JP2005026340A - Method for manufacturing wiring board and wiring board raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a wiring board in which a load applied to a cutting blade is alleviated by reducing a metal cutting length, the lifetime of the cutting blade is lengthened, and oxidation and corrosion are reduced by reducing the exposure of the metal cutting surface, and to provide a wiring board raw material in which deformation hardly occurs irrespective of the shortening of a metal coupling part, and cutting/separating works, etc. of a plurality of wiring boards can be accurately conducted. <P>SOLUTION: The method for manufacturing the wiring board includes a step S3 of etching a metal plate 4 formed with an etching resist layer 8R and forming a slot 6; a step S4 of superposing prepregs each having a predetermined thickness and made of the composite material of an epoxy resin and a silica filler on front and rear surfaces of the metal plate 4, and hardening the prepregs and forming a resin insulation layer 5; and a step S5 of cutting a cross-like coupling part 7 of the resin insulation layer 5 and the metal plate 4 filled in the slit 6 along a line 3 scheduled to be cut of the wiring board raw material 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a wiring board and a wiring board material.
[0002]
[Prior art]
Conventionally, a wiring board provided with a metal plate as a core material has been used mainly for the purpose of improving heat dissipation, and it may be used as a wiring board for mounting components that generate large amounts of heat such as power transistors. A wiring board provided with a metal plate as a core material generally uses a cutting blade for a wiring board material (connected wiring board) as an intermediate product from the viewpoint of improving productivity and the like, as shown in Patent Document 1, for example. It is manufactured by cutting. And in the wiring board material shown in patent document 1, the whole part (entire circumference) corresponding to the cutting planned line of a metal plate is formed in the thin part thinner than the original thickness, and generation | occurrence | production of the burr | flash at the time of a cutting | disconnection is suppressed. At the same time, cutting is easy.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-133913
[Problems to be solved by the invention]
However, in such a method of manufacturing a wiring board, the metal plate is cut over the entire circumference of the wiring board, so the load applied to the cutting blade is larger than when the core material is resin or ceramic, for example, There is a possibility that the life of the cutting blade is shortened or breakage is likely to occur. Moreover, since the cut surface of the metal plate is exposed over the entire circumference by cutting, there is a possibility that oxidation, corrosion, and the like are likely to occur.
[0005]
An object of the present invention is to reduce the load applied to the cutting blade by reducing the metal cutting length and extend the life of the cutting blade, and reduce the exposure of the metal cutting surface to improve oxidation and corrosion. Is to provide. Furthermore, an object of the present invention is to provide a wiring board material that is not easily deformed despite the shortening of the metal connecting portion, and that can perform cutting / separation work into a plurality of wiring boards with high accuracy.
[0006]
[Means for Solving the Problems and Effects of the Invention]
In order to solve the above problems, a method for manufacturing a wiring board according to the present invention includes:
A wiring board manufacturing method for cutting and separating a wiring board material having a metal plate as a core material into a plurality of wiring boards by means of vertical and horizontal cutting lines each having a plurality of intersecting positions. And
A slot forming step of forming a slot having a predetermined width by penetrating the metal plate in the front and back direction along the planned cutting line in a form in which at least the crossing position remains as a connecting portion;
An insulating layer forming step of laminating a resin insulating layer on the front and back surfaces of the metal plate and the wall surface of the slot;
In order to separate the wiring board material into individual wiring boards, a cutting step of cutting the wiring board material along a planned cutting line is included.
[0007]
According to this manufacturing method, since the slot is formed so as to penetrate in the front and back direction (plate thickness direction) along the planned cutting line for individual separation, the cutting length of the metal plate is reduced and the cutting blade is applied. It is possible to reduce the load and extend the life of the cutting blade. Moreover, since the exposed area accompanying cutting | disconnection of a metal plate becomes small, oxidation and corrosion can be suppressed. Furthermore, since the exposure of the metal cut surface is reduced, it is possible to improve the situation where moisture penetrates between the metal plate and the resin insulating layer and the resin insulating layer swells or peels off. In addition, a method such as etching or laser processing is used for forming a slot in the metal plate, and a dicing saw, a diamond cutter, a laser processing device, a router processing device, or the like is used for cutting the wiring board material.
