Printed circuit board (PCB)

Abstract

The utility model provides a printed circuit board (PCB), which relates to the technical field of part welding, and comprises a plurality of oval bonding pads which are respectively arranged on the PCB, each oval bonding pad corresponds to a pin of a part to be welded, and the width of each oval bonding pad is larger than that of the corresponding pin. The beneficial effects are that: 1) the shape of the bonding pad is adjusted to be elliptical, which is beneficial for the extension of solder paste, and avoids the problem that the part cannot work normally due to missing soldering or poor soldering of part pins caused by incapability of brushing corners or non-uniform brushing; the position of the bonding pad is set according to the size of the to-be-welded part, the size can be standardized, the standard is unified, and the working efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of parts welding, in particular to a PCB board. Background Art

[0002] Usually after the PCB is washed, it will enter the SMT workshop for component mounting. During this process, various types of parts will be placed on the PCB in batches for welding. Some problems may occur, such as poor soldering of SOP / SOT parts, empty solder joints on pins, easy falling off of parts after welding, and failure to work normally. Utility Model Content

[0003] In view of the problems existing in the prior art, the utility model provides a PCB board, comprising:

[0004] A plurality of elliptical pads are respectively arranged on the PCB board, each of the elliptical pads corresponds to a pin of a part to be welded, and the width of the elliptical pad is greater than the width of the corresponding pin.

[0005] Preferably, the length of the elliptical pad is greater than the length of the contact surface between the corresponding pin and the elliptical pad.

[0006] Preferably, the elliptical welding pad includes multiple specifications, and the width of the elliptical welding pad of each specification is different, and the elliptical welding pad of each specification corresponds to different parts to be welded.

[0007] Preferably, the parts to be welded include at least two rows of pins, corresponding to at least two rows of elliptical welding pads.

[0008] Preferably, the spacing between two rows of the elliptical pads is the distance between the vertices of the two rows of pins minus the length of the contact surface between the pins and the elliptical pads.

[0009] Preferably, the length of each of the elliptical pads is at least greater than the sum of the length of the contact surface between the pin and the elliptical pad plus the reserved length.

[0010] Preferably, the contact surface between the pin and the corresponding elliptical pad is centered in the elliptical pad.

[0011] The above technical solution has the following advantages or beneficial effects:

[0012] 1) The shape of the pad is adjusted to an elliptical shape, which is conducive to the extension of the solder paste and avoids the problem of empty soldering or poor soldering of the pins of the parts due to the corners not being brushed or brushed unevenly, causing the parts to not work properly;

[0013] 2) The position of the welding pad of this embodiment is set according to the size of the parts to be welded, so as to standardize the size, unify the standards and improve the work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of an existing pad in a preferred embodiment of the utility model;

[0015] Figure 2 This is a schematic diagram of an elliptical pad welding a part to be welded in a preferred embodiment of the present utility model;

[0016] Figure 3 The following is a size comparison table of the parts to be welded and the welding pads in the preferred embodiment of the utility model. DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to the implementation mode, and other implementation modes may also fall within the scope of the present invention as long as they meet the purpose of the present invention.

[0018] In a preferred embodiment of the present utility model, based on the above problems existing in the prior art, a PCB board is provided, such as Figure 2 As shown, including:

[0019] A plurality of oval pads 1 are respectively arranged on the PCB board 2, each oval pad 1 corresponds to a pin 31 of a part 3 to be soldered, and the width of the oval pad 1 is greater than the width of the corresponding pin 31;

[0020] The contact surface of the pin 31 with the corresponding oval pad 1 is centered in the oval pad 1 .

[0021] Specifically, in this embodiment, the comparison Figure 1 and Figure 2 It can be seen that the original solder pad 100 is rectangular, and when brushing solder paste on the four corners, there is a problem that the solder paste cannot be brushed or is brushed unevenly. In this embodiment, the shape of the solder pad is adjusted to an elliptical shape, which is conducive to the extension of the solder paste and avoids the problem that the solder paste cannot be brushed or is brushed unevenly on the corners.

[0022] Moreover, the width of the original pad is only slightly larger than the width of the pin 31, which is not conducive to the pin 31 to absorb tin, and there are poor tin absorption and tin flow phenomena. In this embodiment, the width of the pad 1 is set to be larger than the width of the pin 31, which is conducive to tin absorption, and the contact surface between the pin 31 and the corresponding elliptical pad 1 is centered in the elliptical pad 1 to prevent the contact surface A from being too close to one side of the elliptical pad 1 to cause solder paste overflow.

