CN201115000Y - circuit board - Google Patents

Abstract

A circuit board comprises a substrate having at least one chip soldering part, wherein the chip soldering part is a predetermined distance away from the edge of the substrate; the scrap side plate is connected to the edge of the substrate corresponding to the chip welding part, has the size corresponding to the chip welding part, is arranged on the scrap side plate close to the chip welding part and is aligned with the opening of the edge, and therefore the risk of tin cracking of the chip welding part caused by stress generated when the scrap side plate is folded is reduced.

Description

circuit board

technical field

The utility model relates to a circuit board structure, in more detail, relates to a circuit board with the function of preventing tin cracking at the soldering part of the chip.

Background technique

During the production and assembly process of Printed Circuit Board (PCB), in order to ensure that the components close to the border of the circuit board are not damaged, it is necessary to add waste edge boards around the printed circuit board and complete the printed circuit board. After the assembly and plugging of the components, use the corresponding tools to chisel out a break line that passes through the circuit board and separates the circuit board and the waste side board from the waste side board around the printed circuit board. If the existing V-Cut Make this break line in a way that makes it easier to separate the scrap edge panels.

In addition, with the rapid growth of various portable products such as communication, network and computer, Ball Grid Array (BGA) can reduce the area of integrated circuit (IC) and has high density and multi-pin characteristics. ; BGA) components, flip chip (Flip Chip; FC) components, chip size package (Chip Size Package; CSP) components and multi-chip module (Multi ChipModule; MCM) components and other packaging components have gradually become the mainstream in the packaging market. Due to the continuous miniaturization of integrated circuits, the density of components arranged in the same printed circuit board is very high, and the above-mentioned packaged components may be arranged in an area too close to the edge of the printed circuit board due to space problems. The overall size of the components relative to the circuit board is large and has multiple pins. Therefore, when the waste edge board around the printed circuit board is folded, the stress is often too large, causing the components near the edge of the printed circuit board, especially the above-mentioned The pins of chip components that are too large in size and have too many pins are cracked, thereby reducing the product yield.

To sum up, how to propose a circuit board that can avoid the various defects of the above-mentioned prior art, so as to reduce the risk of tin cracking of the pins of the chip soldering part after the chip is soldered due to the stress generated when the scrap side board is folded, Further improving the product yield rate is actually a technical problem that needs to be solved at present.

Utility model content

In view of the above-mentioned shortcomings of the prior art, the main purpose of this utility model is to provide a circuit board to reduce the risk of tin cracking of the pins of the chip soldering part after the chip is soldered due to the stress generated when the scrap side board is folded, and then Improve product yield.

In order to achieve the above purpose and other purposes, the utility model provides a circuit board, including a substrate with at least one chip welding part, and the chip welding part is a predetermined distance away from the edge of the substrate; connected to the substrate corresponding to the chip welding part The edge waste side plate has an opening corresponding to the size of the chip welding part, which is arranged on the waste side plate close to the chip welding part and cut to align with the edge.

In the circuit board of the present invention, there is a break line at the connection between the substrate and the edge of the waste side board, and correspondingly, the length of the hole is greater than the length of the chip soldering portion corresponding to the direction of the hole. In a preferred embodiment, the opening is arranged symmetrically with respect to the perpendicular bisector of the die bonding portion corresponding to the opening direction.

Compared with the prior art, the circuit board of the present utility model mainly forms an opening at the junction of the printed circuit board and the waste side board corresponding to each of the chip soldering parts of the waste side board, thereby preventing existing In the technology, because the size of the chip soldering part is too large and there are too many contacts, and the layout is too close to the edge of the printed circuit board, it is easy to cause the chip soldering part to weld the chip under the influence of stress during the process of folding the waste edge board around the printed circuit board. The disadvantages of tin cracking of the final pins.

Description of drawings

Fig. 1 is a perspective view showing a circuit board of the present invention; and

Fig. 2 is a top view showing the circuit board of the present invention.

Description of main component symbols

1 scrap edge board

10a, 10b opening

2 substrates

20a, 20b chip soldering part

200a, 200b chip components

21a, 21b edge of substrate

22 break line

L opening length

L1 Chip soldering length

S1 Predetermined distance

S2 Safety distance

Detailed ways

The implementation of the present utility model is described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present utility model from the contents disclosed in this specification. The utility model can also be implemented or applied through other different specific examples, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the utility model.