[0008]
Therefore, in order to solve the above problems, the wiring board material of the present invention is
A wiring board material that is cut and separated into a plurality of wiring boards by using a metal plate as a core material, and a cutting line in a vertical direction and a horizontal direction in which a plurality of intersecting positions are formed,
A slot formed by penetrating the metal plate with a predetermined width in the front and back direction along the planned cutting line in a form in which at least the crossing position remains as a connecting portion;
And a resin insulation layer laminated on the front and back surfaces of the metal plate and the wall surface of the slot.
[0009]
According to this wiring board material, even if the connecting portion of the metal plate is shortened (reduced) by the slots formed in the front and back direction (plate thickness direction) along the planned cutting line, the metal is crossed at the intersection of the planned cutting line. Since the plates are connected to each other, a structure that is difficult to deform can be maintained. For this reason, warping and bending of the wiring board material can be suppressed during handling, and cutting / separation work into a plurality of wiring boards can be performed with high accuracy.
[0010]
In addition, in order to solve the above-described problem, a method for manufacturing a wiring board according to the present invention includes:
A wiring board material for cutting and separating a wiring board material having a metal plate as a core material into a plurality of wiring boards by cutting lines parallel to the vertical direction and the horizontal direction, each of which is formed with a plurality of orthogonal crossing positions. A manufacturing method comprising:
A slot forming step of forming a slot having a predetermined width by penetrating the metal plate in the front and back direction along the planned cutting line in a form in which only the crossing position remains as a cross-shaped connecting portion,
An insulating layer forming step in which a resin insulating layer is formed which fills the inside of the slot formed in the metal plate and covers each of the front and back surfaces of the metal plate with a thickness equal to or less than the thickness of the metal plate; ,
In order to separate the wiring board material into individual wiring boards, a cutting step of cutting the cross-shaped connecting portion of the metal plate and the resin insulating layer with a cutting blade along the planned cutting line, It is characterized by including.
[0011]
According to this manufacturing method, since a cross-shaped connecting portion is left only at an orthogonal crossing position and a slot is formed by penetrating along the planned cutting line in the front and back direction (plate thickness direction). By reducing the cutting length of the plate as much as possible, the load on the cutting blade can be reduced and the life of the cutting blade can be extended. Moreover, since the exposed area accompanying cutting | disconnection of a metal plate can be reduced, oxidation and corrosion can be suppressed. Further, in the cutting process, the cross-shaped connecting portion of the metal plate to be cut by the cutting blade is surrounded by a resin insulating layer filled inside the slot and a resin insulating layer covering the front and back surfaces of the metal plate. Since it is all covered, a flat cut surface can be obtained without the generation of burrs associated with cutting. At this time, since the resin insulating layer is coated with a thickness equal to or less than the thickness of the metal plate, the heat dissipation from the metal plate is improved in the wiring board. In the cutting process, resin chips generated when the resin insulating layer is cut by the cutting blade are relatively reduced. Therefore, the occurrence of poor conduction due to such resin chips adhering to a through-hole conductor layer (plating layer) or the like formed in a later process is reduced.
[0012]
And in order to solve the said subject, the wiring board material of this invention is the following.
A wiring board material that is cut and separated into a plurality of wiring boards by using a metal plate as a core material, and cutting lines parallel to the vertical direction and the horizontal direction, each of which is formed with a plurality of orthogonal intersection positions,
In a form in which only the crossing position remains as a cross-shaped connecting portion, a slot formed through the metal plate with a predetermined width in the front and back direction along the planned cutting line,
A resin insulating layer that fills the inside of the slot formed in the metal plate and covers the front and back surfaces of the metal plate with a thickness equal to or less than the thickness of the metal plate,
In order to separate the individual wiring boards, it is planned to cut the cross-shaped connecting portion of the metal plate and the resin insulating layer with a cutting blade along the planned cutting line. To do.
