WO2020241697A1 - Composite substrate, composite substrate manufacturing method, circuit substrate manufacturing method, method for manufacturing assembly of plurality of circuit substrates, and method for manufacturing plurality of circuit substrates - Google Patents

Abstract

This composite substrate is provided with a ceramic substrate, a first metal layer bonded to a front surface side of the ceramic substrate, and a second metal layer bonded to a back surface side of the ceramic substrate. The first metal layer and/or the second metal layer is formed with at least one cut-out or hole enabling identification of a front surface and a back surface of the ceramic substrate. The ceramic substrate is rectangular when viewed from a thickness direction thereof. In this case, the at least one cut-out is formed in the second metal layer and/or the first metal layer so that at least one of the four corners of the ceramic substrate is exposed.

Description

Composite board, manufacturing method of composite board, manufacturing method of circuit board, manufacturing method of aggregate of multiple circuit boards, and manufacturing method of multiple circuit boards

The present invention relates to a composite substrate, a method for manufacturing a composite substrate, a method for manufacturing a circuit board, a method for manufacturing an aggregate of a plurality of circuit boards, and a method for manufacturing a plurality of circuit boards.

A circuit board is known in which a ceramic substrate is used as a base substrate and a circuit pattern is formed on one surface thereof. Such a circuit board is used for, for example, a power module because it is excellent in terms of high thermal conductivity and high insulation.

Here, in Patent Document 1, metal layers are joined to both sides of a ceramic substrate having a scribing line formed on the surface to form a composite substrate, and the metal layer on the surface is processed into a circuit pattern by etching, and then the scribing line is formed. A technique for manufacturing a plurality of circuit boards by dividing a composite substrate along the above is disclosed.

JP-A-2007-324301

According to the present invention, the front and back surfaces of a composite substrate including a ceramic substrate, a first metal layer bonded to the front surface side of the ceramic substrate, and a second metal layer bonded to the back surface side can be easily identified. An object of the present invention is to provide a composite substrate.

The composite substrate of the first aspect of the present invention comprises a ceramic substrate, a first metal layer bonded to the front surface side of the ceramic substrate, and a second metal layer bonded to the back surface side of the ceramic substrate. In addition, one or both of the first metal layer and the second metal layer are formed with at least one notch or hole that enables identification of the front surface and the back surface of the ceramic substrate.
Here, "enables identification of the front surface and the back surface" means that a person who handles the composite substrate or the like can visually distinguish between the front surface and the back surface of the composite substrate.
The following are examples of modes that enable identification of the front surface and the back surface.
(First aspect) An aspect in which at least one notch or hole is formed in one of the first metal layer and the second metal layer.
(Second aspect) At least one notch or hole is formed in both the first metal layer and the second metal layer, but one formed in the first metal layer and the other formed in the second metal layer. A mode that differs from the existing one in terms of shape, position, quantity or size.
(Third aspect) At least one notch or hole is formed in both the first metal layer and the second metal layer, and the one formed in the first metal layer and the second metal layer are formed. A mode in which the shape, position, quantity, and size are the same or substantially the same, but differ depending on the color, material, or pattern in the notch or hole.

The composite substrate of the second aspect of the present invention is the composite substrate, the ceramic substrate is rectangular when viewed from the thickness direction thereof, and the at least one notch is among the four corners of the ceramic substrate. It is formed on one or both of the first metal layer and the second metal layer so as to expose at least one corner portion of the above.

In the composite substrate of the third aspect of the present invention, in the composite substrate, at least one notch or a hole is formed in both the first metal layer and the second metal layer, respectively, and both of them. The at least one notch or hole formed in the above is different from each other in any one or more of positions, sizes and shapes.

In the composite substrate of the fourth aspect of the present invention, the at least one notch or hole has a function as an alignment mark in the composite substrate.

In the composite substrate of the fifth aspect of the present invention, in the composite substrate, a circuit pattern in which electronic components are mounted is formed on one of the first metal layer and the second metal layer.

In the composite substrate of the sixth aspect of the present invention, in the composite substrate, the other of the first metal layer and the second metal layer functions as a heat radiating layer.

In the composite substrate of the seventh aspect of the present invention, at least one scribe line is formed on one of the front surface and the back surface of the ceramic substrate in the composite substrate.

In the composite substrate of the eighth aspect of the present invention, in the composite substrate, the at least one notch or hole is such that a part of the at least one scribe line is located inside the notch or hole when viewed from the thickness direction. Is formed on one of the first metal layer and the second metal layer.

The composite substrate of the ninth aspect of the present invention is formed in the composite substrate in a plurality of regions of one of the first metal layer and the second metal layer, which are partitioned by at least one scribing line. A circuit pattern is formed in which electronic components are mounted.

In the composite substrate according to the tenth aspect of the present invention, in the composite substrate, a plurality of regions on the other side of the first metal layer and the second metal layer, which are partitioned by at least one scribe line, are heat dissipation layers, respectively. Functions as.

The method for manufacturing a composite substrate according to the first aspect of the present invention is a method for manufacturing a composite substrate in which a first metal layer and a second metal layer are bonded to the front surface side and the back surface side of the ceramic substrate, respectively. A notch forming step of forming at least one notch or a hole in one of the one metal layer and the second metal layer, which enables identification of the front surface and the back surface of the ceramic substrate, and the first metal layer and the first metal layer. The two metal layers include a joining step of joining the front surface side and the back surface side of the ceramic substrate, respectively.

The method for manufacturing a composite substrate according to a second aspect of the present invention is a method for manufacturing a composite substrate in which a first metal layer and a second metal layer are bonded to the front surface side and the back surface side of the ceramic substrate, respectively. A notch forming step of forming at least one notch or a hole in both the 1 metal layer and the 2nd metal layer, which enables identification of the ceramic substrate, and the 1st metal layer and the 2nd metal, respectively. A joining step of joining the layers to the front side and the back side of the ceramic substrate, respectively.
including.

The method for manufacturing a composite substrate according to a third aspect of the present invention is the method for manufacturing a composite substrate, wherein in the notch forming step, at least one of the above is different from each other in any one or more of positions, sizes, and shapes. Notches or holes are formed in both of the above.

The method for manufacturing a circuit board of the present invention is a step performed after the method for manufacturing a composite substrate and the joining step, and is a step performed on one or both of the first metal layer and the second metal layer. A pattern forming step of identifying the front surface and the back surface of the ceramic substrate from one notch or hole to form a circuit pattern in which electronic components are mounted on one of the first metal layer and the second metal layer. including.

The method for manufacturing a composite substrate according to a fourth aspect of the present invention is a step performed before the method for manufacturing the composite substrate and the joining step, and at least one scribe line is provided on the front surface or the back surface of the ceramic substrate. The step of forming a scribing line to be formed is included.

In the method for manufacturing a composite substrate according to the fifth aspect of the present invention, in the method for manufacturing the composite substrate and in the notch forming step, at least one notch or a hole is formed in the thickness direction during the joining step. The at least one notch or hole is formed in one of the first metal layer and the second metal layer so that a part of the at least one scribe line is located.

The method for manufacturing an aggregate of a plurality of circuit boards of the present invention is a step for manufacturing the composite substrate and a step performed after the joining step, and is applied to one or both of the first metal layer and the second metal layer. The front surface and the back surface of the ceramic substrate are identified from the formed at least one notch or hole, and are partitioned by the at least one scribing line in one of the first metal layer and the second metal layer. A pattern forming step of forming a circuit pattern in each of the plurality of regions is included.

The method for manufacturing a plurality of circuit boards of the present invention includes the method for manufacturing an aggregate of the plurality of circuit boards and the assembly of the plurality of circuit boards by cutting the ceramic substrate along at least one scribing line. Includes a division step of dividing the body.

The composite substrate of the present invention is a composite substrate including a ceramic substrate, a first metal layer bonded to the front surface side of the ceramic substrate, and a second metal layer bonded to the back surface side. Can be identified.

