JP4044986B2 - Manufacturing method of wiring board assembly - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method of the wiring board assembly having a plurality of substrate portions comprising a plurality of wiring boards.
[0002]
[Prior art]
In general, ceramic multilayer wiring boards are mass-produced by taking a large number of pieces. In the state of the assembly of a plurality of such wiring boards, an element such as a crystal resonator is mounted on the upper surface of each wiring board and the electrical characteristics are individually measured. A substrate may be obtained.
[0003]
An assembly 70 of such ceramic multilayer wiring boards includes, for example, a plurality of substrate portions 72 partitioned by dividing grooves 74 and through holes formed vertically on the dividing grooves 74 as shown in the plan view of FIG. A hole 76 and an element terminal 78 partially connected to the through hole 76 are provided. Each substrate portion 72 is divided along the dividing groove 74 to become an individual wiring board. The terminal 78 is electrically connected to an element mounted on the upper surface of the substrate portion 72.
Further, as shown in FIG. 6 (B), the entire inner peripheral surface of the through hole 76 is soldered to the mother board following the wiring pattern of each substrate portion 72, so that it has a hollow tubular shape. A conductive portion 80 is formed.
[0004]
In this case, as shown in FIG. 6C, the wiring patterns 73 are electrically connected to each other between the substrate portions 72 adjacent to each other with the dividing groove 74 interposed therebetween.
For this reason, even if an element such as a crystal resonator is fixed to the element mounting portion on the upper surface of each substrate portion 72 in the aggregate 70 and this element is electrically connected to the terminal 78, the electrical properties of the individual substrate portions 72 are not affected. In some cases, characteristics cannot be measured accurately. If the electrical characteristics of each substrate portion 72 cannot be measured in the state of the aggregate 70, the inspection efficiency is also lowered.
[0005]
In addition, in order to obtain a conductive portion 80 that becomes an external terminal after being divided in the through-hole 76, the Pd catalyst nucleus or the like is applied to the base metallization before the electroless plating of Ni and Au together with the element terminal 78. An activation treatment is applied to adhere the. At this time, Pd catalyst nuclei also adhere to the bottom of the dividing groove 74 having a V-shaped cross section, so that Ni and Au plating layers are formed linearly along the bottom of the dividing groove 74.
As a result, as shown in FIG. 6D, when divided into each substrate portion 72 along the dividing groove 74, the adjacent semicircular concave external terminals 84 on the side surfaces 82 are linear Ni and Au. There is a case where a short circuit occurs through the plating layer 86, causing a problem that obstructs the original circuit formation.
[0006]
[Problems to be Solved by the Invention]
The present invention solves the above-described problems in the prior art, and provides a method for manufacturing a wiring board assembly that enables measurement of electrical characteristics of a board portion to be an individual wiring board in the state of the wiring board assembly. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention forms a plurality of conductor layers formed in the through holes of the wiring board assembly separately for each adjacent board portion, and conductors on the side surfaces of the divided wiring board The idea is to break the short circuit between layers.
That is, according to the method for manufacturing a wiring board assembly of the present invention (claim 1), a plurality of green sheets serving as the wiring board assembly are arranged along a planned dividing line formed by dividing grooves for dividing a plurality of substrate portions. Forming a substantially oval or substantially elliptical through-hole having a major axis parallel to the planned dividing line, and an inner peripheral surface of each of the through-holes in the plurality of green sheets and away from the planned dividing line. forming a plurality of base metallization on the position of each substrate portion facing Te, the steps of the plurality of green sheets above through hole to form a laminate stacked so and the underlying metallization is connected communicated a step of forming the dividing lines dividing groove along in the laminate, a step of firing the laminate, is the underlying metallized ceramic body obtained by firing according fired And forming a conductive layer by plating into the formation, and characterized in that.
[0008]
According to this, the wiring pattern of each substrate portion is insulated from the wiring pattern of the adjacent substrate portion, and the plurality of conductor layers on the dividing grooves of each substrate portion are also insulated, so that the plurality of substrate portions are aggregated. It is possible to reliably provide a wiring board assembly that can measure the respective electrical characteristics in the state of the body .
[0009]
The substrate portion refers to a portion in the assembly that becomes an individual wiring substrate after division.
Further, the above-mentioned divided grooves include intersections of the grooves, corners of each groove, and bent portions.
