JP2002190373A - Manufacturing method of ceramic heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a ceramic heater, with which trimming according to a preset condition can be carried out, without the occurrence of breakage of wires and the like, on a resistance heating element upon performing the trimming by irradiation using laser beam irradiation. SOLUTION: Upon forming (n+1)-th groove after having formed (n-th) groove by irradiating the laser beam on the resistance heating element, the grooves are formed by irradiating the laser beam in such a way that the successive groove following it is each alternately formed in the opposite side across the first groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ceramic heater (hot plate) mainly used for manufacturing and inspecting semiconductors.

[0002]

2. Description of the Related Art Conventionally, heaters and wafer probers using a metal base material such as stainless steel or an aluminum alloy have been used as semiconductor manufacturing / inspection devices including etching devices and chemical vapor deposition devices. Was.

However, since the heater made of metal has a thick heater plate, there is a problem that the heater is heavy and bulky.
Further, there is a problem in the temperature followability due to these.

Therefore, Japanese Patent Application Laid-Open No. 11-40330 discloses a plate-like body (ceramic substrate) made of a nitride ceramic or a carbide ceramic having a high thermal conductivity and a high strength as a substrate. On the surface of
A ceramic heater provided with a heating element formed by sintering metal particles is disclosed.

As a method of forming a resistance heating element when manufacturing such a ceramic heater, conventionally, a ceramic substrate having a predetermined shape is manufactured, and then the resistance heating element is formed by a coating method using a method such as screen printing. And a method of forming a resistance heating element using a physical vapor deposition method such as sputtering or a plating method.

In the method of forming a resistance heating element by a coating method, a ceramic substrate having a predetermined shape is manufactured, and then a conductor paste layer of a heating element pattern is formed on the surface of the ceramic substrate by a method such as screen printing. , Heating and baking to form a resistance heating element.

However, in this method, although a resistance heating element can be formed at a relatively low cost, there is a problem that the resistance value of the formed resistance heating element varies because the thickness of printing varies. I was

In a method of forming a resistance heating element using a physical vapor deposition method such as sputtering or a plating method, after a ceramic substrate having a predetermined shape is manufactured, a metal layer is formed on a predetermined region of the ceramic substrate by these methods. After that, an etching resist is formed so as to cover a portion of the heating element pattern, and then an etching process is performed to form a resistance heating element having a predetermined pattern. The other parts are covered with a resin or the like, and thereafter, the above-described processing is performed, thereby forming a predetermined pattern of the resistance heating element on the surface of the ceramic substrate by one processing.

[0009] However, in this method such as sputtering or plating, a precise pattern can be formed. However, in order to form a resistive heating element having a predetermined pattern, the surface of the ceramic substrate is etched using a photolithography technique. Since it is necessary to form a resist, a plating resist and the like, there has been a problem that the cost is high.

As a method for solving these problems, a method having an advantage that a precise heating element pattern can be formed at a relatively low cost, that is, a strip-shaped or ring-shaped conductor layer having a predetermined width is used. After the formation, a portion other than the heating element pattern is removed (trimmed) using a laser beam irradiation device or the like to form a precise heating element pattern, or after forming a resistance heating element by the above method, A method of precisely adjusting the resistance value by irradiating a laser beam to remove (trim) a part of the resistance heating element has been performed.

In such a trimming method, in order to adjust the width of the groove formed by trimming, a plurality of grooves are formed in parallel with a portion adjacent to the initially formed groove, and the width of the groove is expanded. Was.

[0012]

However, when the width of the groove is increased, if the groove is formed continuously on only one side of the groove formed first, the groove formed first by laser irradiation can be formed. When the position is shifted or the formed heating element pattern is shifted, there is a problem that the resistance heating element is liable to be disconnected and a pattern different from the intended heating element pattern is formed. .

[0013]

Means for Solving the Problems In view of the above-mentioned problems, the present inventors have conducted intensive studies, and as a result, a conductor layer such as a resistance heating element or an annular shape is irradiated with laser light twice or more to broaden the width. When the resistance value of the resistance heating element is adjusted by forming the groove of
When forming a groove after the first, first, after forming a groove adjacent to the first formed groove, then, with the first formed groove sandwiched, sequentially formed grooves to be on the opposite side. As a result, it has been found that the resistance heating element or the conductor layer can be trimmed almost as set, and the present invention has been completed.

That is, in the first method of manufacturing a ceramic heater according to the present invention, after forming a predetermined pattern of a resistance heating element on the surface of a ceramic substrate, the resistance heating element is irradiated with laser light to form two or more grooves. A method for manufacturing a ceramic heater for forming and adjusting a resistance value of the resistance heating element, wherein the method of forming the groove includes forming a groove on an upper surface of the resistance heating element along a direction in which a current flows, When forming a second or subsequent groove by irradiating a laser beam so as to be adjacent to the groove, the groove is sequentially formed on the opposite side with the first formed groove interposed therebetween. It is assumed that. That is, after forming the first groove, the second groove is formed adjacent to the first groove, and the third groove is formed on the opposite side of the first formed groove, and , And a fourth groove is formed on the opposite side of the first formed groove and adjacent to the already formed second groove, and the process is further continued. When forming the n-th groove and then forming the (n + 1) -th groove, it is on the opposite side of the first formed groove and adjacent to the (n-1) -th groove As described above, the grooves are formed by sequentially irradiating the laser beam, and the trimming width is gradually increased (see FIG. 3D).

According to a second method of manufacturing a ceramic heater according to the present invention, a band-shaped or annular conductor layer is formed in a predetermined region of a ceramic substrate surface, and then a groove is formed in the conductor layer by irradiating a laser beam. A method of manufacturing a ceramic heater for forming a resistance heating element having a predetermined pattern by removing a part thereof, wherein the method of forming the groove includes irradiating a central region of a removed region of the conductor layer with laser light, After forming the removal groove, forming a second removal groove adjacent to the removal groove,
It is characterized in that grooves are sequentially formed on the opposite side. That is, a laser or the like is applied to a substantially central region of the conductor layer to be removed to form a removal groove, and then a second removal groove is formed adjacent to the first removal groove,
Further, a third removal groove is formed on the opposite side of the firstly formed removal groove, at a position adjacent to the formed removal groove, and the fourth removal groove is first formed with the removal groove. On the opposite side of the sandwich, it is formed adjacent to the already formed second removal groove, and this step is further continued to form the nth removal groove, and further to form the (n + 1) th removal groove. In this case, the laser light is sequentially irradiated so as to be on the opposite side of the first formed groove and adjacent to the (n-1) th removed groove to form the removed groove, and the trimming width is set. Is gradually increased to remove the conductor layer.

According to the first and second aspects of the present invention, when the second and subsequent grooves are formed as described above, the grooves are sequentially formed on the opposite sides of the first formed groove. Therefore, even if there is a misalignment in the irradiation position of the laser beam or the position of the resistive heating element pattern, a groove is sequentially formed on one side of the groove, and compared with the conventional method of expanding the groove. hand,
The position of the groove is unlikely to shift significantly, and as a result, disconnection and the like are unlikely to occur.