Further, according to the method for manufacturing a composite substrate of the present invention, it is possible to manufacture a composite substrate whose front and back surfaces can be easily identified. Along with this, according to the method for manufacturing a circuit board, the method for manufacturing an aggregate of a plurality of circuit boards, and the method for manufacturing a plurality of circuit boards of the present invention, each manufacturing defect does not occur or is unlikely to occur.

It is a flow chart which shows the manufacturing method of the plurality of mounting boards of this embodiment. It is a flow chart of the green sheet forming process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the molding process included in the green sheet forming process of this embodiment, and is the schematic figure for demonstrating the state which the band-shaped green sheet is produced from a slurry using a doctor blade molding apparatus. is there. It is a figure for demonstrating the cutting process included in the green sheet forming process of this embodiment, and is for demonstrating the state which cuts a strip-shaped green sheet using a cutting apparatus, and is producing a single leaf green sheet. It is a schematic view (side view) of. FIG. 2C is a schematic view of FIG. 2C viewed from the front side. It is a schematic diagram of a plurality of ceramic substrates in a stacked state produced by the method for manufacturing a ceramic substrate of the present embodiment. It is a figure for demonstrating the scrib line forming process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a flow chart of the metal layer formation process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the metal layer formation process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 5C-5C is a sectional view taken along the line 5C-5C of FIG. 5B. It is a figure for demonstrating the resist printing process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the etching process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the division process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the metal layer formation process of the 1st modification. It is a figure for demonstrating the metal layer formation process of the 2nd modification. It is a figure for demonstrating the metal layer formation process of the 3rd modification. It is a figure for demonstrating the metal layer formation process of the 4th modification. It is the figure of the motherboard of the 5th modification, and is the sectional view cut at the same part as the sectional view of FIG. 5C of this Embodiment. It is a figure for demonstrating the metal layer formation process of the 6th modification. It is a figure for demonstrating the metal layer formation process of the 7th modification. 15B-15B sectional view of FIG. 15A. It is a figure for demonstrating the metal layer formation process of the 8th modification.

≪Overview≫
Hereinafter, this embodiment will be described with reference to the drawings. Specifically, a method for manufacturing a plurality of mounting substrates (not shown) of the present embodiment will be described in the order of each process shown in FIG. 1 with reference to FIG. 1 and the like. Ceramic substrate 40 (see FIG. 3), motherboard 60 (example of composite substrate, see FIGS. 5B and 5C), assembly substrate 60B (another example of composite substrate, see FIGS. 7 and 8) manufactured after each step. And the circuit board 60C (see FIG. 8) will be described in the description of each step corresponding to each manufacturing process.
Next, the effect of this embodiment will be described.
Next, a modified example of the present embodiment will be described with reference to, for example, FIGS. 9 to 12.
In all the drawings referred to in the following description, similar components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

<< Manufacturing method of a plurality of mounting boards of the present embodiment >>
As shown in FIG. 1, the method S100 for manufacturing a plurality of mounting substrates of the present embodiment (hereinafter, referred to as the manufacturing method S100 of the present embodiment) includes a green sheet forming step S10, a sintering step S20, and a scribing line forming. The process includes a step S30 (hereinafter referred to as SL forming step S30), a metal layer forming step S40, a resist printing step S50, an etching step S60, a surface treatment step S70, a dividing step S80, and a mounting step S90. Each of these steps is performed in the order described.

Further, the relationship between the end of each step in the manufacturing method S100 of the present embodiment and the product at that time is as follows.

========================================
Each process at the end Product at that time ======================================= = =
Sintering step S20 Ceramic substrate 40 (see FIG. 3)
SL forming step S30 Ceramic substrate with SL 40A (see FIG. 4)
Metal layer forming step S40 Motherboard 60 (see FIGS. 5B and 5C)
Etching step S60 Assembly substrate 60B (see FIG. 7)
Division step S80 Multiple circuit boards 60C (see FIG. 8)
Mounting process S90 Multiple mounting boards ========================================

In the present specification, the motherboard 60 is an example of a composite substrate, and the collective substrate 60B is an example of an aggregate.

In addition, the description of this embodiment includes embodiments of the following inventions. Specifically, it is as follows.

(Invention relating to composite substrate)
The motherboard 60 (an example of a composite substrate) of the present embodiment has a ceramic substrate 40, a first metal layer 50A bonded to the front surface side of the ceramic substrate 40, and a second metal layer 50A bonded to the back surface side of the ceramic substrate 40. A metal layer 50B is provided, and at least one notch NT1 or a hole HL2 is formed in one or both of the first metal layer 50A and the second metal layer 50B so that the front surface and the back surface of the ceramic substrate 40 can be identified. (See FIGS. 5B, 5C, 11 to 12, 13, etc.).
Here, the "notch" in the present specification is a part while opening at the peripheral edge of the formed object (specifically, one or both of the first metal layer 50A and the second metal layer 50B). It means the part where. The "notch" referred to here includes a form in which the entire portion in the thickness direction of the object is removed (see reference numeral NT1 in FIG. 5B, reference numeral NT2 in FIG. 10, reference numeral NT4 in FIG. 16 and the like). A form in which a part of the portion in the thickness direction of the above is removed (see reference numeral NT3 in FIG. 13) is included. In this case, the "notch" can also be regarded as a depression. On the other hand, the “hole” in the present specification does not open at the peripheral edge of the formed object (specifically, one or both of the first metal layer 50A and the second metal layer 50B). It means a portion that is removed from the front surface or the back surface in the thickness direction (see reference numerals HL1, HL1, HL2, etc. in FIGS. 14A and 15B). The "hole" referred to here includes a through hole that penetrates the object to be formed (see reference numeral HL1 in FIG. 14 and reference numeral HL1 in FIGS. 15A and 15B) and a non-penetration that does not penetrate the object to be formed. A hole (recess) (see reference numeral HL2 in FIGS. 15A and 15B) is included. This non-through hole can also be regarded as a depression or groove.

(Invention relating to a method for manufacturing a composite substrate)
The method for manufacturing the motherboard 60 (an example of a composite substrate) of the present embodiment is a method for manufacturing the motherboard 60 in which the first metal layer 50A and the second metal layer 50B are bonded to the front surface side and the back surface side of the ceramic substrate 40, respectively. The first is a notch forming step of forming at least one notch or a hole in one of the first metal layer 50A and the second metal layer 50B so that the front surface and the back surface of the ceramic substrate 40 can be distinguished. It includes a joining step of joining the metal layer 50A and the second metal layer 50B to the front surface side and the back surface side of the ceramic substrate 40, respectively (see FIGS. 5A, 5B, etc.).

(Invention relating to a method for manufacturing a circuit board)
The method for manufacturing the circuit board 60C of the present embodiment is a step of manufacturing the motherboard 60 (an example of a composite substrate) of the present embodiment and a step performed after the joining step S42, and is a step performed after the first metal layer 50A and the second metal layer. The front and back surfaces of the ceramic substrate 40 are identified from at least one notch NT1 or hole HL1 formed in one or both of the 50Bs, and an electronic component (illustrated) is provided in one of the first metal layer 50A and the second metal layer 50B. It includes an etching step S60 (an example of a circuit pattern forming step) for forming a circuit pattern CP on which (omitted) is mounted (see FIGS. 1, 7, etc.).

(Invention relating to a method for manufacturing an aggregate of a plurality of circuit boards)
The method for manufacturing the aggregate substrate 60B (an example of an aggregate) of the plurality of circuit boards 60C of the present embodiment is a method for manufacturing the motherboard 60 (an example of a composite substrate) of the present embodiment and a step performed after the joining step S42. The front and back surfaces of the ceramic substrate 40 are identified from at least one notch NT1 or hole HL1 formed in one or both of the first metal layer 50A and the second metal layer 50B, and the first metal layer 50A and the second metal layer 50B are identified. An etching step S60 (an example of a circuit pattern forming step) for forming a circuit pattern CP in each of a plurality of regions partitioned by at least one scribing line SL on one of the second metal layers 50B is included (FIG. 1). , See Fig. 7 etc.). The method for manufacturing the plurality of circuit boards 60C of the present embodiment corresponds to the steps from the green sheet forming step S10 to the dividing step S80 in the manufacturing method S100 of the present embodiment (see FIG. 1).