[0013]
According to this wiring board material, even if the connecting portion of the metal plate is limited to the orthogonal crossing position by the slots formed in the front and back direction (plate thickness direction) along the planned cutting line, Since the metal plates are connected to each other in the shape of a cross, it is possible to maintain a structure that is not easily deformed. For this reason, warping and bending of the wiring board material can be suppressed during handling, and cutting / separation work into a plurality of wiring boards can be performed with high accuracy. Further, since the resin insulating layer is coated with a thickness equal to or less than the thickness of the metal plate, the heat dissipation from the metal plate in the wiring board material is also improved.
[0014]
Here, in the present invention, “scheduled cutting line” means “scheduled center line”. On the other hand, the “connecting portion” refers to a non-slotted portion formed at each crossing position when a slot is formed along the planned cutting lines in the vertical and horizontal directions intersecting each other in the metal plate. When the planned lines intersect perpendicularly, the connecting portion is formed in a cross shape. In consideration of conductivity, workability, etc., for example, copper, a copper alloy, or an iron / nickel alloy (for example, Invar) can be used for the metal plate. Of these, Invar has a low coefficient of thermal expansion. It is suitable for a wiring board provided with a plate as a core material. The resin insulation layer is impregnated with a thermosetting resin such as epoxy resin in fluorine resin such as epoxy resin, polyimide resin or continuous porous polytetrafluoroethylene (PTFE) in consideration of insulation and heat resistance. The composite material etc. which were made to adopt are employable. As a cutting blade for cutting the wiring board material, a blade of a dicing saw, a cutter blade of a diamond cutter, or the like is used.
[0015]
In the insulating layer forming step (or wiring substrate material) of such a wiring board manufacturing method, the thickness of the metal plate is T, and the thickness of the resin insulating layer formed on the front or back surface of the metal plate is TR. When
0.05 ≦ TR / T ≦ 0.25
It is desirable to form a resin insulating layer so as to satisfy the above. As a result, heat dissipation from the metal plate is further improved in the wiring board, and resin chips generated when the resin insulating layer is cut by the cutting blade in the cutting process are further reduced. Therefore, the occurrence of poor conduction due to such resin chips adhering to a through-hole conductor layer (plating layer) formed in a later process is further reduced.
[0016]
Here, when the ratio TR / T between the thickness TR of the resin insulating layer formed on the front surface or the back surface of the metal plate and the thickness T of the metal plate is less than 0.05, it is uniform over the entire front and back surfaces of the metal plate. There is a possibility that a resin insulating layer having a thickness may not be formed. On the other hand, when the ratio TR / T is greater than 0.25, the amount of insulating resin used may increase, leading to an increase in cost or a decrease in heat dissipation.
[0017]
Further, in the slot forming step (or wiring board material) of the method for manufacturing a wiring board, the length of any one of the rectangular sections surrounded by the planned cutting lines parallel to the vertical direction and the horizontal direction is L, and the side When the total slot length in LS is LS,
0.5 ≦ LS / L ≦ 0.9
It is desirable to form the slot so as to satisfy. As a result, the metal cutting length can be relatively reduced, and the load on the cutting blade such as a dicing blade can be reduced and the life of the cutting blade can be extended. Further, since the exposure of the metal cut surface is reduced by reducing the metal cut length, it becomes easy to improve the oxidation and corrosion. The rectangular section includes a rectangular section and a square section.
[0018]
Here, when the ratio LS / L of the total slot length LS to the side length L is less than 0.5, the cutting load and the exposed cutting area may increase due to the increase of the metal cutting length. On the other hand, when the ratio LS / L is more than 0.9, the strength of the wiring board material may be insufficient due to the decrease in the metal connecting portion, and may be easily deformed.
[0019]
Furthermore, in the slot forming step (or wiring board material) of the method for manufacturing a wiring board, when the width of the slot sandwiching the planned cutting line is WS and the width of the connecting part sandwiching the planned cutting line is W,
1.5 ≦ W / WS ≦ 3.0
It is desirable to form the slot so as to satisfy. Thereby, even in the case where the connecting portion of the metal plate is formed only at the orthogonal crossing position, it is possible to maintain the strength of the wiring board material and make it difficult to deform.