[0010]
Furthermore, the present invention may include a method for manufacturing a wiring board assembly in which in the step of forming the through hole, the through hole and the through hole are alternately formed along the planned dividing line.
[0011]
Embodiment
In the following, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 relates to a wiring board assembly 1 manufactured according to the present invention.
FIG. 1A shows a plan view of the assembly 1. In the plate-like main body 2 made of ceramic such as alumina, the substrate portions 6 divided into four parts vertically and horizontally by the dividing grooves 4 are arranged on the same plane. Have. In the drawing, a plurality of oval through-holes 5 are formed along the horizontal dividing grooves 4, and the element is formed on the upper surface 7 of each substrate portion 6 at the upper edge of the central portion of each through-hole 5. A part of the terminal 8 is connected. Each substrate portion 6 is formed with a plurality of wiring patterns (not shown).
[0012]
As shown in FIG. 1 (B), a conductor layer 10 is formed substantially vertically in the central portion in a plan view of a pair of longitudinal surfaces in each through-hole 5, and is electrically connected to a part of the terminal 8 at the upper end thereof. is doing. Further, the conductor layer 10 is electrically connected to any of the wiring patterns in each substrate portion 6. The dividing groove 4 having a V-shaped cross section is formed at the same position on both the upper and lower surfaces of the main body 2, but may be formed only on at least one surface.
[0013]
According to the wiring board assembly 1, each conductor layer 10 of the substrate portion 6 is insulated from the adjacent conductor layer 10 along the dividing groove 4 by the left and right side portions 5 a in the through hole 5, and the through hole 5 The opposing conductor layers 10 of the substrate portions 6 adjacent to each other are also insulated.
[0014]
Accordingly, in the state of the assembly 1, an element (not shown) is mounted at the center of the upper surface 7 of each substrate portion 6, and when this is soldered to the element terminal 8, the wiring pattern of each substrate portion 6 is obtained. The electrical characteristics of each substrate portion 6 including the above elements can be measured. For this reason, since the inspection can be performed on the assembly 1 before dividing each wiring board, the efficiency of the inspection process can be increased.
In addition, insulation between the conductor layers 10 on the side surface of each wiring board obtained by dividing the main body 2 along each dividing groove 4 is also ensured.
[0015]
The shape of the through hole 5 is not limited to the oval shape. For example, as shown in FIG. 1C, the through hole 5b in which the central portion of the upper and lower sides of the horizontally long oval shape is further recessed into a substantially semi-oval shape. A through hole 5c in which the central part of the upper and lower sides of a horizontally long oval is further recessed into a substantially semicircular shape as shown in FIG. 1 (D), or the central part of the upper and lower sides of a horizontally long ellipse as shown in FIG. Furthermore, it can also be set as the through-hole 5d dented in the substantially semicircle.
As described above, when the central portion of the through-hole 5 is further recessed into a substantially semi-oval shape or a substantially semi-circular shape, the metallization that becomes the conductor layer 10 is partly provided through the mask in the central portion of the through-hole 5 as will be described later. Therefore, the metallized ink to be injected can be prevented from getting wet and spread, and the ink can be applied to the central portion of the through hole 5 more easily.
Further, as shown in the lower side of the through hole 5b in FIG. 1C, a plurality of conductor layers 10 can be insulated and provided side by side.
[0016]
FIG. 2 relates to a different form of wiring board assembly 11 manufactured according to the present invention .
FIG. 1A shows a plan view of the aggregate 11, which has a substrate portion 16 divided into four by dividing grooves 14 in a plate-like main body 12 made of the same ceramic as described above. In the figure, a plurality of oval through holes 15 are formed at equal intervals along the horizontal dividing grooves 14, and the upper edge of each through hole 15 is for an element formed on the upper surface 17 of each substrate portion 16. A part of the terminal 18 is connected. A round through hole 19 that blocks the dividing groove 14 is passed between the through holes 15 and 15. Each substrate portion 16 also has a plurality of wiring patterns (not shown).
[0017]
As shown in FIG. 2 (B), a conductor layer 20 is vertically formed in the central portion in a plan view of a pair of longitudinal surfaces in each through-hole 15, and is electrically connected to a part of the terminal 18 at the upper end thereof. ing. The conductor layer 20 is also electrically connected to the wiring pattern of each substrate portion 56.