(Invention relating to a method for manufacturing a plurality of circuit boards)
The method for manufacturing the plurality of circuit boards 60C of the present embodiment is as follows.
The method for manufacturing the aggregate substrate 60B (an example of the aggregate) of the plurality of circuit boards 60C of the present embodiment and the ceramic substrate 40 (or the ceramic substrate 40A with SL) are cut along at least one scribing line SL. It includes a division step of dividing the assembly substrate 60B.

Hereinafter, each step will be described.

<Green sheet forming process and sintering process>
The step of combining the green sheet forming step S10 and the sintering step S20 in the present embodiment and performing in the order described corresponds to the method for manufacturing the ceramic substrate 40.
Hereinafter, the method for manufacturing the ceramic substrate 40 of the present embodiment will be described with reference to FIGS. 2A, 2B, 2C and 2D, and FIG.

Here, the ceramic substrate 40 is, for example, a ceramic substrate included in a circuit board for a power module mounted on an electric vehicle, a railroad vehicle, or other industrial equipment. As an example, the ceramic substrate 40 is obtained by sintering a single-wafer green sheet 30 (see FIG. 2C) described later in a laminated state (see FIG. 3). The single-wafer green sheet 30 is obtained by cutting the strip-shaped green sheet 20 (see FIGS. 2B and 2C). That is, the relationship between the ceramic substrate 40 and the single-wafer green sheet 30 is the relationship between the finished product and the intermediate product (the product manufactured in the process before becoming the finished product), or the first intermediate product and the second intermediate product. It has a relationship with (the product manufactured in the process before becoming the first intermediate product). Therefore, the single-wafer green sheet 30 of the present embodiment is manufactured by the steps up to the intermediate stage of the manufacturing method of the ceramic substrate 40 of the present embodiment.
The ceramic substrate 40 of the present embodiment is, as an example, a rectangular plate (see FIG. 4).

<Green sheet forming process>
Hereinafter, the green sheet forming step S10 will be described with reference to FIGS. 2A, 2B, 2C and 2D. As shown in the flow chart of FIG. 2A, the green sheet forming step S10 of the present embodiment includes a slurry manufacturing step S11, a molding step S12, a cutting step S13, a laminating step S14, a degreasing step S15, and a sintering step. It includes S20 and is performed in the order described above.

[Slurry preparation process]
This step is a step of mixing the raw material powder described later and an organic solvent to prepare the slurry 10. The slurry 10 produced in this step (see FIG. 2B) is molded into a band-shaped green sheet 20 in the next step (molding step).

The raw material powder of the slurry 10 is a powder containing a main component and a sintering aid, which will be described later. Main component is 80 wt% to 98.3 wt% of silicon nitride as an example _(Si 3 _{N 4),} sintering aid of at least one 1 wt% to 10 wt% as an example (as oxide) Rare earth elements and 0.7% by mass to 10% by mass (oxide equivalent) of magnesium (Mg). The pregelatinization rate of the silicon nitride powder is preferably 20% to 100% in consideration of the density, bending strength and thermal conductivity of the ceramic substrate 40.
Here, supplementing the meaning of "-" used in the present specification, for example, "20% to 100%" means "20% or more and 100% or less". And, "-" used in this specification means "more than the description part before"- "and less than the description part after"- "".

The reason for the 80 wt% to 98.3 wt% as an example ratio in the raw material powder of silicon nitride (Si 3 _{N 4),} it flexural strength and thermal conductivity of the ceramic substrate 40 obtained is not too low, sintering This is due to ensuring the denseness of the ceramic substrate 40 due to the lack of auxiliary agent.

Hereinafter, for simplification of the description, the raw material powder of silicon nitride is Si ₃ N ₄ powder (also known as silicon nitride powder or an example of ceramic powder), the raw material powder of Mg is MgO powder, and the powder of rare earth element raw material is Y ₂ O ₃ powdered denoted. However, the raw material powder of silicon nitride and the raw material powder of the sintering aid do not have to be Si ₃ N ₄ powder, Mg O powder and Y ₂ O ₃ powder, respectively.

Then, the Si ₃ N ₄ powder, the Mg O powder and the Y ₂ O ₃ powder blended as described above are mixed with a plasticizer, an organic binder and an organic solvent to prepare a slurry 10. Therefore, the slurry 10 produced in this step contains ceramic powder.

The above is the description of the slurry preparation step S11.

[Molding process]
Next, the molding step S12 will be described. As shown in FIG. 2B, this step is a step of manufacturing the band-shaped green sheet 20 from the slurry 10.

This step is performed using the doctor blade forming apparatus 100 shown in FIG. 2B as an example. Here, the doctor blade forming apparatus 100 includes a belt conveying mechanism 110, a forming unit 120, and a heating unit 130. The belt transport mechanism 110 has a roller 112A on the upstream side, a roller 112B on the downstream side, and a belt 114, and drives the roller 112 on the downstream side to move the belt 114 from the roller 112 on the upstream side to the roller 112 on the downstream side. Move (along the X direction). The molding unit 120 is arranged on the upper side of the belt 114 (on the Z direction side of the belt 114) and faces the belt 114. The molding unit 120 has an accommodating portion 122 accommodating the slurry 10 and a doctor blade 124.

Then, as shown in FIG. 2B, the molding unit 120 is a sheet having a film thickness determined by regulating the slurry 10 taken out from the accommodating portion 122 by its own weight and the adhesive force with the moving belt 114 by the doctor blade 124. Make it into a shape. The heating unit 130 blows warm air WC onto the slurry 10 on the belt 114 having a predetermined film thickness to form the slurry 10 into a sheet (vaporizes the organic solvent). As a result, in the molding step, a strip-shaped green sheet 20 having a width defined from the slurry 10 (the Y direction in the drawing corresponds to the width direction) is produced. That is, in the molding step, the slurry 10 is formed into a band shape by doctor blade molding to obtain a band-shaped green sheet 20 composed of Si ₃ N ₄ (ceramic) as an example.

As an example, this step is performed after defoaming the slurry 10 produced in the slurry production step S11 and thickening the slurry 10. Further, the film thickness of the band-shaped green sheet 20 produced in this step is set in consideration of the film thickness of the ceramic substrate 40 finally produced. Along with this, the regulation conditions (distance from the belt 114, etc.) of the doctor blade 124 for regulating the slurry 10 to a predetermined film thickness are also set in consideration of the film thickness of the finally manufactured ceramic substrate 40. Will be done.

The above is the explanation of the molding process S12.

[Cutting process]
Next, the cutting step S13 will be described. As shown in FIG. 2C, this step is a step of cutting the strip-shaped green sheet 20 to produce the single-wafer green sheet 30.

This step is performed using the cutting device 200 shown in FIG. 2C as an example. Here, the cutting device 200 includes a sheet transport mechanism 210 and a cutting portion 220.
The sheet transport mechanism 210 has a support portion 212, a first transport portion 214, and a second transport portion 216. The support portion 212 rotatably supports the roller 112B (see FIGS. 2B and 2C) in which the strip-shaped green sheet 20 produced in the molding step S12 is wound around the outer peripheral surface. The first transport portion 214 arranges the posture of the strip-shaped green sheet 20 transported from the support portion 212 and conveys the strip-shaped green sheet 20 to the cutting portion 220 along the X direction (along the longitudinal direction of the strip-shaped green sheet 20). To do. The second transport section 216 transports the single-wafer green sheet 30 produced by cutting the strip-shaped green sheet 20 at the cutting section 220 further downstream (in the X direction).
Further, the cutting portion 220 has a housing 222, an irradiation portion 224, and a moving mechanism 226. The irradiation unit 224 irradiates the laser beam LB as an example. The moving mechanism 226 scans the irradiation unit 224 from one end to the other end of the strip-shaped green sheet 20 in the lateral direction (Y direction in the drawing). The irradiation unit 224 and the moving mechanism 226 are attached to the housing 222.

