CN210075711U

CN210075711U - Circuit board and electronic equipment

Info

Publication number: CN210075711U
Application number: CN201920806159.0U
Authority: CN
Inventors: 刘云
Original assignee: Kunshan Visionox Technology Co Ltd
Current assignee: Suzhou Qingyue Optoelectronics Technology Co Ltd
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2020-02-14
Anticipated expiration: 2029-05-30

Abstract

The embodiment of the application provides a circuit board. The circuit board includes a substrate, a pad, a pin, and a barrier layer. The bonding pad is arranged on the substrate; the pins are arranged on the substrate and connected with the bonding pads; the barrier layer is arranged on the surface of the pin far away from the substrate; the barrier layer is disposed proximate to the pad. When the barrier layer is kept away from during tin is gone up to one side of pad, because the blocking of barrier layer, liquid tin can not by the pin orientation the flow of pad has guaranteed the satiation of liquid tin on the pin, and the problem of rosin joint when consequently can avoid welding the device on the pin.

Description

Circuit board and electronic equipment

Technical Field

The present application relates to the field of soldering, and more particularly, to a pad, a circuit board, and an electronic device.

Background

The quad flat non-leaded (QFN) package of the conventional circuit board generally employs a film opening process, and has a large window area at a pad position with high precision. Therefore, the connecting part of the pin bonding pad is exposed, and the problem of pin cold joint is easily caused after the pins are tinned.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a circuit board and an electronic device for solving the problem that the pin is likely to be soldered after the pin is soldered.

A circuit board, comprising:

a substrate;

a pad disposed on the substrate;

the pins are arranged on the substrate and connected with the bonding pads;

and the blocking layer is arranged on the surface of the pin far away from the substrate and close to the bonding pad.

In one embodiment, the barrier layer is disposed across the leads, and the barrier layer completely blocks the channels between the leads and the pads, thereby ensuring that liquid tin does not flow toward the pads.

In one embodiment, the vertical projection of the barrier layer on the substrate is a rectangle, the length of the rectangle is 0.5 mm to 1.2 mm, the width of the rectangle is 0.25 mm to 0.3 mm, and the vertical projection of the barrier layer on the substrate cuts the vertical projection of the pins on the substrate, so that the solder can be effectively prevented from crossing the barrier layer, and the material of the barrier layer can be saved.

In one embodiment, the vertical projection of the barrier layer on the substrate is a semi-surrounding structure, the opening direction of the semi-surrounding structure deviates from the bonding pad, the vertical projection of the semi-surrounding structure on the substrate cuts the vertical projection of the pin on the substrate, the semi-surrounding structure can intercept the pin, and can prevent liquid tin from diffusing towards the periphery of the pin, so that the plumpness of the surface of the pin can be ensured.

In one embodiment, the vertical projection of the barrier layer on the substrate is a V-shaped structure, and the liquid tin flows and is fixed along two straight sidewalls forming the V-shaped structure, so that the liquid tin can be prevented from flowing quickly, and the working efficiency can be improved.

In one embodiment, the barrier layer is in the vertical projection of base plate is oval structure, the major diameter of oval structure with the pin is in the extending direction of base plate is criss-cross, because the edge of oval structure is the camber line, consequently can increase liquid tin with the area of contact of barrier layer has increased the interception area that liquid tin flows, can effectively avoid the diffusion of liquid tin.

In one embodiment, the thickness of the barrier layer is 150 microns to 200 microns, the barrier layer is effective to prevent the liquid tin from spreading at the thickness, and the barrier layer does not affect the soldering of the device on the lead.

In one embodiment, the material of barrier layer is printing ink, when printing components and parts position number, can print simultaneously the barrier layer can improve preparation and production efficiency.

In one embodiment, the solder paste layer is disposed on the surface of the lead and on a side of the barrier layer away from the pad, and the electrical component can be fixed to the lead through the solder paste layer.

An electronic device, comprising:

the circuit board;

the display panel is electrically connected with the circuit board; and the number of the first and second groups,

and a housing surrounding to form a receiving space in which the circuit board and the display panel are received.

The embodiment of the application provides a circuit board and electronic equipment. The circuit board includes a substrate, a pad, a pin, and a barrier layer. The bonding pad is arranged on the substrate. The pins are arranged on the substrate and connected with the bonding pads. The barrier layer set up in the pin is kept away from the surface of base plate, the barrier layer is close to the pad setting. When the barrier layer is kept away from during tin is gone up to one side of pad, because the blocking of barrier layer, liquid tin can not by the pin orientation the flow of pad has guaranteed the satiation of liquid tin on the pin, and the problem of rosin joint when consequently can avoid welding the device on the pin.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. Moreover, the drawings and the description are not intended to limit the scope of the inventive concept in any way, but rather to illustrate it by those skilled in the art with reference to specific embodiments.

Fig. 1 is a schematic diagram of a circuit board provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of a circuit board provided in another embodiment of the present application;

FIG. 3 is a schematic diagram of a circuit board provided in accordance with another embodiment of the present application;

FIG. 4 is a schematic diagram of a circuit board provided in accordance with another embodiment of the present application;

FIG. 5 is a schematic diagram of a circuit board provided in accordance with another embodiment of the present application;

fig. 6 is a schematic view of an electronic device according to an embodiment of the present application.

