JP2002280734A - Paste filling method and paste filling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paste filling method and a device which are excellent in productivity and capable of surely filling a fine blind via provided to a base material with paste of high viscosity. SOLUTION: High-viscosity paste is reduced in viscosity by heating, a fine blind via bored in a base material is nearly filled up with the paste of low- viscosity by the use of a squeegee 104, the base material is heated up in a vacuum dome 106, air bubbles left in the fine blind via are removed through a vacuum deaeration action, and then the high-viscosity paste is reduced in viscosity by heating and made to fill up the fine blind via by the use of the squeegee 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste filling method and a paste filling apparatus for fine vias, which are used when manufacturing double-sided or multilayer wiring boards used for various electronic devices.

[0002]

2. Description of the Related Art In recent years, densification of a multilayer wiring board has been particularly advanced, and vias for interlayer connection have been miniaturized accordingly, and the connection resistance has been increased when a conventional paste is used. . In order to reduce the connection resistance, it is necessary to miniaturize the conductive filler blended in the paste. However, due to the miniaturization of the conductive filler, the viscosity of the paste is higher than that of the conventional paste.

A conventional paste filling method and paste filling apparatus will be described below.

As a first conventional example, an apparatus using a roller squeegee for filling paste into a penetrating via (Japanese Patent Laid-Open Publication No.
237986) will be described with reference to FIG. Base material 6
In filling the paste 603 into the through via 602 provided on the base material 601, the roller squeegee 604 is brought into close contact with the mask plate 605 closely arranged on the base material 601, and the roller squeegee 604 is rotated with respect to the base material 601. Move relatively. At this time, the paste 603 is filled in the through vias 602 by supplying the paste 603 to the surface of the mask plate 605. Note that a mask hole 606 is provided in the mask plate 605 so as to match the position of the through via 602.

When the roller squeegee 604 is rotated in a state in which the roller squeegee 604 is brought into close contact with the mask plate 605 and is moved in the horizontal direction with respect to the substrate 601, the roller squeegee 604 is supplied to the front side in the moving direction of the roller squeegee 604. Paste 60
The roller 3 is rolled backward in the moving direction by the rotational force of the roller squeegee 604. Further, when the paste 603 moves between the peripheral surface of the roller squeegee 604 and the surface of the mask plate 605, the paste 603
Is pressed by the mask hole 606 and the through via 602. At this time, the air in the through via 602 is discharged from the back surface of the base material 601 by the pressed paste 603 to fill the paste.

As a second conventional example, an apparatus using a vacuum chamber for filling paste into minute blind vias will be described with reference to FIG. In filling the paste 603 into the minute blind via 702 provided in the base material 701, the inside of the vacuum chamber 703 connected to the vacuum exhaust means (not shown) is evacuated, and then the squeegee 704 is brought into close contact with the base material 701. It is brought into contact with the arranged mask plate 705. The mask plate 705 has minute blind vias 70.
A mask hole 706 is provided so as to match the position 2.

Further, a squeegee 7 on the surface of the mask plate 705 is provided.
04 paste 603 is supplied to the front side in the moving direction, and the squeegee 704 is relatively moved with respect to the mask plate 705.
The paste 603 is printed on the mask plate 705 by printing. Then, the paste 603 is filled in the minute blind via 702 by opening the inside of the vacuum chamber 703 to the atmosphere.

When the paste 603 is applied by printing with a squeegee 704 while the inside of the vacuum chamber 703 is evacuated, at least the mask holes 70 provided in the mask plate 705 are provided.
6 and the surface portion of the minute blind via 702 are filled with the paste 603. At this time, the unfilled space of the paste 603 in the minute blind via 702 is in a vacuum state, and further, due to the pressure difference due to the opening of the atmosphere in the vacuum chamber 703, the mask hole 706 of the mask plate 705 is formed in the unfilled space of the minute blind via 702. Is filled with the already filled paste 603. Here, the volume of the mask hole 706 of the mask plate 705 is larger than the volume of the minute blind via 702.

