JP2005150219A - Method and apparatus for manufacturing laminated electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve bonding force between green sheets and also to easily peel the green sheet and a temporary base material. <P>SOLUTION: The green sheet 331 is deposited with pressure on a laminated green sheet material 330 while the ultrasonic wave is applied using an ultrasonic wave head unit 120. With the ultrasonic wave, organic binders are bonded with each other owing to friction heat at the surfaces where the green sheets 331 are bonded with each other. Since acoustic impedances are different with each other in the green sheet 331 having the soft property and the temporary base material 340 having the hard property, the bonding force is lowered by applying the ultrasonic wave and thereby the temporary base material can be peeled off easily from the green sheet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a multilayer electronic component, and more specifically, a green sheet used in multilayer electronic components such as chip capacitors and inductors and a temporary substrate such as a PET film are peeled off. The present invention relates to a manufacturing method and a manufacturing apparatus.

  With the recent miniaturization of electronic equipment, the demand for high-density mounting of electronic components is increasing, and in order to mount electronic components with high density, multilayer electronic components such as surface mount chip capacitors and inductors are required. Widely used. The demand for high-density mounting does not stop, and further miniaturization of multilayer electronic components is required.

  In general, a multilayer electronic component is configured by laminating a green sheet in which a conductor pattern is formed on an insulator layer such as ceramic. This green sheet has been reduced in thickness with the miniaturization of parts, and in recent years, a sheet having a thickness of several micrometers has been used.

  Thus, since one green sheet is extremely thin and easily damaged, the green sheet before lamination is formed on a temporary substrate such as a PET film. Then, while holding the green sheet by the temporary substrate, the green sheet is sequentially laminated on the lamination stage, and the green sheet is pressed and heated from above the temporary substrate toward the green sheet laminate. The sheets are bonded together. In this way, after the green sheets are stacked, the temporary substrate that is no longer needed is peeled off from the green sheets. By repeating this process, a laminate composed of a plurality of green sheets is completed.

  However, since the green sheets are bonded to each other by heating and pressing in the green sheet bonding step, the green sheet and the conductor pattern may be deformed or damaged. Moreover, as a result of applying an excessive pressure to the laminated body, serious problems such as distortion of the structure of the laminated body and disconnection due to deviation of the laminated conductor patterns have occurred. In particular, such a problem is remarkable in a green sheet having a thin film thickness in recent years.

  Further, in the process of peeling the temporary substrate from the green sheet, excessive stress is applied to the green sheet, causing problems such as breakage of the green sheet, deformation of the conductor pattern, and defects in the laminate. Usually, in order to facilitate peeling, the surface of the temporary substrate to be bonded to the green sheet is subjected to release treatment (water repellent treatment) such as silicon treatment. It is difficult to avoid this problem. As the green sheet thickness is reduced, the mechanical strength of the green sheet is reduced. On the other hand, the adhesive strength between the green sheet and the temporary substrate is constant regardless of the thickness of the green sheet. It can be said that it was easier to break than before.

  In view of the above problems, various techniques have been devised. In order to facilitate the peeling of the green sheet, a method has been devised in which a ceramic raw sheet formed on a PET film is heat-pressed and then a PET film such as a carrier film is linearly peeled (for example, Patent Document 1). ). That is, in this method, a 70 ° C. temperature and a pressure of 100 Kg / cm 2 are applied to the laminated sheets for 10 seconds, and then the PET film is peeled off, thereby facilitating peeling and problems such as breakage of the ceramic raw sheet. Is to be avoided.

  However, when the ceramic sheet is pressure-bonded under the above-described conditions, the temperature of the ceramic raw sheet and the PET film rises as a whole, and plastic deformation easily occurs, and the adhesion strength between the PET film and the ceramic raw sheet increases. End up. As a result, there is a drawback in that the PET film tends to be incompletely peeled off.

  As another conventional technique, a transfer laminating method has been devised in which a conductor is formed on a releasable stainless steel plate (temporary substrate) and the stainless steel plate is deformed to peel the conductor from the stainless steel plate. (For example, patent document 2). However, in this method, there is no substantial difference from the conventional peeling method in that the releasability of the stainless steel plate is used, and it is difficult to avoid the above problem.

