JPH10224015A - Method and apparatus for manufacturing circuit forming substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality hole processing without losing the speed of laser processing in a method of manufacturing a circuit forming substrate used for a small electronic device, etc., and to realize a low-cost and highly reliable circuit. An object of the present invention is to provide a method for manufacturing a formed substrate. SOLUTION: A laser 9 is irradiated on a substrate material 6,
Hard and brittle altered portion 11 on the hole wall surface when forming through hole 10
The high-frequency vibrating plate 13 is caused to adhere to the surface of the substrate material 6 by vibrating the high-frequency vibrating plate 13 close to the substrate material 6, and the substrate material 6 is vibrated to remove the deteriorated portion 11 and the processing powder 12. Thus, a substrate material 6 having a good hole shape can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for manufacturing a circuit board and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art With the recent miniaturization and high-density of electronic equipment, circuit-forming boards on which electronic components are mounted have been increasingly adopted from conventional single-sided boards to double-sided, multi-layer boards. Development of a high-density circuit formation substrate that can be integrated in a semiconductor device is underway.

In the case of high-density circuit-forming substrates, the use of a laser processing method capable of higher-speed and finer processing has been studied instead of drilling (through-hole) processing on a substrate by drilling, which has been widely used in the past. (For example, Y.
Yamanaka et al., ExcimerLaser Processing In The M
icroelectronics Fields etc.). In addition, a circuit forming substrate has been proposed in which interlayer connection is performed by using fine hole processing by a laser and a connection means such as a conductive paste (Japanese Patent Application Laid-Open No. Hei 6-1994).
No. 268345).

However, in the hole drilling by laser, the object to be processed is locally heated and sublimated by the laser to form a hole, and as shown in FIG. Remains, further heated substrate material 1
Becomes the processing powder 4 and adheres to the inside of the through hole 2 and the surface of the substrate material 1. Further, a laser was used for a composite material represented by a glass fiber woven fabric and a thermosetting resin or an aromatic polyamide fiber (hereinafter referred to as aramid) nonwoven fabric and a thermosetting resin which are generally used as the substrate material 1. In this case, since the processing rate is different depending on each of the combined materials, remarkable unevenness is generated on the inner wall of the through hole 2 as shown in FIG. Further, it is actually difficult to completely and uniformly distribute the fibers 5 such as aramid in the substrate material 1, and even if the processing is performed by a laser pulse having an equal energy amount, the size of the through hole 2 is locally limited. Affected by fiber density.

As a result, the diameter of the through hole 2 after processing has a considerable variation from the target value even when the processing energy by the laser is optimized.

[0006]

However, as described above, the purpose of forming a hole in the substrate material 1 is to interconnect circuits formed on the front and back surfaces or the inner layer of the substrate. Thereafter, connection means such as plating and filling of a conductive paste are formed.

In the high-density circuit forming substrate, the size of the hole and the connecting means is very small, so that the altered portion 3 inside the through hole 2, the processing powder 4 attached to the substrate material 1, The hole processing quality such as the unevenness of the inner wall of the hole 2 has a significant effect on the reliability of the connection means.

When filling the conductive paste, the diameter of the through hole is an important management item together with the filling method, the viscosity of the conductive paste, the thickness of the substrate material, and the like. May be insufficiently filled.

On the other hand, if the laser energy is set to a large value to prevent insufficient filling of the conductive paste and the diameter becomes larger than a designed value, there is a concern that problems such as poor insulation with an adjacent circuit may occur. You.

As described above, when a hole is formed in a substrate material in a high-density circuit forming substrate, an allowable range of a variation in a hole diameter with respect to a design value is very narrow.

In order to improve the hole processing quality, there are a method of irradiating a laser with a low processing energy many times and a method of irradiating a low energy laser pulse for cleaning after an original laser pulse. The number of holes that can be machined per hour) is not satisfactory.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-cost and highly-reliable method for manufacturing a circuit-forming substrate, which realizes high-quality drilling without losing the speed of laser processing, and an apparatus for manufacturing the same.

