JP2002171035A - Large-scaled circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a large-scaled circuit board, which enables inspection of each circuit board region for high-frequency characteristics on the large-sized circuit board to be carried out, and which can prevent the generation of cracks due to a sharp shrinkage of itself, when it is baked. SOLUTION: The large-sized circuit board 10 is formed with separate division recesses 2 and 3 for extracting the respective circuit board regions 9, at least on each side of each circuit board region 9. By dividing the large-sized circuit board 10 along the division recesses 2 and 3, a plurality of substrates are obtained. Blank regions 5 are formed between the circuit board regions 9, which are adjacent at least in either X or Y direction. In part of a region wherein the division recesses 2 and 3 cross the blank region 5, a part 4 through which ceramic sections holding the division recesses 2 and 3 in between are connected is formed. In a boundary between each circuit board region 9 and the blank regions 5, terminal electrodes 6 and 7 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-sized circuit board from which a plurality of circuit boards can be extracted by arranging circuit board regions to be circuit boards vertically and horizontally and performing division processing along division grooves.

[0002]

2. Description of the Related Art A circuit board is required to have a smaller board size and a higher frequency of a mounted circuit. For example, an alumina ceramic material having excellent heat resistance, durability, heat conductivity, etc. is required. Is often used. On the circuit board, various electronic component elements such as semiconductor elements such as IC chips and LSI chips are mounted on the surface, or are housed in cavities formed on the surface. In addition, a semicircular through-hole electrode formed on the end face of the circuit board is used to connect the predetermined circuit network formed on the circuit board to the circuit on the motherboard. In order to efficiently manufacture such a circuit board, a large-sized circuit board is used in which circuit board areas to be each circuit board are arranged vertically and horizontally, and the circuit board area is vertically and horizontally arranged in the final process of manufacturing the circuit board. The dividing process was performed by the dividing groove.

[0003] The divided grooves (hereinafter referred to as snap lines) are formed by pressing a mold so that the grooves have a depth of 30 to 70% of the thickness of the substrate before firing the large circuit board made of ceramic. Was formed. After firing, various components were mounted on the board, and a plurality of circuit boards were extracted along the snap line in the final stage.

FIG. 3 is a plan view showing a conventional large-sized circuit board from which a plurality of circuit boards on which snap lines are formed can be extracted. FIG. 4 is a plan view showing a general substrate manufacturing method. In the figure, 30 is a large circuit board, 31 is a circuit board, 32 is a snap line in the Y direction, 33 is a snap line in the X direction, 35 is a blank area on the outer peripheral portion of the large circuit board, and 39 is the divided circuit board 31 Circuit board regions.

According to FIG. 1, before firing the large circuit board 30, snap lines 32 and 33 are formed, and if necessary, internal wiring and surface wiring are sintered together with the substrate, or after sintering. Forming surface wiring on the surface of the circuit board region 39;
After mounting various electronic components, snap lines 32, 33
Thus, each circuit board 31 was obtained. FIG. 4 shows a dividing step in which the large circuit board 30 is divided into two stages to obtain the circuit board 31. That is, FIG.
The large circuit board 30 shown in FIG.
A primary division process is performed along (FIG. 4B).
Snap line 33 remaining on strip-shaped circuit board 30 '
According to the above, a secondary division process is performed to obtain individual circuit boards 31.

[0006]

Generally, after various electronic components are mounted on a circuit board area to form a predetermined circuit network, an inspection process is required to check whether the predetermined circuit network operates normally. . In the case of manufacturing using the above-mentioned large circuit board, each circuit board area 39 is divided and the circuit board 31 is processed.
The large circuit board 3 before splitting is not measured after
It is desirable to measure in the state of 0.