Then, in the cutting device 200 of the present embodiment, the strip-shaped green sheet 20 is conveyed by the sheet conveying mechanism 210 for the length of the single-wafer green sheet 30 to stop the strip-shaped green sheet 20, and the strip-shaped green sheet 20 is stopped by the cutting portion 220. Disconnect. In this case, the cutting portion 220 moves the irradiation portion 224 along the Y direction from one end side to the other end side in the lateral direction of the band-shaped green sheet 20 by the moving mechanism 226, while the laser light LB is transferred to the irradiation portion 224. (See FIG. 2). Further, the irradiation unit 224 scanned by the moving mechanism 226 intermittently irradiates the laser beam LB. Here, "intermittently" means repeating irradiation for a certain period of time and non-irradiation for a certain period of time. Therefore, the moving mechanism 226 scans the irradiation unit 224 by causing the irradiation unit 224 to repeatedly move and stop (see FIG. 2D).
As described above, in this step, the band-shaped green sheet 20 is irradiated with the laser beam LB to cut the band-shaped green sheet 20 to obtain the single-wafer green sheet 30. The laser light LB may be carbon dioxide gas laser light, infrared laser light, ultraviolet laser light or other laser light as long as the band-shaped green sheet 20 can be cut. Further, in the description of this step, as an example, it is assumed that the strip-shaped green sheet 20 is cut by using the cutting device 200 shown in FIG. 2C to manufacture the single-leaf green sheet 30, but the single-leaf green sheet 30 is formed from the strip-shaped green sheet 20. Other methods may be used as long as they can be produced. For example, a strip-shaped green sheet 20 may be punched out by a press using a press working apparatus (not shown) to produce a single-wafer green sheet 30.

The above is the explanation of the cutting step S13.

[Laminating process]
Next, the laminating step S14 will be described. As shown in FIG. 3, this step is a step of stacking a plurality of single-wafer green sheets 30 in the thickness direction thereof. This step is a step performed for efficiently sintering the single-wafer green sheet 30 in a later step (sintering step S20).

In this step, as shown in FIG. 3, a plurality of single-wafer green sheets 30 are laminated via a non-reactive powder layer (not shown) described later. Here, if the number of sheets of the sheet-fed green sheets 30 that overlap each other is small, the number of sheets that can be processed at one time in the sintering furnace (not shown) in the subsequent sintering step S16 is small (the production efficiency is low). On the other hand, if the number of sheets of the sheet-fed green sheet 30 stacked is large, the binder contained in the sheet-fed green sheet 30 is less likely to be decomposed in the next step (defatting step S15). For the above reasons, the number of sheet-fed green sheets 30 to be stacked in this step is 8 to 100, preferably 30 to 70.

Further, the non-reactive powder layer of the present embodiment is, for example, a boron nitride powder layer (BN powder layer) having a film thickness of about 1 μm to 20 μm. The BN powder layer has a function of easily separating the ceramic substrate 40 after the next step (sintering step S16). The BN powder layer is applied as a slurry of BN powder on one surface of each sheet-fed green sheet 30 by, for example, spraying, brush coating, roll coater, screen printing, or the like. The BN powder has a purity of 85% or more, and preferably has an average particle size of 1 μm to 20 μm.

The above is the explanation of the laminating process S14.

[Degreasing process]
Next, the degreasing step S15 will be described. This step is a step for degreasing the binder and the plasticizer contained in the single-wafer green sheet 30 before the next step (sintering step S16).
In this step, as an example, a plurality of single-wafer green sheets 30 (see FIG. 3) stacked in the laminating step S14 are held in a temperature environment of 450 ° C. to 750 ° C. for 0.5 hours to 20 hours. As a result, the binder and the plasticizer contained in the plurality of single-wafer green sheets 30 are degreased.

The above is the explanation of the degreasing step S15. Further, the above is the description of the green sheet forming step S10 of the present embodiment.

<Sintering process>
Next, the sintering step S16 will be described with reference to FIG. In this step, a plurality of single-wafer green sheets 30 (hereinafter referred to as a plurality of single-wafer green sheets 30 in FIG. 3), which are laminated in the laminating step S14 and degreased by the binder and the plasticizer in the degreasing step S15, are baked. This is a step of sintering using a binder (not shown). When this step is completed, a plurality of ceramic substrates 40 are manufactured in a stacked state.

The above is the explanation of the sintering process S20. Moreover, the above is the description of the manufacturing method of the ceramic substrate 40 of this embodiment.

The type of the ceramic substrate 40 is not particularly limited, and examples thereof include carbides, oxides, and nitrides. Specific examples thereof include silicon carbide, alumina, silicon nitride, aluminum nitride and boron nitride, and more preferably silicon nitride and aluminum nitride.

<Scribe line formation process>
Next, the SL forming step S30 will be described with reference to FIG. In this step, at least one scribe line SL (three as an example in this embodiment) is formed on one surface (front surface 40A1 as an example in this embodiment) of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40. It is a process to do. When this step is completed, the ceramic substrate 40A with SL is manufactured (see FIG. 4).
In this step, as shown in FIG. 4, the surface 40A1 of the ceramic substrate 40 is divided into three equal parts in the width direction and three equal parts in the length direction as an example by a laser beam irradiated from an irradiation unit (not shown). A total of three straight lines are formed, and the entire area of the surface 40A1 is divided into six equal parts. Here, as an example, each scribe line SL is composed of a plurality of dents arranged in a straight line (see FIG. 5C). Therefore, the irradiation unit (for example, a carbon dioxide laser light source, a YAG laser light source, etc.) used in this step can intermittently irradiate laser light, for example.
Each scribe line SL is used as a cutting line when the ceramic substrate 40 is divided into a plurality of sheets (six in the present embodiment) in the dividing step S80 (see FIG. 1), which is a later step.

The above is the explanation of the SL forming step S30.

<Metal layer forming process>
Next, the metal layer forming step S40 will be described with reference to FIGS. 5A, 5B and 5C. As shown in the flow chart of FIG. 5A, this step includes a notch forming step S41 and a joining step S42, and is performed in the order described thereof.

[Cut formation process]
The notch forming step S41 is a step of forming the notch NT1 on the first metal layer 50A joined to the surface 40A1 side of the ceramic substrate 40A with SL, which is rectangular when viewed from the thickness direction thereof (see FIG. 5B). .. For example, in this step, when a strip-shaped metal layer (not shown) is cut using a device such as the cutting device 200 shown in FIG. 2C to produce a rectangular single-wafer metal layer, the metal layer is attached to the device. The first metal layer 50A may be manufactured by forming a notch NT1 in the single-wafer metal layer by the press unit (not shown). On the other hand, in this step, a notch is not formed in the second metal layer 50B which is rectangular when viewed from the thickness direction and is joined to the back surface 40A2 side of the ceramic substrate 40A with SL.

Since the first metal layer 50A and the second metal layer 50B are joined to the ceramic substrate 40A with SL in the joining step S42 described later to form a layer, in the present specification, the ceramic with SL is formed in the joining step S42. The plate-shaped first metal layer 50A and second metal layer 50B before being joined to the substrate 40A are referred to as they are. Further, the second metal layer 50B and the ceramic substrate 40A with SL as viewed from the respective thickness directions have the same outer peripheral shape and size. The first metal layer 50A and the second metal layer 50B have the same thickness, shape, size, and material, respectively, except that the notch NT1 is formed in the first metal layer 50A.

The types of the first metal layer 50A and the second metal layer 50B are not particularly limited, and examples thereof include copper, copper alloys, aluminum, and aluminum alloys.