According to the wiring board assembly 11, the conductor layer 20 of each board portion 16 is insulated from each other by the left and right side portions 15 a in the through hole 15 and the through holes 19 between the through holes 15, and sandwiches the through holes 15. The opposing conductor layers 20 of the adjacent substrate portions 16 are also insulated from each other.
[0018]
Therefore, when the element mounted on the center of the upper surface 17 of each substrate portion 16 and the terminal 18 for the element are soldered and conducted in the state of the aggregate 11, the wiring pattern of each substrate portion 16 can be conducted. The electrical characteristics of each substrate portion 16 including the element can be measured. For this reason, since the inspection can be reliably performed on the assembly 11 before being divided for each wiring board, the efficiency of the inspection process can be increased.
In addition, insulation between the conductor layers 20 on the side surface of the wiring board obtained by dividing the main body 12 along each dividing groove 14 is also ensured.
As shown in FIG. 2 (C), when a circular conducting portion 60 ′ is formed on the entire inner peripheral surface of the through hole 15, a through hole 19 is formed on the dividing groove 14 between the through holes 15 and 15. Thus, the wiring board assembly 11 ′ in the reference form can be obtained.
[0019]
Next, the manufacturing method of the present invention for the wiring board assembly 11 will be described with reference to FIG .
3 (A) and 3 (A ′) are mainly made of alumina, and show a cross section and a partial plan view of the green sheet 21 for forming the main body 12.
Next, as shown in FIGS. 3 (B) and 3 (B '), a plurality of oval penetrations are formed along the planned dividing lines (virtual lines) formed by the dividing grooves 14 of each green sheet 21 later. The holes 15 and the round through holes 19 are punched alternately by pressing.
Furthermore, a conductive paste made of a refractory metal such as tungsten (W) or molybdenum (Mo) is applied to the upper surface of each green sheet 21 by screen printing following a predetermined pattern.
[0020]
Further, as shown in FIGS. 3C and 3D, a mask 23 having a suction hole 22 indicated by a broken line in the drawing is brought into contact with the opening of each through hole 15 of each sheet 21, and W or Mo or the like is contacted. Inject metallized ink consisting of The ink is sucked by the negative pressure from the opening on the opposite side, and forms a base metallization 24 at the center of the longitudinal surface in the through hole 15 as shown. The metallization 24 is also formed on the upper surface of the sheet 21.
Next, as shown in FIG. 3E, the green sheets 21 are laminated so that the through holes 15 and the through holes 19 communicate with each other to form a laminated body 26. At this time, the base metallizations 24 in the through holes 15 are also connected to each other in the vertical direction.
[0021]
Further, as shown in FIG. 3 (F), the dividing grooves 14 having a V-shaped cross section are formed on the upper and lower green sheets 21 of the laminate 26 along the planned dividing line. The dividing grooves 14 may be formed in advance on the individual green sheets 21.
The laminated body 26 of the sheet 21 is heated and held at about 1500 ° C. for a predetermined time while being pressed in the vertical direction, and fired to obtain the ceramic body 12 shown in FIG. At the same time, the conductive paste becomes a wiring pattern or an element terminal 18. The base metallization 24 becomes a base layer.
Next, the base layer in each through-hole 15 is activated through a mask, and then a catalyst core for plating is attached. The activation treatment is performed to adhere a surfactant and ensure adhesion of the catalyst core for plating. The plating catalyst nucleus is Pd (palladium), and is deposited by a so-called catalyst and an acceleration treatment.
[0022]
At this time, the Pd catalyst nucleus does not remain in the through hole 19 even if it remains in the narrow dividing groove 14 (particularly the bottom portion). Further, the Pd catalyst nucleus also flows down with the processing liquid in the through hole 15. Finally, electroless Ni and Au plating is performed on each underlayer.
Since this plating is formed only on the portion where the Pd catalyst nucleus adheres, even if the plating is deposited in each of the underlayers and the division grooves 14, the left and right side portions 15a and the through holes 19 are not covered with the Ni and Au plating. It does not precipitate. As a result, the wiring board assembly 11 in which the conductor layers 20 are insulated from each other can be obtained.
[0023]
A plurality of wiring boards can be obtained by breaking and dividing the aggregate 11 along the dividing grooves 14.
Moreover, the wiring board assembly 1 of FIG. 1 can be manufactured by punching the through holes 15 in the respective green sheets 21 and omitting the formation of the through holes 19 and performing the same processes, and this assembly. A plurality of wiring boards can also be obtained by dividing 1.