When a predetermined network of each circuit board 31 operates at a high frequency, the characteristic impedance is measured together with the operation of the network. At this time, a measurement probe is applied to the input / output terminal electrode and the ground terminal electrode to measure characteristic impedance and the like. Since the input terminal electrode and the ground terminal electrode are formed on the end surface of the circuit board 31, the large circuit board 30 has a dividing groove (actually, an extension of the dividing groove) for partitioning the adjacent circuit board regions 39. line)
Must be formed. That is, after the dividing process,
It is necessary to form a through hole serving as a concave portion and to form a conductor film serving as each terminal electrode on the inner wall surface of the through hole. In FIG.
For example, a through-hole is formed in the shape of the dividing groove 32, and a conductor film to be the terminal electrodes 36 and 37 is formed on the inner wall surface.

Here, as shown in FIG. 5, in the large circuit board 30, the adjacent circuit board area 39 has a repetitive pattern of a circuit network, and also straddles a dividing groove which partitions the adjacent circuit board area 39. Is formed, the terminal electrodes 36, 3 between the adjacent circuit boards 39 are formed.
7 will be in contact. That is, the input / output terminal electrodes 36 of the adjacent circuit board regions 39 and the ground terminal electrodes 37 or the input / output terminal electrode force 36 and the ground terminal electrodes 37 are joined. Therefore, even if an attempt is made to inspect various characteristics of a circuit network formed in one circuit board region, since the terminal electrodes 36 and 37 that are bonded to each other are present, it is necessary to measure the characteristics of the single circuit board region 39. Could not.

For this reason, it has been necessary to inspect the high frequency characteristics after mounting a semiconductor element, a thick-film resistance element, various electronic components, and the like on the large-sized circuit board 30, and then perform a dividing process. For this reason, there is a problem that useless processes increase due to delay in finding defective products.

On the other hand, it is conceivable to form a characteristic measuring electrode on the surface of each circuit board 31, but there is a problem that the area occupied by the board is restricted, and it is not possible to meet the demand for miniaturization.

Further, when manufacturing the large circuit board 30,
As shown by the thick line in FIG. 6, there is a problem that the cracks 38 enter the substrate 30. This is considered to be due to distribution of the firing temperature depending on the position in the firing furnace during the firing process. The generation of the cracks 38 was more likely to occur closer to the center of the large circuit board 30, and was more likely to occur as the shrinkage of the ceramic material of the large circuit board 30 was larger. When the cracks 38 enter the large-sized circuit board 30, when mounting various electronic components on the large-sized circuit board 30, the large-sized circuit board 30 is completely broken or a positional shift occurs during mounting. was there. In order to solve such a problem, it is conceivable to adjust the firing profile to suppress rapid substrate shrinkage, or to reduce the snap lines 32 and 33 to suppress the cracks 38. However, in the method of adjusting the firing profile, although the generation of the crack 38 can be suppressed, the large circuit board 30 may be warped. In the method of making the snap lines 32 and 33 partially shallow, the large circuit board 30 is
At the time of division into ones, stress is likely to be applied, so that burrs are generated at the ends, which causes dimensional variations.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to easily perform a characteristic test of circuit operation in a state of a large circuit board before division, and An object of the present invention is to provide a large-sized circuit board capable of preventing generation of cracks due to rapid contraction of the board when firing the circuit board.

[0013]

According to the present invention, there is provided a circuit board region which becomes a rectangular circuit board in which a concave portion extending in the thickness direction is provided on an end face of the substrate, and a terminal electrode is formed on an inner wall surface of the concave portion. A large-sized circuit board having a margin area provided in the periphery and arranged vertically and horizontally, wherein the circuit board area and the margin area are separated by intermittent divided grooves that are discontinuous in margin areas intersecting vertically and horizontally. In addition, a through hole serving as the concave portion is formed in a division groove between the circuit board region and the blank region, and a terminal electrode that is not conductive with another circuit board region adjacent to an inner wall surface of the through hole is formed. This is a large-sized circuit board characterized by the following.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A large circuit board according to the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view of a large circuit board according to the present invention, FIG. 1B is an enlarged view of a circle in FIG. 1A, and FIG. FIG. 3 is a partially enlarged view focusing on only six adjacent circuit board regions.

