JP2006313791A - Collective printed wiring board and soldering method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of a solder bridge by providing a solder reservoir land. <P>SOLUTION: A series of lands 5 are formed close to each other in individual substrates 2a and 3b. A land 5c at one end is provided close to a perforation 3 to an adjoining individual substrate 3b. A solder reservoir land 7 is provided close to the land 5c at one end through the perforation 3 in the adjoining individual substrate 2b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a collective printed wiring board having a multi-sided singulated board portion and a solder pool land formed in the vicinity of the land, and a soldering method for the printed wiring board.

  A printed wiring board on which electronic components are mounted is provided with lands to which the lead terminals of the electronic components are soldered. The lands are formed in rows corresponding to the leads of the electronic components to be mounted. As the printed wiring board is downsized, the lands are electrically connected to the lead terminals of the electronic component by reflow after the solder is printed and the electronic component is temporarily fixed.

  In a printed wiring board that has been reduced in size and increased in density, since adjacent lands are close to each other, a solder bridge may occur. Therefore, solder pool lands are formed in the vicinity of the lands on the printed wiring board (see Patent Document 1).

  However, when the printed wiring board is miniaturized or densified, there is a case where a space for providing a solder pool land is lost. When a soldering land cannot be provided, it is necessary to perform a solder bridge removal operation on each printed wiring board.

JP 2003-142810 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a collective printed wiring board and a soldering method capable of preventing the occurrence of solder bridges.

  The collective printed wiring board according to the present invention is a collective printed wiring board in which the singulated substrate portions are multi-faced, and each of the singulated substrate portions has a land arranged adjacent to each other, and one land is adjacent to each other. A solder pool land is provided in a position adjacent to the land at one end through the boundary portion, provided adjacent to the boundary portion with the matching individualized substrate portion. ing. This collective printed circuit board soldering method is performed in order so that solder is applied to each land and an electronic component is placed at a predetermined position, and then the solder pool land is on the downstream side in the soldering direction.

  According to the present invention, each singulated substrate portion is provided with a land row adjacent to each other, and a land at one end on the downstream side in the soldering direction is provided close to a boundary portion between adjacent singulated substrate portions. In addition, since the soldering land is provided at the position adjacent to the land at the one end through the boundary portion in the adjacent individualized board portion located downstream in the soldering direction, each individualized board Generation of solder bridges can be prevented while reducing the size of the portion. That is, even when there is no area where the solder pool lands are provided in each singulated substrate portion, the solder pool lands can be provided in the adjacent singulated substrate portions to prevent the occurrence of solder bridges.

  Hereinafter, a collective printed wiring board to which the present invention is applied will be described with reference to the drawings.

  As shown in FIG. 1, the collective printed wiring board 1 is a board in which a single-sided board portion 2 on which a wiring pattern constituting an electric circuit used in one electronic device is formed is multi-sided. A perforation 3 or the like for separating the individual substrate portions 2 by a mold or the like is formed at the boundary portion of the individual substrate portions 2 to be formed. As shown in FIG. 2, each singulated substrate portion 2 is formed with land rows 5 continuous with the conductor pattern 8 in the mounting portion for mounting the electronic component 4. The individual singulated substrate sections 2 partitioned by the perforations 3 are extremely miniaturized in accordance with, for example, the casing of the electronic device to be mounted, and the land rows 5 are provided at positions close to the perforations 3. .

  The land 5a constituting the land row 5 is formed with an insertion hole 5b into which the lead terminal of the electronic component 4 is inserted at the center, and the periphery of the land 5a with the copper foil facing outside. Around the land 5a, a solder resist 6 is formed by screen printing using a resist ink or a photographic method of exposing and developing using a photosensitive resist ink or film.

  On the land 5a, cream solder or the like for soldering the lead terminals of the electronic component 4 is printed by screen printing or the like. The solder used here is, for example, lead-free solder that does not contain lead as a component. The electronic component 4 is inserted into the insertion hole 5b by being soldered to the mounting portion with an adhesive or the like, and then the solder of the land 5a is melted by reflow such as an infrared heating method, a hot air method, or a vapor phase soldering method. It is electrically connected to the lead terminal of the electronic component 4.

  By the way, as shown in FIG. 2, the land 5c at one end of the land row 5 is provided close to the perforation 3 serving as a boundary portion with the adjacent singulated substrate portion 2, A solder pool land cannot be provided in one singulated substrate portion 2a. Therefore, the collective printed wiring board 1 is a separate substrate portion 2b adjacent to the downstream side with respect to the soldering direction indicated by the arrow D in FIGS. A solder pool land 7 is provided at a position close to the perforation 3 of the substrate portion 2b. That is, the solder pool land 7 is provided at a position close to the land 5 c at one end of the land row 5 through the perforation 3. The solder pool land 7 is formed at the same time as the above-described land 5c, and is formed so that the copper foil of the conductor pattern 8 of the singulated substrate portion 2b is exposed to the outside. A resist 6 is formed. This conductor pattern 8 may be a wiring pattern constituting a part of the electric circuit of the singulated substrate portion 2b, or may be a dummy pattern. Even in the separated substrate portion 2b, the conductor pattern 8 is formed along the perforation 3 in order to reduce the size, and a dedicated area for the solder pool land 7 cannot be provided. The conductor pattern 8 is provided.

  The collective printed circuit board configured as described above is held by the transport member and transported in the direction of the arrow D in FIGS. 1 and 2. The land row 5 of the singulated substrate portion 2a is soldered in order from the land 5e side of the other end to the land 5c at one end and further toward the adjacent singulated substrate portion 2b.