As a method of filling the paste when the mask plate 705 is not used, vacuum evacuation means (not shown)
After the inside of the vacuum chamber 703 connected to the vacuum chamber 703 is evacuated, the paste 603 is applied to the surface of the substrate 701 with the squeegee 704 slightly spaced from the substrate 701 (for example, at an interval corresponding to the thickness of the mask plate). After uniform application, the inside of the vacuum chamber 703 is opened to the atmosphere, so that the minute blind via 702 is filled with the paste 603 by a differential pressure effect. Thereafter, the squeegee 704 is brought into contact with the base material 701 to scrape off the paste 603 remaining on the base material 701.

[0010]

As described above, in the first conventional example, the filling of the paste into the penetrating via is performed. In filling the micro-vias with viscous paste, even with the pressing action of the paste by the peripheral surface during the rotation of the roller squeegee, the paste filling resistance at the time of filling increases, so the high-viscosity paste can be reliably filled in the micro vias. Was difficult to fill. That is, in the conventional paste filling method or paste filling apparatus, there is a problem that it is difficult to reliably fill the minute via with the high-viscosity paste.

In the second conventional example, it is necessary to go through a procedure in which, after the inside of the vacuum chamber is evacuated, a paste is printed and applied with a squeegee, and the inside of the vacuum chamber is opened to the atmosphere for filling. In particular, since a mechanism for printing and applying a paste is built in, the volume in the vacuum chamber is already large, and much time is required to bring the vacuum chamber into a vacuum state. For this reason, it is necessary to repeat the above procedure every time the paste is filled for each base material, which is a factor that significantly impairs productivity. That is, in the conventional paste filling method or paste filling apparatus, there is a problem that the productivity is significantly impaired because the vacuum chamber having a large volume needs to be evacuated.

In addition, in the use of a high-viscosity paste, in addition to uncertainty about vacuum defoaming in a vacuum chamber,
The high-viscosity paste is repeatedly defoamed in a vacuum chamber at each printing application step, and the resin component added to the paste is discharged as a gas, so that the paste viscosity is significantly increased in a shorter time. For this reason, it has been a factor of poor filling due to deterioration of paste filling property and an increase in paste usage due to shortening of the paste life. That is, in the conventional paste filling method or paste filling apparatus, there is a problem that the life of the paste is shortened and the amount of paste used increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paste filling method and a paste filling apparatus capable of reliably filling a high-viscosity paste in a micro via provided in a base material in consideration of the above problems.

Another object of the present invention is to provide a paste filling method and a paste filling apparatus which are excellent in productivity and fill a small via provided in a base material with a high-viscosity paste in consideration of the above-mentioned problems. Is what you do.

Further, the present invention has been made in consideration of the above problem, and has a paste filling method and a paste filling method which do not increase the amount of paste used when filling a high-viscosity paste into a micro via provided in a base material. It is an object to provide a filling device.

[0016]

According to a first aspect of the present invention, there is provided a method for filling a micro via provided in a base material with a paste, the method comprising:
The base and the paste supplied in front of the squeegee in the traveling direction of the squeegee, which are held in close contact with each other, reach a predetermined temperature, and the squeegee is closely arranged on the front surface of the base and the paste is formed into minute vias by moving the squeegee. A paste filling method characterized by filling.

Further, the second invention (corresponding to claim 2)
Is a method of filling the paste into the minute blind via provided in the base material, the paste supplied in front of the squeegee in the traveling direction of the squeegee and the base material in close contact with the back side, to reach a predetermined temperature, After filling the paste into the minute blind vias by disposing the squeegee closely on the surface side of the base material and moving the squeegee, the base material is allowed to reach a predetermined temperature and a predetermined degree of vacuum, and then released to the atmosphere. Again, the paste supplied in front of the squeegee in the traveling direction of the squeegee and the substrate with the back surface closely contacted is allowed to reach a predetermined temperature, and the squeegee is closely arranged on the surface of the substrate and the paste is moved. And filling the paste into the minute blind vias by filling the paste into the minute vias.