In the figure, 10 is a large circuit board, 9 is a circuit board area, 5 is a blank area formed continuously with each circuit board area, and 2 and 3 are a circuit board area 9 and a blank area. This is an intermittent snap line that separates 5 and 5.
Note that reference numeral 2 denotes an intermittent snap line in the Y direction, and reference numeral 3 denotes a snap line in the X direction. Reference numeral 4 denotes a margin connecting portion formed by interrupting the snap lines 2 and 3 in a margin area extending to the other side, 6 denotes an input / output terminal, and 7 denotes a ground terminal. In the drawings, numbers are not distinguished before and after firing.

The large circuit board 10 has a single-plate or multi-layer structure, and is made of, for example, a ceramic substrate. For example, 85
It is made of a glass-ceramic material that can be fired at a relatively low temperature of about 0 to 1050 ° C. As the ceramic material, insulating ceramic materials such as cristobalite, quartz, corundum (α-alumina), mullite, cordierite, BaTiO ₃ , Dielectric ceramic materials such as Pb ₄ Fe ₂ Nb ₂ O ₁₂ and TiO ₂ , Ni—Zn ferrite, M
n-Zn ferrite (ceramic in a broad sense)
And other magnetic ceramic materials. In addition,
Its average particle size is 1.0 to 6.0 μm, preferably 1.5 to 6.0 μm.
Use the one crushed to 4.0 μm. Further, two or more ceramic materials may be used in combination. In particular, the use of corundum is advantageous in terms of cost. The glass material may be any one that precipitates a crystal phase of a cordierite, mullite, anorthite, serdian, spinel, garnite, willemite, dolomite, a crystal of petalite or a substituted derivative thereof or a spinel structure by firing, and for example, , B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , Z
Glass frit containing nO and alkaline earth oxides is exemplified. Such a glass frit has a wide vitrification range and a yield point around 600 to 800 ° C.

Although not shown, surface wiring is formed on the surface of each circuit board region 9, and various components such as IC chips, SAW elements, resistors, capacitors, and inductance elements are mounted as necessary. Further, on the end surface of the circuit board, that is, on the end surface of each circuit board area, an input / output terminal electrode 6 and a ground terminal electrode 7 connected to the surface wiring are formed on the inner wall surface in the through hole 11 penetrating the thickness of the board. Have been. These surface wiring, input / output terminal electrode 6 and ground terminal electrode 7 are made of Ag (Ag alone, Ag-Pd, Ag-Pt).
(Ag alloy, etc.). The input / output terminal electrode 6 and the ground terminal electrode 7 are used as check terminals when measuring the characteristics of the circuit network formed in each circuit board region 9.

In FIGS. 1 and 2, snap lines 2 and 3 orthogonal to each other are formed on one surface or both main surfaces of a large circuit board 10. This snap line 2,3
Are formed on the respective sides of the circuit board region 9 which is a rectangular circuit board arranged vertically and horizontally. A margin region 5 is formed around each circuit board region 9.

Accordingly, when viewed from one direction, the large-sized circuit board 10 includes the blank area 5, the circuit board area 9, the blank area 5,
The circuit board areas 9 are arranged in the order of the blank area 5. The same applies to the other direction. That is, the snap lines 2 and 3 are conventionally formed to separate the circuit board area from the circuit board area. However, in the present invention, the snap lines 2 and 3 are formed to separate the circuit board area 9 from the blank area 5.

The snap lines 2 and 3 are formed intermittently in accordance with the individual circuit board areas 9 and are formed continuously along a plurality of circuit board areas 39 as in the prior art. It is different from the one. That is, the snap lines 2 and 3 are formed so as to be interrupted at the intersecting blank area 5. The part where this breaks is the margin connecting part 4 of the margin area 5, and the margin area 5 is continuous around each circuit board area 9 without being divided by the snap lines 2 and 3. In other words, strip lines 2, 3
Is an intermittent groove that is discontinuous near the center of the orthogonal blank area 5.