  Furthermore, as another conventional technique, a method of peeling a sheet material (soft body) attached to a continuous sheet using ultrasonic waves has been devised (for example, Patent Document 3). In such a method, the release sheet is peeled while transmitting the ultrasonic wave generated from the ultrasonic vibration unit to the suction mechanism and applying the ultrasonic wave to the release sheet from the suction mechanism.

  However, this prior art is not intended to improve the structure of laminating sheet materials, that is, to improve the adhesion of the sheet materials, but merely to peel the sheet materials. That is, the prior art does not use the difference in acoustic impedance as in the present invention. For this reason, it is impossible to simultaneously achieve the two effects of facilitating peeling of the temporary substrate and improving adhesion of the green sheet.

As another conventional technique, a method of transferring an electrode forming transfer sheet to an electronic component using ultrasonic waves has been devised (for example, Patent Document 4). However, this method does not mention anything that facilitates peeling of the sheet. That is, there is no suggestion of a configuration in which the sheet is peeled and bonded at the same time using the difference in acoustic impedance between the green sheet and the temporary substrate.
JP-A-5-47595 Japanese Patent Laid-Open No. 2003-17351 Japanese Patent Application Laid-Open No. 11-1114896 JP-A-5-167225

  The present invention has been made in view of the above-described problems, and a problem to be solved by the present invention is to facilitate the peeling of the temporary substrate from the green sheet and to improve the adhesion between the green sheets.

  In order to solve the above-described problems, the present invention provides a stacked electronic device for laminating a green sheet adhered to a sheet-like temporary substrate on another green sheet and peeling the temporary substrate from the green sheet. A method of manufacturing a component, the step of transporting and placing the green sheet made of a material having an acoustic impedance different from the acoustic impedance of the temporary substrate on the other green sheet, and toward the temporary substrate While applying an ultrasonic wave, it has the process of crimping | bonding the said green sheet to the said other green sheet, and the process of peeling the said temporary base | substrate from the said green sheet.

  According to the present invention, by applying ultrasonic waves to the green sheets, frictional heat is generated at the contact surfaces between the green sheets, and the adhesive strength between the two can be increased. Moreover, since the acoustic impedance of the temporary substrate is different from the acoustic impedance of the green sheet, the adhesive force between the two is reduced by the ultrasonic wave, and the temporary substrate can be easily peeled off.

  The present invention includes a step of simultaneously applying ultrasonic waves to each part of the green sheet or sequentially applying ultrasonic waves to each part of the green sheet.

  Furthermore, the present invention includes a step of heating the green sheet when the green sheet is pressure-bonded to the other green sheet.

  The green sheet has a binder and a ceramic material. For this reason, by applying ultrasonic vibration to the green sheets, the binders are bonded to each other by frictional heat, and the adhesion between the green sheets can be increased.

  Furthermore, the material of the temporary substrate is made of resin, metal, glass, ceramics, or a composite containing these. Further, the surface of the temporary substrate that is in contact with the green sheet is subjected to a mold release process. Therefore, the acoustic impedance of the temporary substrate becomes higher than the acoustic impedance of the green sheet, the adhesive force between the temporary substrate and the green sheet can be weakened by ultrasonic vibration, and the temporary substrate can be easily peeled off.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic view of a multilayer electronic component manufacturing apparatus according to a first embodiment. The manufacturing apparatus includes a manufacturing apparatus main body 1 for laminating green sheets and a controller 2 for controlling the manufacturing apparatus main body 1. The manufacturing apparatus main body 1 includes a table 101, a stand 102, an air cylinder 103, a piston arm 104, an ultrasonic head unit 120, a stack stage 130, and the like.

  A stack stage 130 is disposed on the upper surface of the table 101, and a green sheet laminate 330 is formed on the stack stage 130. A heater 131 is embedded inside the stack stage 130, and the green sheet 330 can be heated from below by the heater 131. The heater 131 has a temperature sensor, and the detection signal output from the temperature sensor is input to the controller 2. The controller 2 can control the temperature of the heater 131 based on the detection signal.