[0013]

In order to solve the above-mentioned problems, a method of manufacturing a circuit forming substrate according to the present invention is directed to a method of forming a through hole or a non-through hole in a substrate material composed of a single material or a plurality of materials. Forming step, and a step of forming connecting means for mutually connecting a circuit formed on the surface of the circuit forming substrate or a circuit formed therein to the through or non-through hole formed in the hole forming step. A step of irradiating the substrate material with a laser to form a first-stage penetrating or non-penetrating hole shape in the hole forming step; At least one or both of the altered part formed on the inner wall of the shape and the powdery or massive alteration substance which is released from the substrate material during or after the process and is reattached to the substrate material is removed. Selectively removing from the substrate material by vibrating the substrate material, thereby obtaining a desired penetration or non-penetration of hole shape.

According to this method, high-quality drilling can be realized without losing the speed of laser processing, and a low-cost and highly reliable circuit board can be provided.

[0015]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, there is provided a hole forming step of forming a penetrating or non-through hole in a substrate material composed of a single or a plurality of materials, and the hole forming step. Forming a connection means for interconnecting a circuit formed on the surface of the circuit-forming substrate or a circuit formed therein in the through-hole or non-through-hole formed in the step, wherein the hole forming step includes using a laser. Irradiating the substrate material to form a first-stage penetrating or non-penetrating hole shape; and an altered portion formed in the surface of the substrate material and the first-stage penetrating or non-penetrating hole shape by the process. By vibrating the substrate material by vibrating the substrate material at least one or both of the powdery or lump-like alteration substance which has re-adhered to the substrate material after being released from the substrate material during or after the process. A method for manufacturing a circuit forming substrate, comprising a step of selectively removing from a substrate material to obtain a desired penetrating or non-penetrating hole shape. Even if the shape includes the altered portion formed on the inner wall of the hole and the processing powder re-adhered to the substrate material, it has the effect of being removed thereafter.

According to a second aspect of the present invention, the total amount of altered portions or altered substances removed from the inside of the hole by vibrating the substrate material is 1% or more in average by volume ratio to the desired hole shape. Since the amount of the substance that can be removed by the removal is sufficient, the laser processing energy can be minimized.

According to a third aspect of the present invention, the substrate material is made of a sheet-like composite material in which a sheet-like reinforcing material is impregnated with a thermosetting resin, and is generated when a laser is used for the composite material. It has the effect of removing significant irregularities on the inner wall of the hole in the next removal step.

According to a fourth aspect of the present invention, a polymer material is bonded to both sides or one side of a sheet-like composite material to form a substrate material, and laser processing energy can be minimized. In addition, it has the effect of reducing the thermal shrinkage of the polymer film in the periphery of the hole.

According to a fifth aspect of the present invention, the thermosetting resin is a so-called B stage including an uncured component,
This has the effect of reducing damage during laser processing of a B-stage resin having a significantly higher processing rate than a reinforcing material.

According to a sixth aspect of the present invention, the reinforcing material is a glass fiber woven fabric or a non-woven fabric, and has an effect of reducing unevenness of the inner wall of the hole due to a difference in processing rate between the thermosetting resin and the glass fiber. .

According to a seventh aspect of the present invention, the reinforcing material is a woven or non-woven aramid fiber, and has an effect of reducing unevenness of the inner wall of the hole due to a difference in processing rate between the thermosetting resin and the aramid fiber. .

The eighth aspect of the present invention vibrates the substrate material by directly contacting the high-frequency vibrator with the substrate material, and has an effect that vibration transmission efficiency is high.

According to a ninth aspect of the present invention, the substrate material is vibrated by radiating sound waves from the high-frequency vibrator or the diaphragm to the substrate material, and the vibration energy transmitted to the substrate material is easily made uniform. Has an action.