Therefore, the terminal electrodes 6 and 7 attached in the concave portions formed on the end face of the circuit board are formed on the snap lines 2 and 3 that separate the circuit board area 9 and the blank area 5 from each other. It is in a non-conductive state with the terminal electrodes 6 and 7 facing the adjacent circuit board region 9.

An embodiment applied to the above-described manufacturing method will be described. _{First, CaO-Al 2 O 3 -SiO} 2 -B 2 O
₃ series glass powder 60wt% and alumina powder 40wt%
, A plasticizer such as DOP, a binder such as an acrylic resin or a butyral resin, and a solvent such as toluene, xylene, and alcohols, and sufficiently kneaded to obtain a viscosity of 2,000 to 40,000 c.
A ps slurry is prepared, and a plurality of low-temperature firing green sheets having a thickness of, for example, 0.2 mm are formed by a doctor blade method.

Next, using a punching die, a punching machine, or the like, a hole serving as a through-hole conductor and a via-hole conductor having an end face of, for example, 0.2 mmφ is punched out at a plurality of predetermined positions of each green sheet. , Ag-P
A conductive paste such as d, Au, or Cu is filled. A conductor pattern for wiring is screen-printed on each green sheet.

Next, a plurality of green sheets on which conductor patterns are screen-printed are laminated, and the large-sized circuit board 10 is integrated by thermocompression bonding at, for example, 80 to 150 ° C. and 50 to 250 kg / cm ² .

Next, snap lines 2 are formed on both the front and back surfaces of the large-sized circuit board 10 which is thermocompression-bonded by pressing.
Next, a snap line 3 in a direction indicated by an arrow X is formed on both front and back surfaces of the large-sized circuit board 10, and as shown in FIG. 1, a large-sized circuit in which a snap line 2 in the Y direction and a snap line 3 in the X direction are formed. A substrate 10 is obtained.

Next, the large-sized circuit board 10 is fired in an air at 900 ° C. for 20 minutes using an electric continuous belt furnace. When the conductive paste is Ni or Cu, the paste is reduced or fired in a neutral atmosphere. Here, semiconductor elements, thick-film resistance elements, various electronic components, and the like are joined and mounted on the large circuit board 10 by soldering or the like.

Next, the fired large circuit board 10 is divided along the snap line 2 in the Y direction by hand or a machine such as a break roller. Next, the large circuit board 10 is divided along the snap line 3 in the X direction.

In this manner, a circuit board as a final product is obtained.

Thus, according to the large-sized circuit board 10 of the present invention, the blank area 5 is provided at least between the circuit board areas 9 adjacent in any of the X and Y directions, and as shown in FIG. An input / output terminal electrode 6 serving as a characteristic measuring terminal and a ground terminal electrode 7 are formed on the inner wall of a through hole (a portion of the circuit board that becomes a concave portion of an end face) extending over the margin region 5 and are disposed adjacent to each other. Since the input / output terminal electrode 6 and the ground terminal electrode 7 in the circuit board area 9 are not electrically connected to each other, even if the characteristics of each circuit board area 9 itself are measured in the state of the large circuit board 10, the circuit board area 9 is located adjacently. The circuit network of the circuit board region 9 is not affected at all. In other words, the characteristics can be measured in the state of the large circuit board 10, and the defective product can be removed at an early stage of the manufacturing process.
The waste process is reduced.

Further, since the margin connecting portion 4 is provided at a portion where the snap lines 2 and 3 cross the margin region 5 orthogonal to each other,
Cracking of the large circuit board 10 along the snap lines 2 and 3 of each circuit board area 9 during firing can be suppressed.
When the width of the margin connection part 4 is less than 200 μm,
Since the effect of suppressing cracks becomes insufficient, the lower limit of the width of the margin connection portion 4 is preferably 200 μm or more.

If the width of the one-way margin connecting portion 4 exceeds one-third of the length of the circuit board region 9 in one direction, the large circuit board 10 can be stably divided during the dividing process. As a result, burrs are generated at the time of division. For this reason, it is desirable that the upper limit of the width of the margin connection portion 4 be equal to or less than １ ／ of the length of the circuit board region 9 extending in the same direction.