[Joining process]
The joining step S42 is a step of joining the first metal layer 50A and the second metal layer 50B to the front surface 40A1 side and the back surface 40A2 side of the ceramic substrate 40A with SL, respectively. In this case, the first metal layer 50A and the second metal layer 50B are joined to the front surface 40A1 side and the back surface 40A2 side, respectively, via a brazing material (not shown). Specifically, a paste-like active metal brazing material is uniformly applied to the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 by a method such as a roll coater method, a screen printing method, or a transfer method, and further, a uniformly applied paste. The first metal layer 50A and the second metal layer 50B are joined to the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 by the active metal method, respectively, via the active metal brazing material. Here, in this step, the screen printing method is preferable in that the paste-like brazing material is uniformly applied. Further, in this case, it is preferable to control the viscosity of the paste-like active metal brazing material to 5 Pa · s to 20 Pa · s. An excellent paste-like active metal brazing material can be obtained by blending the organic solvent amount in the paste-like active metal brazing material in the range of 5% by mass to 25% by mass and the binder amount in the range of 2% by mass to 15% by mass. Can be done. The heating temperature of the joint may be, for example, 700 ° C. to 900 ° C. The atmosphere in the heating furnace may be an inert gas such as nitrogen. The joint may be heated under reduced pressure below atmospheric pressure or under vacuum. The heating furnace may be a continuous type that heats a plurality of joints while continuously supplying them, or may be a type that heats one or a plurality of joints in a batch type. The heating of the joint may be performed while pressing the joint in the stacking direction.
In the case of the present embodiment, when the first metal layer 50A is joined to the ceramic substrate 40A with SL via a brazing material, a part of the scribe line SL is located inside the notch NT1 (see FIG. 5B). .. That is, in the notch forming step S41 of the present embodiment, the notch is formed so that a part of the scribing line SL is located inside the notch NT1 when viewed from the thickness direction of the ceramic substrate 40A with SL during the joining step S42. This is a step of forming NT1 on the first metal layer 50A, which is one of the first metal layer 50A and the second metal layer 50B.

As described above, this step is performed in the order of the notch forming step S41 and the joining step S42, and when this step is completed, the motherboard 60 is manufactured (see FIGS. 5B and 5C).
The shape of the notch NT1 formed in the notch forming step S41 is rectangular in FIG. 5B, but the shape of the notch NT1 is such that a part of the scribe line SL is inside the notch NT1 at the end of the joining step S42. It does not have to be rectangular as long as it is positioned. For example, it may have an arc shape, a triangular shape, or other shape.

The above is the explanation of the metal layer forming step S40.

(Explanation about motherboard)
Next, the motherboard 60 of the present embodiment manufactured at the end of the metal layer forming step S40 will be described with reference to FIGS. 5B and 5C.
As described above, the motherboard 60 of the present embodiment has a ceramic substrate 40, a first metal layer 50A bonded to the front surface side of the ceramic substrate 40, and a second metal layer bonded to the back surface side of the ceramic substrate 40. 50B is provided, and one or both of the first metal layer 50A and the second metal layer 50B (the first metal layer 50A in this embodiment) are cut so that the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 can be distinguished. The notch NT1 is formed.
Further, a scribe line SL is formed on one of the front surface 40A1 and the back surface 40A2 (front surface 40A1 in this embodiment) of the ceramic substrate 40 included in the motherboard 60 of the present embodiment. That is, the ceramic substrate 40 included in the motherboard 60 of the present embodiment is a ceramic substrate 40A with SL in which a scribe line SL is formed on the surface 40A1. The notch NT1 is one of the first metal layer 50A and the second metal layer 50B (the first in the present embodiment) so that a part of the scribe line SL is located inside the notch NT1 when viewed from the thickness direction of the motherboard 60. It is formed in one metal layer 50A) (see FIG. 5B).

In the case of the present embodiment, the notch NT1 is formed in only one of the first metal layer 50A and the second metal layer 50B (an example of the above-mentioned first aspect). Therefore, based on the premise that the surface on the side where the notch NT is formed is the front surface, the notch NT1 of the present embodiment has a function of enabling the identification of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40. ..
Further, in the case of the present embodiment, the notch NT1 is formed in the first metal layer 50A so that a part of the scribe line SL is located inside the notch NT1. Therefore, based on the premise that the surface of the ceramic substrate 40 on which the scribe line SL is formed is the front surface, the notch NT1 of the present embodiment has a function of enabling the identification of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40. Has.

<Resist printing process>
Next, the resist printing step S50 will be described with reference to FIG. In this step, the first metal layer 50A of the motherboard 60 is coated with a photosensitive resist film PRF, and each circuit described later is formed in six regions of the first metal layer 50A partitioned by three scribe lines SL. This is a step of forming a resist pattern PRP corresponding to the pattern CP. Specifically, in this step, as an example, an exposure apparatus (not shown) is used to print a resist pattern PRP on the resist film PRF (the resist pattern PRP is cured, and a portion of the resist film PRF other than the resist pattern PRP is printed. Leave uncured). As a result, the motherboard 60A with PRP is manufactured.
Since the notch NT1 is formed in the first metal layer 50A, the operator in this step can easily identify the first metal layer 50A of the notched motherboard 60A. Further, the resist pattern PRP (circuit pattern CP) is not formed in the portion of the first metal layer 50A where the notch NT1 is formed.

The above is the explanation of the resist printing process S50.

<Etching process>
Next, the etching step S60 (an example of the circuit pattern forming step) will be described with reference to FIG. 7. In this step, the uncured resist film PRF in the resist film PRF of the motherboard 60A with PRP is removed, the exposed portion of the first metal layer 50A is etched, and then the remaining resist pattern PRP is removed to remove the circuit pattern CP. Is the process of forming. As a result, the motherboard 60A with PRP before this step becomes a collective substrate 60B in which the circuit pattern CP is formed in each of the six regions partitioned by the three scribe lines SL. Further, when the assembly substrate 60B is formed, all the portions of the three scribe lines SL formed in the SL forming step S30 are exposed as the first metal layer 50A is etched. Along with this, the portion of the first metal layer 50A where the notch NT1 is formed disappears. That is, the notch NT1 that does not function in the assembly substrate 60B is eliminated in this step.
Then, in each circuit pattern CP formed in this step, electronic components (not shown) such as an IC, a capacitor, and a resistor are mounted in the mounting step S90 described later. That is, this step is a step performed after the joining step S42, and is formed on one or both of the first metal layer 50A and the second metal layer 50B (in the case of this embodiment, the first metal layer 50A). The front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 are identified from the notch NT1, and an electronic component (illustrated) is placed on one of the first metal layer 50A and the second metal layer 50B (first metal layer 50A in the case of this embodiment). ) Is a step of forming a circuit pattern CP to which it is mounted.
Further, after this step, at least one of the first metal layer 50A and the second metal layer 50B (first metal layer 50A in this embodiment) of the motherboard 60 of the present embodiment (see FIGS. 5B and 5C). Circuit pattern CPs on which electronic components (not shown) are mounted are formed in each of a plurality of regions (six in the present embodiment) partitioned by the scribing lines SL (three in the present embodiment). It will be.
In the above description, the etching step S60 is taken as an example of the circuit pattern forming step, but the combination of the resist printing step S50 and the etching step S60 may be regarded as an example of the circuit pattern forming step.

The above is the explanation of the etching process S60.

<Surface treatment process>
Next, the surface treatment step S70 will be described. In this step, the resist remaining on the surface of the metal layer of the etched assembly substrate is removed, and Ni-P plating or Ag plating is performed by an rust preventive treatment or an electroless plating method to prevent the metal layer from rusting. Solder resist is printed on the circuit pattern of the assembly board to prevent solder from squeezing out. A protective layer such as a solder resist (not shown) is formed on the surface of the assembly board 60B on the side where a plurality of (six in this embodiment) circuit patterns CP are formed, except for the jointed portion to which the electronic components are bonded. This is a step of coating with and surface-treating a portion other than the joint portion. Further, in this step, the joint portion to which the electronic component is joined is plated by, for example, an electrolytic plating method, and the surface treatment of the joint portion is performed. Here, in the above description, the product at the end of the etching step S60 is the assembly substrate 60B, but the product at the end of the surface treatment step S70, that is, the substrate in which the assembly substrate 60B is coated with the protective layer is assembled. You may think of it as a substrate.

The above is the explanation of the surface treatment step S70.

