JP3929302B2 - Large circuit board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, a conductor pattern areas corresponding to the plurality of individual circuit board, to a large circuit board arranged collectively.
[0002]
[Prior art]
Circuit boards such as semiconductor packages are obtained by collectively forming conductor pattern regions corresponding to a plurality of individual circuit boards on a large circuit board and finally cutting along the boundary lines of the individual circuit boards. .
Before cutting and separating into individual circuit boards, electroplating films such as nickel plating and gold plating are often formed on required portions such as external connection terminals (pads) of the conductor pattern.
[0003]
FIG. 7 is a plan view of an essential part showing a structural example in which conductor pattern regions corresponding to a plurality of individual circuit boards are collectively formed on a conventional large circuit board, and a part of four circuit boards before separation. Is shown. In FIG. 7, reference numeral 50 denotes an individual circuit board, and a conductor pattern 56 disposed on the circuit board is connected to a pad electrode 51 and a through hole 52 as necessary. (Not shown). In addition, the common electrode line 53 for plating formed along the boundary line of the individual circuit board 50 is connected to a conductor pattern that requires plating, and the common electrode line 53 for plating is used to electrically connect the conductor pattern. I am trying to do plating. After the electroplating is completed, the connection between the conductor pattern 56 and the common electrode line 53 for plating is cut along the cut lines 54 and 55, and the individual circuit board 50 is separated from the large circuit board. I got a substrate.
[0004]
However, in the above method, in order to cut and separate one plating common electrode line 53, two cutting steps are required, and the portion where the plating common electrode line 53 is formed is finally removed. As a result, there is a problem that a wasteful portion is generated in the material.
[0005]
Therefore, a circuit board structure that solves this problem is described in Japanese Patent Application Laid-Open No. 11-340609. According to FIG. 1 of the publication, a plurality of unit wiring boards 32 are formed, and plating leads 36 for connecting the wiring patterns 34 are formed in order to perform electroplating on required exposed portions such as terminal portions of the wiring patterns 34. In the printed wiring board 30, the plating lead 36 connects between the corresponding required wiring patterns 34 of the adjacent unit wiring boards 32 between the adjacent unit wiring boards 32 and cuts the unit wiring boards 32. It is bent and provided so as to cross the line 33.
[0006]
According to the above structure, since all the wiring patterns 34 can be separated by cutting once along the cutting line 33, the cutting man-hour is halved compared to the conventional structure, and there is an effect that the material is not wasted. However, there are the following problems. In the unit wiring board 32 of FIG. 1, if the wiring interval between the wiring patterns 34 is narrow, the interval between the adjacent plating leads 36 remaining on the unit wiring board 32 after being cut by the cutting line 33. However, it becomes smaller in the vicinity of the cutting line 33, and both are likely to be short-circuited. Therefore, in such a structure, it is necessary to widen the wiring interval between the wiring patterns 34, and there is a problem that the wiring density cannot be increased.
[0007]
Therefore, a circuit board structure which further solves this problem is described in WO01 / 78139. FIG. 4 of the same publication shows a plan view of the main part of a large circuit board in which two circuit boards 20A are formed adjacent to each other. The two circuit boards 20A are each formed with a through hole 11 as a conductor pattern. On the surface side of the circuit board 20A, the through holes 11 facing each other across the cut line X for individually dividing the circuit board 20A are connected one by one with the common electrode line 22A for plating, and further, the circuit board On the back side of 20A, the through holes 11 having a diagonal relationship are connected to each other by a common electrode line 22B for plating so as to cross the cut line X diagonally. In other words, the common electrode lines 22A and 22B for plating meander the cut line X in a plane, but they are separately formed on the front and back of the circuit board 20A, so that the problem of short-circuiting due to the contact between them is solved. In addition, it is possible to increase the wiring density by narrowing the interval between the through holes 11 (the same as the interval between the wiring patterns).