According to the first method for manufacturing a ceramic heater of the present invention, the resistance value is adjusted using a laser beam, so that the resistance value can be adjusted precisely in a relatively short time. , The surface that heats the semiconductor wafer, etc.
(Referred to as a heating surface) can be made uniform, and an object to be heated such as a semiconductor wafer can be heated at a uniform temperature.

Further, according to the second method of manufacturing a ceramic heater of the present invention, it is possible to easily form a resistive heating element pattern in a relatively short time, thereby reducing the manufacturing cost and increasing complexity. Thus, a precise pattern can be formed. Therefore, the ceramic heater having such a heating element pattern is relatively inexpensive, has a complicated and precise pattern, and can make the temperature of the heating surface uniform with high accuracy.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, description will be made in accordance with embodiments. In the first aspect of the present invention, the resistance value of the resistance heating element is adjusted by trimming the resistance heating element formed in a predetermined pattern. In that a resistive heating element pattern is formed by removing a part of the pattern. However, both inventions are common in that a specific region of the ceramic substrate is irradiated with laser light and the irradiated portion of the conductor layer (resistance heating element) is removed, and the same laser trimming device can be used.

Therefore, in the following, the two inventions will be described in parallel except for the case where they need to be described separately. In particular, when it is not necessary to distinguish between the two inventions, , Simply referred to as the present invention.

First, in the method of manufacturing a ceramic heater according to the present invention, a trimming apparatus used for performing laser trimming will be described, and then laser trimming using this apparatus will be described.

FIG. 1 is a block diagram showing an outline of a laser trimming apparatus used for manufacturing the ceramic heater of the present invention. When performing laser trimming, as shown in FIG. 1, the conductor layer 12m is formed in a concentric shape (annular shape) having a predetermined width so as to include the circuit of the resistance heating element to be formed, or The ceramic substrate 11 on which a resistance heating element of a predetermined pattern is formed is fixed on the stage 10c.

The stage 10c is provided with a motor and the like (not shown). The motor and the like are connected to the control unit 17, and the motor and the like are driven by a signal from the control unit 17. , The stage 10c can be freely moved in the θ direction (the rotation direction of the ceramic substrate) and the xy direction.

On the other hand, a galvanometer mirror 15 is provided above the stage 10c, and the angle of the galvanometer mirror 15 can be freely changed in the x direction by a motor 16. The laser beam 22 emitted from the laser irradiation device 14 similarly arranged above the stage 10c is configured to irradiate the galvanomirror 15 to be reflected and irradiate the ceramic substrate 11.

The motor 16 and the laser irradiation device 1
Reference numeral 4 is connected to the control unit 17, and drives the motor 16 and the laser irradiation device 14 by a signal from the control unit 17, thereby rotating the galvanometer mirror by a predetermined angle around the x direction. The table is rotated in the θ direction by driving a motor (not shown) provided on the stage 10 c by a signal from the control unit 17. The irradiation position on the ceramic substrate 11 can be freely set by rotation of the galvanometer mirror around the x direction and rotation of the table in the θ direction.
The table can be moved not only in the θ direction but also in the xy directions.

As described above, by moving the stage 10c on which the ceramic substrate 11 is mounted and / or the galvanomirror 15, it is possible to irradiate the laser light 22 to an arbitrary position on the ceramic substrate 11.

On the other hand, above the stage 10c, a camera 21 is also provided, whereby the ceramic substrate 1
1 (x, y) can be recognized. The camera 21 is connected to the storage unit 18, thereby recognizing the position (x, y) of the conductor layer 12 m of the ceramic substrate 11 and irradiating the position with the laser beam 22.

The input unit 20 is connected to the storage unit 18 and has a keyboard or the like (not shown) as a terminal. A predetermined instruction or the like is input through the storage unit 18 or the keyboard. It is supposed to be.

Further, the laser trimming device includes an arithmetic unit 19, and based on data such as the position of the ceramic substrate 11 and the thickness of the conductor layer and the resistance heating element recognized by the camera 21, the laser beam 22 is output. For controlling the irradiation position, irradiation speed, laser light intensity, etc. of the laser beam, and issues an instruction from the control unit 17 to the motor 16, the laser irradiation device 14, etc. based on the calculation result, and rotates the galvanomirror 15. Alternatively, the laser beam 22 is irradiated while moving or rotating the stage 10c to trim unnecessary portions of the conductor layer 12m.

The laser trimming device has a resistance measuring unit 23. The resistance measurement unit 23 includes a plurality of tester pins 24, divides the resistance heating element into a plurality of sections, and contacts the tester pins 24 for each section to measure the resistance value of the formed resistance heating element pattern. . Then, based on the measured resistance value, a laser is irradiated to a section having a low resistance value to form a groove (see FIG. 2) substantially parallel to the direction in which the current of the resistance heating element flows, or to form a groove By forming the notch, the resistance value is adjusted, and a resistance heating element with less variation in resistance value is obtained.

Next, a trimming method using such a laser trimming device will be specifically described. Here, a method of forming a resistance heating element by removing unnecessary portions of a ceramic substrate on which a strip-shaped or annular conductor layer is formed will be described first, and a method of adjusting a resistance value of the resistance heating element will be described. Will be described later. The steps other than the laser trimming step in the method for manufacturing a ceramic heater according to the present invention will be described in detail later, and will be briefly described here.

First, a ceramic substrate is manufactured.
First, a formed body made of a ceramic powder and a resin is prepared. As a method of producing the formed body, a method of producing granules containing a ceramic powder and a resin, then putting the granules in a mold or the like and applying a press pressure, and a method of laminating and pressing green sheets are used. There is a manufacturing method, and a more appropriate method is selected depending on whether or not another conductive layer such as an electrostatic electrode is formed inside. Thereafter, the formed substrate is degreased and fired to produce a ceramic substrate. Thereafter, a through hole for inserting a lifter pin into the ceramic substrate, a bottomed hole for burying a temperature measuring element, and the like are formed.

Next, a conductor paste layer having the shape shown in FIG. 1 is formed by screen printing or the like on a wide area including a portion serving as a resistance heating element on the ceramic substrate 11, and thereafter, the conductor paste is fired. Layer 12m. The conductor layer may be formed using a physical vapor deposition method such as a plating method or a sputtering method. In the case of plating, a plating resist is formed, and in the case of sputtering or the like, selective etching is performed to form a conductive layer 1 in a predetermined region.
2 m can be formed. Further, a part of the conductor layer may be formed as a resistance heating element pattern as described above.

In forming this conductor layer, the surface roughness Ra of the conductor layer is preferably at least 0.01 μm.
This is to prevent the reflection of the laser beam on the surface of the resistance heating element and to form a groove having a width and length as set.

Next, as shown in FIG.
The ceramic substrate 11 is fixed on the stage 10c by using the fixing protrusions 10b formed in contact with the side surfaces of the ceramic substrate 11 and the fitting protrusions (not shown) fitted in the through holes into which the lifter pins are inserted. I do.

The data of the resistance heating element pattern is input from the input unit 20 in advance and stored in the storage unit 18. That is, the data of the resistive heating element pattern to be formed by trimming is stored. The resistance heating element pattern data is planar (so-called solid or annular)
Is used to form a resistance heating element pattern by trimming the printed conductor layer.