Further, the third invention (corresponding to claim 3)
Is the paste filling method according to the first or second aspect of the present invention, wherein the predetermined temperature is in a range of 30 ° C. to 50 ° C.

The fourth invention (corresponding to claim 4)
Is the paste filling method according to the second aspect of the present invention, wherein the predetermined degree of vacuum is in a range of 100 Pa to 30 Pa.

Further, the fifth invention (corresponding to claim 5)
A base provided with a heat source for holding and fixing and heating the base material provided with micro vias, and abutting on an outer peripheral portion excluding a paste filling region of the base material placed on the upper surface of the base. A plate frame provided with a heat source for heating the paste, and having a squeegee for filling the fine via with the paste supplied forward in the traveling direction by moving relatively to the base material. Paste filling device.

The sixth invention (corresponding to claim 6)
A mounting table provided with a heat source for mounting a base material filled with a paste in advance and heating the substrate to a predetermined temperature, and disposed opposite to the mounting table, And a vacuum dome that is opened to the atmosphere after reaching a degree of vacuum.

A seventh aspect of the present invention (corresponding to claim 7)
Is the paste filling apparatus according to the fifth or sixth aspect of the present invention, wherein the predetermined temperature is in a range of 30 ° C. to 50 ° C.

The eighth invention (corresponding to claim 8)
Is the paste filling apparatus according to the sixth aspect of the present invention, wherein the predetermined degree of vacuum is in a range of 100 Pa to 30 Pa.

[0024]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. FIG.
FIG. 2A is a configuration sectional view of a base material and vias according to Embodiment 1 of the present invention. In Embodiment 1, a base film 501 having a thickness of about 0.02 mm and a cover film 501b attached to both sides of the base film 501a is used.

The micro vias are formed by irradiating an ultraviolet laser from one surface of the cover film 501b of the base material 501 to place a via 502 having a hole diameter of about 0.05 mm through the base material 501 at a predetermined position at a predetermined position. Formed. In addition, a conductive paste containing copper powder as a main component was manufactured and used as a paste filled in the via 502 to form a conductor circuit in the via.

As the conductive paste, copper powder having an average particle diameter of 1 μm was used as a conductive filler, a thermosetting epoxy resin (solvent-free type) was used as a resin, and an acid anhydride-based curing agent was used as a curing agent. . Compounding ratio is 85% by weight of copper powder, 12.5% by weight of epoxy resin, 2.5% by weight of hardener
And kneaded well.

Each of the viscosities was 2 at a paste temperature of 20 ° C.
50 Pa · S, 140 Pa · S at a paste temperature of 30 ° C.
50Pa · S at a paste temperature of 40 ° C, paste temperature of 50
20Pa · S at 10 ° C, 10Pa · S at a paste temperature of 60 ° C
S.

Next, the configuration of the paste filling apparatus according to the first embodiment will be described with reference to FIG. The filling device includes a base 101, a bar-shaped heater 101d embedded in the base 101, a plate frame 102, a planar heater 102d attached to the lower surface of the plate frame 102, a guide shaft 103, a squeegee 104, a support 104a, The squeegee 104 is constituted by an elevating guide shaft 104b. The function of the squeegee 104 is to hold and heat the base material, to closely arrange the squeegee 104 on the plate frame 102, and to heat the paste supplied in the forward direction of the squeegee 104. To pass over the minute via.

The detailed configuration will be described with reference to the sectional view of FIG. First, in order to uniformly hold and fix the substrate 501 so that wrinkles and undulations do not occur, at least the substrate 50
1. An adsorbing member 201 having an infinite number of adsorbing holes 201a made of porous sintered metal in a region inside the outer shape of No. 1
Are embedded in the upper surface of the base 101. A plurality of suction grooves 201b are provided on the lower surface of the suction member 201,
After being assembled together, the suction grooves 201b are evacuated from a vacuum exhaust port 201c provided through the inside of the base 101 by vacuum exhaust means (not shown) such as a vacuum pump.