[0008]
[Problems to be solved by the invention]
However, the circuit board structure described in the above-mentioned WO01 / 78139 has the following problems. In general, the formation of a metal film in a through hole uses electroless plating on a circuit board substrate. Although the metal film thickness by electroless plating varies depending on the processing time, it is a very thin film and therefore has a higher resistance value than a wiring pattern formed by pasting a copper foil on the surface of a circuit board in advance. Therefore, when electroplating is performed using the common electrode wires for plating 22A and 22B described in the above-mentioned WO01 / 78139, the film thickness on the side near the electrode terminals for electroplating is passed through the plurality of through holes 11. The thickness of the electroplated portion was very thin, and the plating film had a large variation in thickness. When the thickness of the plating film is different, the wiring resistance is different, which is a big problem for an electric circuit.
The present invention solves the above-described problems, and provides a large circuit board and a circuit board with a small number of man-hours when cutting individual circuit boards from a large circuit board and with less variation in the thickness of electroplated plating films. It is.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a large circuit board according to the present invention includes a conductor pattern region corresponding to a plurality of individual circuit boards, and a common electrode line for plating connected to the conductor pattern. In the large circuit board for obtaining the individual circuit board by cutting after plating, the first and second common electrode lines for plating are provided at positions separated in the surface direction of the large circuit board. , wherein without respect first plating common electrode line at least a portion of the conductor pattern on the opposite side of the common electrode line for plating the second, through the common electrode line for plating the first connected to the second plating common electrode line, to the second plating common electrode line at least a portion of the conductor pattern on the opposite side of the common electrode line for plating the first, the second Common electrode wire for plating While connected to the first plating common electrode line without passing through the first and second plating common electrode line is characterized in that provided on the different substrates face each other.
[0012]
The large circuit board according to claim 2 is connected to the first or second plating common electrode line between the first and second plating common electrode lines according to claim 1. It is characterized by having a conductor pattern.
[0013]
The large circuit board according to claim 3 is the conductor pattern according to claim 1 or 2 , wherein the conductor pattern is on the opposite side to the second common electrode line for plating with respect to the first common electrode line for plating. Is connected to the first plating common electrode line, or at least one of the conductor patterns on the opposite side of the first plating common electrode line with respect to the second plating common electrode line. part is characterized in that it is connected to the common electrode line for plating the second.
[0014]
According to a fourth aspect of the present invention, in the large-sized circuit board according to the first to third aspects, a cutting line is provided between the first common electrode line for plating and the second common electrode line for plating . It is characterized by that.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
1 is a plan view of the front surface side of a large circuit board showing an embodiment of the present invention, FIG. 2 is a plan view of the back side of the large circuit board, and FIG. The common electrode line for plating on the surface side is indicated by a broken line. FIG. 4 is an enlarged plan view of a main part showing a part of FIG.
1 and 2, reference numeral 1 denotes a large circuit board in which conductor pattern regions corresponding to four individual circuit boards 2 to 5 are arranged, and each of the individual circuit boards 2 to 5 is a ball grid array (hereinafter abbreviated as BGA). It is a circuit board. Symbols A, B, C, and D attached to the four sides of the large circuit board 1 are symbols indicating the four sides that are attached to be used for explanation of directions and parts of the large circuit board 1 and the individual circuit boards 2 to 5. 2 and FIG. 3 are similarly applied.
[0017]
As shown in FIG. 1, an IC chip mounting area 6 is disposed at the center of the individual circuit boards 2 to 5, and a lead pattern 7 is disposed so as to surround the periphery of the IC chip mounting area 6. Reference numeral 8 denotes a through hole connected to the lead pattern 7, and is connected to the wiring pattern 9 disposed on the back side of the individual circuit boards 2 to 5 shown in FIG. In FIG. 2, reference numeral 10 denotes an external connection pad electrode arranged in a substantially lattice pattern, and is connected to the wiring pattern 9. In this embodiment, the lead pattern 7, the through hole 8, the wiring pattern 9, and the pad electrode 10 are conductor patterns.