Next, the position of the conductor layer 12m is stored in the storage unit 18 by photographing the fixed ceramic substrate 11 with the camera 21. An operation is performed in the operation unit 19 based on the data on the position of the conductor layer, and the result is stored in the storage unit 18 as control data.

Then, a control signal is generated from the control unit 17 based on the calculation result, and a laser beam is emitted while driving the motor 16 of the galvanomirror 15 and / or the motor of the stage 10c. An unnecessary portion of the conductor layer 12m is trimmed, and the resistance heating element 1
Form 2

FIGS. 3A to 3D are plan views schematically showing a method of forming a groove by trimming according to the present invention.
When trimming unnecessary portions of the conductor layer 12m, first, as shown in FIG. 3A, the first groove 130a is formed in the conductor layer 12m. Next, the first formed groove 130a
The groove 1 is located on either side (right side in FIG. 3B).
A groove 130b adjacent to 30a is formed in parallel. Next, the first formed groove 130a is sandwiched, and
The side opposite to the side where b was formed (left side in FIG. 3 (c))
Next, a groove 130c adjacent to the groove 130a is formed in parallel. Thereafter, when forming the n-th groove and then forming the (n + 1) -th groove, the n-th groove is on the opposite side of the first formed groove and adjacent to the (n-1) -th groove. The grooves are formed by sequentially irradiating the laser so as to reach the positions, and the trimming width is gradually increased (see FIG. 3D).

By forming the groove by such a method, the position of the groove is unlikely to be largely deviated even when the irradiation position of the laser beam or the position of the resistance heating element pattern is deviated. A resistance heating element having a desired pattern can be formed. Further, even when the resistance value of the resistance heating element is adjusted by trimming, disconnection or the like is unlikely to occur. The width of the groove formed by one laser beam is preferably 50 to 500 μm, and 100 to 150 μm.
μm is optimal. If it is less than 50 μm, the number of laser irradiations increases, and if the laser exceeds 500 μm, the ceramic substrate is damaged. Further, the number of grooves is desirably from 1 to 10, and optimally from 2 to 3.

FIGS. 4A to 4C are plan views showing a conventional method for forming a groove. As shown in FIGS. 4A to 4C, one of the grooves 131a formed first is formed. Side (Fig. 4
In (a) to (c), only the grooves 131b, 13
... 131n, when there is a positional shift in the irradiation position of the laser beam or the position of the resistance heating element pattern, the shift becomes large, so that the resistance of the pattern different from the target pattern is increased. A heating element is formed. Further, even when the resistance value of the resistance heating element is adjusted by trimming, disconnection or the like is likely to occur.

When an unnecessary portion such as the conductor layer is removed in this manner, the portion to be trimmed such as the conductor layer is trimmed by the laser beam irradiation, but the ceramic substrate thereunder is trimmed by the laser beam irradiation. It is important not to have a significant impact.

Therefore, it is necessary to select a laser beam which is well absorbed by metal particles and the like constituting the conductor layer and the like, but is hardly absorbed by the ceramic substrate. Examples of such a type of laser include a YAG laser, a carbon dioxide laser, an excimer (KrF) laser, a UV (ultraviolet) laser, and the like. Among them, YAG
Lasers and excimer (KrF) lasers are most suitable.

As the YAG laser, an SAG manufactured by NEC Corporation is used.
L432H, SL436G, SL432GT, SL41
1B can be adopted. As a laser, 2
Preferably, pulsed light having a frequency of 1 kHz or less is used, and more preferably, pulsed light having a frequency of 1 kHz or less and 2 kHz or less is used. This is because large energy can be applied to the resistance heating element in an extremely short time, and damage to the ceramic substrate can be reduced. In addition, the energy of the first pulse is not increased, and a groove having the set width can be formed. If the frequency of the pulse of the laser light exceeds 2 kHz, the energy of the first pulse becomes too large, and a groove wider than the setting is formed, so that a resistive heating element having the set shape cannot be formed.

The processing speed is desirably 100 mm / sec or less. If the speed exceeds 100 mm / sec, grooves cannot be formed unless the frequency is increased. As described above, since the upper limit of the frequency is 2 kHz or less, the frequency is preferably 100 mm / sec or less.

The output of the laser is desirably 0.3 W or more. If it is less than 0.3 W, the conductor layer to be removed to form the pattern of the resistance heating element may not be completely trimmed. In particular, when the resistance heating element is a sintered body of metal particles, by performing trimming with an output of 0.3 W or more, trimming reaching the ceramic substrate can be realized, and the conductor layer can be completely removed.

The trimming may be performed on the conductor paste layer. However, as described above, it is preferable that the resistance heating element paste is printed and then fired to form the conductor layer, and then the trimming is performed. This is because the resistance value may fluctuate due to firing, or the paste may be peeled off due to irradiation with laser light. The present invention is a method in which a conductor paste is formed in an annular shape (so-called solid shape) and patterned by trimming, so that a heating element pattern having a uniform thickness can be obtained. If it is attempted to print the heating element pattern from the beginning, the thickness will vary depending on the printing direction, making it difficult to form a resistance heating element having a uniform thickness.

In the above description, a method of forming a resistance heating element by irradiating a laser beam has been described. After a resistance heating element having a predetermined pattern is formed on a ceramic substrate, the resistance value of the resistance heating element is adjusted by trimming. in case of,
Using the trimming method of the present invention shown in FIG. 3, a groove 130 is formed substantially parallel to the direction in which the current of the resistance heating element 12 flows as shown in FIG. 2, thereby adjusting the resistance value of the resistance heating element. I do. A method of forming a notch substantially perpendicularly to the direction in which the current of the resistance heating element flows to adjust the resistance is not preferable because the heating element may be disconnected. In this case, as described above, the formed resistance heating element is divided into a number of sections using the tester pins 24, the resistance value is measured, and the resistance value is adjusted by trimming.

The pattern of the resistance heating element formed by such laser trimming is not particularly limited. For example, a ceramic heater having a resistance heating element pattern as shown below is formed.

FIG. 5 is a bottom view schematically showing a ceramic heater manufactured by the first method of manufacturing a ceramic heater according to the present invention, and FIG. 6 is a partially enlarged sectional view thereof. The grooves formed by trimming are not shown in the resistance heating elements 12a to 12g shown in FIG.

The ceramic heater 10 has a resistance heating element 12 (12a to 12g) on a bottom surface 11b opposite to a heating surface 11a of a disk-shaped ceramic substrate 11.
Are formed.

Since the resistance heating element 12 is heated so that the entire temperature of the heating surface 11a becomes uniform, a pattern composed of arcs and concentric circles formed repeatedly so as to draw a part of concentric circles is used. Is formed.

That is, the resistance heating element 12 closest to the outer periphery
In a to 12d, an arc-shaped pattern obtained by dividing a concentric circle into four parts is repeatedly formed, and ends of adjacent arcs are connected by bending lines to form a series of circuits. Then, the 4 comprising the resistance heating elements 12a to 12d having such a pattern.
Two circuits are formed close to each other around the outer circumference,
An overall annular pattern is formed.

