JPH11340609A - Manufacture of printed wiring board and manufacture of unit wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed wiring board and a unit wiring board, whereby a lead for plating can be cut completely and short circuit can be prevented between wiring patterns. SOLUTION: In a printed wiring board 30 having a plurality of unit wiring boards 32 and plating bars 36 which connect wiring patterns 34 for performing an electrolysis plating on required exposed parts such as terminal parts of the wiring patterns 34, the plating bars 36 connect the required wiring patterns 34 between the adjacent unit wiring boards 32 and are bent so as to cross virtual cutting lines 33 which divide the unit wiring boards 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printed wiring board and a method for manufacturing a unit wiring board.

[0002]

2. Description of the Related Art As shown in FIG. 10, a plurality of unit wiring boards 12 are formed on a printed wiring board 10, and the printed wiring boards 10 are finally cut along the boundaries of the unit wiring boards 12 and separated into unit wiring boards 12. There are types that do. Before separation, an electrolytic plating film such as nickel plating or gold plating is often formed on a required portion of the wiring pattern 14 such as a terminal (pad) for external connection. In this case, a common plating lead 16 for connecting the wiring patterns 14 of both unit wiring boards 12 is provided between the unit wiring boards 12, and electrolytic plating is performed. After plating, it is necessary to remove the plating leads 16 in order to make each wiring pattern 14 independent. The plating lead 16 is removed by forming a slit in the substrate portion inside the four-sided lead 16 by press working or router processing and removing it when separating into the unit wiring board 12 or including the plating lead 16. Then, the substrate portion is cut to be wider than the lead width and removed.

[0003]

However, in the former method, an area for forming a slit is required, and there is a problem that a useless portion is generated in the material. In the case of the latter, the plating lead 16 may vary due to variations in processing accuracy (positioning of the plating lead 16 and the cutting blade, etc.).
May be left unremoved, and a short circuit between the wiring patterns 14 is likely to occur. In particular, when plating leads are formed on the back side of the board and cut from the front side of the board, or when a multilayer printed wiring board has plating leads on the inner layer, etc., cut off the plating leads. In many cases, the blade is misaligned. In this case, if the cutting is performed with a cutting line slightly wider than the plating lead as described above, there is a problem that the unremoved portion of the lead is significantly generated. is there.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a printed wiring board capable of completely cutting a lead for plating and preventing a short circuit between wiring patterns. And a method of manufacturing a unit wiring board.

[0005]

The present invention has the following arrangement to achieve the above object. That is, in the printed wiring board according to the present invention, since a plurality of unit wiring boards are formed and a required exposed portion such as a terminal portion of the wiring pattern is subjected to electrolytic plating, a printed lead formed with a plating lead for connecting the wiring pattern is formed. In the wiring board, the lead for plating is
The adjacent unit wiring boards are connected to required wiring patterns corresponding to both adjacent unit wiring boards and are bent so as to intersect a virtual cutting line separating the two unit wiring boards. It is characterized by.

[0006] Since the plating lead is provided to cross the virtual cutting line, the position and width of the cutting line may be slightly shifted,
Even if there is variation, the lead for plating can be reliably cut, and short circuit of the wiring pattern can be prevented. Preferably, the printed wiring board is a multilayer printed wiring board, and the plating lead is a plating lead for connecting between wiring patterns in an inner layer. Preferably, the unit wiring board includes a semiconductor chip housing recess. The printed wiring board can be cut into individual unit wiring boards by cutting along a cutting line crossing the plating lead.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of a printed wiring board 30. The printed wiring board 30 is formed by connecting a large number of unit wiring boards 32 in a row and a row.
The unit wiring board 32 is a virtual cutting line 3 indicated by a dashed line in FIG.
It is a part surrounded by 3. A required wiring pattern 34 is formed on the unit wiring board 32. Semiconductor chip (not shown) mounted on unit wiring board 32 and wiring pattern 34
Are electrically connected by a wire or the like.

[0008] The wiring pattern 34 is subjected to required plating such as gold plating with nickel plating as a base. 36 is a lead for plating. The plating leads 36 connect portions of the wiring pattern 34 corresponding to both sides of the virtual cutting line 33 in the unit wiring boards 32 adjacent to each other. As shown in FIG. 2 in an enlarged manner, the plating leads 36 are connected to the wiring patterns 34a and 34a, 34b and 34b of the adjacent unit wiring board 32, which correspond to the cutting lines 33 therebetween.
4b, 34c and 34c, and a line 36a that linearly connects 34d and 34d, and a line 36b that connects wiring patterns 34a and 34b, which are diagonally located on opposite sides, are provided in a substantially zigzag shape. ing. Thereby, as shown in FIG. 1, all the wiring patterns 34 are electrically connected by the plating leads 36, and the required electrolytic plating can be performed on the wiring patterns 34.