[0020]
Here, when the ratio W / WS between the width W of the connecting portion sandwiching the planned cutting line and the width WS of the slot sandwiching the planned cutting line is less than 1.5, the strength of the wiring board material is reduced due to the reduction of the metal connecting portion. There is a risk that it will become deformed due to lack of. On the other hand, when the ratio W / WS is more than 3.0, the cutting load and the cutting exposed area may increase due to an increase in the metal cutting length.
[0021]
Next, in the slot forming step (or wiring board material) of the wiring board manufacturing method, when the width of the slot sandwiching the planned cutting line is WS and the thickness of the metal plate is T,
1.0 ≦ WS / T ≦ 3.0
It is desirable to form the slot so as to satisfy. Thereby, the resin filling property into the slot is improved, and the resin insulating layer is easily laminated (filled) onto the slot wall surface.
[0022]
Here, when the ratio WS / T between the width WS of the slot sandwiching the planned cutting line and the thickness T of the metal plate is less than 1.0, the resin filling property into the slot deteriorates due to the surface tension of the resin, The metal wall surface of the slot may be exposed. On the other hand, when the ratio WS / T is more than 3.0, the metal plate is likely to be bent or deformed at the slot forming portion, or a recess is formed in the resin insulating layer of the slot due to an insufficient amount of filled resin in the slot. It may occur and adversely affect the formation of the wiring pattern layer and the build-up layer.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
(Example)
Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.
[0024]
FIG. 1 is a plan view showing an embodiment of a wiring board material according to the present invention. 2A is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 2B is a cross-sectional view taken along the line BB. As shown in FIG. 1, the wiring board material 1 is a rectangular section 2 ′ (a part to be a wiring board 2 described later by cutting) having a rectangular shape (including a rectangle and a square in this embodiment; a square in FIG. 1). Are connected to each other (in the embodiment, a total of 9 in 3 rows × 3 columns) and are formed in a panel shape. The wiring board material 1 is divided (cut / separated) along a planned cutting line 3 (meaning a planned cutting center line in this embodiment) in a cutting process described later. A plurality of (four in total in the embodiment) crossing positions (orthogonal crossing positions) orthogonal to each other are formed by a plurality of cutting lines 3 (two in the embodiment) parallel to the vertical and horizontal directions. ing. The wiring board 2 (see FIG. 5) is manufactured by cutting along the planned cutting lines 3 individually.
[0025]
As shown in FIG. 2, the wiring board material 1 includes a metal plate 4 (see FIG. 3) and a resin insulating layer 5. The metal plate 4 has a rectangular shape (square in FIG. 3), and is made of Invar made of iron / nickel alloy in consideration of thermal expansion coefficient, conductivity, workability, and the like. The resin insulation layer 5 is formed by layering prepregs (semi-cured sheets) made of a composite material of an epoxy resin and a silica filler selected in consideration of insulating properties, heat resistance, etc. on both the front and back surfaces of the metal plate 4. In addition, this is vacuum thermocompression-bonded and the prepreg is cured, so that the metal plate 4 is laminated (coated) on both the front and back surfaces.
[0026]
Next, FIG. 3 is a plan view of the metal plate 4 and an enlarged explanatory view thereof. 4A is a cross-sectional view taken along the line A′-A ′ of FIG. 3A, and FIG. 4B is a cross-sectional view taken along the line B′-B ′. In FIG. 3, the metal plate 4 of the wiring board material 1 has an elongated groove-like slot 6 penetrating in the front and back direction (plate thickness direction) along the planned cutting line 3, and a partition metal plate 41 ′ (rectangular partition portion 2). Corresponding to ', it is formed in a form that surrounds the four circumferences of a portion that should become an individual metal plate 41 to be described later by cutting. That is, in the partition metal plate 41 ′ partitioned by the planned cutting line 3, slots 6, 6, 6, and 6 are formed on the four surrounding sides except for the four corners (corners). Specifically, the slot 6 is formed so that the position where the planned cutting line 3 intersects orthogonally and its periphery (cross-cross portion) remain as the connecting portion 7. The slot 6 is formed by etching as will be described later.