Further, the upper surface 101a of the base 101 including the base material holding surface 201d on the upper surface of the adsorption member 201 is finished to a flatness of 0.02 mm or less, so that a step difference from the base material holding surface 201d is generated. This is for uniformly holding and fixing the substrate 501 without performing. Note that the thin paper 101e having a uniform thickness of 0.03 mm and having a size exceeding at least the base material 501 is interposed between the base material 501 and the base material holding surface 201d to prevent the paste 202 from entering the suction holes 201a. ing. Substrate 5 by interposing thin paper 101e
There was no problem of the close contact holding of No. 01 on the substrate holding surface 201d.

Further, the base 101, which is located below the adsorption member 201, has an insulator 10 surrounding the heating element 101b.
A plurality of rod-shaped heaters 101d made of 1c are incorporated at predetermined intervals to enable uniform heating of the base 101 and the adsorption member 201, and to a temperature sensor (not shown) embedded in the adsorption member 201 and the rod-shaped heater 101d. The substrate holding surface 201 is controlled by a control mechanism (not shown) for controlling the energization of the substrate.
d can be maintained at a uniform and set temperature. Thus, the entire surface of the substrate 501 held and fixed on the substrate holding surface 201d can be uniformly heated to a predetermined temperature.

The plate frame 102 abutting on the outer peripheral portion of the base material 501 held and fixed to the base 101 excluding the paste filling area.
The substrate holding surface 201 of the suction member 201 is moved by a plate frame lifting guide (not shown) and a plate frame lifting drive mechanism (not shown).
It is possible to move up and down in parallel to d. This enables uniform contact with the outer peripheral portion of the plate frame 102 except for the paste-filled region of the substrate 501. Further, the substrate 50
A chamfer of 60 degrees is formed on at least two corners of the inner periphery of the plate frame 102 that is in contact with the outer periphery of the plate frame 102 at right angles to the squeegee moving direction, and a sloped edge 102a having a knife edge shape with a tip angle of 30 degrees is formed. Provided.

The upper surfaces of the inclined portion 102a and the plate frame 102 are mirror-finished by buffing. Thus, the upper surface of the plate frame 102 and the inclined portion 102a can be smoothly moved when the squeegee abuts. Furthermore, the printing frame 10
2, a planar heater 102d composed of an insulator 102c surrounding the planarly arranged heating element 102b is incorporated into
The plate frame 102 can be heated uniformly, and the plate frame 10 can be heated.
The upper surface of the plate frame 102 is uniformly and set by a temperature sensor (not shown) provided at a position not interfering with the squeegee 104 on the upper surface 2 and a control mechanism (not shown) for controlling energization to the planar heater 102d. It is possible to maintain the temperature. Thereby, the entire paste 202 supplied forward in the traveling direction of the squeegee 104 can be heated to a predetermined temperature.

Above the base 101, a pair of guide shafts 1
Numerals 03 are supported in parallel to each other and parallel to the base material holding surface 201d of the suction member 201. The guide shaft 103 has a support 10 on which a squeegee 104 is mounted.
4a is attached via a sliding member such as a slide bearing so as to be movable in the longitudinal direction of the guide shaft 103, and the support 104a is driven by a ball screw or an air cylinder or the like so as to be driven in the longitudinal direction of the guide shaft 103. It can be driven by means (not shown). Thus, the support 104a can move in the longitudinal direction of the guide shaft 103 with respect to the substrate 501 uniformly held on the substrate holding surface 201d.

An up-down guide shaft 1 is mounted on the support 104a.
04b and a pressure adjusting mechanism (not shown) such as a regulator, and a squeegee 104 is attached to the lower end of the vertical lifting guide shaft 104b in parallel with the base material 501. As a result, the squeegee 104 can move in the vertical direction and can obtain a predetermined pressing force.

Next, a filling method will be described with reference to FIG.
FIG. 4 shows that the base material 501 is attached to the base material holding surface 201d by the thin paper 101.
e and the rod-shaped heater 101d
And the outer peripheral portion excluding the paste filling region is pressed by the plate frame 102.
The squeegee 104 indicated by a broken line is positioned at the squeegee initial position P1 above the plate frame 102.