Description of reference numerals:

circuit board 10

Substrate 100

Bonding pad 110

Pin 120

Barrier layer 130

Semi-enclosing structure 140

V-shaped structure 150

Oval-shaped structure 160

Solder layer 170

Housing 180

Two droplet structure 190

Electronic device 20

Display panel 200

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

When the circuit board 10 is subjected to quad flat non-leaded 120 package (QFN) by Surface Mount Technology (SMT), a die sinking process is usually adopted. When the circuit board 10 is manufactured, the base material is generally required to be etched, and copper is exposed; a thin layer of Polyimide (PI) was then applied to cover the surface of the substrate. And the polyimide film has been windowed in some places as needed to expose devices such as pins 120. The inventor researches and discovers that due to the large fitting tolerance, windows cannot be opened in a precise place, namely, a film layer cannot be accurately removed according to the position design of a device. Thus, some of the device portions may be fully windowed. Therefore, the open window portion may have exposed copper not covered. The lead 120 and the pad 110 may be made of the bare copper. The pin 120 refers to a connection wire leading out from an internal circuit chip of the integrated circuit to a peripheral circuit, and the pin 120 may form an interface of the chip. The pad 110 may be a brazing sheet. Pad 110 may be used for ground.

The pin 120 may be used to connect with the pad 110. It can be appreciated that the liquid tin has a low resistance to flow over the surface of the same material. After tin is coated on the surface of the lead 120, the lead 120 and the pad 110 are made of the same material, and the pad 110 has a larger volume, so that the pad 110 has a stronger adsorption effect on the liquid tin. Therefore, under the physical adsorption of the pad 110, the liquid tin flows toward the pad 110, which affects the appearance of the pad 110 and tends to result in an insufficient amount of tin on the lead 120. After the lead 120 is soldered, a device is soldered on the surface of the solder, which is likely to cause a problem of cold joint.

The two sides of the lead 120 are provided with the substrate 100, the material of the substrate 100 is different from that of the lead 120, and the liquid tin encounters a large flow resistance at the interface of the different materials, so that the liquid tin does not flow toward the two sides of the lead 120.

Referring to fig. 1, an embodiment of the present application provides a circuit board 10. The circuit board 10 includes a substrate 100, a pad 110, a lead 120, and a barrier layer 130. The pad 110 is disposed on the substrate 100. The lead 120 is disposed on the substrate 100 and connected to the pad 110. The barrier layer 130 is disposed on the surface of the pin 120 away from the substrate 100. The barrier layer 130 is disposed adjacent to the pad 110.

The substrate 100 may be a carrier for an electrical circuit. The pads 110 may be used for soldering various electrical components. The shape of the pad 110 may be designed according to the particular electrical component being soldered. The pad 110 may have a rectangular, circular or other polygonal configuration. The pins 120 may be connected to other pads 110 or devices. The width of the pin 120 may be set according to current and device power. The pad 110 and the lead 120 may be integrally formed. The barrier layer 130 may be formed on the surface of the lead 120 before tin is applied to the pad 110. The lead 120 may include two ends, and one end of the lead 120 may be connected to the pad 110. The barrier layer 130 may be disposed near an end of the lead 120 connected to the pad 110. The barrier layer 130 is disposed close to the pad 110, so as to prevent the liquid tin from flowing to the pad 110, and leave more tin-coating space for the pin 120.

When tin is coated on the side of the barrier layer 130 far away from the pad 110, due to the blocking of the barrier layer 130, the liquid tin cannot flow from the pin 120 to the pad 110, and the satiation of the liquid tin on the pin 120 is ensured, so that the problem of cold joint during soldering devices on the pin 120 can be avoided.

In one embodiment, the barrier layer 130 is disposed across the leads 120. That is, at least a portion of the barrier layer 130 may overlap the leads 120, so that the overlapping portion can block the liquid tin from flowing to the pad 110. In one embodiment, a vertical projection of the barrier layer 130 on the substrate 100 may be perpendicular to a vertical projection of the leads 120 on the substrate 100.

In one embodiment, the barrier layer 130 completely blocks a path extending from the lead 120 to the pad 110. It is thus ensured that the liquid tin cannot flow toward the pad 110.

Referring to fig. 2, in one embodiment, the blocking layer 130 may be two droplet structures 190, and the two droplet structures are spaced apart from the leads 120 in a direction crossing the leads 120, and since the liquid tin is viscous, the liquid tin is attracted and blocked by the two droplet structures 190 due to surface tension, so that the liquid tin is prevented from flowing to the pad 110. The two droplet structures 190 may be tangential, thereby completely intercepting the flow of liquid tin to the pad 110. The two droplet structures 190 may be separated from each other, and the distance between the two droplet structures 190 may be within 3 mm, in which range the liquid tin is not easily flowed between the two droplet structures 190 according to the principle of physical adsorption.