The ends of the circuit composed of the resistance heating elements 12a to 12d are formed inside an annular pattern to prevent the occurrence of cooling spots and the like.
Therefore, the end of the outer circuit is extended toward the inner side.

Resistance heating elements 12a-12 formed on the outer periphery
On the inner side of d, resistance heating elements 12e, 12f, and 12g, each of which is formed of a circuit of a concentric pattern with a very small part thereof cut off, are formed, and these resistance heating elements 12e, 12f, and 12g are formed.
In g, a series of circuits is configured by connecting the ends of adjacent concentric circles sequentially with a resistance heating element formed of a straight line.

The resistance heating elements 12a to 12a
Between d, 12e, 12f and 12g, belt-like (annular)
Heating element non-forming area is provided, and also in the center part,
A circular heating element non-formation area is provided.

Therefore, as a whole, the annular resistance heating element forming area and the heating element non-forming area are alternately formed from the outside to the inside, and these areas are formed by the size (diameter) of the ceramic substrate. ), Thickness, etc., the temperature can be made uniform by setting the temperature appropriately.

After the resistance heating elements 12a to 12g are trimmed, as shown in FIG. 6, a metal coating layer 120 is formed to prevent corrosion and the like. The external terminal 33 is connected via the solder layer 120.

The ceramic substrate 11 is provided with three through holes 35 at positions where no heating element is to be formed. An object to be heated such as a silicon wafer 39 is brought into contact with the heating surface 11 a of the ceramic substrate 11. In addition to being placed and heated in a state in which it is heated, as shown in FIG. 6, a lifter pin 36 is inserted through these through-holes 35, and an object to be heated such as a silicon wafer 39 is held by the lifter pin 36. The object to be heated can be heated while being separated from the substrate 11 by a certain distance.

By moving the lifter pins 36 up and down, a heated object such as a silicon wafer 39 is received from the transfer device, the heated object is placed on the ceramic substrate 11, and the heated object is supported. It can be heated as it is. A recess or the like is formed on the heating surface 11a of the ceramic substrate 11, and the heating surface 11a is formed on the recess or the like.
A support pin is provided so as to slightly protrude from a, and by supporting the silicon wafer 39 with the support pin, the silicon wafer 39 is supported at a distance of 5 to 5000 μm from the heating surface, and heating is performed. Is also good.

A bottomed hole 34 is formed in the area of the bottom surface 11b of the ceramic substrate 11 where no heating element is formed. A temperature measuring element 37 such as a thermocouple is inserted into the bottomed hole 34, and the ceramic substrate 11 The temperature of a portion near the heating surface 11a can be measured.

In the ceramic heater having the above-described resistance heating element pattern, a pattern in which a series of circuits are formed by a combination of arcs and bent lines repeatedly formed so as to draw a part of a concentric circle on a disk-shaped ceramic substrate. (Hereinafter, also referred to as a circular arc repetition pattern), and a partially cut concentric circle is linearly connected at adjacent ends to form a series of circuits (hereinafter, also referred to as a concentric pattern). Since the heating element is configured, most of such a resistance heating element pattern can be represented by the distance r from the center of the ceramic substrate and the rotation angle (θ ₁ −θ ₂ ).

Therefore, when performing laser trimming,
If the ceramic heater is rotated around the center, the resistance value of the resistance heating element can be adjusted relatively easily. In a ceramic heater having a resistance heating element whose resistance value is adjusted by such a method, the heating surface can be adjusted. The temperature becomes uniform, and an object to be heated such as a semiconductor wafer can be heated at a uniform temperature.

The ceramic heater having the heating element pattern shown in FIG. 5 can also be obtained by trimming the conductor layer of the ceramic heater on which the annular conductor layer is formed, according to the second manufacturing method of the present invention. Can be manufactured. The same applies to a ceramic heater having a resistance heating element having a shape described below.

The ceramic heater manufactured by the manufacturing method of the present invention is not limited to the resistance heating element having the pattern shown in FIG. 5, but may be, for example, the above-described arc repetition pattern, concentric pattern, or bent line. A single repetitive pattern or the like may be formed, or these patterns may be arbitrarily combined.

FIG. 7 is a plan view schematically showing another embodiment of the ceramic heater manufactured by the method according to the present invention. In this ceramic heater, as shown in FIG.
The resistance heating elements 42a, 42b, and 42c, each of which is formed in a wide annular shape, mainly having a bending line, sandwich the annular heating element non-forming area and the central heating element non-forming area, It is formed radially as a whole.

It is desirable that the resistance heating element formed on the surface of the ceramic substrate be divided into at least two or more circuits as shown in FIGS. This is because, by dividing the circuit, the amount of heat generated can be changed by controlling the power supplied to each circuit, and the temperature of the heating surface of the silicon wafer can be adjusted.

When such a resistive heating element pattern is formed, if the pattern between the wirings of the resistive heating element is wide as shown in FIG. 7, the resistive heating element can be easily formed by screen printing. However, when forming a complicated (crowded) pattern with a narrow interval as shown in FIG. 5, an annular conductor layer composed of a wide band-shaped line is formed, and a laser beam is used. A method of trimming a portion (unnecessary portion) that is not the resistance heating element is advantageous because the resistance heating element can be formed relatively easily.

When the resistance heating element is formed on the surface of the ceramic substrate, the thickness of the resistance heating element is preferably 1 to 30 μm, more preferably 1 to 10 μm. Further, the width of the resistance heating element is preferably 0.1 to 20 mm, and 0.1 to 5 mm.
Is more preferred. Although the resistance value of the resistance heating element can be varied depending on its width or thickness, the above range is most practical.

The resistance heating element may have a rectangular or elliptical cross section, but is preferably flat. This is because the flat surface is more likely to dissipate heat toward the heating surface, so that the temperature distribution on the heating surface is less likely to occur. The aspect ratio of the cross section (the width of the resistance heating element / the thickness of the resistance heating element) is 10 to 50.
00 is desirable. By adjusting to this range, the resistance value of the resistance heating element can be increased, and the uniformity of the temperature of the heating surface can be ensured.

When the thickness of the resistance heating element is constant, if the aspect ratio is smaller than the above range, the amount of heat propagation in the direction of the heating surface of the ceramic substrate becomes small, and the heat distribution approximates the pattern of the resistance heating element. If the aspect ratio is too large, on the other hand, if the aspect ratio is too large, the temperature immediately above the center of the resistance heating element becomes high, and eventually, a heat distribution similar to the pattern of the resistance heating element occurs on the heating surface. Would. Therefore, considering the temperature distribution, the aspect ratio of the cross section is 1
It is preferably from 0 to 5000.

Regarding the variation of the resistance value of the resistance heating element, the variation of the resistance value with respect to the average resistance value is preferably 5% or less, more preferably 1%. Although the resistance heating element of the present invention is divided into a plurality of circuits, by reducing the variation of the resistance value in this way, the number of divisions of the resistance heating element can be reduced, and the temperature can be easily controlled. further,
It is possible to make the temperature of the heating surface uniform during the transition of the temperature rise.