According to a tenth aspect of the present invention, a high-frequency vibrator or a vibrating plate and a substrate material are immersed in a liquid.
This has the effect that the substance removed from the substrate material by the removal processing can be easily collected together with the liquid.

According to the eleventh aspect of the present invention, the liquid is water or purified pure water, and has an effect that the running cost of the process is low and a device for collecting the evaporated liquid is unnecessary.

According to a twelfth aspect of the present invention, the liquid is an organic solvent, and has an effect of easily drying the substrate material after the removal processing.

According to a thirteenth aspect of the present invention, the hole formed in the substrate material is filled with a paste containing conductive particles during the step of forming the connecting means, and the inner wall of the hole is processed with a shape having little unevenness. Since there is no adhesion of powder, it has an effect that the filling property of the paste into the hole is good.

The invention according to claim 14 includes plating during the step of forming the connection means, and the hole inner wall has a shape with little unevenness and there is no adhesion of processing powder, so that the throwing power of the plating is good. It has the action of:

According to a fifteenth aspect of the present invention, there is provided a laser oscillating device, an optical system for condensing a laser derived from the laser oscillating device at a desired position on a substrate material, and A first processing area having a stage that operates in conjunction with the above, a high-frequency vibrating member for vibrating the substrate material, an oscillator for supplying high frequency to the high-frequency vibrating member, and collecting processing debris released from the substrate material Means for manufacturing a circuit-formed substrate comprising a second processing area provided with a means, wherein a hole shape formed by a laser is a deteriorated portion formed on an inner wall of the hole shape, a processing powder reattached to a substrate material, or the like. Has the effect of being subsequently removed.

According to a sixteenth aspect of the present invention, the first processing area and the second processing area are provided as independent chambers, and a shutter for carrying in and out the processing object is provided in the chamber. This has the effect that processing waste generated from the substrate material during drilling does not diffuse outside the manufacturing apparatus.

According to a seventeenth aspect of the present invention, a processing material carry-in portion to the first processing area, a connection portion between the first processing area and the second processing area, and a processing material take-out portion from the second processing area. And a chamber is provided at one or more locations, and the function that processing waste generated from the substrate material during drilling does not diffuse outside the manufacturing apparatus can be completed.

The invention according to claim 18 uses a chamber in which a liquid is retained as a second processing area, and a high-frequency vibration member is attached to the chamber, and has an effect of easily collecting processing waste together with the liquid. .

[0033] According to a nineteenth aspect of the present invention, the vibration frequency is in the ultrasonic range of 20 kHz or more.
Since a frequency higher than the audible frequency is used, there is an effect that a large amount of energy contributes to the removal processing.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a process sectional view showing a method of manufacturing a circuit forming substrate according to a first embodiment of the present invention.
The substrate material 6 is a composite material of a thermosetting epoxy resin 7 and an aramid fiber 8 as shown in FIG. The thermosetting epoxy resin 7 is not completely cured, but is in a so-called B-stage state including an uncured portion, and the substrate material 6 is usually called a prepreg.

Next, as shown in FIG. 1B, a laser 9 is irradiated onto the substrate material 6 to form a through hole 10. At that time, the thermosetting epoxy resin 7 and the aramid fiber 8 in the substrate material 6 are sublimated by heat and scattered around. But,
Thermosetting epoxy resin 7 that could not be sublimated on the hole wall
Alternatively, the aramid fiber 8 remains as a hard and brittle deteriorated portion 11. Further, since the aramid fiber 8 has a higher heat resistance and a lower processing rate by a laser as compared with the thermosetting epoxy resin 7, the aramid fiber 8 is likely to remain without being sublimated completely, and the inner wall of the hole has an uneven shape as shown in the figure. On the other hand, a part of the thermosetting epoxy resin 7 or the aramid fiber 8 scattered around is processed powder 1
2 and adhere to the surface of the substrate material 6 or the inside of the through hole 10.