<Division process>
Next, the division step S80 will be described with reference to FIG. In this step, a plurality of assembly substrates 60B (or ceramic substrates 40A with SL) are cut along a plurality of (three as an example in this embodiment) scribing line SL, and a plurality of assembly substrates 60B (in this embodiment) are cut. As an example, it is a step of dividing into 6 circuit boards 60C. That is, this step is a step of cutting the ceramic substrate 40 along at least one scribe line SL (three as an example in this embodiment) to divide the collective substrate 60C of the plurality of circuit boards 60B.

When this process is completed, a plurality of circuit boards 60C are manufactured. In the case of this embodiment, the first metal layer 50A becomes the circuit pattern CP of each circuit board 60C by the steps so far. On the other hand, in the second metal layer 50B, the region partitioned by the three scribe lines SL is the metal on the side opposite to the side on which the circuit pattern CP is formed in each circuit board 60C by the steps so far. Become a layer. Then, the metal layer functions as a heat radiating layer for radiating heat generated by electronic components mounted on the circuit pattern CP when the mounting board (not shown) manufactured in the mounting step S90 described later is used. .. Then, after this step, at least one of the first metal layer 50A and the second metal layer 50B (second metal layer 50B in this embodiment) of the motherboard 60 of the present embodiment (see FIGS. 5B and 5C). Each of the plurality of regions (six in the present embodiment) partitioned by the scribing line SL (three in the present embodiment) functions as a heat dissipation layer.

The above is the explanation of the division step S80.

<Mounting process>
Next, the mounting process will be described. This step is a step of mounting an electronic component (not shown) on each circuit board 60C (see FIG. 8). In this step, a mounting device (not shown) is used to attach solder (not shown) to a joint portion where electronic components are joined in the circuit pattern CP (see FIG. 8) of each circuit board 60C, and the joint portion is attached. Join the joining terminals of electronic components to.

When this process is completed, multiple mounting boards will be manufactured. In the above description, this step is a step after the split step S80, but the split step S80 may be performed after the main step. That is, the manufacturing method S100 of the present embodiment may be performed in the order of the mounting step S90 and the dividing step S80 after the surface treatment step S70.

The above is the description of the mounting process S90. After manufacturing the plurality of mounting boards, for example, an inspection device (not shown) is used to inspect the circuit pattern CP, inspect the operation of electronic components, and the like.
The above is the description of the manufacturing method S100 of the present embodiment.

<< Effect of this embodiment >>
Next, the effect of this embodiment will be described.

In the present embodiment, the notch NT1 is formed in the first metal layer 50A of the motherboard 60.
Therefore, the motherboard 60 of the present embodiment can easily identify the front and back sides of the motherboard 60 in the resist printing step S50. Along with this, according to the metal layer forming step S40 of the present embodiment (manufacturing method of the motherboard 60 of the present embodiment), it is possible to manufacture the motherboard 60 whose front and back can be easily identified. Further, according to the manufacturing method of the plurality of circuit boards 60C of the present embodiment (S10 to S80 in FIG. 1) and the manufacturing method S100 of the present embodiment, manufacturing defects do not occur or are unlikely to occur.

Further, in the case of the present embodiment, the means for identifying the front and back surfaces of the motherboard 60 is not, for example, a mark (for example, a printed pattern) attached to the first metal layer 50A. When the means for identifying the mark is the above-mentioned mark, the mark may be lost due to rubbing or the like during any step of the manufacturing method of the present embodiment.
On the other hand, in the case of the present embodiment, the notch NT1 which is a means for identifying the front and back of the motherboard 60 is not lost by rubbing or the like.
Therefore, in the present embodiment, the front and back surfaces of the motherboard 60 can be reliably identified as compared with the case where the means for identifying the front and back surfaces of the motherboard 60 is a mark attached to the first metal layer 50A.

Further, as described above, the notch NT1 of the present embodiment can be formed at the time of manufacturing the first metal layer 50A. Specifically, when a strip-shaped metal layer (not shown) is cut using a device such as the cutting device 200 shown in FIG. 2C to produce a rectangular single-wafer metal layer, the metal layer is attached to the device. The first metal layer 50A may be manufactured by forming a notch NT1 in the single-wafer metal layer by the press unit (not shown).
Therefore, according to the present embodiment, the cutout NT1 which is a means for distinguishing the front and back sides of the motherboard 60 can be formed easily or at low cost.

Further, the notch NT1 of the present embodiment is formed in a portion of the first metal layer 50A other than the portion where the circuit pattern CP is formed (see FIG. 7). Therefore, the portion of the first metal layer 50A where the notch NT1 is formed disappears in the etching step S60.
Therefore, according to the present embodiment, the influence of the notch NT1 does not remain on the plurality of circuit boards 60C and the plurality of mounting boards to be manufactured.

Further, in the present embodiment, the first metal layer 50A is joined to the ceramic substrate 40A with SL so that a part of the scribe line SL is located inside the notch NT1 (see FIG. 5B).
Therefore, in the case of the present embodiment, the front and back surfaces of the motherboard 60 can be identified by directly visually recognizing the scribe line SL in the resist printing step S50.

The above is the explanation of the effect of this embodiment. Moreover, the above is the description about this embodiment.

≪Modification example≫
As described above, an example of the present invention has been described with reference to the above-described embodiments (see FIGS. 1 to 8), but the present invention is not limited to the above-described embodiments. The technical scope of the present invention also includes, for example, the following forms (modifications).

For example, in the description of this embodiment, an example of ceramic powder has been described as silicon nitride. However, an example of the ceramic powder may be another ceramic powder. For example, aluminum nitride may be used.

Further, in the explanation of the molding step S12 (see FIG. 2A) included in the green sheet forming step S10 of the present embodiment, it is assumed that the doctor blade molding is used. However, if the slurry 10 can be molded into the band-shaped green sheet 20, the molding step S12 may be performed by another method. For example, the molding step S12 may be performed by extrusion molding.

Further, in the description of the cutting step S13 (see FIG. 2A) included in the green sheet forming step S10 of the present embodiment, the irradiation unit 224 is moved from one end side to the other end side of the band-shaped green sheet 20 in the lateral direction. However, it was decided to cut the strip-shaped green sheet 20. However, if the strip-shaped green sheet 20 can be cut to obtain the single-wafer green sheet 30, the cut portion of the strip-shaped green sheet 20 is one end side of the strip-shaped green sheet 20 in the lateral direction as in the case of the present embodiment. It does not have to be a straight portion extending from the other end to the other end. For example, even if the strip-shaped green sheet 20 is cut so as to separate (or hollow out) the single-leaf green sheet 30 from the strip-shaped green sheet 20 by making a hole in the strip-shaped green sheet 20 in the shape of the single-leaf green sheet 30. Good. That is, the single-wafer green sheet 30 obtained by cutting the strip-shaped green sheet 20 may have at least a part of all end faces thereof as a cut surface.

Further, in the present embodiment, the scribe line SL has been described as having a plurality of dents arranged in a straight line (see FIG. 5C). However, the scribe line SL may be, for example, a continuous groove, a plurality of dents having different lengths, widths, etc., as long as the function can be exhibited.

Further, in the present embodiment, the plurality of scribe lines SL has been described as being three scribe lines SL (see FIG. 4). However, the plurality of scribe lines SL may be at least one or more scribe lines SL.

Further, in the present embodiment, it has been described that the plurality of scribe lines SL divide the motherboard 60 into six equal parts (see FIG. 4). However, the plurality of scribe lines SL do not have to divide the motherboard 60 into equal parts.

Further, in the present embodiment, the first metal layer 50A and the second metal layer 50B have thickness, shape, size and material, respectively, except that the notch NT1 is formed in the first metal layer 50A. Was explained as equivalent. However, the thickness of the first metal layer 50A and the thickness of the second metal layer 50B may be different from each other.

Further, in the present embodiment, it has been explained that the circuit pattern CP is formed in the first metal layer 50A in which the notch NT1 is formed (see FIGS. 6 and 7). However, the circuit pattern CP may be formed on the second metal layer 50B in which the notch NT1 is not formed. That is, the notch NT1 that enables identification of the front surface and the back surface of the ceramic substrate 40 (motherboard 60) may be formed on one of the first metal layer 50A and the second metal layer 50B.