  A plurality of protrusions 132 are provided on the stack stage 130. By fitting these projections 132 into positioning holes formed in the temporary base 340, the temporary base 340 can be accurately positioned.

  A columnar stand 102 is provided at the end of the upper surface of the table 101, and an air cylinder 103 is attached to the upper side surface of the stand 102. The air cylinder 103 can move the piston arm 104 up and down using air pressure. An ultrasonic head unit 120 is provided at the lower end of the piston arm 104.

  The ultrasonic head unit 120 is for performing pressurization and heating while applying ultrasonic waves to the green sheet laminate 330 on the stack stage 130, and includes an ultrasonic actuator 121, a booster 122, and a horn 123. ing. The ultrasonic actuator 121 is for generating an ultrasonic wave having a frequency and amplitude determined based on a signal given from the controller 2. The booster 122 and the horn 123 are for amplifying the vertical amplitude of the ultrasonic wave emitted from the ultrasonic actuator 121, that is, the vertical amplitude with respect to the green sheet laminate 330. For example, the booster 122 has a double amplitude amplification factor, and the horn 123 has a 1.5 times amplitude amplification factor. Thereby, it is possible to apply ultrasonic waves with sufficient amplitude to the green sheet laminate 330. For example, when an ultrasonic wave having an amplitude of 20 μm is emitted from the actuator 121, the amplitude is amplified to 30 μm by the booster 122 and further amplified to 60 μm by the horn 123.

  The horn 123 is provided with an adsorber for adsorbing the temporary base 340. In addition, you may utilize an independent conveyance adsorption apparatus, without providing an adsorption device in the horn 123. FIG.

  When it is necessary to heat the horn 123 of the ultrasonic actuator 120, it is conceivable that hot air is applied from the outside of the horn 123 with an air heater (not shown) or the heater 124 is directly embedded in the horn. The upper part of the green sheet laminated body 330 can also be heated by these heaters. The heater 124 has a temperature sensor, and a signal from the temperature sensor is output to the controller 2.

  FIG. 2 is a block diagram showing the configuration of the controller 2. The controller 2 includes a bus 200, a CPU 201, a memory 202, a hard disk drive 203, a display unit 204, an input unit 205, an A / D converter 206, a D / A converter 207, and a digital interface 208.

  The bus 200 includes a data bus and an address bus, and has a function of transferring data between the CPU 200 and the memory 202 and the like. The memory 202 is used as a work memory for the operation of the CPU 201, and the hard disk drive 203 is for storing a control program. The display unit 204 includes a liquid crystal display, an LED display, and the like, and is used to display the operating conditions of the control program and the operating conditions of the manufacturing apparatus 1 to the operator. The input unit 205 includes buttons, a keyboard, and the like, and has a function of inputting operating conditions of the manufacturing apparatus.

  The A / D converter 206 converts an analog signal from the temperature sensor into a digital signal and sends it to the CPU 201. The D / A converter 207 converts the amplitude instruction signal and frequency instruction signal of the ultrasonic wave determined by the CPU 201 into an analog signal and sends it to the ultrasonic actuator 121. Thereby, the ultrasonic actuator 121 generates an ultrasonic wave having an amplitude and a frequency based on these signals. The D / A converter 207 also has a function of converting the heater control signal determined by the CPU 201 into an analog signal. The CPU 201 determines a heater control signal based on a signal from the temperature sensor so that the temperature of the green sheet laminate 330 becomes a set temperature, and can control the temperature of the heaters 124 and 131 based on the heater control signal. is there.

  The digital interface 208 is for sending signals for controlling various operations of the manufacturing apparatus main body 1. That is, a signal for instructing the operation of the air cylinder 103, the operation of the transport plate, and the like is output from the digital interface 208.