Normally, such a resistance heating element is formed by applying a conductive paste containing metal particles or conductive ceramic particles for securing conductivity on a ceramic substrate and firing it. The conductive paste is not particularly limited, but preferably contains not only the metal particles or the conductive ceramic but also a resin, a solvent, a thickener, and the like.

As the metal particles, for example, noble metals (gold, silver, platinum, palladium), lead, tungsten, molybdenum, nickel and the like are preferable. These may be used alone or in combination of two or more. This is because these metals are relatively hard to oxidize and have a resistance value sufficient to generate heat. Examples of the conductive ceramic include carbides of tungsten and molybdenum. These may be used alone or in combination of two or more.

The particle size of these metal particles or conductive ceramic particles is preferably 1 to 100 μm. If it is too fine, less than 1 μm, the surface roughness Ra of the resistance heating element is 0.01
μm, it is easy to reflect laser light during trimming by irradiation with laser light, and it is not possible to form grooves or the like as set, while if the particle size of metal particles etc. exceeds 100 μm This is because sintering becomes difficult and the resistance value increases.

Although the shape of the metal particles is spherical,
It may be scaly, but more preferably spherical. This is because the surface roughness of the resistance heating element tends to be rougher. Further, even if it has a scale shape, if its aspect ratio (width or length / thickness) is not so large, it tends to be perpendicular or oblique to the surface on which the resistance heating element is formed. The roughness can be increased.

When these metal particles are used, they may be a mixture of the above-mentioned spherical material and the above-mentioned scaly material. When the metal particles are scaly, or a mixture of spherical and scaly, it is easy to hold the metal oxide between the metal particles, and the adhesion between the resistance heating element and the nitride ceramic, etc. And it is advantageous because the resistance value can be increased. Furthermore, if the needle-like particles have a small aspect ratio (length with respect to the diameter), the surface tends to be perpendicular or oblique to the surface on which the resistance heating element is formed, so that the surface roughness is increased. be able to.

As the resin used for the conductor paste,
For example, an epoxy resin, a phenol resin, and the like can be given. Examples of the solvent include isopropyl alcohol. Examples of the thickener include cellulose and the like.

As the conductor paste, it is preferable to use a paste obtained by adding a metal oxide to metal particles, apply this on a ceramic substrate, and then sinter the metal particles and the metal oxide. . By sintering the metal oxide together with the metal particles in this manner, the ceramic substrate, such as a nitride ceramic, and the metal particles can be more closely adhered to each other.

It is not clear why the mixing with the metal oxide improves the adhesion to the nitride ceramic or the like, but the surface of the metal particles or the surface of the nitride ceramic is slightly oxidized to form an oxide film. It is considered that these oxide films are sintered and integrated via the metal oxide, and the metal particles and the nitride ceramics or the like adhere to each other. Further, when the ceramic constituting the ceramic substrate is an oxide ceramic, the surface is naturally made of an oxide, so that a conductor layer having excellent adhesion is formed.

As the metal oxide, for example, oxidized
Lead, zinc oxide, silica, boron oxide (B _Two O_Three ), Al
Selected from the group consisting of Mina, Yttria and Titania
At least one is preferred. These oxides have resistance
Without increasing the resistance value of the heating element 12,
Adhesion with nitride ceramics etc. can be improved
Because.

The ratio of the above-mentioned lead oxide, zinc oxide, silica, boron oxide (B ₂ O ₃ ), alumina, yttria, and titania is calculated by weight ratio when the total amount of the metal oxide is 100 parts by weight. 1-10, silica 1-30, boron oxide 5-50, zinc oxide 20-70, alumina 1
-10, yttria 1-50, titania 1-50, and the total is preferably adjusted within a range not exceeding 100 parts by weight. By adjusting the amounts of these oxides within these ranges, the adhesion to nitride ceramics and the like can be particularly improved.

The amount of the metal oxide added to the metal particles is preferably 0.1% by weight or more and less than 10% by weight. The area resistivity when the resistance heating element 12 is formed using the conductor paste having such a configuration is 1 to 45 mΩ / □.
Is preferred.

When the area resistivity exceeds 45 mΩ / □, the amount of heat generated becomes too large with respect to the applied voltage, and the amount of heat generated in the ceramic substrate 11 provided with the resistance heating element 12 on the surface of the ceramic substrate is controlled. Because it is hard to do. If the addition amount of the metal oxide is 10% by weight or more, the sheet resistivity exceeds 50 mΩ / □, the calorific value becomes too large, the temperature control becomes difficult, and the uniformity of the temperature distribution decreases. . Further, if necessary, the sheet resistivity is set to 50 mΩ.
/ □ to 10Ω / □. When the sheet resistivity is increased, the width of the pattern can be increased, so that there is no problem of disconnection.

When the resistance heating element is formed on the surface of the ceramic substrate, it is desirable that a metal coating layer is formed on the surface of the resistance heating element. This is to prevent the internal metal sintered body from being oxidized to change the resistance value.
The thickness of the metal coating layer to be formed is preferably 0.1 to 10 μm. Such a metal coating layer is formed after performing the above-described trimming processing.

The metal used for forming the metal coating layer is not particularly limited as long as it is a non-oxidizing metal, and specific examples thereof include gold, silver, palladium, platinum and nickel. . These may be used alone or in combination of two or more. Of these, nickel is preferred.

The resistance heating element requires a terminal for connection to a power source, and this terminal is attached to the resistance heating element via solder. Nickel prevents thermal diffusion of solder. Examples of the connection terminal include those made of Kovar.

The ceramic substrate in the ceramic heater of the present invention is desirably a disk, and has a diameter of 1 mm.
Those exceeding 90 mm are desirable. This is because the larger the diameter, the greater the temperature variation on the heating surface.

The thickness of the ceramic substrate of the ceramic heater of the present invention is desirably 25 mm or less. This is because if the thickness of the ceramic substrate exceeds 25 mm, the temperature followability decreases. Also, its thickness is
More preferably, it is more than 1.5 mm and 5 mm or less. If the thickness is more than 5 mm, the heat is difficult to propagate, and the heating efficiency tends to decrease. May occur, and the strength of the ceramic substrate may be reduced to cause breakage.

In the ceramic heater 10 of the present invention, ceramic is used as the material of the substrate. However, the ceramic is not particularly limited.
Examples thereof include carbide ceramics and oxide ceramics. Among these, a nitride ceramic or a carbide ceramic is preferable as the material of the ceramic substrate 11. This is because it has excellent heat conduction characteristics.

As the nitride ceramic, for example,
Examples include aluminum nitride, silicon nitride, boron nitride, and titanium nitride. Examples of the carbide ceramic include silicon carbide, titanium carbide, and boron carbide.
Further, examples of the oxide ceramic include alumina, cordierite, mullite, silica, beryllia and the like. These may be used alone or in combination of two or more. Of these, aluminum nitride is most preferred. This is because the thermal conductivity is the highest at 180 W / m · K.