[0018]
In FIG. 1, reference numerals 11 and 12 denote plating common electrode lines for guiding current to each conductor pattern during electroplating, and a part thereof is disposed in a completed region of the individual circuit boards 2 to 5. . In the surface side shown in FIG. 1, the common electrode line 11 for plating is disposed along the B side of the individual circuit boards 2 to 5 and is adjacent to the B side of the individual circuit boards 2 to 5. Are connected to a through hole 8 disposed on the D side.
[0019]
Similarly, the common electrode line 12 for plating is disposed along the A side of the individual circuit boards 2 to 5, and on the C side of each individual circuit board adjacent to the A side of each individual circuit board 2 to 5. It is connected to the disposed through hole 8. That is, the common electrode lines 11 and 12 for plating supply plating current to the through holes 8 and the lead patterns 7 arranged along the C side and D side on the front surface side of the individual circuit boards 2 to 5 and These are electrode lines for supplying a plating current to the wiring pattern 9 and the pad electrode 10 connected to the through holes 8 arranged along the C side and the D side.
[0020]
Similarly, in FIG. 2, reference numerals 13 and 14 denote common electrode lines for plating for guiding current to each conductor pattern at the time of electroplating, and a part thereof is disposed in a completed region of the individual circuit boards 2 to 5. Yes. 2, the common electrode line 13 for plating is disposed along the D side of the individual circuit boards 2 to 5 and is adjacent to the D side of the individual circuit boards 2 to 5. To the through hole 8 disposed on the B side.
[0021]
Similarly, the common electrode line 14 for plating is disposed along the C side of the individual circuit boards 2 to 5, and on the A side of each individual circuit board adjacent to the C side of each individual circuit board 2 to 5. It is connected to the disposed through hole 8. In other words, the plating common electrode lines 13 and 14 supply a plating current to the through hole 8, the wiring pattern 9, and the pad electrode 10 disposed along the A side and the B side on the back side of the individual circuit boards 2 to 5. These are electrode wires for supplying a plating current to the lead pattern 7 connected to the through holes 8 arranged along the A side and the B side on the surface side.
[0022]
Next, with reference to FIGS. 3 and 4, the arrangement relationship of the common electrode lines 11 to 14 for plating will be described. In each drawing, the common electrode lines 11 and 12 for plating are indicated by broken lines, and the common electrode lines 13 and 14 for plating and the conductor pattern on the back surface side are indicated by solid lines. At this time, the plating common electrode lines 13 and 14 are defined as the first plating common electrode lines, and the plating common electrode lines 11 and 12 are defined as the second plating common electrode lines.
[0023]
The relationship between the first plating common electrode line 13 and the second plating common electrode line 11 will be described. The first plating common electrode line 13 and the second plating common electrode line 13 are spaced apart from each other in the surface direction of the large circuit board 1. A common electrode line for plating 11 is provided, and at least a part of the conductor pattern 8b on the opposite side of the first common electrode line 11 for plating to the second common electrode line 11 for plating is used for the first plating. The second common electrode line 11 is connected to the second common electrode line 11 without going through the common electrode line 13, and the second common electrode line 11 is opposite to the first common electrode line 13 for plating. At least a part of the conductor pattern 8 a is connected to the first plating common electrode line 13 without passing through the second plating common electrode line 11.
[0024]
The same applies to the relationship between the first common electrode line 14 for plating and the second common electrode line 12 for plating. In the above explanation, reference numeral 11 is 12, reference numeral 13 is 14, reference numeral 8a is 8c. , 8b may be read as 8d.
[0025]
In FIG. 3, the broken line wiring and the solid line wiring are shifted so that the connection between the plating common electrode lines 11 to 14 and each through-hole 8 can be seen. However, in actuality, as shown in FIG. Since wirings can be overlapped, high-density wiring with a narrow vertical wiring interval in FIG. 4 is possible.