Next, on the plate frame 102 heated to 50 ° C. by the sheet heater 102d, the width covering at least the filling region of the paste 202 and the amount capable of filling a predetermined number of sheets are determined by using a supply means such as a dispenser. Supply. Here, the paste 202 has a viscosity of 20 Pa by heating at 50 ° C.
-The viscosity has decreased to S.

Next, the squeegee 104 shown by a solid line is
02 to the squeegee movement start position P2.
At this time, the squeegee 104 is in close contact with the plate frame 102 at a predetermined pressure. Next, when the squeegee 104 is moved in the direction of the arrow in a state in which the squeegee 104 is in close contact with the plate frame 102, the paste 202 supplied onto the plate frame 102 is scraped up while the mirror-finished plate frame 102 and the inclined portion 102a are lifted. And smoothly passes over the base material 501 while maintaining a predetermined pressing force, and further reaches the squeegee movement end position P3.

During the movement, when the squeegee 104 reaches the minute via 502 provided in the base material 501, the paste 2
02 is pressed into the minute via 502 and the thin paper 101
The filling is repeatedly performed in the filling region of the base material 501 by the vacuum suction action of the suction member 201 via e. Here, the filled paste 202 is a thin paper 10
1e prevents clogging of the adsorbing member 201 and also has an effect of increasing the filling amount of copper powder by adsorbing the resin component contained in the paste 202 filled in the minute via 502.

Since the squeegee 104 moves on the substrate 501 at a predetermined pressure, the squeegee 104
No paste 202 remains in the region except for
After the movement of the squeegee 104 is completed, the squeegee 104 is raked to the squeegee movement end position P3 on the plate frame 102.

Here, when the heating temperature of the plate frame 102 and the base material 501 is set to 60 ° C., the resin component contained in the paste 202 evaporates and the paste viscosity increases with an increase in the filling quantity, and the predetermined number of sheets is increased. Could not be filled. However, when the heating temperature of the plate frame 102 and the base material 501 was set to 30 ° C., by setting the moving speed of the squeegee 104 appropriately, the filling of the paste 202 into the minute via 502 was ensured.

The paste 2 supplied on the plate frame 102
02 is heated to 50 ° C., and the substrate 501 is not heated, the paste 202
When the temperature reached 01, the paste surface temperature decreased to near the surface temperature of the base material holding surface 201d and the viscosity increased, so that the minute via 502 could not be reliably filled. When only the base material 501 is heated to 50 ° C. and the paste 202 supplied onto the plate frame 102 is not heated, the paste viscosity is high particularly in the filling start region, and the minute via 502
The state of filling into the resin varied, and the filling could not be performed reliably.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described. FIG. 5B is a configuration sectional view of a base material and a via according to the second embodiment of the present invention.
In the second embodiment, a circuit is formed by patterning a copper foil 503b having a thickness of about 0.01 mm on a base film 503a having a thickness of about 0.02 mm.
A substrate film 503a having a thickness of 02 mm is laminated and cover films 503c are attached to both sides of the base film 503a.
Used as 3.

In forming the minute via, an ultraviolet laser is irradiated from one surface of the cover film 503c of the base material 503 so that the hole diameter with the surface of the copper foil 503b as the bottom surface is about 0.05 m.
A predetermined number of m blind vias 504 were formed at predetermined positions. Further, as a paste filled in the blind via 504 to form the conductor circuit in the via, a conductive paste containing copper powder as a main component is the same as that used in the first embodiment in terms of components, mixing ratio, viscosity and the like. Are identical.

Next, the configuration of the paste filling apparatus according to the second embodiment will be described with reference to FIG. The filling device includes a mounting table 105 having an O-ring groove 105a and an O-ring 105b, a rod-shaped heater 105g embedded in the mounting table 105, a flange 106a, and a vertical lift guide 106.
b, a vacuum dome 106 having an evacuation port 106c and an air opening port 106d. The function of the vacuum dome 106 is to heat the entire substrate 503 in which the paste 202 is filled in the blind via 504 with the paste filling apparatus according to the first embodiment. And to open to the atmosphere after vacuuming.