The wiring pattern 34 and the plating lead 36
It is needless to say that the above-mentioned required pattern can be formed by etching a copper foil provided on a resin substrate. FIG. 3 is a cross-sectional view showing an example of a single-layer printed wiring board 30. The wiring pattern 34 is formed on one surface side of the resin substrate 35, and the wiring pattern (terminal portion) 40 is formed on the other surface side. The wiring pattern 34 and the terminal 40 are electrically connected by through-hole plating 38. The corresponding wiring pattern 34 of the adjacent unit wiring board 32 is the plating lead 3 indicated by a circle in the figure.
6 are electrically connected. Therefore, electrical conduction is provided by the common plating lead 36, and a plating film can be formed on required portions of the wiring pattern 34 and the terminals 40.

The separation into the unit wiring patterns 32 can be performed by cutting along a cutting line 33 shown by a one-dot chain line in the figure. At this time, as is clear from FIG. 2, since the line segments 36 a and 36 b of the plating lead 36 intersect with the cutting line 33, even if the position and width of the cutting line 33 are slightly varied, The plating lead 36 can be reliably cut and separated,
Short circuit of the wiring pattern 34 can be prevented. It should be noted that a solder ball (not shown) may be provided on the terminal portion 40 to serve as an external connection terminal. Unit wiring board 3
A semiconductor chip (not shown) can be mounted on one surface of the second. That is, the unit wiring board 32 can be used as a package for mounting a semiconductor chip.

FIG. 4 is a sectional view showing an example of a printed wiring board 30 formed in a multilayer (three layers in the illustrated example). 35
Denotes a first-layer resin substrate, 37 denotes a second-layer resin substrate, and 39 denotes a third-layer resin substrate, which are adhered and laminated by an adhesive layer (not shown). Through holes are formed in the second-layer resin substrate 37 and the third-layer resin substrate 39, and by laminating them, a concave portion 41 for housing a semiconductor chip is formed in the center of each unit wiring board 32. . Second-layer resin substrate 37
A wiring pattern 34 whose tip side is exposed on the stepped portion of the second-layer resin substrate 37 is formed between the second-layer resin substrate 37 and the third-layer resin substrate 39. A pattern (terminal portion) 40 is formed, and the wiring pattern 34 and the terminal portion 40 are electrically connected by a through-hole plating film 38.

The corresponding wiring pattern 34 of the adjacent unit wiring board 32 is formed by the plating lead 3 shown by a circle in FIG.
6 are electrically connected. Therefore, electrical conduction is provided by the common plating lead 36, and a plating film can be formed on required portions of the wiring pattern 34 and the terminals 40. The separation into the unit wiring pattern 32 can be performed by cutting along a cutting line 33 shown by a dashed line in the figure. At this time, as is clear from FIG. 2, since the line segments 36 a and 36 b of the plating lead 36 intersect with the cutting line 33, even if the position and width of the cutting line 33 are slightly varied, The leads 36 for plating can be reliably cut and separated, and the short circuit of the wiring pattern 34 can be prevented. The plating lead 36 is located on the inner layer side and cannot be seen from the outside, but since it is in a zigzag shape, it can be reliably cut. Further, the zigzag portion remaining after being cut is hidden by the inner layer and cannot be seen from the outside, so that the appearance is good. It should be noted that a solder ball (not shown) may be provided on the terminal portion 40 to serve as an external connection terminal. A semiconductor chip (not shown) can be mounted in the storage recess 41 of the unit wiring board 32. That is, the unit wiring board 32 can be used as a package for mounting a semiconductor chip.

FIG. 5 shows a printed wiring board 30 having a heat sink.
FIG. 3 is a cross-sectional view showing one example. A metal radiator plate 47 is fixed to one surface of the resin substrate 35 with an adhesive 45. On the other surface side of the resin substrate 35, the wiring pattern 3
4 are formed in the same pattern as described above. A wiring pattern 49 is formed in the chip mounting portion at the center of each unit wiring board 32 so as to correspond to the electrodes of the semiconductor chip to be mounted. The wiring pattern 49 corresponds to the corresponding wiring pattern 3
4 is electrically connected. The connection between the wiring pattern 34 and the wiring pattern 49 can be easily performed by a known means by forming the resin substrate 35 in a multilayer structure.