Please refer to Fig. 1 and Fig. 2 at the same time. Fig. 1 shows a perspective view of the circuit board of the present invention, and Fig. 2 shows a top view of the circuit board of the present invention; In the substrate 2 of the side board 1, and the junction of the substrate 2 and the edge of the waste side board 1 has a breaking line 22, which is a groove of a V-shaped section or a dotted line hole such as a stamp hole in this embodiment, so as to facilitate The waste side plate 1 is removed from the substrate 2; wherein, the substrate 2 has at least one chip bonding portion (in this embodiment, two chip bonding portions 20a, 20b are taken as an example, but not limited thereto), preferably , the predetermined distance (S1) between each of the chip soldering portions 20a, 20b and the edges 21a, 21b of the substrate 2 is less than a safety distance (the safety distance is based on the influence of the stress on the substrate 2 when the waste side plate 1 is folded) In this embodiment, the safety distance is set to 400mil as an example), and the chip soldering parts 20a, 20b are for ball grid array (Ball Grid Array; BGA) chip components, chip Flip-chip (FlipChip; FC) chip components, chip size package (Chip Size Package; CSP) components, or multi-chip module (Multi Chip Module; MCM) components and other packaging components with large overall size and multiple pins. The circuit board of the present invention is a protective measure taken against the chip components 200a, 200b that are too close to the edge of the printed circuit board and have too large a size and too many pins to be soldered to the chip soldering portions 20a, 20b.

In more detail, the circuit board of the present utility model is formed on the waste side board 1 corresponding to the chip soldering portions 20a, 20b at the junction of the substrate 2 and the waste side board 1 to align the substrate edges 21a, 21b respectively. The holes 10a, 10b are opened to reduce the risk of cracking of the pins after the chip components 200a, 200b are soldered to the chip soldering portions 20a, 20b due to the stress generated when the scrap side plate 1 is folded.

In addition, the opening 10a (10b) is aligned with the edge 21a (21b) of the substrate 2 close to the die bonding portion 20a (20b). The length of the opening 10a (10b) is greater than the length of the die bonding portion 20a (20b) corresponding to the direction of the edge 21a (21b) of the substrate 2, so as to disperse the stress generated on the substrate 2 when the waste edge plate 1 is folded. Furthermore, the opening 10a (10b) can be formed by an auxiliary tool by cutting, and the width of the opening 10a (10b) is set according to the width of the auxiliary tool, but it is not limited thereto, it can also be The width of the opening 10a (10b) is set according to other forming tools of the opening 10a (10b). In addition, in this embodiment, the position of the opening 10a (10b) is set so that the die bonding portion 20a (20b) is located at the perpendicular bisector of the opening 10a (10b) in the direction corresponding to the edge 21a (21b) of the substrate 2 On the line, that is, taking the opening 10a as an example, the length L of the opening 10a is calculated according to the length L1 of the chip bonding portion 20a corresponding to the direction of the edge 21a of the substrate 2 and another safety distance S2 to calculate the opening The length L of the hole 10a, wherein, the calculation method of the length L of the opening 10a is shown in equation (1):

L=L1+2*S2 (1).

Wherein, the safety distance ( S2 ) is set according to the optimization principle of stress dispersion principle, and in this embodiment, the safety distance ( S2 ) is set between 200 and 300 mil. Furthermore, the structures of the openings 10a ( 10b ) that can achieve the same effect of dispersing stress all belong to the application scope of the present invention. In this way, the setting of the opening 10a (10b) can be used to prevent the chip soldering part from being too large in size, too many pins, and too close to the edge of the printed circuit board in the prior art, which is easy to scrape the edge board. During the folding process, due to the influence of stress, there is a risk of tin cracking of the pins after the chip components 200a and 200b are soldered in the chip bonding part.

Based on the above, the circuit board of the present utility model is that the waste side board corresponds to each of the chip welding parts (especially the chip welding part whose distance from the frame of the substrate is less than a safe distance) at the junction of the substrate and the waste side board An opening is formed at each position, thereby reducing the risk of tin cracking of the pins after the chip components 200a, 200b are soldered to the chip bonding portion due to the stress generated when the waste side plate is folded, thereby reducing the product yield.

The above-mentioned embodiments only illustrate the principles and effects of the present utility model, but are not intended to limit the present utility model. Any person skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present utility model should be listed in the scope of the following claims.

Claims (7)

1. circuit board is characterized in that it comprises:

Substrate has at least one chips welding portion apart from this substrate edges one preset distance; And

The waste material side plate is connected in this substrate to edge that should chips welding portion, and has should chips welding portion size and trim the perforate at this edge.

2. circuit board according to claim 1 is characterized in that, this substrate and this junction, waste material side plate edge have broken line.

3. circuit board according to claim 2 is characterized in that, this broken line is the groove of V-shape cross-section structure.

4. circuit board according to claim 2 is characterized in that, this broken line is the dotted lines hole.

5. circuit board according to claim 1 is characterized in that, the length of this perforate greater than this chips welding portion to length that should the perforate direction.

6. circuit board according to claim 1 is characterized in that, this perforate is with this chips welding portion perpendicular bisector that should the perforate direction to be symmetrical arranged.

7. circuit board according to claim 1 is characterized in that, this chips welding portion is one of them of chip component of corresponding spherical grid array type, flip-chip, chip size packages, multi-chip module type.

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