Further, since it is not necessary to adjust the firing profile or to make the snap lines 2 and 3 shallow in order to suppress the generation of cracks, the warpage of the substrate becomes large and burrs are generated at the end. There is no.

The inventor has determined the frequency of occurrence of cracks in the large circuit board 10 from which a plurality of circuit boards can be extracted.
The size of the large circuit board 10 after firing is 75 to 80 mm
The corner and thickness used were 0.75 to 1.0 mm, and 35 to 45 substrates were obtained by division.

The snap lines 3 and 2 in the X and Y directions
Has a width of 25 to 80 μm and a depth of 1/5 with respect to the thickness of the large circuit board 10.

As a criterion of pass / fail, 100 large fired large-sized circuit boards 10 were visually observed, and the rate of occurrence of cracks was determined.

As a result of the experiment, the conventional large-sized circuit board 30 shown in FIG. 3 had a crack generation rate of 5%, but the large-sized circuit board 10 of this embodiment shown in FIG. The rate was 0%.

It should be noted that the present invention is not limited to the above embodiment, and various changes and improvements may be made without departing from the scope of the present invention.

For example, the ceramic material for the substrate is not limited to a low-temperature fired substrate, but may be applied to any large-sized circuit substrate such as an alumina substrate, an aluminum nitride substrate, and a mullite substrate. Not only the substrate but also a press-formed body or an extruded body may be used.

In the present embodiment, the snap lines 2 and 3 in the X and Y directions are formed on both the front and back surfaces of the large-sized circuit board 10, but may be formed on only one surface.

Also, the first and second snap lines 2,
A portion where 3 intersects may be deeper than other portions of the snap lines 2 and 3. As a result, the stress applied at the time of division can be reduced, the occurrence of burrs can be reduced, and dimensional variations can be prevented.

[0042]

As described above, according to the present invention, a blank area is provided at least between circuit board areas adjacent to one of the X and Y directions, and between the circuit board area and the blank area, A terminal electrode is formed in a non-conductive state with an adjacent circuit board region. Therefore, the characteristics of each circuit board area itself can be stably measured in the state of the large circuit board.

Further, since the margin connecting portion is formed at a portion where the snap line crosses a margin region orthogonal to the orthogonal direction, it is possible to suppress cracking of the large circuit board along the snap line of each circuit board region during firing. Handling at the time of manufacturing a large circuit board becomes easy.

[Brief description of the drawings]

1A and 1B show a large-sized circuit board according to the present invention, wherein FIG. 1A is a plan view thereof, and FIG. 1B is an enlarged plan view of an intersection of a blank area.

FIG. 2 is a partial plan view showing a shape of a terminal electrode of a large circuit board.

FIG. 3 is a plan view showing a conventional large circuit board.

FIG. 4 is a plan view illustrating a method for manufacturing a general large-sized circuit board.

FIG. 5 is an enlarged plan view of a terminal electrode portion of a conventional large circuit board.

FIG. 6 is a plan view illustrating a crack that has occurred on a conventional large circuit board.

[Explanation of symbols]

 10, 30 Large circuit board 31 Board 2, 32 Snap line in Y direction 3, 33 Snap line in X direction 4 Margin connection part 5, 35 Margin part 6, 36 Input / output terminal 7, 37 Ground terminal 38 Board crack 9, 39 Circuit board area

Claims (1)

[Claims] 1. A circuit board region, which is a rectangular circuit board having a concave portion extending in the thickness direction at an end surface of the substrate and having terminal electrodes formed on the inner wall surface of the concave portion, and a blank region provided around the circuit board region. A large circuit board arranged in the circuit board area, and the circuit board area and the blank area are separated by intermittent divided grooves that are discontinuous in a blank area crossing vertically and horizontally, and the circuit board area and the A large-sized circuit, wherein a through-hole serving as the concave portion is formed in a dividing groove between a blank region and a terminal electrode in a non-conductive state with another circuit board region adjacent to an inner wall surface of the through-hole. substrate.