  FIG. 3 shows a cross-sectional view of the green sheet laminate 330 according to the present embodiment. As shown in this figure, a temporary adhesive film 320 for temporarily fixing the green sheet laminate 330 is placed on the stack stage 130. The temporary adhesive film 320 is made of a foamed adhesive sheet, a UV release sheet, or the like, and fixes the green sheet laminate 330 until the green sheet laminate 330 is laminated. In addition, after a lamination process is complete | finished, the green sheet laminated body 330 is peeled from a temporary adhesive film. In addition, it is good also as having the function to vacuum-suck the green sheet laminated body 330 to the stack stage 130, without using the temporary adhesive film 320. FIG.

  On the temporary adhesive film 320, a plurality of green sheets 331a, 331c,. The green sheet 331a is composed of a slurry containing a dielectric material such as ceramic or a magnetic material such as ferrite, and a metal pattern formed thereon.

  Specifically, the green sheet 331a is formed by the following process. First, a slurry made of a dielectric material or magnetic material, an organic binder, and an organic solvent is applied on the temporary substrate 340 to a predetermined thickness using a doctor blade method, and then sufficiently dried. Thereafter, a metal pattern 332 made of a metal powder-containing paste is formed on the green sheet 331a using a screen printing method or the like. Through the above steps, one green sheet 331a is completed.

  Since the green sheet contains a soft material as described above, the sound velocity is relatively low, for example, 1,500 m / sec, and the acoustic impedance is 1.5 kg / m 2 · S × 105. On the other hand, since the temporary substrate is made of a hard material such as PET film or metal, the sound velocity is 3,000 to 5,000 m / sec, and the acoustic impedance is 3 to 5 kg / m 2 · S × 105. That is, it can be confirmed from this result that the acoustic impedance of the green sheet 331a is greatly different from the acoustic impedance of the temporary substrate. In the present invention, by utilizing the difference in acoustic impedance in this way, the adhesive strength between the green sheet 331a and the temporary substrate 340 having different acoustic impedances without weakening the adhesive strength between the ceramic sheets 331a having the same acoustic impedance. It is aimed at weakening.

  The green sheets 331a thus obtained are sequentially laminated on the temporary adhesive sheet 320, and ultrasonic waves are applied, heated, and pressurized by the ultrasonic head unit 120 for each lamination.

  Next, the green sheet bonding step and the temporary substrate peeling step according to the present embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 shows a cross-sectional view of the green sheet laminate 330 and the like in the bonding step and the peeling step, and FIG. 6 is a flowchart for explaining the bonding step and the peeling step.

  First, the operator operates the controller 2 and inputs the heater temperature, pressure, amplitude and frequency of ultrasonic vibration, and then starts the operation of the manufacturing apparatus body 1. The controller 2 turns on the heaters 124 and 130, and heats the heaters 124 and 130 so that the temperature detected by the temperature sensor becomes the set temperature (step S61). When the heaters 124 and 130 reach the set temperature (room temperature is acceptable), the controller 2 outputs an instruction for suction and transport operations to the ultrasonic head unit 120. Thereby, the ultrasonic head unit 120 sucks the green sheet 331 (step S62) and conveys it onto the stack stage 130 (step S63).

  Then, the ultrasonic head unit 120 places the green sheet 331 on the temporary adhesive film 320 and performs a pressure bonding process while applying ultrasonic waves to the green sheet through the temporary base 340 (step S64) (step S65). ). At this time, the temporary substrate 340 is pressed against the green sheet 331, but due to the difference in acoustic impedance between them, the adhesive force between the surfaces of the temporary substrate 340 and the green sheet 331 that contact is reduced. The ultrasonic head unit 120 peels off the temporary substrate 340 from the green sheet 331 while adsorbing the temporary substrate 340 (step S66). Thereby, the first green sheet 331 is formed on the temporary adhesive film 320.

  The controller 2 determines whether or not the stacking process for a predetermined number of sheets has been completed (step S67), and if the result of determination is NO, repeats the processing from step S62. When the second and subsequent green sheets 331 are stacked, as shown in FIG. 5A, the ultrasonic head unit 120 adsorbs the green sheet 331a (step S62), and on the green sheet 331b. Then, the green sheet 331a is placed on the green sheet 331b.