[0024]
Next, the wiring board 31 obtained by dividing the assembly 1 will be described.
FIG. 4A shows a plan view of the wiring board 31 obtained by the manufacturing method of the present invention. The substrate 31 has a plate-like main body 32 made of ceramic such as alumina, and a plurality of element terminals 34 formed on the upper surface (surface) 33 of the main body 32.
As shown in FIG. 4B, the side surface 36 of the main body 32 is provided with a plurality of concave portions 38 that are recessed in a semi-oval shape with respect to the main body 32, and serves as a terminal at the center portion of the concave portion 38 in plan view. The conductor layer 40 is formed substantially vertically. The conductor layer 40 is electrically connected to the element terminal 34 at the upper end thereof, and is also electrically connected to a plurality of wiring patterns 35 and 35 built in the main body 32 as shown in FIG.
[0025]
The main body 32 has a thickness of about 0.5 mm, for example, the length along the side surface 36 of each recess 38 is about 1 mm, the recess is about 0.3 mm, and the width of each conductor layer 40 is about 0.3 mm. Therefore, the left and right sides of the conductor layer 40 have both side portions 39, 39 of the recess 38 each having a width of about 0.3 mm. In order to partially form the conductor layer 40 in the recess 38, the recess 38 itself is elongated along the side surface 36, and the base metallization that becomes the conductor layer 40 is formed through the mask as described above. It is made by.
According to this wiring board 31, the conductor layer 40 is formed at the center of the recess 38, and is reliably insulated from the conductor layer 40 in the recess 38 adjacent on the same side surface 36 by both side portions 39, 39. Even if the linear plating layer 86 shown in FIG. 6D is generated in the manufacturing process, an inadvertent short circuit between the conductor layers 40 can be surely prevented, and the malfunction can be prevented. FIG. 4D shows a state where the conductor layer 40 is provided in the recess 38.
[0026]
The wiring board 51 obtained by dividing the assembly 11 will be described.
FIG. 5A shows a plan view of a wiring board 41 obtained by dividing the assembly 11. The substrate 41 has a plate-like main body 42 made of the same ceramic as described above, and a plurality of element terminals 44 formed on the upper surface (surface) 43 of the main body 42.
As shown in FIG. 5B, the side surface 46 of the main body 42 is provided with a plurality of concave portions 48 which are recessed in a semi-oval shape with respect to the main body 42 at equal intervals. A conductor layer 50 serving as a terminal is formed substantially vertically. The conductor layer 50 is electrically connected to the element terminal 44 at the upper end thereof, and is electrically connected to one of the wiring patterns (not shown) of the main body 42. In addition, a semicircular vertical groove 49 is provided on the side surface 46 between the conductor layers 50 so as to continue from the upper surface 43 to the lower surface (back surface).
[0027]
As described above, the conductor layer 50 is formed by sucking the metallized ink with a negative pressure in the central portion of the oval through-hole 15 forming the pair of recesses 48, as described above. 49 is also formed by punching with a press.
According to the wiring board 41, since the conductor layer 50 is formed in the central portion of the recess 48 and the groove portion 49 is formed in the side surface 46 between the recesses 48, the linear shape shown in FIG. Even if the plated layer 86 is formed, it is blocked by the left and right side portions 48 a of the recess 48 and the groove 49. Therefore, an inadvertent short circuit between the conductor layers 50 can be surely prevented, and the malfunction can be prevented.
Note that arcs 49 ′ at the four corners of the wiring board 41 indicate the traces of the through holes 19 that are punched across the board portions 16 adjacent to each other when the board 41 is in the state of the assembly 11.
[0028]
Furthermore, the wiring board 51 of the reference form obtained by dividing the assembly 11 ′ of the reference form will be described.
FIG. 5C shows a wiring board 51 of a reference form, and a plurality of concave portions 58 that are recessed in a semi-oval shape with respect to the main body 52 are provided on the side surface 56 at a predetermined interval. A conductor layer 60 is formed. In addition, the conductor layer 60 is electrically connected to an element terminal 54 formed on the upper surface (surface) 53 at the upper end thereof, and is electrically connected to one of the wiring patterns (not shown) of the main body 52. Further, a groove portion 59 perpendicular to the thickness direction is provided between the concave portions 58.
In this wiring board 51, an inadvertent short circuit between the conductor layers 60 is more reliably prevented by the groove 59 between the recesses 58 on the side surface 56, and malfunction is prevented.