However, the ceramic substrate 11 is preferably made of a material that does not easily absorb laser light. For example, in the case of an aluminum nitride substrate, the carbon content is 5000p.
Those having a small carbon content of pm or less are preferred. Also,
Polish the surface to determine the surface roughness of the surface according to JIS B 0601
It is desirable that Ra be 20 μm or less. This is because when the surface roughness is large, the laser light is absorbed. If necessary, a heat-resistant ceramic layer may be provided between the resistance heating element and the ceramic substrate. For example, in the case of a non-oxide ceramic, an oxide ceramic may be formed on the surface.

As a method of forming the resistance heating element on the surface of the ceramic substrate by using the above method, a conductor paste is applied in a planar shape (annular shape) to a predetermined region of the ceramic substrate, and then the heating element pattern is formed by laser trimming. Or a method of baking a conductive paste and then performing laser trimming to form a resistive heating element having a predetermined pattern. Of these methods, after baking the conductor paste, a method of forming a resistance heating element pattern,
This is preferable because peeling of the conductive paste layer due to laser light irradiation does not occur.

It is sufficient that the metal is sintered as long as the metal particles and the metal particles and the ceramic are fused.
Alternatively, a conductor layer may be formed in a predetermined region by using a method such as plating or sputtering, and a resistance heating element pattern may be formed by laser trimming.

Next, a method of manufacturing a ceramic heater according to the present invention other than the laser trimming step described above will be described with reference to FIG.
It will be described based on. FIGS. 8A to 8D are cross-sectional views schematically showing a part of the method for manufacturing a ceramic heater of the present invention including laser processing.

(1) Manufacturing process of ceramic substrate Powder of ceramic such as aluminum nitride is added as necessary.
And yttria (Y_Two O _Three ), Na, Ca
Is prepared by blending a compound containing
After that, this slurry is granulated by a method such as spray drying.
And put the granules in a mold and press
It is formed into a plate or the like to produce a green body (green).
Note that the green sheet formed by the doctor blade method, etc.
The formed form may be produced by laminating the sheets.

Next, as necessary, a portion serving as a through-hole 35 for inserting a lifter pin 36 for carrying an object to be heated such as a silicon wafer 39 and a temperature measuring element such as a thermocouple are provided in the formed body. A portion having a bottomed hole for embedding is formed.

Next, the formed body is heated, fired and sintered to produce a ceramic plate. Thereafter, the ceramic substrate 11 is manufactured by processing into a predetermined shape (see FIG. 8A), but may be formed into a shape that can be used as it is after firing. Further, for example, by performing heating and baking while applying pressure from above and below, it becomes possible to manufacture a ceramic substrate 11 having no pores.
Heating and firing may be at least the sintering temperature, for example,
For nitride ceramics, the temperature is 1000-2500C.

Usually, after firing, a through hole 35 and a bottomed hole (not shown) for inserting a temperature measuring element are provided. The through holes 35 and the like can be formed by performing blasting such as sand blasting using SiC particles or the like after surface polishing.

(2) Step of Printing Conductor Paste on Ceramic Substrate The conductor paste is generally a high-viscosity fluid composed of metal particles, resin and solvent. The viscosity of the conductor paste is preferably from 70 to 90 Pa · s from the viewpoint that a conductor layer having a relatively uniform thickness can be formed.

The conductor paste is printed in a band or ring shape integrally with the area where the resistance heating element is to be provided by screen printing or the like, so that the conductor paste layer 12 is formed.
m is formed (FIG. 8B). Since it is necessary to make the temperature of the entire ceramic substrate uniform, the pattern of the resistance heating element is based on an arc or a concentric circle repeatedly formed so as to draw a part of a concentric circle as shown in FIG. Patterns are preferred. Note that, in addition to the method described above, the conductor layer can be formed by plating.

(3) Firing of Conductive Paste The conductive paste layer printed on the bottom surface of the ceramic substrate 11 is heated and fired to remove the resin and the solvent, and sinter the metal particles.
A conductor layer having a predetermined width is formed (see FIG. 6). Thereafter, using the above-described trimming method of the present invention, a groove is formed, and unnecessary portions are removed to form a resistance heating element (see FIG. 8C). The temperature of heating and firing is 5
00-1000 ° C is preferred. After forming the conductive paste layer of the resistance heating element pattern by screen printing, plating method, sputtering, or the like using the above method, firing is performed to obtain the resistance heating element 12, and the resistance value of the resistance heating element is adjusted by laser trimming. Good.

(4) Formation of Metal Coating Layer It is desirable to provide a metal coating layer 120 on the surface of the resistance heating element 12 as shown in FIG. Metal coating layer 120
Can be formed by electrolytic plating, electroless plating, sputtering, or the like, but in consideration of mass productivity, electroless plating is optimal.

(5) Attachment of Terminals, etc. Terminals (external terminals 33) for connection to a power supply are attached to the ends of the pattern of the resistance heating element 12 via solder (see FIG. 8D). In addition, a thermocouple is inserted into the bottomed hole 34 (not shown) and sealed with a heat-resistant resin such as polyimide or the like, thereby completing the manufacture of the ceramic heater.

The ceramic heater of the present invention can be used as an electrostatic chuck by providing an electrostatic electrode inside the ceramic substrate, and a chaptop conductor layer is provided on the surface, and a guard electrode or the like is provided inside. By providing a ground electrode, it can be used as a wafer prober.

[0106]

The present invention will be described in more detail with reference to the following examples. Example 1 Adjustment of Resistance Value of Resistance Heating Element by Laser Trimming (1) Aluminum Nitride Powder (Average Particle Size: 0.6 μm) 1
A composition comprising 00 parts by weight, 4 parts by weight of yttria (average particle size: 0.4 μm), 12 parts by weight of an acrylic binder and alcohol was spray-dried to prepare a granular powder.

(2) Next, this granular powder was placed in a mold and formed into a flat plate to obtain a formed product (green).

(3) Next, the green compact was hot-pressed at 1800 ° C. and a pressure of 20 MPa to obtain an aluminum nitride plate having a thickness of about 3 mm. Next, a disk having a diameter of 210 mm was cut out from the plate to obtain a ceramic plate (ceramic substrate 11). The ceramic substrate was drilled to form a through hole 35 for inserting a lifter pin 36 of a silicon wafer and a bottomed hole 34 (diameter: 1.1 mm, depth: 2 mm) for embedding a thermocouple.

(4) The ceramic substrate 11 obtained in the above (3)
Then, a conductor paste layer was formed by screen printing. The printing pattern was a pattern as shown in FIG.
Ag: 48% by weight, Pt:
21 wt%, SiO _2: 1.0 _{wt%, B 2 O 3: 1} .
2% by weight, ZnO: 4.1% by weight, PbO: 3.4% by weight, ethyl acetate: 3.4% by weight, butyl carbitol:
A composition having a composition of 17.9% by weight was used. This conductor paste is an Ag-Pt paste, and the silver particles (Ag-540 manufactured by Shoei Chemical Co., Ltd.) have an average particle size of 4.5 μm.
Was scaly. The Pt particles (Pd-221 manufactured by Shoei Chemical Co., Ltd.) were spherical with an average particle size of 6.8 μm. At this time, the viscosity of the conductor paste is 80P.
a · s.