  Further, the ultrasonic head unit 120 presses the green sheet 331a to the green sheet 331b while applying ultrasonic vibration to the green sheet 331a via the temporary substrate 340 and the temporary substrate 340 (step S65). At this time, frictional heat is generated on the contact surfaces of the green sheet 331a and the green sheet 331b, and the organic binders contained in both adhere to each other. Furthermore, the adhesive force between the green sheet 331a and the green sheet 331b is further increased by heating with the heater. Thereby, the adhesive strength of the green sheet 331a and the green sheet 331b increases. As described above, sufficient adhesive strength can be obtained without heating with a heater.

  On the other hand, at the contact surface between the temporary base 340 and the green sheet 331a, the adhesive force is reduced due to the difference in acoustic impedance between the two. As a result, the temporary base 340 can be easily peeled from the green sheet 331a, and the deformation or breakage of the green sheet accompanying the peeling can be prevented (see FIGS. 5B and 5C). .

  When the stacking of the predetermined number of green sheets 331 is completed through the above steps (YES in step S67), the controller 2 ends the process, and the green sheet stack 330 is completed.

It is desirable that the ultrasonic wave, temperature, and pressure to be applied in the above manufacturing method have the following numerical values.
Ultrasonic vibration mode: preferably longitudinal vibration Ultrasonic frequency: 15-40 KHz (preferably 20 KHz)
Ultrasonic vibration amplitude: 6 to 60 μm (preferably 6 to 20 μm)
Stack stage temperature: room temperature to 60 ° C. (preferably room temperature to 40 ° C.)
Ultrasonic head unit temperature: room temperature to 60 ° C. (preferably room temperature)
Press pressure: 0.5 to 20 kg / cm 2 (preferably 5 to 10 kg / cm 2)
Ultrasonic application time: 0.1 to 3 seconds (preferably 0.3 to 1 second)

  In the conventional lamination method, the temperature of the stack stage 130 is 70 to 90 ° C., the heating mold temperature is 70 to 90 ° C., and the pressing pressure is 30 to 150 kg / cm 2. On the other hand, in the present embodiment, the necessary temperature and pressure can be greatly reduced, and the stress applied to the green sheet 331 can be reduced.

  In addition, according to the present embodiment, the heating temperature of the green sheet can be lower than that in the prior art. Conventionally, when a plurality of green sheets are laminated, the temporary substrate cannot be separated unless the green sheets are cooled to some extent. According to the present embodiment, since it is not necessary to consider the cooling time of the green sheet, it is possible to shorten the time required for peeling off the temporary substrate. As a result, the time required for the entire green sheet stacking process is shortened. For example, in the past, the total time of heating, pressurization, and cooling was about 10 seconds, but according to the present embodiment, it can be shortened to 3 to 5 seconds.

Furthermore, in the past, bubbles were easily mixed between the green sheet and the green sheet laminate, but according to this embodiment, the bubbles can be discharged to the outside by ultrasonic vibration.
(Second embodiment)
Subsequently, a manufacturing apparatus according to a second embodiment of the present invention will be described with reference to FIG. In this embodiment, an ultrasonic head unit 140 that applies ultrasonic waves to a part of the green sheet 331 is provided. Further, the ultrasonic head unit 140 includes moving means (not shown) for moving while scanning the surface of the green sheet 331 in the horizontal direction. Since other configurations are the same as those of the manufacturing apparatus according to the first embodiment, the description thereof is omitted.

  In this embodiment, the ultrasonic head unit 140 moves in the horizontal direction (arrow direction in the figure) while pressing and heating a part of the temporary base 340. Thereby, pressurization, heating, and ultrasonic application can be performed over the entire temporary substrate 340.

  Also in this embodiment, the same effects as in the first embodiment can be obtained. That is, the bonding strength between the green sheets 331 increases due to adhesion of the organic binder due to frictional heat at the contact surfaces of the green sheets 331. In addition, the contact strength between the green sheet 331 and the temporary base 340 decreases the bonding strength between the two due to the difference in acoustic impedance, and as a result, peeling becomes easy.