[0026]
After electroplating the large circuit board 1 having the plating common electrode lines 11 to 14 as described above, as shown in the figure, between the plating common electrode lines 11 and 13 and the plating common electrode line 12. And 14 are each cut once (denoted as virtual cutting lines in each figure), unnecessary connection between the conductor pattern and the common electrode lines 11 to 14 for plating is cut, and each conductor pattern is predetermined. The individual circuit boards 2 to 5 can be obtained in a state where the above connection relationship is maintained.
[0027]
According to the above embodiment, since only one through hole is inserted in the path from the common electrode lines for plating 11 to 14 to each conductor pattern, the variation in wiring resistance can be reduced and the difference in plating current can be reduced. For this reason, there is no difference in plating thickness, and when the individual circuit boards 2 to 5 are cut and separated, the number of steps can be reduced because one cutting is sufficient.
[0028]
In FIG. 3, the plurality of conductor patterns 8 e on the opposite side of the first plating common electrode line 14 from the second plating common electrode line 12 are connected to the first plating common electrode line 14. Has been. Therefore, a plurality of conductor patterns on the individual circuit boards 2 to 5 remain in the plating common electrode line 14 in a state of being cut into the individual circuit boards 2 to 5. The configuration can be used as a wiring connecting two or more conductor patterns, such as a power supply wiring.
[0029]
That is, the without passing through the first common electrode line 12 for the second plating at least a portion of the conductor pattern 8e with respect to plating the common electrode line 14 on the opposite side of the second plating common electrode line 12 connect to plating the common electrode line 14 of 1 or the first plating at least a portion of the second to plating the common electrode line 12 on the opposite side of the first plating the common electrode line 14 conductor pattern 8c It is possible to connect to the second plating common electrode line 12 without going through the common electrode line 14 .
[0030]
In the above embodiment, the common electrode lines 11 to 14 for plating are used as a part of the conductor pattern. However, the present invention is of course not limited thereto and is isolated from the effective conductor pattern while being in a non-conductive state. In this state, the common electrode lines 11 to 14 for plating may be left on the individual circuit boards 2 to 5.
[0031]
In this case, meaningless common electrode lines 11 to 14 for plating remain on the individual circuit boards 2 to 5, but the board space can be effectively used as a space for mounting large parts or a board holding space, for example. As a result, the number of individual circuit boards 2 to 5 that can be obtained from the large circuit board 1 can be increased. Of course, the effects of improving the wiring density, reducing the number of cutting steps, and uniform plating thickness are not changed.
[0032]
Next, another embodiment of the present invention will be described with reference to FIG. FIG. 5 is a main part plan view showing the boundary line partial back side of the individual circuit boards 2 to 5, and the common electrode lines 11 and 12 for plating on the front side are indicated by broken lines. A difference from the above-described embodiment is that a part of the through holes 8f constituting the conductor pattern are disposed between the common electrode lines 12 and 14 for plating.
[0033]
In this embodiment, one of the pad electrodes 10a is electrically connected to the conductor pattern disposed on the surface side of the individual circuit boards 2 to 5 through the through holes 8f, thereby using the individual circuit boards 2 to 5. When the BGA is mounted on a motherboard (not shown), the electrical connection with the motherboard-side conductor pattern can be confirmed by the conductor pattern disposed on the surface side of the individual circuit boards 2 to 5. That is, the present embodiment shows that a conductor pattern connected to the first or second plating common electrode line may be provided between the first and second plating common electrode lines.
[0034]
In the above embodiment, the common electrode wire for plating formed along the same side of the individual circuit boards 2 to 5 is formed on the back and front of the individual circuit board, that is, on different circuit board surfaces. It is not limited to this, and both may be disposed on the same surface side. In this case, however, both of the common electrode lines for plating need to be led by the through holes to the side where the common electrode line for plating is not formed, and then guided to the adjacent circuit board side.
[0035]
This configuration can be suitably implemented for the purpose of avoiding interference between the component and the common electrode line for plating when the space occupied by the common electrode line for plating is used as a component mounting space as described above. . Although the above-described effect of improving the wiring density is reduced, the effects of reducing the number of cutting steps and uniform plating thickness are not changed.