(5) Further, after the conductor paste layer of the heating element pattern is formed, the ceramic substrate 11 is heated at 850 ° C. for 1 hour.
Ag in the conductor paste by heating and baking for 0 to 20 minutes,
Pt was sintered and baked on the ceramic substrate 11.

As shown in FIG. 5, the pattern of the resistance heating element includes seven channels 12a to 12g. Perimeter 4
The variation of the resistance value in one of the channels (the resistance heating elements 12a to 12d) before trimming is 7.4 to
12.4%. Note that a channel refers to a circuit that performs one control by applying the same voltage when performing control. In the present embodiment, each resistance heating element (12a to 12g) formed as a continuous body is shown. .

Each channel (the resistance heating elements 12a to 12a)
The resistance variation in 12d) was obtained as follows. That is, first, the channel is divided into 20, the resistance is measured at both ends within the divided range, the average is taken as the average divided resistance value, and the difference between the highest resistance value and the lowest resistance value in the channel and the average divided value Variation was calculated from the resistance value. In addition, each channel (the resistance heating elements 12a to 12
The resistance value in d) is the sum of all resistance values measured separately.

(6) Next, as a trimming device, a YAG laser having a wavelength of 1060 nm (S14 manufactured by NEC Corporation)
3AL output 3W, pulse frequency setting range 0.1 to 4
0 kHz) and the pulse frequency was set to 1.0 kHz. This device consists of an XY stage, a galvanometer mirror,
It has a CCD camera, an Nd: YAG laser, and a built-in controller that controls the stage and galvanometer mirror. The controller is a computer (NEC FC
-9821). The computer has a CPU that doubles as an arithmetic unit and a storage unit. In addition, it has a hard disk serving as a storage unit and an input unit, and a 3.5-inch FD drive.

The heating element pattern data is input from the FD drive to the computer, and the position of the resistance heating element is read (reading is based on a specific portion of the conductor layer or a marker formed on the ceramic substrate). The required control data is calculated, the heating element pattern is irradiated substantially parallel to the direction in which the current flows, the conductor layer in that part is removed, and a groove having a width of 50 μm reaching the ceramic substrate is formed. The value was adjusted. When forming the grooves, as shown in FIG. 3, the grooves were formed in parallel to the right and left sides of the first formed groove in parallel, and the width of the groove was adjusted.
The number of grooves formed to expand the grooves was three in total. The resistance heating element has a thickness of 5 μm and a width of 2.4 m.
m. The laser is 0.4 W at a frequency of 1 kHz
Output, byte size is 10 μm, machining speed is 10
mm / sec.

After the trimming is performed and the resistance value of the resistance heating element is adjusted, the variation in resistance value of the four outer peripheral channels (resistance heating elements 12a to 12d) is 1.0%.
５5.0%.

(8) Next, a portion to which the external terminal 33 for securing the connection with the power supply is to be plated with Ni, and then a silver-lead solder paste (manufactured by Tanaka Kikinzoku Co., Ltd.) is printed by screen printing to perform soldering. A layer was formed. Next, the external terminal 33 made of Kovar was placed on the solder layer, and heated and reflowed at 420 ° C., and the external terminal 33 was attached to the surface of the resistance heating element 12. (9) A thermocouple for temperature control was sealed with polyimide to obtain a ceramic heater 10.

Example 2 Production of Ceramic Heater (Formation of Resistance Heating Element by Laser Trimming) In this example, a ceramic heater having the resistance heating element pattern shown in FIG. 5 was produced. (1) First, aluminum nitride powder (average particle size: 1.1 μm)
m) 100 parts by weight, yttria (average particle size: 0.4 μm)
m) A composition comprising 4 parts by weight, 12 parts by weight of an acrylic binder and alcohol was spray-dried to prepare a granular powder. (2) Next, this granular powder was placed in a mold and formed into a flat plate to obtain a formed product (green).

(3) Next, the formed body was hot-pressed at 1800 ° C. and a pressure of 20 MPa to obtain an aluminum nitride plate having a thickness of about 3 mm. Next, a disk having a diameter of 210 mm was cut out from the plate to obtain a ceramic plate (ceramic substrate 11). This ceramic substrate is drilled, a through hole 35 for inserting a lifter pin 36 of a silicon wafer, a bottomed hole (not shown) for embedding a thermocouple (diameter: 1.1 mm, depth: 2 mm)
Was formed (see FIG. 8A).

(4) The ceramic substrate 11 obtained in the above (3)
Then, a conductor paste layer 12m was formed by screen printing. The printing pattern was a concentric pattern (annular shape) having a predetermined width and applied in a plane so as to include the resistance heating elements 12a to 12g to be the respective circuits of the resistance heating element 12 in FIG. 8 (b)). The conductor paste is a silver paste. Lead oxide: 5% by weight, zinc oxide: 55% by weight, silica: 10 based on 100 parts by weight of silver.
A material containing 7.5 parts by weight of a metal oxide consisting of 25% by weight of boron oxide and 25% by weight of alumina was used. In addition, silver particles (Ag-540 manufactured by Shoei Chemical Co., Ltd.)
Was scaly with an average particle size of 4.5 μm.
At this time, the viscosity of the conductor paste was 80 Pa · s.

(5) Further, after the conductor paste layer of the heating element pattern is formed, the ceramic substrate 11 is heated at 780 ° C. for 2 hours.
By heating and baking for 0 minutes, silver in the conductor paste was sintered and baked on the ceramic substrate 11.

(6) Next, trimming was performed using a YAG laser having a wavelength of 1060 nm (S143AL output 5W, pulse frequency setting range: 0.1 to 40 kHz, manufactured by NEC Corporation) with a laser pulse frequency of 1.0 kHz. . This device consists of an XY stage, a galvanometer mirror,
It has a CD camera, an Nd: YAG laser, and has a built-in controller for controlling the stage and the galvanometer mirror. This controller is connected to a computer (FC-9821 manufactured by NEC Corporation). In addition, the computer has a CPU that also serves as an arithmetic unit and a storage unit, and has a hard disk and a 3.5-inch FD drive that also serves as a storage unit and an input unit. X-
The Y stage can be rotated by an arbitrary angle θ about the center axis A of the fixed ceramic substrate.

The heating element pattern data is input from the FD drive to the computer, and the position of the conductor layer is read (reading is performed with reference to a specific portion of the conductor layer or a marker formed on the ceramic substrate). After calculating the appropriate control data, while rotating the ceramic substrate 11, the portion of the conductive paste layer other than the area where the heating element pattern is to be formed is irradiated with laser light, and the conductive paste layer in that portion is removed. Was formed (see FIG. 8C). When removing the portion outside the region, as shown in FIG.
The grooves adjacent to the left and right were sequentially formed in parallel across the groove, and the width of the groove to be removed was adjusted. The silver-lead resistance heating element had a thickness of 5 μm, a width of 2.4 mm, and an area resistivity of 7.7 mΩ / □.

(7) The above electroless nickel plating bath consisting of an aqueous solution having a concentration of 80 g / l of nickel sulfate, 24 g / l of sodium hypophosphite, 12 g / l of sodium acetate, 8 g / l of boric acid, and 6 g / l of ammonium chloride was used. The ceramic substrate 11 prepared in (6) is immersed in the silver-lead resistance heating element 1.
2 a 1 μm thick metal coating layer (nickel layer) 12
0 was precipitated.