Next, as shown in FIG. 1C, the high-frequency vibration plate 13 is vibrated while approaching the substrate material 6. The sound wave energy radiated from the high frequency vibration plate 13 causes the substrate material 6
Vibrates, and the deteriorated portion 11 and the processing powder 12 fall off and peel off from the substrate material 6, and the substrate material 6 having a good hole shape as shown in FIG. 1D is obtained. In the removal processing step, the thermosetting epoxy resin 7 and the aramid fiber 8 in the B-stage state are not damaged by vibration because they have flexibility, and the hard and brittle deteriorated portion 11 and the processing powder 12 are selectively removed. You.

Next, as shown in FIG. 1E, the conductive paste 14 is filled into the through holes 10 by means such as printing.
Since the through hole 10 has a good shape, the conductive paste 1
4 is completely filled in the through hole 10 without any hindrance.

Next, as shown in FIG. 1 (f), the substrate material 6 is sandwiched between metal foils 15 and heated and pressed using a hot press device (not shown) so that the substrate material 6 is simultaneously formed and electrically conductive. Metallic foil 15 and metallic foil 15 are electrically connected by conductive paste 14. Next, the metal foil 15 is patterned into a desired shape to obtain a double-sided circuit forming substrate having a circuit pattern 16 as shown in FIG.

In this embodiment, the double-sided circuit forming substrate has been described. However, it is needless to say that a multilayer circuit forming substrate can be obtained by repeating the steps a plurality of times.

FIG. 2 is a diagram showing the diameter and the frequency of occurrence of through holes 10 obtained by performing a plurality of times of laser drilling on a substrate material 6 using a composite material of a thermosetting epoxy resin 7 and an aramid fiber 8. is there. FIG. 2A shows the case where the removal processing by vibration is not performed. Even when the laser beam diameter and the processing energy on the substrate material 6 are kept constant, the diameter of the through-hole 10 becomes uneven or adheres to the inner wall of the hole. Variations due to processing powder. FIG. 2B shows the case where the removal is performed. Since the removal removes irregularities on the inner wall of the hole, processing powder, and the like, variations in the hole diameter are significantly reduced.

(Embodiment 2) FIG. 3 is a process sectional view showing a method of manufacturing a circuit forming substrate according to a second embodiment of the present invention. First, as shown in FIG. 3A, an insulating layer 17 is formed on the substrate material 6 on which the circuit pattern 16 has been formed. As a material of the insulating layer 17, a resin such as epoxy or polyimide can be used. Next, as shown in FIG. 3B, a non-through hole 18 is formed in the insulating layer 17 by irradiating a laser 9. The insulating layer 17 below and around the non-through hole 18 becomes the altered portion 11 due to the processing heat.

Next, as shown in FIG. 3C, the substrate material 6 is vibrated in pure water 19 to remove the altered portion 11. In the removal, the altered portion 11 is completely removed, exposing the circuit pattern 16 as shown in FIG. The removed altered portion 11 is carried together with the circulation of the pure water 19 and is collected by a collecting means (not shown). Next, as shown in FIG. 3E, a plating layer 20 is formed by electroless or electrolytic plating. Next, as shown in FIG. 3 (f), the plating layer 20 is patterned to form a circuit pattern 16, thereby obtaining a multilayer circuit forming substrate.

According to the experiment of the present inventor, even if the depth of the non-through hole 18 is several% of the thickness of the insulating layer 17, it is possible to expose the circuit pattern 16 by the removal processing. This means that most processing is performed by removal after laser processing in terms of volume ratio. However, it is necessary that the deteriorated portion 11 generated by the laser processing reaches the circuit pattern 16.