The concave portions 38, 48, 58 and the groove portions 49, 59 can be similarly formed on the left and right vertical side surfaces of the substrates 31, 41, 51 shown in the drawing.
[0029]
The present invention is not limited to the embodiments described above.
Several sizes of the through holes of the wiring board assembly are formed along the dividing grooves, and a plurality of conductor layers are formed in parallel in the relatively long through holes, and the recesses of the wiring board are similarly formed. It is also possible to form one or more conductor layers in each recess.
The ceramic forming the wiring board and the aggregate thereof is not limited to alumina, and aluminum nitride, glass ceramic, mullite, and the like can also be used.
Also, the material of the conductor layer, terminal, and wiring pattern is not limited to W or Mo, but Cu, Co, alloys based on these, Mo-Mn, Ag, Ag-Pd, Ag-Pt, etc. are applied. Is also possible.
[0030]
Furthermore, the wiring board assembly can be assembled prior to the inspection, such as mounting the above elements on each board portion and sealing with a lid.
The wiring board also includes a surface mount wiring board such as a multichip module on which a plurality of electronic components and elements are mounted. Further, in addition to the crystal resonator, elements such as a transistor, a diode, and an EFT can be mounted. The mounted elements and the like are sealed with a lid on the wiring board.
[0031]
【The invention's effect】
According to the method for manufacturing a wiring board assembly of the present invention described above, the conductor layers along the dividing grooves and the conductor layers of each board part facing the through hole are insulated from each other, and the electrical characteristics of each board part Thus, it is possible to reliably provide a wiring board assembly capable of efficiently and efficiently assembling elements and the like in each board portion .
[Brief description of the drawings]
1A is a plan view showing an embodiment of a wiring board assembly obtained by the present invention, FIG. 1B is a partial perspective view of a portion B indicated by a one-dot chain line in FIG. 1A, and FIGS. E) is a partial plan view showing different forms of through holes.
2A is a plan view showing different forms of a wiring board assembly obtained according to the present invention, FIG. 2B is a partial perspective view of a one-dot chain line part B in FIG. 2A, and FIG. 2C is a reference form; The partial perspective view which shows a wiring board aggregate | assembly.
FIG. 3 is a schematic sectional view or a partial view showing a manufacturing process of a wiring board assembly according to the present invention .
4A is a plan view showing one embodiment of a wiring board obtained by the present invention, FIG. 4B is a partial perspective view of a portion B indicated by a one-dot chain line in FIG. 4A, and FIG. CC sectional drawing in the inside, (D) is a fragmentary perspective view of a different aspect.
[5] (A) is a plan view showing different forms of the wiring board obtained by the present invention, (B) is a partial perspective view of the one-dot chain line portion B in (A), (C) the wire reference embodiment The fragmentary perspective view which shows a board | substrate.
6A is a plan view showing a conventional wiring board assembly, FIG. 6B is a partial perspective view of a portion B indicated by a one-dot chain line in FIG. 6A, and FIG. The fragmentary perspective view containing C cross section, (D) is the fragmentary perspective view containing the side surface of the conventional wiring board.
[Explanation of symbols]
1, 11 ……………………………… Wiring board assembly 4, 14 …………………………… Divided grooves 5, 5 b to 5 d, 15 ………… Through hole 6 16 ……………………………… Substrate portion 10, 20, 30, 40, 50… Conductive layer 19 ………………………………… Through hole 21 ………………… ……………… Green Sheet 24 ………………………………… Underly Metallized Layer 26 …………………………………… Laminated 31, 41 ……………… ………… Wiring board

Claims (1)

In a plurality of green sheets to be a wiring board assembly, along the planned dividing line formed by dividing the dividing grooves for dividing the plurality of substrate portions, the divided line and the major axis are substantially oval or substantially elliptical in parallel. Forming a through hole of
Forming a plurality of base metallization on the position of each substrate portion facing away from and the dividing line in the inner circumferential surface of each the through hole in the plurality of green sheets,
A step of laminating the plurality of green sheets so that the through holes communicate with each other and the base metallization is connected ;
Forming a dividing groove along the planned dividing line in the laminate ,
Firing the laminate ,
Forming a conductor layer by plating the base layer on which the base metallization of the ceramic body obtained by the firing is fired ,
A method of manufacturing a wiring board assembly.

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