[0027]
Next, an embodiment of a method for manufacturing a wiring board according to the present invention will be described with reference to FIG.
[0028]
<Etching resist layer forming step: S1 and S2>
In step S <b> 1, a photosensitive resist 8 is applied to the front and back surfaces of the metal plate 4. Next, in step S2, this is exposed and developed to form an etching resist layer 8R having an opening corresponding to the slot 6 to be formed.
[0029]
<Slot formation step: S3>
In step S3, the metal plate 4 on which the etching resist layer 8R is formed is etched to form the slots 6. Thereafter, when the etching resist layer 8R is peeled off, the metal plate 4 having the slots 6 is formed. In this slot forming step, a plurality (for example, four) of through-holes 9 (see FIG. 3B) penetrating the metal plate 4 through the front and back are simultaneously formed.
[0030]
<Insulating layer forming step: S4>
Next, in step S4, a prepreg having a predetermined thickness made of a composite material of an epoxy resin and a silica filler is superimposed on the front and back surfaces of the metal plate 4. Then, in a state where the prepreg is laminated on the metal plate 4, vacuum thermocompression bonding is performed, and the prepreg is cured to form the resin insulating layer 5. The inside of the slot 6 of the metal plate 4 is filled with an epoxy resin that has oozed from the prepreg. The wall surface of the slot 6 is covered with the resin insulating layer 5 so that the opening of the slot 6 is filled. In the case where the through-hole 9 (see FIG. 3B) is simultaneously formed in the metal plate 4, the inner portion thereof is also filled with epoxy resin in the insulating layer forming step.
[0031]
<Wiring pattern layer forming step: S100>
A wiring pattern layer is formed outside the resin insulating layer 5. In addition, one or a plurality of lamination wiring pattern layers may be formed (overlaid) outside the wiring pattern layer via an insulating resin build-up layer. Further, a resin solder resist layer and a solder bump may be formed on the outermost insulating resin buildup layer. In the present embodiment, each of these layers is formed by a known method (for example, see JP-A-2001-203295). Note that all or part of the step S100 may be performed after the cutting step S5. That is, at the stage where the insulating layer forming step S4 is completed or at the middle of the wiring pattern layer forming step S100, the wiring board material 1 is cut and separated into a plurality of wiring boards 2 (see the next step S5), and thereafter The remaining steps of S100 may be performed on each cut and separated wiring board 2.
[0032]
<Cutting step: S5>
In step S <b> 5, in the wiring board material 1, the resin insulating layer 5 filled in the slot 6 and the cross-shaped connecting portion 7 of the metal plate 4 are cut along the planned cutting line 3. Specifically, the width center of the dicing blade 10 (cutting blade) is made to coincide with the planned cutting line 3 (cutting center line), the resin insulating layer 5 and the connecting portion 7 are cut, and a plurality of wiring board materials 1 are formed. The wiring boards 2 are separated (in this case, 9 pieces) (see FIGS. 3A and 4B). The entire circumference of the metal plate 4 is not exposed, and only a part thereof (only the cut end face of the connecting portion 7) is exposed. Therefore, compared with the case where the entire circumference is exposed, there is an effect that the exposed portion of the metal plate 4 is excellent in oxidation resistance and corrosion resistance. In some cases, the cut end face of the connecting portion 7 exposed by cutting is re-coated with the resin insulating layer 5.
