JPH01187894A - Printed board - Google Patents

Abstract

PURPOSE:To provide proper solder quantities, enhance a self-alignment effect of the surface tension of solder, reduce the number of interlayer contact holes and jumper wires to improve a mounting density and improve the reliability by a method wherein island parts are formed by etching a copper plate on the surface of a board for mounting a surface mount component on the board and one of the island ports is divided into two or more lands. CONSTITUTION:A land 1 and a land 2 are obtained by dividing one of the lands for mounting a surface mount component 5. A land 3 and a land 4 are obtained in a same way. Wiring patterns 7 run between those lands and a land P and a land Q are connected to each other without interlayer contact holes and jumper wires. As the sizes of the divided lands can be nearly the same as the sizes of lands 8 for the other small component 9, if a quantity of solder applied to one land is determined, proper quantities of solder for all the lands can be obtained. As uniform surface tensions can be applied to the surface mount component 5 by solder on the lands of four corners, it is accurately aligned to the correct direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printed circuit board on which electronic circuit components and the like are mounted.

[Summary of the Invention] The present invention optimizes the amount of solder by dividing the land for surface-mounted components into multiple parts in a printed circuit board, promotes the self-positioning effect due to the surface tension of the solder, and further improves the self-positioning effect of the solder. To provide a printed circuit board with high mounting density and high reliability by reducing interlayer connection holes and jumper wires by passing a wiring pattern between them.

[Prior Art] A conventional printed circuit board is constructed using a land 16 for surface mount components as shown in FIG. This was done using layer wiring 15. Furthermore, although the area of the land varies depending on each surface-mounted component, the amount of solder cannot be finely adjusted, so it is determined by trial and error. Furthermore, if the shape of the component 5 varies slightly and the surface tension of the solder is not sufficient, and the self-positioning effect is not achieved and the component 5 is mounted diagonally, it may be corrected manually later. was.

[Problems to be Solved by the Invention] Such a conventional configuration requires a large number of interlayer connection holes and jumper wires, which not only does not increase the packaging density but also reduces reliability. In addition, with large lands, the amount of solder was small, resulting in a decrease in strength and the surface tension of the solder was not obtained, while with small lands, the amount of solder was too large, causing solder bridges. Furthermore, the work of correcting crookedly mounted parts requires skill and increases mounting costs.

The purpose of the present invention is to solve these problems, optimize the amount of solder, promote self-positioning effect due to the surface tension of solder, reduce interlayer connection holes and jumper wires, and achieve high mounting density and reliability. Our goal is to provide high quality printed circuit boards.

[Means for Solving the Problems] The printed circuit board of the present invention is characterized in that at least one land for surface-mounted components is divided into at least two parts.

[Example] An example of the printed circuit board of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a part of a mounting diagram of a printed circuit board according to the present invention, and FIG. 2 is a sectional view taken along line AA' in FIG. Land 1 and land 2 are obtained by dividing one of the lands for surface mount component 5 into two, and land 3 and land 4 are also the same. A wiring pattern 7 passes between these lands, and connects lands P and lands Q without interlayer connection holes or jumper wires. In addition, the size of the divided lands can be approximately equal to the land 8 for other small parts 9, so if the amount of solder used for one land is kept constant, the appropriate amount of solder will be applied to all the lands. quantity is obtained. Furthermore, since the surface mount component 5 receives uniform surface tension from the solder on the lands at the four corners, it is properly positioned in the correct direction. Furthermore, it is known that applying insulator 6 by silk printing or the like in the direction separating the electrodes of surface-mounted components (the direction separating land 1 and land 3) has the effect of preventing solder bridging between the electrodes. However, by applying insulator 6 in the direction perpendicular to this, it is possible to maintain the orientation of the component parallel to the board, which can more effectively prevent solder bridging between electrodes, and at the same time to prevent solder bridging between electrodes. This has the effect of protecting the wiring pattern 7. The divided lands 1 and 2 and 3 and 4 are electrically connected by mounting the surface mount component 5, although this may be a little unnecessary.

In this embodiment, the land is divided into two, but the same effect can be achieved even if the land is divided into three or more.

Furthermore, if the land is divided into an even number and the insulator 6 is colored in a color that can be distinguished from the board, the center position of the surface-mounted component 5 can be clearly indicated by the intersection of the insulators 6, making it extremely easy to set up the automatic mounting equipment. And it can be done accurately.

[Effects of the Invention] According to the present invention, since the land for surface-mounted components is divided into a plurality of parts, the amount of solder is optimized, and at the same time, the self-positioning effect due to the surface tension of the solder is promoted.
Furthermore, by passing a wiring pattern between them, it is possible to reduce the number of interlayer connection holes and jumper wires, thereby increasing the packaging density and reliability.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the printed circuit board of the present invention. FIG. 2 is a sectional view taken along line AA' in FIG. Figure 3 shows an example of a conventional printed circuit board. 1.2... Divided lands for surface mount components 3.4... Divided lands for surface mount components 5... Surface mount components 6...・Silk-printed insulator 7...
...Pattern 8 connecting land P and land Q...Land 9 for small surface mount components...
...Small surface mount components 10...Solder. 11... Resist 12... Substrate 13.14... Interlayer connection hole 15... Other layer pattern 16... For conventional surface mount components Rand and above Applicant Seiko Epson Corporation 1st 2nd

Claims (1)

[Claims] In order to mount surface-mounted components on the board, at least one of the island-shaped parts (hereinafter referred to as lands for surface-mounted components) formed by etching or the like on the copper plate on the surface of the board is divided into at least two parts. A printed circuit board characterized by being divided.