  Here, when the solder applied excessively to the land 5a at one end overflows from the land 5a, the solder is guided to the solder pool land 7 through the perforation 3, and the land 5f adjacent to the land 5a at one end. It is possible to prevent a solder bridge from occurring between the two. Further, since the solder resist 6 is formed between the land 5a at one end and the solder pool land 7, and the perforation 3 is also formed, it is possible to prevent a solder bridge from being formed. Even when the bridge is generated, when the singulated substrate portion 2 is separated by the perforation 3, the solder bridge is also broken at the same time.

  As described above, the singulated substrate portion 2b located on the downstream side in the soldering direction has the perforation 3 at a position close to the land 5a at one end of the land row 5 of the singulated substrate portion 2a on the upstream side. Since the solder pool land 7 is formed therethrough, it is possible to prevent the occurrence of a solder bridge or the like. Moreover, since the collective printed wiring board 1 is provided with the land rows 5 and the solder pool lands 7 on the separate singulated substrate portions 2, each singulated substrate portion 2 can be reduced in size.

  Next, a modified example of the solder pool land 7 will be described with reference to FIG. In the example of FIG. 3, a blank area 12 for the solder pool land 11 is formed on the individualized board portion 2 b adjacent to one individual board portion 2 a, and the conductor pattern 8 along the perforation 3 is shown in FIG. 3. It is provided by curving to the downstream side in the soldering direction indicated by the arrow D direction, and the conductor pattern 13 is exposed to the outside in the blank region 12 to provide the solder pool land 11. Even in this example, the solder pool land 11 is formed at the same time as the solder resist 6 is formed. Also by the example shown in FIG. 3, the same effect as the collective printed wiring board 1 shown in FIG. 2 can be obtained.

  Furthermore, with reference to FIG. 4, the further modification of this invention is demonstrated. FIG. 4 is a modification of FIG. 2 and is a case where an SOP (Small Outline Package) is mounted. The SOP 21 is provided with lead terminals 21a on both side surfaces of the long side of the rectangular case, and the land rows 5 of the singulated substrate portion 2b are also provided in two rows corresponding to the lead terminals 21a. The individualized substrate portions 2b on the extension lines of the land rows 5 and 5 are connected to the solder pool lands 7 on the conductor pattern 8 along the perforation 3 adjacent to the lands 5a and 5a of the land rows 5 and 5. , 7 are formed. Each of the solder pool lands 7 and 7 is formed at the same time as the above-described land 5c, and the solder foil 6 is formed around the copper foil of the conductor pattern 8 of the singulated substrate portion 2b. Has been.

  Soldering is performed in the direction of arrow D in FIG. 4, and the solder overflowing the lands 5 a and 5 a of the land rows 5 and 5 during the soldering is guided to the solder pool lands 7 and 7 through the perforations 3. The solder bridge can be prevented from occurring between the land 5a and the land 5f adjacent to the land 5c. Here, as shown in FIG. 4, two solder pool lands 7 may be provided corresponding to the land rows 5 and 5, but in addition to these, these may be provided integrally.

  Furthermore, with reference to FIG. 5, the further modification of this invention is demonstrated with reference to FIG. FIG. 5 is a modification of FIG. 3 and is a case where the SOP 21 is mounted. In FIG. 5, a blank area 12 for the solder pool land 11 is formed on the separated board portion 2b adjacent to the one separated board portion 2a, and the conductor pattern 8 along the perforation 3 is indicated by an arrow D in FIG. The solder pattern lands 11 and 11 are provided by bending the conductor pattern 13 to the outside in the blank area 12. That is, two rows of land rows 5 and 5 are provided in parallel with each other so as to correspond to the lead terminals 21a parallel to each other of the SOP 21, and one individual substrate portion 2a is provided between adjacent individual substrate portions 2b. Solder pool lands 11 are provided in the extending direction of the land rows 5 and 5. Soldering is performed in the direction of arrow D in FIG. 5, and the solder overflowing the lands 5 a and 5 a of the land rows 5 and 5 at the time of soldering is guided to the solder pool lands 11 and 11 through the perforations 3. It is possible to prevent a solder bridge from occurring between the land 5a and the land 5f adjacent to the land 5a. Here, as shown in FIG. 5, two solder pool lands 11 may be provided corresponding to the land rows 5 and 5, but in addition to these, these may be provided integrally.

  In addition to the above-mentioned SOP, the mounted electronic components are particularly surface mount components such as QFP (Quad Flat Package), SIP (Single In-line Package), and SOJ (Small Outline J-leaded Package). It is not limited.

It is a top view of the collective printed wiring board to which the present invention is applied. It is a top view which shows a solder pool land. It is a top view which shows the modification of a solder pool land. It is a top view which shows the modification of FIG. It is a top view which shows the modification of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collective printed wiring board, 2 piece board part, 3 perforation, 4 electronic parts, 5 land row, 5a land, 5b insertion hole, 6 solder resist, 7 solder pool land

Claims (2)

It is a collective printed wiring board in which the singulated substrate part is multifaceted,
Each of the singulated substrate portions is provided with lands arranged close to each other, and a land at one end is provided close to a boundary portion between adjacent singulated substrate portions,
The collective printed wiring board according to claim 1, wherein a solder pool land is provided in a position adjacent to the land at the one end via the boundary portion in the adjacent singulated substrate portion. The singulated substrate portions are multi-faced, and lands are arranged in each singulated substrate portion, and lands on one end are provided close to the boundary between adjacent singulated substrate portions, and solder pool lands are provided. Solder is applied to the land of the collective printed wiring board provided at a position close to the land of the one end through the boundary portion of the adjacent singulated substrate parts, and then the electronic component is attached to the printed circuit board of the collective printed circuit board. Soldering method characterized by arranging at a predetermined position and then performing soldering so that the solder pool land is on the downstream side in the soldering direction.

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