(8) A silver-lead solder paste (manufactured by Tanaka Kikinzoku Co., Ltd.) was printed by screen printing on the portion where the external terminal 33 for securing the connection with the power supply was to be formed, to form a solder layer. Next, an external terminal 33 made of Kovar was placed on the solder layer, and heated and reflowed at 420 ° C. to attach the external terminal 33 to the surface of the resistance heating element 12 (FIG. 8).
(D)). (9) A thermocouple for temperature control was sealed with polyimide to obtain a ceramic heater 10.

(Comparative Example 1) Adjustment of Resistance Value of Resistance Heating Element by Laser Trimming In forming a groove in the resistance heating element, a groove was formed using the conventional method shown in FIG. In the same manner as in Example 1, a ceramic heater was manufactured.

Comparative Example 2 Manufacturing of Ceramic Heater (Formation of Resistance Heating Element by Laser Trimming) When forming a pattern of the resistance heating element, a groove was formed by using the conventional method shown in FIG. A ceramic heater was manufactured in the same manner as in Example 2 except that the portion outside the region to be formed was removed.

[0127]Evaluation method  (1) Observation of Groove Width and Forming Position In Example 1 and Comparative Example 1, resistance was formed on a ceramic substrate.
Forming a heating element and forming multiple grooves on the surface of the resistance heating element
After that, the width of the groove and its formation position are
Observed with a microscope (SEM). The results are shown in Table 1.

(2) Observation of Position of Heating Element Pattern In Example 2 and Comparative Example 2, it was determined whether or not the formed heating element pattern was formed at the set position and in the set pattern. Observed for the photo. The results are shown in Table 1.

(3) Temperature Measurement of Heating Surface The ceramic heaters according to the above-described embodiment and comparative example
After preparing the individual pieces and raising the temperature to 300 ° C., the temperature of the heating surface of the ceramic substrate was measured using a thermoviewer (IR-1 made by Nippon Datum Co., Ltd.).
62012-0012), the temperature difference between the minimum temperature and the maximum temperature was determined, and the average value was calculated for 10 ceramic heaters. Table 1 shows the results. The temperature difference in Table 1 is a temperature difference between the minimum temperature and the maximum temperature.

[0130]

[Table 1]

As is clear from the results shown in Table 1, in the case of Example 1, the grooves were formed at the set positions and with the set widths, and disconnection and the like due to overheating and melting occurred in the resistance heating element. No temperature distribution was generated on the heating surface, and the surface was uniform. Also, the variation in resistance value of the resistance heating element after trimming was small. On the other hand, in the case of Comparative Example 1,
The groove was misaligned from the setting, and the average of the temperature difference on the heating surface was 0.8 ° C., which was the same as in Example 1, but was 10%.
% Of the resistance heating element was broken by heating and melting.

Further, in the case of the second embodiment, the resistance heating elements are formed in the set pattern, so that the resistance heating elements do not break due to overheating and the temperature difference between the heating surfaces is 0.8 ° C.
In contrast, in the case of Comparative Example 2, there was a portion where a resistive heating element having a pattern as set could not be formed, and the average of the temperature difference on the heated surface was 0.8 ° C.
However, about 20% of the resistance heating elements were broken by heating and melting.

[0133]

As described above, according to the first method for manufacturing a ceramic heater of the present invention, the grooves are formed so as to be sequentially opposite to each other with the groove formed first in the resistance heating element interposed therebetween. Therefore, the resistance heating element can be trimmed as set without causing disconnection or the like, and the resistance value of the resistance heating element can be precisely adjusted.

Further, according to the second method of manufacturing a ceramic heater of the present invention, the grooves are formed so as to be sequentially opposite to each other with the groove formed first in the conductor layer interposed therebetween.
Unnecessary portions of the conductor layer can be trimmed as set, whereby a ceramic heater having a precise pattern and excellent heating surface temperature uniformity can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of a laser trimming apparatus used in a method of manufacturing a ceramic heater according to the present invention.

FIG. 2 is a perspective view schematically showing a groove formed when the resistance heating element is subjected to a trimming process.

FIG. 3 is a plan view showing a trimming method by laser beam irradiation according to the present invention.

FIG. 4 is a plan view showing a conventional trimming method by laser beam irradiation.

FIG. 5 is a bottom view schematically showing an example of a ceramic heater manufactured by the method for manufacturing a ceramic heater of the present invention.

FIG. 6 is a partially enlarged sectional view of the ceramic heater shown in FIG.

FIG. 7 is a plan view schematically showing another example of the ceramic heater manufactured by the manufacturing method of the present invention.

FIGS. 8A to 8D are cross-sectional views schematically showing a part of the manufacturing process of the ceramic heater of the present invention.

[Explanation of symbols]

10, 40 Ceramic heater 11, 41 Ceramic substrate 11a Heating surface 11b Bottom surface 12 (12a to 12g), 42 (42a to 42d) Resistance heating element 120 Metal coating layer 130 Groove 10b Fixing projection 10c Stage 12m Conductive layer 14 Laser irradiation device 15 Galvanometer mirror 16 Motor 17 Control unit 18 Storage unit 19 Operation unit 20 Input unit 21 Camera 22 Laser light 33 External terminal 34, 44 Bottom hole 35, 45 Through hole 36 Lifter pin 39 Silicon wafer

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) QB76 QB78 QC02 QC18 QC32 QC38 QC52 RF03 RF11 RF17 RF22 UA05 UA17 UA18 UC07 VV18 VV22 VV28

Claims (4)

[Claims] After a resistance heating element having a predetermined pattern is formed on the surface of a ceramic substrate, two or more grooves are formed by irradiating the resistance heating element with a laser beam to adjust the resistance value of the resistance heating element. A method of manufacturing a ceramic heater, comprising forming a groove in the resistance heating element along a direction in which current flows, and then irradiating a laser beam so as to be adjacent to the groove.
Forming a groove of the ceramic heater. 2. The method according to claim 1, wherein the resistive heating element is irradiated with a laser beam to form an n-th groove, and then, when forming an (n + 1) -th groove, the laser light is successively arranged on the opposite side of the first formed groove. The method for manufacturing a ceramic heater according to claim 1, wherein the groove is formed by irradiating the ceramic heater. 3. A ceramic heater for forming a predetermined pattern by forming a belt-like or annular conductor layer in a predetermined region on the surface of a ceramic substrate and irradiating a laser beam to remove a part of the conductor layer. In a manufacturing method, a laser light is irradiated to a central region of a removal region of a conductor layer to form a removal groove, and then a second removal groove is formed by irradiating a laser beam adjacent to the groove. And removing the conductor layer. 4. After forming the n-th removal groove by irradiating the resistance heating element with a laser beam, when forming the (n + 1) -th removal groove,
4. The method of manufacturing a ceramic heater according to claim 3, wherein the removal groove is formed by sequentially irradiating laser light so as to be on the opposite side of the firstly formed groove.