[0033]
In this way, the cross-shaped connecting portion 7 is left only at the orthogonal crossing position, and the other portions are penetrated along the planned cutting line 3 in the front and back direction (plate thickness direction) to form the slot 6. As a result, the cutting length of the metal plate 4 is shortened and the load applied to the dicing blade 10 is reduced, so that the life of the dicing blade 10 is prolonged. Moreover, since the exposed area accompanying the cutting | disconnection of the metal plate 4 becomes only the end surface of the connection part 7, it becomes difficult to oxidize and corrode. Further, the connecting portion 7 cut by the dicing blade 10 is entirely covered with the resin insulating layer 5 filled inside the slot 6 and the resin insulating layer 5 covering the front and back surfaces of the metal plate 4. For this reason, a flat cut surface can be obtained without generation of burrs associated with cutting.
[0034]
The ratio of the length LS (for example, 30 mm) of the slot 6 to the length L (for example, 37.8 mm) of any one side of the rectangular section 2 ′ (the section metal plate 41 ′) is set to LS / L = 0.79. (See FIG. 3). As a result, the metal cutting length is reduced to about 21% of the entire length, and the load applied to the dicing blade 10 is reduced, so that the life is extended. Further, since the exposure of the metal cut surface of the connecting portion 7 is reduced due to the reduction of the metal cutting length, it is difficult to oxidize and corrode.
[0035]
The ratio of the width WS (for example, 500 μm) of the slot 6 that sandwiches the planned cutting line 3 to the width W (for example, 1050 μm) of the cross-shaped connecting portion 7 that sandwiches the planned cutting line 3 is W / WS = 2.1 It is set (see FIG. 3). Thereby, even if the connection part 7 of the metal plate 4 is formed only in the orthogonal crossing position, the strength of the wiring board material 1 is maintained and it is difficult to deform. Note that the planned cutting line 3 coincides with the width center of the slot 6 and the width center of the connecting portion 7.
[0036]
The ratio of the width WS (for example, 500 μm) of the slot 6 to the thickness T (for example, 250 μm) of the metal plate 4 is set to WS / T = 2.0 (see FIG. 4B). Thereby, the resin filling property into the slot 6 is improved, and the resin insulating layer 5 is easily laminated (filled) on the wall surface of the slot 6.
[0037]
Further, the ratio of the thickness TR (for example, 40 μm) of the resin insulating layer 5 to the thickness T (for example, 250 μm) of the metal plate 4 is set to TR / T = 0.16 (see FIG. 2). As a result, the heat dissipation from the metal plate 4 in the wiring board 2 is improved, and resin chips generated when the resin insulating layer 5 is cut by the dicing blade 10 in the cutting process are relatively reduced. Therefore, the occurrence of poor conduction due to such resin chips adhering to a through-hole conductor layer (plating layer) or the like formed in a later process is reduced.
[0038]
The width WB of the dicing blade 10, the width WS of the slot 6, and the width W of the connecting portion 7 across the planned cutting line 3 are WB (for example, 300 μm): WS (for example, 500 μm): W (for example, 1050 μm) = 3: 5: 10.5 (see FIG. 3). As a result, the dicing blade 10 is prevented from cutting the metal wall surface of the slot 6, and the connecting portion 7 makes it difficult for the wiring board material 1 to be deformed (bent, bent, etc.), so that the accuracy during cutting can be increased. Further, since WB / WS = 0.6 is set, the resin filling property into the slot 6 is improved, and the resin insulating layer 5 is easily laminated (filled) on the wall surface of the slot 6.
[0039]
In the case of a multilayer wiring board material (build-up wiring board material) in which a plurality of wiring pattern layers and build-up layers are formed on the wiring board material 1 (S100 in FIG. 5), the following settings are made. The That is, the difference WS−WB between the width WS of the slot 6 and the blade width WB of the dicing blade 10 includes an alignment deviation WA (not shown) that is an allowable deviation from the planned cutting line 3 of each wiring pattern layer. To be included. This prevents the dicing blade 10 from cutting the metal wall surface of the slot 6 even in the case of a multilayer wiring board material (build-up wiring board material).