(Embodiment 3) FIG. 4 is a sectional view showing an apparatus for manufacturing a circuit-formed substrate according to a third embodiment of the present invention. The chambers 21a to 21d are independent of each other, and shutters 23a to 23e are provided so that the substrate material 6 fixed on the stage 22 can sequentially move in each of the chambers 21a to 21d. The chamber 21
Suction ports 24a to 24d are connected to a to 21d. In the chamber 21b, a laser 9 is introduced from a laser oscillator 25 via an optical system 26 in order to subject the substrate material 6 to laser processing. The chamber 21c is provided with a high-frequency vibration plate 13 for applying vibration to the substrate material 6 and removing the altered portion 11 and the processing powder 12 generated by the laser processing.

Next, the operation of the circuit forming substrate manufacturing apparatus according to the third embodiment of the present invention will be described in order. First, the substrate material 6 is fixed on the stage 22 as shown at the left end in FIG. Next, the shutter 23a is opened, the stage 22 is put into the chamber 21a, and the shutter 23a is closed. Next, the shutter 23b is opened and the stage 22 is put into the chamber 21b. Next, the shutter 23b is closed, and the dust flowing into the chamber 21a from the inside of the chamber 21b is discharged from the suction port 24a. Next, the chamber 21b
Laser processing is performed on the substrate material 6 in the inside. The generated dust is discharged from the suction port 24b.

Next, the shutter 23c is opened and the stage 22 is opened.
Into the chamber 21c and close the shutter 23c.
Next, the high frequency vibration plate 13 is driven to vibrate the substrate material 6 to perform removal. The generated dust is discharged from the suction port 24c. Next, the shutter 23d is opened, the stage 22 is put into the chamber 21d, and the shutter 23d is closed. Next, the dust that has flowed into the chamber 21d from the chamber 21c is discharged from the suction port 24d. Next, the shutter 23e is opened, the stage 22 is moved out of the chamber 21d, and the shutter 23e is closed. Next, the substrate material 6 on which the desired hole processing has been completed is removed from the stage 22.

In the operation described above, the chamber 21
The outside and inside of a to 21d are completely shut off, and the substrate material 6
Also, since it is carried out without the deteriorated portion 11 and the processing powder 12 due to the laser processing, dust and the like accompanying the processing do not go outside, which is convenient when the present manufacturing equipment is installed in a clean room.

In this embodiment, the number of chambers is set to four, but the number of chambers can be increased or decreased by setting two chambers for laser processing and removal processing to the minimum number.

[0049]

As described above, according to the method and apparatus for manufacturing a circuit-forming substrate of the present invention, a step of irradiating a laser to the substrate material to form a first or second through-hole or non-through-hole shape is provided. The altered part formed on the surface of the substrate material and the inner wall of the through hole or non-penetration hole of the first stage, or the powdery or lumpy material which is detached from the substrate material during or after the process and then reattached to the substrate material The method comprises a step of selectively removing at least one or both of the altered substance from the substrate material by vibrating the substrate material to obtain a desired through or non-through hole shape. Processing can be realized without losing the high speed of laser processing, and a low-cost and highly reliable method for manufacturing a circuit-formed substrate can be provided.

[Brief description of the drawings]

FIGS. 1A to 1G are cross-sectional views illustrating steps of a method for manufacturing a circuit-formed substrate according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams showing the diameters and occurrence frequencies of through holes obtained by performing laser drilling a substrate material using a composite material of a thermosetting epoxy resin and an aramid fiber many times;

FIGS. 3A to 3F are process cross-sectional views of a method of manufacturing a circuit board according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an apparatus for manufacturing a circuit forming substrate according to a third embodiment of the present invention.

5 (a) and 5 (b) are cross-sectional views of a drilled portion in a conventional method for manufacturing a circuit board.