[0036]
FIG. 6 shows another embodiment of the present invention. When a conductor pattern that requires plating can be extended to one of the opposing sides of each individual circuit board 2 to 5, the conductor pattern is It is only necessary to connect to the common electrode lines 11 and 12 for plating provided in the areas of the individual circuit boards 2 to 5 adjacent to the side, and therefore, only one common electrode line 11 and 12 for plating is required per side. .
[0037]
In the above embodiment, the conductor pattern is formed on both sides of the circuit board, but the present invention is not limited to this, and the same structure can be implemented when the conductor pattern is formed only on one side, The effect is exhibited as well.
[0038]
In all the drawings, the common electrode line for plating is a straight line and is cut by a cutting line orthogonal to the straight line. However, in the present invention, the common electrode line for plating is drawn. May be a curved line, and does not limit the cutting location.
[0039]
【The invention's effect】
As described above, according to the present invention, conductor pattern regions corresponding to a plurality of individual substrates are arranged, and after plating the conductor pattern via the common electrode line for plating, the individual circuit substrate is obtained by cutting. In large circuit boards, variation in wiring resistance from the common electrode line for plating to each conductor pattern can be reduced, variation in plating thickness due to electroplating can be reduced, and the number of cutting steps to be separated into individual circuit boards can be reduced. Can do. In addition, since the interval between the conductor patterns connected to the common electrode line for plating can be reduced, high-density board mounting can be realized.
[0040]
Further, since the remaining common electrode wire for plating can be used as a part of the conductor pattern, or the space of the remaining common electrode wire for plating can be effectively used, as a result, it is possible to remove individual circuit boards that can be obtained from a large circuit board. The number can also be increased.
[Brief description of the drawings]
FIG. 1 is a plan view of a surface side of a large circuit board showing an embodiment of the present invention.
2 is a plan view of the rear surface side of the large circuit board shown in FIG. 1. FIG.
FIG. 3 is a plan view of a principal part showing a boundary line partial back side of an individual circuit board;
4 is an enlarged plan view of a main part showing a part of FIG. 3. FIG.
FIG. 5 is a plan view of the main part showing the back side of the boundary line portion of the individual circuit board according to another embodiment of the present invention.
FIG. 6 is a plan view of the surface side of a large circuit board showing another embodiment of the present invention.
FIG. 7 is a plan view of an essential part showing a conventional large circuit board structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Large circuit board 2, 3, 4 5 Individual circuit board 7 Lead pattern 8 Through hole 9 Wiring pattern 10 Pad electrode 11, 12, 13, 14 Common electrode line for plating

Claims (4)

A conductor pattern region corresponding to a plurality of individual circuit boards is arranged, a common electrode line for plating connected to the conductor pattern is arranged, and the conductor pattern is plated and then cut to obtain the individual circuit board. large circuit in the substrate for the first and second of said plating common electrode line formed at a position spaced in the surface direction of the large-sized circuit board, the second to the first plating common electrode line Connecting at least a part of the conductive pattern on the opposite side of the common electrode line for plating to the second common electrode line for plating without passing through the first common electrode line for plating; plating to plating the common electrode line and the common electrode line for plating the first at least part of the conductor pattern on the opposite side, the first without passing through the common electrode line for plating the second connection to use the common electrode line Then The said first and second plating common electrode line is large circuit board, characterized in that provided on the different substrates face each other. 2. The large size according to claim 1 , wherein a conductor pattern connected to the first or second plating common electrode line is provided between the first and second plating common electrode lines. Circuit board. Wherein at least a portion of the conductor pattern on the opposite side to the first common electrode line for the second plating to the plating for the common electrode line is connected to the common electrode line for plating the first or the second billing at least part of the conductor pattern with respect to plating the common electrode line on the opposite side of the first plating for the common electrode line is characterized in that it is connected to the common electrode line for plating the second The large circuit board according to claim 1 or claim 2 . According to any one of claims 1 to 3, characterized in that cutting lines are provided between the first said common electrode wire for plating in the second plating for the common electrode line Large circuit board.

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