The corresponding wiring pattern 34 of the adjacent unit wiring board 32 is formed by the plating lead 3 shown by a circle in FIG.
6 are electrically connected. Therefore, electrical conduction is provided by the common plating lead 36, and a plating film can be formed on required portions of the wiring patterns 34 and 49. In the example of the printed wiring board 30 shown in FIG. 5, after performing the above-described necessary plating, a V-groove 50 is provided along the boundary line of the unit wiring board 32 from the resin substrate 35 side to the heat sink 47, and The unit wiring boards 32 to be connected to each other are connected by a thin portion 47 a of a heat radiating plate 47.

The V-groove 50 allows the plating lead 6 to be formed.
Are cut and separated, so that the wiring pattern 34 is also separated. Since the unit wiring boards 32 are only connected to each other by the thin portions 47a of the heat radiating plate 47, separation into the unit wiring boards 32 can be easily performed by cutting the thin portions 47a with a press or a cutting blade. . FIG. 6 shows an example in which a semiconductor chip is mounted on the separated unit wiring board 32 (semiconductor chip mounting package) to form a semiconductor device 54. That is, the semiconductor chip 55 is electrically connected to and bonded to the wiring pattern 49 by flip-chip connection, the frame 56 is arranged so as to surround the semiconductor chip 55, and the potting resin 57 is filled in the frame 56. One surface side of the semiconductor chip 55 is sealed. Then, a solder bump 58 for external connection is provided on the wiring pattern 34 to complete the semiconductor device 54 with a heat sink.

FIGS. 7 to 9 show various patterns of the plating lead 36. FIG. In FIG. 7, the wiring patterns 34 are connected in a staggered manner between adjacent unit wiring boards 32, and are connected in a zigzag shape in the example shown in FIG. 8, and in a zigzag curve in the example shown in FIG. I have. As described above, the pattern of the plating lead 36 is not particularly limited, and may be any pattern as long as it crosses the virtual cutting line 36.

[0017]

According to the printed wiring board of the present invention,
Since the plating leads are provided crossing the virtual cutting lines, the plating leads can be reliably cut even if the positions and widths of the cutting lines are slightly displaced or vary, thus preventing short circuit of the wiring pattern. it can. Further, in the method for manufacturing a unit wiring board according to the present invention, it is only necessary to cut the printed wiring board along the virtual cutting line, and even if the cutting position and width vary, the plating lead is reliably cut. It is possible to provide a unit wiring board having no short circuit of the wiring pattern.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a wiring pattern and a pattern of a lead for plating.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a sectional view of a single-layer printed wiring board.

FIG. 4 is a sectional view of a multilayer printed wiring board.

FIG. 5 is a sectional view of a printed wiring board provided with a heat sink.

FIG. 6 is an explanatory view formed in the semiconductor device.

FIG. 7 is an explanatory view showing another example of a pattern of a lead for plating.

FIG. 8 is an explanatory view showing another example of a pattern of a lead for plating.

FIG. 9 is an explanatory view showing still another example of a pattern of a lead for plating.

FIG. 10 is an explanatory diagram showing an example of a wiring pattern and a plating lead pattern on a conventional printed circuit board.

[Explanation of symbols]

 Reference Signs List 30 printed wiring board 32 unit wiring board 33 virtual cutting line 34 wiring pattern 36 lead for plating 38 through-hole plating 40 wiring pattern 47 heat sink

Claims (4)

[Claims] 1. A printed wiring board in which a plurality of unit wiring boards are formed and electroplating is performed on a required exposed portion such as a terminal portion of the wiring pattern, so that a plating lead for connecting the wiring pattern is formed. Lead is between the adjacent unit wiring boards,
A printed wiring board, which is provided so as to connect between corresponding required wiring patterns of adjacent two unit wiring boards and to bend so as to cross a virtual cutting line separating the two unit wiring boards. 2. The printed wiring board according to claim 1, wherein the printed wiring board is a multilayer printed wiring board, and wherein the plating lead is a plating lead for connecting between wiring patterns of an inner wiring pattern. Printed wiring board. 3. The printed wiring board according to claim 1, wherein the unit wiring board includes a semiconductor chip housing recess. 4. The unit wiring board according to claim 1, wherein the printed wiring board according to claim 1, 2 or 3 is cut along a cutting line crossing the plating lead and separated into each unit wiring board. Production method.