[Explanation of symbols]

 Reference Signs List 6 substrate material 7 thermosetting epoxy resin 8 aramid fiber 9 laser 10 through hole 11 altered part 12 processing powder 13 high frequency vibration plate 14 conductive paste 15 metal foil 16 circuit pattern 17 insulating layer 18 non-through hole 19 pure water 20 plating layer 21a to 21d Chamber 22 Stage 23a to 23e Shutter 24a to 24d Suction port 25 Laser oscillator 26 Optical system

Claims (19)

[Claims] 1. A step of forming a through hole or a non-through hole in a substrate material composed of a single or a plurality of materials, and forming a circuit in the through or non-through hole formed in the hole forming step. Forming a connection means for interconnecting a circuit formed on the surface of the substrate or a circuit formed inside the substrate, wherein the hole forming step includes irradiating a laser to the substrate material to pass through or pass through the first stage. Forming a hole shape, and the deformed portion formed on the surface of the substrate material and the inner wall of the penetrating or non-penetrating hole of the first stage by the process or after releasing from the substrate material during or after the process, By vibrating the substrate material, at least one or both of the powdery or massive alteration substances reattached to the substrate material are selectively removed from the substrate material, and the desired penetration Alternatively, a method for manufacturing a circuit forming substrate, comprising a step of obtaining a non-through hole shape. 2. The method according to claim 1, wherein the total amount of altered portions or altered substances removed from the inside of the hole by vibrating the substrate material is 1% or more on average in a volume ratio to a desired hole shape.
3. The method for manufacturing a circuit-formed substrate according to 1. 3. The method according to claim 1, wherein the substrate material is a sheet-like composite material in which a sheet-like reinforcing material is impregnated with a thermosetting resin. 4. The method for producing a circuit-formed substrate according to claim 3, wherein a polymer film is adhered to both sides or one side of the sheet-like composite material to form a substrate material. 5. The method according to claim 3, wherein the thermosetting resin is a so-called B stage including an uncured component. 6. The method according to claim 3, wherein the reinforcing material is a glass fiber woven fabric or a nonwoven fabric. 7. The method according to claim 3, wherein the reinforcing material is an aromatic polyamide fiber woven or nonwoven fabric. 8. The method for manufacturing a circuit-formed substrate according to claim 1, wherein the substrate material is vibrated by directly contacting a high-frequency vibrator on the substrate material. 9. The method according to claim 1, wherein the substrate material is vibrated by radiating sound waves from the high-frequency vibrator or the diaphragm to the substrate material. 10. The method according to claim 9, wherein the high-frequency vibrator or the diaphragm and the substrate material are immersed in a liquid. 11. The method according to claim 10, wherein the liquid is water or purified pure water. 12. The method according to claim 10, wherein the liquid is an organic solvent. 13. The method for manufacturing a circuit-formed substrate according to claim 1, wherein a paste containing conductive particles is filled into holes formed in the substrate material during the step of forming the connection means. 14. The method according to claim 1, wherein the step of forming the connection means includes plating. 15. A laser oscillating device, an optical system for condensing a laser derived from the laser oscillating device at a desired position on a substrate material, and a stage fixed to the substrate material and operated in cooperation with the optical system A first processing area comprising: a high-frequency vibrating member for vibrating the substrate material; an oscillator for supplying a high frequency to the high-frequency vibrating member; and a second means for collecting processing waste released from the substrate material. An apparatus for manufacturing a circuit board, comprising a processing area. 16. The apparatus according to claim 15, wherein the first processing area and the second processing area are independent chambers, and a shutter is provided in the chamber for carrying in and out the workpiece.
3. The apparatus for manufacturing a circuit-formed substrate according to claim 1. 17. A processing material carry-in section into the first processing area, a connection section between the first processing area and the second processing area, and a second processing area.
All or one of the processing material unloading sections from the processing area
17. The apparatus for manufacturing a circuit-formed substrate according to claim 16, wherein a chamber is provided at more than one place. 18. The apparatus according to claim 15, wherein a container for retaining the liquid is used as a second processing area, and a high-frequency vibration member is attached to the container. 19. The apparatus according to claim 15, wherein the frequency of the vibration is in an ultrasonic range of 20 kHz or more.
The circuit forming substrate manufacturing apparatus according to any one of the above.