform, it is possible to determine the direction in which the finger is moved when an external force is applied by an electrode of the semiconductor device or the like.

Embodiment 2
The shape of the mold according to the first embodiment is a shape in which a depression is provided in the center of a predetermined region, and is a shape obtained by cutting a conical shape from a cylindrical shape. On the other hand, in this Embodiment 2, in order to shorten the process after the molding of the resin plate by the mold, further examination is advanced, and the shape of the mold is based on the shape of the target three-dimensional structure. Is defined.
That is, as shown in FIG. 21, the target three-dimensional structure is an electric contact, and the pedestal portion 1013 is connected like a palm, and the finger 1011 extends toward the contact object, The tip of the finger 1011 has a special shape in which an inclined surface 1012 is provided.

This specially-shaped three-dimensional structure is formed by molding the tip portion of the resin plate in a mold with a mold, and instead of the conical surface of the first embodiment, the tip portion of the finger that requires an inclined surface is used. The mold has a protruding shape only.
Specifically, as shown in FIG. 22, the mold 1 has a shape in which a protrusion 14 having an inclined surface 13 at the tip is provided on the main body 11. The common point with the first embodiment is that the center portion of the predetermined region is recessed. In the second embodiment, the structure in which the protrusions 14 are arranged at four positions is shown, but the number can be further increased or decreased.

As shown in FIG. 23 as a perspective view with a part cut away, the mold 1 is provided with a through hole 12 in the main body 11 to provide a resin escape path when the resin plate is molded. Further, as shown in FIG. 24, a plurality of grooves 15 are provided on the side surface of the protrusion 14 of the mold 1 along the direction in which the protrusion 14 pushes the resin (the direction of the arrow in the figure). When the resin is molded using the mold 1, the groove 15 is used to prevent the resin from vibrating due to pressing by the mold 1 and leaving a large number of pulsations in the resin.
Also in the second embodiment, as in the first embodiment, the mold 1 can be arranged on a plurality of planes so as to mold a plurality of portions simultaneously. This state is as shown in FIG.

Note that the tip portion of the protrusion 14 portion of the mold 1 shown in FIG. 22 has not only the inclined surface 13 but also a flat surface portion as shown in the figure. Even if this plane portion is not necessary as the shape of the intended three-dimensional structure, it is a necessary shape as a mold. In other words, in order to have the mechanical strength necessary for a mold, a block structure is required as much as possible. In this mold, if this portion is only an inclined surface, the protrusions are damaged.
When a resin flat plate is molded using the mold according to the second embodiment, as shown in FIG. 26, the shape of the inclined surface of the tip portion of the three-dimensional structure as if the target three-dimensional structure was extracted was obtained. Obtainable.

In the first and second embodiments, the shape of the tip portion of the three-dimensional structure is formed by molding a resin flat plate with a mold. To mold a resin flat plate with a mold, a resin plate As a weight average molecular weight of 1,000 to 100,000 is preferable, and an acrylic plate having a weight average molecular weight of 30,000 or less is particularly suitable. This is because when the resin is molded by a mold, if the molecular weight is small, it is considered that memory of deformation at the time of molding tends to remain.

In the embodiment of the present invention, an example in which an acrylic plate is used as a flat plate has been described. However, it is naturally possible to use other resin flat plates.
It should be noted that within the scope of the present invention, the embodiments can be freely combined, or the embodiments can be appropriately modified or omitted.

Claims (10)

1. By pressing the surface shape of the tip of the three-dimensional structure on a resin flat plate with a mold having a shape in which the central portion of the predetermined region is depressed, a metal layer is formed on the surface of the molded flat plate A method for producing a three-dimensional structure, characterized by producing a three-dimensional structure.
2. The upper surface shape of the three-dimensional structure is molded on the first flat plate of the resin as a reference by a mold, a sacrificial metal layer is formed on the molded surface of the first flat plate, and the upper surface shape A first resist layer is formed around the body, a body metal layer is formed by plating on the surface of the sacrificial metal layer surrounded by an inner wall surface of the first resist layer, and the first flat plate and the first A method for manufacturing a three-dimensional structure in which a resist layer and the main body metal layer are formed as an integral structure, and the integral structure is polished to produce a three-dimensional structure as a reference board.
3. The method for producing a three-dimensional structure according to claim 1 or 2, wherein the resin has a weight average molecular weight of 1,000 to 100,000.
4. The method for producing a three-dimensional structure according to claim 1 or 2, wherein the resin has a weight average molecular weight of 1000 or more and 30000 or less.
5. A second flat plate having a through hole of a predetermined shape is overlaid on the reference plate, and a metal plating layer is formed through the through hole of the second flat plate using the main body metal layer of the reference plate as an electrode. 3. The method for manufacturing a three-dimensional structure according to claim 2, wherein a second metal structure bonded to the layer is formed.
6. A mold used for manufacturing a three-dimensional structure, which is columnar, has a through hole in the pressing direction on the pressing surface, and has an inclined surface from the periphery of the pressing surface toward the through hole.
7. 7. The mold according to claim 6, wherein a groove along the pressing direction is provided on a side surface.
8. The pedestal includes a plurality of fingers extending vertically from the pedestal, and has an inclined surface that is inclined toward the center of the plurality of fingers of the pedestal at the tips of the plurality of fingers. Electric contact.
9. The electrical contact according to claim 8, wherein the plurality of fingers are three.
10. The electric contact according to claim 8, wherein the elastic forces of the plurality of fingers are different.
    

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