JPH04789A - Pattern disposition and connecting structure for printed circuit board - Google Patents

Abstract

PURPOSE:To easily form a contact pin of a checker and to improve to eliminate noise, erroneous operation by so connecting the partial pattern to the other pattern as to provide a function of absorbing excessive solder at the time of mounting a component and a function as electrodes at the time of checking. CONSTITUTION:When a discarding pattern 6 is connected to a pin A5 and a discarding pattern 7 is connected to a pin B4 to bring a checker pin to be contacted with the pins A5, B4 into contact with the patterns 6, 7, intervals between the pins A6, B3 and the pins can be increased. Since the patterns 6, 7 can be increased in area to certain degree, the accuracy of mounting the pins in contact therewith may be rough, and easiness of manufacturing the checker is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to pattern arrangement and connection structure of printed wiring boards.

[Conventional technology]

Conventionally, in printed wiring boards, in order to prevent solder bridges from occurring when mounting components, a pattern called a sacrificial pattern is provided, and when the components to be mounted are soldered, excess solder is absorbed into the sacrificial pattern. How to do it is known.

FIG. 3 shows an example of a pattern arrangement of a printed wiring board including a conventional discarded pattern.

In Figure 3, 1 in the dashed line is the first IC(A).
2 in the dashed line indicates the mounting position of the second IC.
(B) shows the mounting position of the first r
c (A) shows eight pins Al, A2. A3.
A4. A5. A6. A7. Assuming an A8 flat package, the second IC (B) has eight bins 81. B2.83.84.85. B6.87
68 flat package is assumed.

Further, in this example, pins A7 and B3 and A6 and B4 are connected, respectively, and the bins A5 and 82 are patterned to be connected via through holes 3 and 4 on the back side of the mounting surface.

5, 6, 7.8 are discard patterns, and in this example, the soldering iron is moved from top to bottom, and the discard patterns 5 to 7.8 are discarded.
8, in order to absorb excess solder, solder bridges are less likely to occur on pins A1 to A8 and pins B1 to B8. In addition, the pins A5 to A7, pin B2
~ Pins other than B4 are either unconnected or connected to other parts.

By the way, printed wiring boards are inspected using an inspection tool called a checker to check for defects after the board is fabricated.
When checking electrical continuity, it is necessary to electrically contact each pattern of the printed circuit board to be tested with a needle-shaped 1iE& called a contact pin or check bottle.

In the example shown in Figure 3, in order to check the connection of the patterns, the check pins must be brought into contact with pins 5 to A7 and 82 to B4, but in a normal flat package, the pin spacing is 1.27 mm. , Some of them are 0.55mm, and the parts other than the soldered part are insulated with resist, so they can be used in very narrow spaces.
It is now necessary to contact a total of six checkbins, three for the first IC (A) and three for the second IC (8).

[Problem to be solved by the invention]

However, as mentioned above, the discarded patterns 5 to 8 shown in FIG. 3 are electrically insulated from the other patterns, that is, the patterns 5 to 8 are not connected to any other part. First, the potential was uncertain, and it was useless as an electrode.

By the way, in a checker that inspects printed wiring boards, it goes without saying that the larger the pattern of the printed wiring board to be contacted, the rougher the positional accuracy of the contact bin is.
Further, when there are multiple patterns to be contacted in a narrow area, there is a problem in that it is necessary to take measures such as distributing the locations to be contacted with the check pins to other locations.

The present invention aims to solve the above problems. That is, according to the present invention, the waste pattern not only serves to easily absorb excess solder, but also serves as an electrode, thereby making it easier to create a contact bottle for a checker. It is an object of the present invention to provide a pattern arrangement and a connection structure for a printed wiring board, which can determine the potential of the pattern and improve problems such as noise and malfunction.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides that, in a pattern placed beside a land of a plurality of densely arranged printed wiring boards, a part of the pattern is The pattern is connected to other patterns in order to function as an electrode for checking during component mounting and also to absorb excess solder.

[For production]

According to the present invention, some parts of the pattern are connected to other patterns, so conventionally it was used only for the purpose of absorbing excess solder, and some parts of the pattern whose potential is not determined electrically. Since the pattern is connected to other patterns, the part of the pattern will easily absorb excess solder like the conventional discarded pattern, and the pattern will also serve as an electrode. By making the contact bin of the checker easier to create and determining the potential of the pattern, adverse effects such as noise and malfunction are also improved.

〔Example〕

FIG. 1 shows a first embodiment of the invention.

In this first embodiment, mounting positions 1.2,
The through holes 3, 4, IC(A) IC(B), pins A1 to 8, pins 81 to B8, etc. are the same as those in FIG. 3 described above. However, some of the patterns, that is, the discarded patterns 6.7, are different from the case shown in FIG. 3 in that the pattern 6 and the pin A5 are connected, and the pattern 7 and the pin B4 are connected.

In other words, as shown in FIG.
By connecting the discard pattern 7 and the pin 64, the checker pins brought into contact with the pins 5 and B4 are brought into contact with the patterns 6 and 7, respectively, and the pin A
It is possible to increase the distance between the checker bin 6 and the checker bin 83, which makes it easier to create the checker.