Further, in the present embodiment, it has been described that the notch NT1 is formed at one location of the first metal layer 50A (see FIG. 5B). However, a plurality of notches NT1 may be formed in the first metal layer 50A. That is, at least one notch NT1 capable of distinguishing the front surface and the back surface of the ceramic substrate 40 (motherboard 60) may be formed.

Further, at least one notch NT1 may be formed in each of the first metal layer 50A and the second metal layer 50B, and the number of notches NT1 formed in each layer may be different. For example, two notches NT1 are formed in the first metal layer 50A, and one notch NT1 is formed in the second metal layer 50B (an example of the second aspect described above). In this case, based on the premise that two notches are formed on the surface side of the motherboard 60, two notches NT1 formed in the first metal layer 50A and one notch formed in the second metal layer 50B. The notch NT1 enables identification of the front surface and the back surface of the ceramic substrate 40 (motherboard 60).

Further, in the present embodiment, the notch NT1 is formed in the first metal layer 50A in the metal layer forming step S40, the circuit pattern CP is formed in the first metal layer 50A in the etching step S60, and a plurality of circuits are formed in the dividing step S80. It has been explained that when the substrate 60C is manufactured, the second metal layer 50B becomes a plurality of heat dissipation layers. However, the notch NT1 may be formed in the second metal layer 50B, and the circuit pattern CP may be formed in the second metal layer 50B.

Further, in the present embodiment, it has been described that the first metal layer 50A in which the notch NT1 is formed is joined to the ceramic substrate 40 (see the flow chart of FIG. 5A). However, as in the modified example (first modified example) of the metal layer forming step shown in FIG. 9, after the first metal layer 50A is bonded to the ceramic substrate 40, a notch NT1 is formed in the first metal layer 50A. May be good. That is, a notch NT1 that enables identification of the front surface and the back surface of the motherboard 60 may be formed before the resist printing step S50.

Further, in the present embodiment, it has been described that the notch NT1 is formed at a position overlapping a part of the scribe line SL in the first metal layer 50A (see FIG. 5B). However, as in the modified example (second modified example) of the metal layer forming step shown in FIG. 10, the notch NT2 is formed at a position other than a position overlapping a part of the scribe line SL in the first metal layer 50A. May be good. For example, as in this modification, the notch NT2 may be formed in at least one of the four corners of the first metal layer 50A. Note that, unlike the case of this modification, the four notches NT2 may be formed at at least one of the four corners. Further, in the case of this modification, the notch NT2 may be used as, for example, an alignment mark.

Further, in the case of the second modification shown in FIG. 10, as an example, the notch NT2 is also formed at the four corners of the second metal layer 50B. In the case of this modification, for example, the notch NT2 of the first metal layer 50A and the notch NT2 of the second metal layer 50B may be different in size from each other (the second aspect described above). An example). According to this modification, it is possible to identify the front surface and the back surface of the motherboard 60 by recognizing the difference between the size of the notch NT2 of the first metal layer 50A and the size of the notch NT2 of the second metal layer 50B. ..

Further, in the case of the second modification shown in FIG. 10, notches NT2 are formed at each of the four corners of both the first metal layer 50A and the second metal layer 50B. That is, in the case of the second modification, the notch NT2 is formed in the same portion of both the first metal layer 50A and the second metal layer 50B when viewed from the thickness direction. Here, in the explanation of the second modification, for example, the notch NT2 of the first metal layer 50A and the notch NT2 of the second metal layer 50B may be different in size from each other. did.
However, as in the third modification shown in FIG. 11, the shape of the notch NT2 of the first metal layer 50A (rectangular shape as an example) and the shape of the notch NT2 of the second metal layer 50B (triangular shape as an example). May have different shapes from each other (an example of the above-mentioned second aspect). According to the third modification, it is possible to identify the front surface and the back surface of the motherboard 60 by recognizing the difference between the shape of the notch NT2 of the first metal layer 50A and the shape of the notch NT2 of the second metal layer 50B. To do.
In the case of the third modification, the notch NT2 of the first metal layer 50A and the notch NT2 of the second metal layer 50B are formed at the same positions when viewed from the thickness direction of the ceramic substrate 40, respectively. However, based on the premise that the side on which the rectangular notch NT2 is formed is the front surface of the ceramic substrate 40 or the side on which the triangular notch NT2 is formed is the back surface, the notch NT2 in the third modification is It has a function of enabling identification of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40.

Further, it has been described that the SL forming step S30 is performed before the metal layer forming step S40 of the present embodiment (see FIGS. 1 and 4). However, as in the case of the modification of the metal layer forming step (fourth modification) shown in FIG. 12, the first metal layer 50A and the first metal layer 50A and the motherboard 60 on which the scribing line SL is not formed without performing the SL forming step S30. The second metal layer 50B may be joined. In this case, at least one notch NT1 may be formed in one or both of the first metal layers 50A and 50B. In the case of the fourth modification, if the mounting step S90 is performed without performing the dividing step S80 after the surface treatment step S70 (see FIG. 1), one mounting substrate is manufactured from one motherboard 60. ..

Further, as shown in FIGS. 5B, 5C, etc., the notch NT1 of the present embodiment has a form in which the entire portion in the thickness direction of the first metal layer 50A is removed. However, the notch NT1 of the present embodiment may be formed by removing a part of the portion in the thickness direction of the ceramic substrate 40 as in the notch NT3 of the fifth modification shown in FIG. 13 (the first described above). An example of an embodiment).

Further, as shown in FIGS. 5B, 5C and the like, the notch NT1 of the present embodiment has a form in which the entire portion in the thickness direction of the first metal layer 50A is removed. However, the notch NT1 of the present embodiment may be formed (through hole) in which the notch NT1 of the present embodiment is not opened at the peripheral edge of the ceramic substrate 40 and is penetrated in the thickness direction thereof, as in the hole HL1 of the sixth modification shown in FIG. An example of the first aspect described above). In the case of the sixth modification, based on the premise that the side on which the hole HL1 is formed is the surface of the ceramic substrate 40, the hole HL1 of the fifth modification enables the identification of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40. It has the function of doing.
In the sixth modification, the shape of the hole HL1 is circular when viewed from the thickness direction of the first metal layer 50A, but the shape of the hole HL1 when viewed from the thickness direction does not have to be circular.
Further, in the hole HL1 and the hole HL2 described later, the hole HL1 or the hole HL2 is formed in the single-wafer metal layer by a press unit (not shown) in the same manner as the method for forming the notch NT1 in the present embodiment. The layer 50A or the second metal layer 50B may be manufactured.

Further, as in the seventh modification shown in FIGS. 15A and 15B, the first metal layer 50A and the second metal layer 50B form the motherboard 60, and they are located at the same positions when viewed from the thickness direction. , Holes HL1 and HL2 having the same size and shape may be formed (an example of the above-mentioned third aspect). However, in the case of the seventh modification, the hole HL1 formed in the first metal layer 50A is a through hole, and the hole HL2 formed in the second metal layer 50B is a non-through hole. Then, in the case of the seventh modification, it is assumed that the side on which the hole HL1 (through hole) is formed is the front surface of the ceramic substrate 40 and the side on which the hole HL2 (non-through hole) is formed is the back surface. Based on this, one or both of the holes HL1 and the holes HL2 of the seventh modification have a function of enabling the identification of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40. Further, in this case, the color, material or pattern in the holes HL1 and HL2 on the side where the hole HL1 (through hole) is formed and the color, material or pattern in the hole HL2 (non-through hole) and in the HL2 on the side where the hole HL2 (non-through hole) is formed. The color, material or pattern is different depending on that the inside of the hole HL1 is the color and material of the ceramic substrate 40, and the inside of the hole HL2 is the metal color and material.
The holes HL1 and HL2 in the seventh modification are circular when viewed from the thickness direction, but may not be circular as long as they have the same size and shape when viewed from the thickness direction.