FIG. 3 is a cross-sectional view showing a state in which the vacuum dome 106 facing the mounting table 105 is lowered. A detailed configuration will be described below. On the mounting table 105,
In order to position and mount the substrate 503 at a predetermined position, the substrate 5
Approximately 1mm outward from the outer shape of 03, and approximately 2mm high
Is provided. Furthermore, the mounting table upper surface 1
05d, an O-ring 105b is provided as an O-ring groove 105a as a sealing means with the flange portion 106a of the vacuum dome 106.
O-ring groove 105a and flange 1
The contact surface of the 06a with the O-ring 105b is mirror-finished by buffing to improve the adhesion.

Further, a heating element 105 is mounted on the mounting table 105.
e, a bar-shaped heater 105 made of an insulator 105f
g at predetermined intervals to enable uniform heating of the mounting table 105 and to mount the upper surface 1 of the mounting table 105
By using a temperature sensor (not shown) provided on the mounting plate 05d and a control mechanism (not shown) for controlling energization of the rod-shaped heater 105g, the mounting table upper surface 105d can be maintained at a uniform and set temperature. Thus, the entire surface of the base material 503 placed on the mounting table upper surface 105d can be uniformly heated to a predetermined temperature.

The vacuum dome 106 is opposed to the mounting table upper surface 105d and has a pair of vacuum dome elevating guide shafts 106b.
Is vertically guided by an elevating guide 106e, and can be moved up and down by driving means (not shown) such as an air cylinder connected to the vacuum dome elevating guide shaft 106b. The flange 106a is provided so as to protrude outward along the outer periphery of the lower end of the vacuum dome 106, and is integrated with the vacuum dome 106 in an airtight manner by welding, and further, contacts with the O-ring 105b installed on the mounting table upper surface 105d. The surface is mirror-finished by buffing to enhance adhesion. The inside of the vacuum dome 106 has a minimum volume so as not to interfere with the base material regulating frame 105c provided on the mounting table 105.

The vacuum exhaust port 106c is connected to the vacuum dome 1
06, and is connected to an external vacuum source (not shown) such as a vacuum pump via a vacuum pressure regulator (not shown). Further, an atmosphere opening port 106d is provided so as to communicate with the inside of the vacuum dome 106, and communicates with the atmosphere via an on-off valve (not shown) linked to a detector (not shown) for detecting the pressure in the vacuum dome. ing.

In this state, the vacuum dome 106 is lowered, and the flange 106a is brought into contact with the O-ring 105b so that sufficient adhesion is obtained. The inside of the dome 106 can reach a predetermined vacuum pressure, and a signal when the vacuum pressure detector provided at the vacuum exhaust port 106c reaches the predetermined vacuum degree is detected and the on-off valve is opened, so that the predetermined vacuum degree is reached. At the same time, it enables quick release to the atmosphere.

Next, a filling method will be described. First, using the paste filling apparatus according to the first embodiment, the base material 503 is kept in close contact and heated to 50 ° C., and the paste 202 supplied in the forward direction of the squeegee is heated to 50 ° C. The via 504 is filled. However, a small blind via without air escape 5
In 04, unlike the base material 501 having a through via structure, the vacuum suction of the suction member 201 via the thin paper 101e does not work, and therefore the filling state of the paste 202 is incomplete, and in particular, the bottom surface of the minute blind via 504 When the paste 202 is pushed with a squeegee, air bubbles remain. Such a state is repeatedly performed in the paste filling region of the base material 503, and the paste 202 is in an incompletely filled state with respect to all the minute blind vias 504.