Furthermore, as shown in Fig. 1, the discard patterns 6 and 7 can have a somewhat wide area, so the checker bins that come into contact with them can be attached with rough positional accuracy, and furthermore, the checker can be manufactured easily. It will also increase.

In addition, the position where pin A5 and the discarded pattern 6 are connected, pin B4
Considering the solder tank, the position to connect the and discard pattern 7 was set at the center of each pattern, but in the case of manual soldering, it is best to connect the soldering iron to the position where the soldering iron is released at the end. So, if it's on the right, it's better to connect it on the right, and if it's on the left, it's better to connect on the left. Also, if the pattern width for connection is too thick, the solder absorbed by the electrode and the discarded pattern 6.7, which also serves as solder absorption, will return to pin A5 and pin B4, respectively, so it is better to make it somewhat thinner. On the other hand, if it is too thin, problems with connection reliability will occur, so it is better to make it moderately thin.

FIG. 2 shows a 'jiS2 embodiment of the present invention, in which check pin intervals other than pins A5 and A6 and pins B3 and B4 are taken into consideration, and pins A4 and B4 are Connect the discarded pattern 5, the pin B5 and the discarded pattern 8, and connect the extra electrode pattern 9.1.
0.11.12 are provided, and as shown in FIG. 2, pin ^2 and electrode pattern 12, pin A7 and electrode pattern 11, pin B2 and electrode pattern 10, and pin B7 and electrode pattern 9 are connected, respectively. .

By doing as shown in FIG. 2, the checker bins that had to contact pins A1 to A8 and pins 81 to B8 in close contact with each other are as follows: In order, pin A1, electrode pattern 12, pin A3, discard pattern 5, discard pattern 6
, pin A6, electrode pattern 11, and pin A8, and for the second IC (B), pins 81 to
B8 can be brought into contact with pin B1, electrode pattern 10, pin B3, discard pattern 7, discard pattern 8, pin B6, electrode pattern 9, discard pattern 8 in this order, so the interval between the check pins can be increased. It is possible to easily create a board checker. Furthermore, by arranging patterns 5 to 12 as shown in Figure 3, when moving the soldering iron from top to bottom during soldering, the discard patterns 5 to 8 can absorb excess solder. , when moving the soldering iron from the bottom to the top, move the electrode pattern 9
~12 serves as a waste pattern and can absorb excess solder. If the moving direction of the soldering iron is determined, each electrode pattern 9 to 12) is placed at a position away from each pattern row of pins L to A8 and pins B1 to B8, and the check electrode is It is also possible to have only the role of

Depending on the arrangement of the newly established check electrode, the effect of reducing solder bridges can be further increased, especially when soldering is done using a solder bath. Great effect.

That is, as explained in Fig. 3, the conventional discard pattern is only for absorbing excess solder and is electrically breathless. When pulling the solder out of the solder tank by passing it downward from the pin A4. 85. B4. The solder accumulated in B5 is difficult to be absorbed by the discarded patterns 5 to 8 because the patterns 5 to 8 are isolated. Furthermore, even in the licking process performed for the purpose of removing excess solder at the end of soldering using a solder bath, the effect is not perfect.

However, as shown in Figure 2, the discard patterns 5 to 8 are connected to pin A.
4. A5. B4. By connecting with pin A4.B5. A5.84. The solder accumulated in B5 easily passes through the connected patterns to each of the patterns 5 to 8.
It also has the effect of being able to be absorbed. Note that this effect is effective not only for soldering manually or using an automatic soldering bath, but also for reflow soldering baths that use hot air, infrared rays, or laser beams.

In FIGS. 1 and 2, each pattern 5 to 12 is square in shape, but it may be rectangular, circular, semicircular, or the like. Also, although I gave an example of a flat package IC with eight bins, other mounted parts can also be used.
The present invention can be carried out, and the present invention can be carried out without being restricted by the type or material, such as single layer, 5 double-sided layers, multilayer, etc., or printed wiring boards made of glass epoxy, paper phenol, etc. .

〔Effect of the invention〕

As explained above, according to the present invention, some of the patterns are connected to other patterns. Some of the patterns for which the pattern is not determined are connected to other patterns, so some of the patterns not only become discarded patterns and absorb excess solder, but also become IE&, so checker This has the effect of making manufacturing easier, and since the potential of the pattern is determined, it also has the effect of improving adverse effects such as noise and malfunction. Furthermore, by appropriately selecting the width and position of the connection pattern, it is possible to improve solder flow compared to conventional disposable patterns that are insulated from other patterns, reducing the occurrence of solder bridges. Let's do it
Can also be done.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing the second embodiment, and FIG. 3 is an explanatory diagram showing an example of a conventional technique. 1.2...Mounting position 3.4...Through hole 5.6, 7.8...Discard pattern

Claims (1)

[Claims] 1. In a pattern placed near a plurality of densely arranged lands of a printed wiring board, some of the patterns have a function of absorbing excess solder during component mounting;
A pattern arrangement and connection structure of a printed wiring board, characterized in that the pattern is connected to another pattern so as to function as an electrode during checking.