[0023] In a preferred embodiment of the present invention, the length of the elliptical pad 1 is greater than the length of the contact surface A between the corresponding pin 31 and the elliptical pad 1; the length of each elliptical pad 1 is at least greater than the sum of the length of the contact surface A between the pin 31 and the elliptical pad 1 plus the reserved length; the elliptical pad 1 includes multiple specifications, and the width of each specification of the elliptical pad 1 is different, and each specification of the elliptical pad 1 corresponds to a different part 3 to be welded; the part 3 to be welded includes at least two rows of pins 31, which corresponds to at least two rows of elliptical pads 1;

[0024] The center distance between two rows of oval pads 1 is the distance E between the vertices of the two rows of pins 31 minus the length L of the contact surface A between the pins 31 and the oval pads 1 .

[0025] Specifically, in this embodiment, the size of the elliptical pad 1 in each direction and the spacing of the elliptical pad 1 need to be selected according to the model of the part to be welded when setting. Figure 3 As shown, in this embodiment, there are 6 sizes of parts, each with a different pitch (in the terminology related to PCB boards (printed circuit boards), "pitch" is an important concept, which refers to the center-to-center distance between two adjacent conductive bodies (such as pins, pads, wires, etc.), that is, Figure 2 and Figure 3 P in is the distance between the centers of adjacent pins. Figure 3 It can be seen that the P between the pins of the part 3 to be welded is 1.27mm, the corresponding width X of the elliptical pad 1 is 25mil, and the length Y of the elliptical pad 1 is L+40mil, L is the length of the contact surface A between the pin 31 and the elliptical pad 1, and 40mil is the reserved length set in this embodiment. The original pad Y-direction size is too large, which wastes the space for placing parts on the PCB board, and the Y-direction size of the elliptical pad 1 provided in this embodiment is reduced, saving the space for placing parts. CC=EL, CC is the midpoint of the contact surface A of the upper and lower rows of pins 31, E is the spacing between the vertices of the upper and lower rows of pins 31, and L is the length of the contact surface A between the pin 31 and the elliptical pad 1. This embodiment sets the position of the pad in this embodiment according to the size of the part to be welded, which can standardize the size, unify the standard, and improve work efficiency. The same is true for the parts 3 to be welded of other sizes, which will not be repeated.

[0026] In general, the utility model can achieve the following beneficial effects:

[0027] 1) The shape of the pad is adjusted to an elliptical shape, which is conducive to the extension of the solder paste and avoids the problem of empty soldering or poor soldering of the pins of the parts due to the corners not being brushed or brushed unevenly, causing the parts to not work properly;

[0028] 2) Setting the position of the pad according to the size of the parts to be welded can standardize the size, unify the standards and improve work efficiency.

[0029] 3) After the standard is unified, this table specification is applied. Different manufacturers provide parts of the same specification (the Pitch, L, and E of the parts are the same), and the spacing and size of the pads drawn are the same. This avoids different manufacturers providing different parts recommendation drawings for parts of the same specification, causing the designer to draw two different package libraries, which greatly saves design time;

[0030] 4) After the pads are unified, if a parts manufacturer's parts inventory is insufficient, you can use materials from other manufacturers with the same specifications (Pitch, L, and E are the same) as substitutes, without worrying about whether the pad size of the parts meets the welding conditions of the new materials (because the pad standards are unified).

[0031] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A PCB board, characterized in that: include: A plurality of elliptical pads are respectively arranged on the PCB board, each of the elliptical pads corresponds to a pin of a part to be welded, and the width of the elliptical pad is greater than the width of the corresponding pin.

2. The PCB board according to claim 1, characterized in that: The length of the elliptical pad is greater than the length of the contact surface between the corresponding pin and the elliptical pad.

3. The PCB board according to claim 1, characterized in that: The oval pads include multiple specifications, and the widths of the oval pads of each specification are different. The oval pads of each specification correspond to different parts to be welded.

4. The PCB board according to claim 1, characterized in that: The part to be welded includes at least two rows of pins, corresponding to at least two rows of elliptical welding pads.

5. The PCB board according to claim 4, characterized in that: The spacing between the two rows of elliptical pads is the distance between the vertices of the two rows of pins minus the length of the contact surface between the pins and the elliptical pads.

6. The PCB board according to claim 2, characterized in that: The length of each of the elliptical pads is at least greater than the sum of the length of the contact surface between the pin and the elliptical pad plus the reserved length.

7. The PCB board according to claim 1, characterized in that: The contact surface between the pin and the corresponding oval pad is centered in the oval pad.

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