In FIG. 3, the base material 503 filled with the paste in advance is regulated and placed on the base material regulating frame 105 c provided on the mounting table 105, and is heated to 50 ° C. by the heating element 105 e incorporated in the mounting table 105. It is in a state of being heated. In this state, the vacuum dome 106 was lowered, the flange 106a was brought into contact with the O-ring 105b, and the inside of the vacuum dome 106 was depressurized by evacuating through the vacuum exhaust port 106c. Here, the air bubbles remaining on the bottom surface of the minute blind via 504 are discharged from the inside of the minute blind via 504 by the defoaming action as the pressure inside the vacuum dome 106 is reduced. Since the entire substrate 503 is in the vacuum dome 106, the defoaming acts on the entire paste filled in all the blind vias 504 provided on the substrate 503 and simultaneously. further,
Since the volume of the air bubbles remaining in the minute blind via 504 is very small as is apparent from the volume of the blind via 504, after the pressure inside the vacuum dome 106 having the minimum volume is reduced, Since the air in the vacuum dome can be quickly released to the atmosphere without any need for a standby, bubbles in the paste can be defoamed in a short time.

Here, the filling state of the paste 202 in the minute blind via 504 is such that the air bubbles remaining on the bottom surface are removed by the defoaming action, so that the connection with the copper foil 503b on the bottom surface of the minute blind via 504 is not performed. Although completely formed, the paste surface on the upper surface of the blind via is depressed by an amount corresponding to the bubble volume.

Here, the relationship between the ultimate vacuum degree in the vacuum dome 106 and the defoaming state of the air bubbles remaining in the minute blind via 504 has been obtained in advance by experiments. The experimental base material used in the experiment was prepared by temporarily laminating a cover film 501b on both sides of a base film 501a at 80 ° C. in advance, and using an ultraviolet laser to form a through hole having a hole diameter of about 0.05 mm using an ultraviolet laser.
After the opening, the cover film 501b was peeled off on one side only, and a transparent thickness of about 0.1
mm blind film was used to form a blind via. This experimental substrate has an advantage that the state of bubbles remaining on the bottom surface of the minute blind via can be easily observed with a microscope from the transparent film side. According to experiments, paste temperature 5
At a temperature of 0 ° C. and a viscosity of 20 Pa · S, the ultimate vacuum degree is 100
All the bubbles on the bottom surface of the minute blind via were erased by Pa, but elimination of all remaining air bubbles at a paste temperature of 30 ° C. and a viscosity of 140 Pa · S required a final vacuum degree of 30 Pa.

Next, in the apparatus of Embodiment 1, the base material 503 having been subjected to the defoaming of the fine blind vias 504 is used again to compensate for the shortage of the paste in which the paste surface on the upper surface of the blind via is depressed by the bubble volume. This is achieved by repeating the initial procedure of filling the conductive paste.
Thus, the paste 202 is completely filled without bubbles remaining in the minute blind via.

It should be noted that the present invention is not limited to the above-described embodiment, and similar effects can be obtained by changing the configuration as described below.

(A) The paste supplied onto the heated plate frame may be previously heated to a predetermined temperature to have a low viscosity.

(B) In the above embodiment, the paste is supplied on the heated plate frame. However, when the plate frame is not used, the paste may be supplied on the heated substrate.

(C) The squeegee movement is not limited to one direction, and the squeegee movement may be one reciprocation or more.

(D) In the second embodiment, only one substrate is loaded into the vacuum dome. However, a plurality of substrates may be loaded using a cassette or the like.

(E) In the second embodiment, the mechanism for raising and lowering the vacuum dome is used, but a mechanism for raising and lowering the mounting table may be used.

(F) The base material is not limited to a divided one, and it is also possible to use a roll sheet-shaped base material and add the functions of a supply unit and a winding unit to the apparatus and continuously fill the apparatus. .

(G) The base material is not limited to the one used in the present embodiment. For example, a mask plate provided with holes corresponding to via positions may be attached to a ceramic green sheet or the like. Is also good.