  It should be noted that the present invention is not limited to the above-described embodiments, and can be modified without departing from the spirit of the present invention. For example, although the multilayer ceramic capacitor has been described in the above-described embodiments, it goes without saying that the present invention can also be applied to a multilayer inductor. Further, the material of the temporary substrate is not limited to the resin film, and may be a metal such as a stainless plate having no flexibility, glass, ceramics, or a composite thereof. The surface treatment of the temporary substrate may be a resin-based mold release treatment such as silicon / fluorine treatment, a metal-type mold release treatment such as nickel / chromium / titanium / molybdenum, or a combination of Ni / PTFE eutectoid plating or Ti / N / Al / N composite release processing may also be used.

  Furthermore, the process of applying ultrasonic waves may be divided into two. For example, in the first ultrasonic application step, a profile that can maximize the adhesion between green sheets is used, and in the second ultrasonic application step, the adhesion between the green sheet and the temporary substrate is the highest. A decreasing profile can be used.

It is a figure which shows the outline of the manufacturing apparatus which concerns on 1st Example of this invention. It is a block diagram of the controller concerning the 1st example of the present invention. It is sectional drawing of the multilayer electronic component which concerns on 1st Example of this invention. It is sectional drawing of the multilayer electronic component which concerns on 2nd Example of this invention. It is a figure for demonstrating the manufacturing method which concerns on 1st Example of this invention. It is a flowchart showing the manufacturing method which concerns on 1st Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus main body 2 Controller 120 Ultrasonic head unit 130 Stack stage 140 Ultrasonic head unit 330 Green sheet laminated body 331 Green sheet 340 Temporary substrate

Claims (11)

A method for producing a laminated electronic component for laminating a green sheet attached to a sheet-like temporary substrate on another green sheet, and peeling the temporary substrate from the green sheet,
Transporting and placing the green sheet made of a material having an acoustic impedance different from the acoustic impedance of the temporary substrate on the other green sheet; and
Applying ultrasonic waves toward the temporary substrate and crimping the green sheet to the other green sheet;
And a step of peeling the temporary substrate from the green sheet.   The method for manufacturing a multilayer electronic component according to claim 1, wherein an ultrasonic wave is simultaneously applied to each portion of the green sheet.   The method for manufacturing a multilayer electronic component according to claim 1, wherein ultrasonic waves are sequentially applied to each portion of the green sheet.   The method for manufacturing a multilayer electronic component according to claim 1, wherein the green sheet is heated when the green sheet is pressure-bonded to the other green sheet.   The method for manufacturing a multilayer electronic component according to claim 1, wherein the green sheet includes a binder and a ceramic material.   6. The method of manufacturing a multilayer electronic component according to claim 1, wherein the material of the temporary substrate is made of resin, metal, glass, ceramics, or a composite containing these.   The method for manufacturing a multilayer electronic component according to claim 6, wherein a release treatment is performed on a surface of the temporary substrate that is in contact with the green sheet. A laminated electronic component manufacturing apparatus for peeling a temporary substrate from the green sheet after laminating a green sheet adhered to a sheet-like temporary substrate on another green sheet,
Conveying means for conveying and placing the green sheet made of a material having an acoustic impedance different from the acoustic impedance of the temporary substrate on the other green sheet;
Ultrasonic application means for applying ultrasonic waves toward the temporary substrate;
Pressure means for pressure-bonding the green sheet to the other green sheet;
An apparatus for manufacturing a multilayer electronic component, comprising: peeling means for peeling the temporary substrate from the green sheet.   9. The apparatus for manufacturing a multilayer electronic component according to claim 8, wherein the ultrasonic wave application means applies ultrasonic waves simultaneously to each part of the green sheet.   The apparatus for manufacturing a multilayer electronic component according to claim 8, wherein the ultrasonic wave application unit sequentially applies ultrasonic waves to each portion of the green sheet. The apparatus for manufacturing a multilayer electronic component according to claim 9, further comprising a heating unit that heats the green sheet when the green sheet is pressure-bonded to the other green sheet.

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