[0040]
Next, FIG. 6 shows a rectangular section 2 ′ (partition metal plate 41 ′) in the middle of cutting, and FIG. 7 shows a cut wiring board 2 (individual metal plate 41). As shown in FIG. 6, the width WB of the dicing blade 10, the width WS of the slot 6, and the width W of the connecting portion 7 have a relationship of WB ≦ WS ≦ W. A part of the cut connecting portion 7 remains as a remaining cutting portion, and forms a protruding portion 41b (reinforcing portion).
[0041]
Specifically, the cross-shaped connecting portion 7 formed at the orthogonal crossing position of the metal plate 4 is cut by the dicing blade 10 (see FIG. 6). At this time, the protruding portion 41b (reinforcing portion) as a cutting residual portion formed by the left and right cutting edges 10 ′ and 10 ′ of the dicing blade 10 is formed on each side of the individual metal plate 41 (hereinafter also simply referred to as a metal plate). It is formed integrally with a main body portion 41a as a central rectangular portion formed by extending the inner edge 41d of the outer shape line (see FIG. 7A). As shown in FIG. 7A, the protruding portion 41 b is formed so as to protrude outward in parallel from two sides sandwiching the corner of the main body portion 41 a of the metal plate 41. As described above, the protruding portion 41b is formed so as to extend over two sides sandwiching the corner so as to cover the corner portion of the metal plate 41, so that the strength of the corner portion is improved, and damage (chip, crack, etc.) is caused during handling. And deformation (breaking, bending, bending, etc.) are less likely to occur. Furthermore, since the protruding portion 41b is formed in the process of cutting the connecting portion 7, the function of the wiring board 2 (metal plate 41) can be improved without increasing the manufacturing cost.
[0042]
Further, the overhang width WH (for example, 100 μm) of the protrusion 41b with respect to the thickness T (for example, 250 μm) of the metal plate 41 is set to WH / T = 0.4 (see FIG. 7). Thereby, the overhang width WH of the protrusion 41b necessary for reinforcing the corner of the metal plate 41 can be secured.
[0043]
Furthermore, the total LH (for example, 7.5 mm) of the protruding length of the protruding portion 41b on the side with respect to the maximum length L ′ (for example, 37.5 mm) of the side after being cut by the dicing blade 10 is expressed as LH / L ′ = 0. .2 (see FIG. 7). Thereby, the overhang length LH of the protrusion 41b necessary for reinforcing the corner of the metal plate 41 can be secured. From FIG. 6 and FIG.
L ′ = L−WB
LH = L'-LS = L-WB-LS
Can be expressed as
LH / L '= (L-WB-LS) / (L-WB) = 1- {LS / (L-WB)}
There is a relationship. However, L is the length of one side of the rectangular section 2 ′ (section metal plate 41 ′) surrounded by the planned cutting line 3, LS is the total length of the slot on that side, and WB is the blade width of the dicing blade 10. This is shown (see FIG. 6). Also, between the width W of the cross-shaped connecting portion 7 before cutting and the total LH of the overhang length after cutting,
LH = W-WB
(See FIGS. 6 and 7).
[0044]
(Modification)
Next, FIG. 8 shows a modification of the slot. FIGS. 8A and 8B are explanatory views (plan views) corresponding to FIGS. 3B and 7A, respectively. In this modification, the slot 6 in FIG. 3B is divided into two in the direction of the planned cutting line 3 and formed as slots 16a and 16b. Therefore, the partition metal plate 42 ′ also exists between the slot 16a and the slot 16b. In such a case, the above-described total slot length LS may be obtained by adding the length La of the slot 16a and the length Lb of the slot 16b.
[0045]
FIG. 8B shows a wiring board 2 (individual metal plate 42; hereinafter also simply referred to as a metal plate) manufactured by forming the slots 16a and 16b in this manner. Similarly to FIG. 7A, projecting portions 42b (reinforcing portions; residual cutting portions) covering the corner portions are integrally formed with the main body portion 42a (central rectangular portion) at the four corners of the metal plate 42. A central projecting portion 42R (reinforcing portion; remaining cutting portion) is integrally formed with the main body portion 42a at the center of the inner edge 42d of the outer line of each side.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of a wiring board material according to the present invention.