As described above, the paste filling method and the paste filling apparatus according to the first embodiment make it possible to reliably fill small vias by reducing the viscosity of the high-viscosity paste by heating. Furthermore, the paste filling method and the paste filling apparatus according to the second embodiment can reduce the viscosity of the high-viscosity paste by heating, so that the air bubbles remaining in the fine blind via previously filled with the paste can be collectively removed. Therefore, the paste can be reliably filled. Furthermore, since the vacuum can be evacuated in the minimum area, the process time is shortened and the productivity is improved. In addition, since the filling paste is not exposed to vacuum, there is no noticeable change in viscosity in a short time, and stable paste filling is performed. And the consumption of paste can be reduced.

[0065]

As is apparent from the above description,
The present invention can provide a paste filling method and a paste filling apparatus capable of reliably filling a micro via and a micro blind via provided in a base material with a paste.

Further, the present invention can provide a paste filling method and a paste filling apparatus which are excellent in productivity for filling a fine via and a minute blind via provided on a base material with a paste.

Further, the present invention can provide a paste filling method and a paste filling apparatus which do not increase the amount of paste used when filling the minute blind via provided on the base material with the paste. .

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a paste filling device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a configuration of a paste filling device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view schematically showing a configuration of a paste filling device according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a paste filling method according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view schematically showing a configuration of a base material and a micro via in the first and second embodiments of the present invention.

FIG. 6 is a view for explaining paste filling according to the first conventional technique.

FIG. 7 is a view for explaining paste filling according to a second conventional technique.

[Description of Signs] 101 Base 101d, 105g Bar-shaped heater 102 Plate frame 102d Planar heater 103 Guide shaft 104 Squeegee 105 Mounting table 106 Vacuum dome

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Nakatani 1006 Kazuma Kadoma, Osaka Prefecture F-term (reference) in Matsushita Electric Industrial Co., Ltd. GG16

Claims (8)

[Claims] 1. A method of filling a micro via provided in a base material with a paste, the method comprising: causing a paste supplied in front of the squeegee in a traveling direction of the squeegee and the base material having a back side adhered to reach a predetermined temperature; A paste filling method, wherein the squeegee is closely arranged on the surface side of the base material and the paste is filled in the micro vias by moving the squeegee. 2. A method of filling a paste into minute blind vias provided on a base material, wherein the paste supplied to the front of the squeegee in the traveling direction of the squeegee and the base material, the back surface of which is held in close contact, reaches a predetermined temperature. After the squeegee is closely arranged on the surface side of the base material and the paste is filled in the minute blind via by moving the squeegee, the base material is allowed to reach a predetermined temperature and a predetermined degree of vacuum. Open, again, the paste supplied to the front of the substrate and the squeegee in the traveling direction of the squeegee, which is held in close contact with the back side, is allowed to reach a predetermined temperature, and the squeegee is closely arranged on the surface side of the base material, and the paste is removed. A paste filling method, wherein the paste is filled in the minute blind vias by filling the minute vias by moving a squeegee. 3. The paste filling method according to claim 1, wherein the predetermined temperature is in a range of 30 ° C. to 50 ° C. 4. The predetermined degree of vacuum is from 100 Pa to 30
The paste filling method according to claim 2, wherein Pa is in a range of Pa. 5. A base provided with a heat source for holding and fixing and heating a base material provided with micro vias, and an outer peripheral portion of the base material placed on an upper surface of the base excluding a paste filling region. A plate frame provided with a heat source for abutting and heating the paste, and a squeegee for filling the fine via with the paste supplied forward in the traveling direction by moving relatively to the base material. A paste filling device. 6. A mounting table provided with a heat source for mounting a substrate filled with a paste in advance and heating the substrate to a predetermined temperature, and disposed opposite to the mounting table, wherein the heating and mounting is performed. A paste filling device, comprising: a vacuum dome that releases the substrate to a predetermined degree of vacuum and then releases the substrate to the atmosphere. 7. The paste filling apparatus according to claim 5, wherein the predetermined temperature is in a range of 30 ° C. to 50 ° C. 8. The predetermined degree of vacuum is from 100 Pa to 30.
The paste filling device according to claim 6, wherein the range is Pa.