In the eighth modification shown in FIG. 16, in a state where the first metal layer 50A and the second metal layer 50B form the motherboard 60, they have the same size and the same shape at the same position when viewed from the thickness direction. A plurality of notches NL4 are formed (an example of the above-mentioned third aspect). Even in this case, if the features that enable the distinction between the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 can be visually recognized from the plurality of notches NT4 in the ceramic substrate 40, the plurality of notches NT4 will be the surface 40A1 of the ceramic substrate 40. It can be said that it is a notch that enables the distinction between the back 40A2 and the back 40A2.
Then, in the case of the eighth modification, since the scribe line SL (an example of the pattern) formed on the surface 40A1 of the ceramic substrate 40 can be visually recognized from a part of the plurality of notches NT4, the scribe line SL has the above-mentioned characteristics. Equivalent to.
Based on the above, based on the premise that the side on which the scribing line SL is formed in the notch NT1 is the surface of the ceramic substrate 40, it is formed on each of the first metal layer 50A and the second metal layer 50B of the eighth modification. The plurality of notches NT4 made have a function of enabling identification of the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40.
In the eighth modification, it is assumed that a plurality of notches NT4 are formed in each metal layer, but only one notch NT4 may be formed in each metal layer. Further, the notch NT4 of the eighth modification may be, for example, the hole HL1 (through hole) of the sixth modification.

As described above, the above-described embodiment (see FIGS. 1 to 8) and the plurality of modifications (see, for example, FIGS. 9 to 16) have been described separately, but as a mode belonging to the technical scope of the present invention. May be a combination of one of these with some technical elements of the other form. For example, the four notches NT2 of the first metal layer 50A of the motherboard 60 (see FIG. 10) of the second modification may be the notch NT1 (see FIG. 5B) of the above-described embodiment.

This application claims priority based on Japanese Application Japanese Patent Application No. 2019-102590 filed on May 31, 2019, and incorporates all of its disclosures herein.

10 Slurry 20 Band-shaped green sheet 30 Single-wafer green sheet 40 Ceramic substrate 40A Ceramic substrate with SL 40A1 Front surface 40A2 Back surface 50A First metal layer 50B Second metal layer 60 Motherboard (example of composite substrate)
Motherboard with 60A PRP 60B Assembly board (example of assembly)
60C Circuit Board 100 Doctor Blade Molding Device 110 Belt Conveying Mechanism 112 Roller 112A Roller 112B Roller 114 Belt 120 Molding Unit 122 Accommodating Unit 124 Doctor Blade 130 Heating Unit 200 Cutting Device 210 Sheet Conveying Mechanism 212 Support Part 214 First Conveying Part 216 Second Transport unit 220 Cutting unit 222 Housing 224 Irradiation unit 226 Movement mechanism CP circuit pattern HL1 hole (through hole)
HL2 hole (non-through hole)
LB Laser light NT1 Notch NT2 Notch NT3 Notch NT4 Notch PRF Resist film PRP Resist pattern S10 Green sheet forming process S11 Slurry manufacturing process S12 Molding process S13 Cutting process S14 Laminating process S15 Degreasing process S16 Slicing process S20 Sintering process S30 SL forming process (scribing line forming process)
S40 Metal layer forming process S41 Notch forming process S42 Joining process S50 Resist printing process S60 Etching process S70 Surface treatment process S80 Dividing process S90 Mounting process S100 Mounting substrate manufacturing method SL Scribline WC Warm air

Claims (18)

1. With a ceramic substrate
   The first metal layer bonded to the surface side of the ceramic substrate and
   The second metal layer bonded to the back surface side of the ceramic substrate and
   With
   One or both of the first metal layer and the second metal layer are formed with at least one notch or hole that enables identification of the front surface and the back surface of the ceramic substrate.
   Composite board.
2. The ceramic substrate is rectangular when viewed from the thickness direction thereof.
   The at least one notch is formed in one or both of the first metal layer and the second metal layer so as to expose at least one corner of the four corners of the ceramic substrate. ,
   The composite substrate according to claim 1.
3. At least one notch or a hole is formed in both the first metal layer and the second metal layer, respectively.
   The at least one notch or hole formed in both of them differs from each other in any one or more of positions, sizes and shapes.
   The composite substrate according to claim 1 or 2.
4. The at least one notch or hole has a function as an alignment mark.
   The composite substrate according to any one of claims 1 to 3.
5. A circuit pattern on which electronic components are mounted is formed on one of the first metal layer and the second metal layer.
   The composite substrate according to any one of claims 1 to 4.
6. The other of the first metal layer and the second metal layer functions as a heat radiating layer.
   The composite substrate according to claim 5.
7. At least one scribe line is formed on one of the front surface and the back surface of the ceramic substrate.
   The composite substrate according to any one of claims 1 to 4.
8. The first metal layer and the second metal layer are such that the at least one notch or hole is such that a part of the at least one scribe line is located inside the notch or hole when viewed from the thickness direction of the ceramic substrate. Formed on one side,
   The composite substrate according to claim 7.
9. A circuit pattern in which electronic components are mounted is formed in each of a plurality of regions in one of the first metal layer and the second metal layer, which are partitioned by the at least one scribe line.
   The composite substrate according to claim 7 or 8.
10. The plurality of regions of the first metal layer and the other of the second metal layer partitioned by the at least one scribe line each function as a heat dissipation layer.
    The composite substrate according to claim 9.
11. A method for manufacturing a composite substrate in which a first metal layer and a second metal layer are bonded to the front surface side and the back surface side of the ceramic substrate, respectively.
    A notch forming step of forming at least one notch or a hole in one of the first metal layer and the second metal layer, which enables identification of the front surface and the back surface of the ceramic substrate.
    A joining step of joining the first metal layer and the second metal layer to the front surface side and the back surface side of the ceramic substrate, respectively.
    including,
    Manufacturing method of composite substrate.
12. A method for manufacturing a composite substrate in which a first metal layer and a second metal layer are bonded to the front surface side and the back surface side of the ceramic substrate, respectively.
    A notch forming step of forming at least one notch or a hole in both the first metal layer and the second metal layer, which enables identification of the front surface and the back surface of the ceramic substrate, respectively.
    A joining step of joining the first metal layer and the second metal layer to the front surface side and the back surface side of the ceramic substrate, respectively.
    including,
    Manufacturing method of composite substrate.
13. In the notch forming step, at least one or more notches or holes different from each other in any one or more of positions, sizes and shapes are formed in both of them.
    The method for manufacturing a composite substrate according to claim 12.
14. The method for manufacturing a composite substrate according to any one of claims 10 to 13, and the method for manufacturing the composite substrate.
    In a step performed after the joining step, the front surface and the back surface of the ceramic substrate are identified from the at least one notch or hole formed in one or both of the first metal layer and the second metal layer. A pattern forming step of forming a circuit pattern in which electronic components are mounted on one of the first metal layer and the second metal layer.
    including,
    How to manufacture a circuit board.
15. A scribe line forming step, which is a step performed before the joining step and in which at least one scribe line is formed on the front surface or the back surface of the ceramic substrate.
    including,
    The method for manufacturing a composite substrate according to any one of claims 10 to 13.
16. In the notch forming step, the at least one notch is formed so that a part of the at least one scribe line is located inside the at least one notch or the hole in the thickness direction during the joining step. Alternatively, holes are formed in one of the first metal layer and the second metal layer.
    The method for manufacturing a composite substrate according to claim 15.
17. The method for manufacturing a composite substrate according to claim 15 or 16.
    In the step performed after the joining step, the front surface and the back surface of the ceramic substrate are identified from the at least one notch or hole formed in one or both of the first metal layer and the second metal layer. A pattern forming step of forming a circuit pattern in each of a plurality of regions defined by the at least one scribing line in one of the first metal layer and the second metal layer.
    including,
    A method for manufacturing an aggregate of a plurality of circuit boards.
18. The method for manufacturing an aggregate of a plurality of circuit boards according to claim 17,
    A division step of cutting the ceramic substrate along at least one scribe line to divide an aggregate of the plurality of circuit boards is included.
    Manufacturing method for multiple circuit boards.

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