2 is a cross-sectional view taken along line AA and BB of the wiring board material of FIG. 1;
FIG. 3 is a plan view and an enlarged explanatory view of a metal plate.
4A and 4B are cross-sectional views taken along the lines A′-A ′ and B′-B ′ of the metal plate in FIG.
FIG. 5 is an explanatory view showing an embodiment of a method for manufacturing a wiring board according to the present invention.
FIG. 6 is an explanatory diagram of a rectangular section (partition metal plate) in the middle of cutting.
FIG. 7 is a plan view and a front view of a wiring board (individual metal plate).
FIG. 8 is an explanatory view showing a modification of FIGS. 3B and 7A.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wiring board material 2 Wiring board 2 'Rectangular division part 3 Planned cutting line (cutting center line)
4 Metal plate 5 Resin insulating layer 6 Slot 7 Connecting portion 10 Dicing blade (cutting blade)
41 Individual metal plate (metal plate)
41a Body (rectangular center)
41b Reinforcement part (cutting remaining part; projecting part)
41 'section metal plate

Claims (5)

A wiring board manufacturing method for cutting and separating a wiring board material having a metal plate as a core material into a plurality of wiring boards by means of vertical and horizontal cutting lines each having a plurality of intersecting positions. And
A slot forming step of forming a slot having a predetermined width by penetrating the metal plate in the front and back direction along the planned cutting line in a form in which at least the intersecting position remains as a connecting portion;
An insulating layer forming step of laminating a resin insulating layer on the front and back surfaces of the metal plate and the wall surface of the slot;
And a cutting step of cutting the wiring board material along the planned cutting line in order to separate the wiring board material into individual wiring boards. A wiring board material for cutting and separating a wiring board material having a metal plate as a core material into a plurality of wiring boards by cutting lines parallel to the vertical direction and the horizontal direction, each of which is formed with a plurality of orthogonal crossing positions. A manufacturing method comprising:
A slot forming step of forming a slot having a predetermined width by penetrating the metal plate in the front and back direction along the planned cutting line in a form in which only the crossing position remains as a cross-shaped connecting portion,
An insulating layer forming step in which a resin insulating layer is formed which fills the inside of the slot formed in the metal plate and covers each of the front and back surfaces of the metal plate with a thickness equal to or less than the thickness of the metal plate; ,
In order to separate the wiring board material into individual wiring boards, a cutting step of cutting the cross-shaped connecting portion of the metal plate and the resin insulating layer with a cutting blade along the planned cutting line, A method of manufacturing a wiring board, comprising: In the insulating layer forming step, when the thickness of the metal plate is T and the thickness of the resin insulating layer formed on the front or back surface of the metal plate is TR,
0.05 ≦ TR / T ≦ 0.25
The method for manufacturing a wiring board according to claim 1, wherein the resin insulating layer is formed so as to satisfy the above condition. A wiring board material that is cut and separated into a plurality of wiring boards by using a metal plate as a core material, and a cutting line in a vertical direction and a horizontal direction in which a plurality of intersecting positions are formed,
A slot formed by penetrating the metal plate with a predetermined width in the front and back direction along the planned cutting line in a form in which at least the crossing position remains as a connecting portion;
A wiring board material comprising: a resin insulating layer laminated on front and back surfaces of the metal plate and a wall surface of the slot. A wiring board material that is cut and separated into a plurality of wiring boards by using a metal plate as a core material, and cutting lines parallel to the vertical direction and the horizontal direction, each of which is formed with a plurality of orthogonal intersection positions,
In a form in which only the crossing position remains as a cross-shaped connecting portion, a slot formed through the metal plate with a predetermined width in the front and back direction along the planned cutting line,
A resin insulating layer that fills the inside of the slot formed in the metal plate and covers the front and back surfaces of the metal plate with a thickness equal to or less than the thickness of the metal plate,
In order to separate the individual wiring boards, it is planned to cut the cross-shaped connecting portion of the metal plate and the resin insulating layer with a cutting blade along the planned cutting line. Wiring board material to be used.

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