In one embodiment, the vertical projection of the barrier layer 130 on the substrate 100 is a rectangle, and the length of the rectangle is 0.5 mm to 1.2 mm, and the width of the rectangle is 0.25 mm to 0.3 mm. The vertical projection of the barrier layer 130 on the substrate 100 cuts the vertical projection of the leads 120 on the substrate 100. I.e., the length of the rectangle may be greater than the width of the pin 120 and the long side of the rectangle may span the pin 120. The vertical projection of the barrier layer 130 on the substrate 100 divides the lead 120 into two independent parts, so that the liquid tin can be completely blocked by the barrier layer 130, and the liquid tin is prevented from flowing to the bonding pad 110.

Generally, the width of the lead 120 is less than 0.23 mm, so that the length of the rectangular shape of the vertical projection of the barrier layer 130 on the substrate 100 is set to be 0.5 mm to 1.2 mm, which can completely block the flow of liquid tin toward the pad 110. The length of the rectangle of the vertical projection of the barrier layer 130 on the substrate 100 is set to be 0.5 mm to 1.2 mm, which can effectively ensure that the solder does not cross the barrier layer 130 and can also save the material of the barrier layer 130.

In one embodiment, the vertical projection of the barrier layer 130 on the substrate 100 is a half-enclosure structure 140, as shown in fig. 3. The opening direction of the semi-surrounding structure 140 is away from the pad 110. The vertical projection of the semi-surrounding structure 140 on the substrate 100 cuts off the vertical projection of the leads 120 on the substrate 100. That is, the barrier layer 130 completely divides the lead 120 into two separate parts, so that the barrier layer 130 completely cuts off the path of the liquid tin flowing to the pad 110 through the lead 120. The liquid tin may be applied to one side of the lead 120 in the opening direction of the semi-surrounding structure 140. Since the opening direction of the semi-surrounding structure 140 is away from the pad 110, the semi-surrounding structure 140 can increase the blocking area for blocking the liquid tin from diffusing towards the periphery of the lead 120, and particularly can block the liquid tin from diffusing towards the pad 110, so that the satiation of the liquid tin on the surface of the lead 120 can be ensured. The cross section of the semi-enclosed structure 140 in the vertical direction is trapezoidal, that is, the width of the barrier layer 130 decreases from the substrate 100 to the direction away from the barrier layer 130.

In one embodiment, the semi-surrounding structure 140 may be a semi-circle with an opening facing away from the bonding pad 110, or may be composed of a plurality of folding lines with openings facing away from the bonding pad 110. It is understood that the opening of the semi-enclosing structure 140 may be larger than the width of the pin 120. When the opening of the semi-surrounding structure 140 is smaller than the width of the lead 120, the extending path of the lead 120 may pass through the opening of the semi-surrounding structure 140 to intercept the flow of the liquid tin as much as possible.

In one embodiment, the vertical projection of the barrier layer 130 on the substrate 100 is a V-shaped structure 150, as shown in fig. 4. The opening direction of the V-shaped structure 150 is away from the pad 110. It will be appreciated that as the liquid tin flows toward the pad 110, the tin first contacts the V-shaped opening. Due to the physical adsorption of the liquid by the solid, the liquid tin will flow and be fixed quickly along the two straight side walls constituting the V-shaped structure 150, so that the flow of the liquid tin can be prevented quickly, and the working efficiency can be improved.

In one embodiment, the barrier layer 130 may be circular. The diameter of the barrier layer 130 may be the same as the width of the pin 120. In one embodiment, the diameter of the barrier layer 130 is greater than the width of the pin 120.

In one embodiment, the barrier layer 130 has an elliptical configuration 160 in a vertical projection of the substrate 100, as shown in fig. 5. The major diameter of the oval structure 160 intersects with the lead 120 in the extending direction of the substrate 100. Because the edge of the oval structure 160 is arc-shaped, the contact area between the liquid tin and the barrier layer 130 can be increased, and the interception area of the liquid tin flowing is increased, so that the diffusion of the liquid tin can be effectively avoided. In one embodiment, the barrier layer 130 in the oval structure 160 may be obtained by silk-screening.

In one embodiment, the barrier layer 130 has a thickness of 150 microns to 200 microns. The thickness of the solder may be 100-150 microns. The barrier layer 130 is thus at this thickness effective to avoid spreading of the liquid tin.

In one embodiment, the material of the barrier layer 130 is ink. After the polyimide film is covered on the surface of the substrate 100, the position numbers of the components are usually printed by means of ink screen printing or the like. The barrier layer 130 can be printed on the surface of the substrate 100 at the same time of printing the component number, so that the manufacturing and production efficiency can be improved. The basic principle of screen printing is as follows: the basic principle that the meshes of the image-text part and the non-image-text part of the screen printing plate are ink-permeable and ink-impermeable is utilized for printing. When printing, ink is poured into one end of the screen printing plate, a scraping scraper plate is used for applying a certain pressure on the ink part on the screen printing plate, and meanwhile, the ink moves towards the other end of the screen printing plate. The ink is pressed by the squeegee from the mesh of the text portion onto the circuit board 10 while moving. The printing mark is fixed in a certain range due to the viscous action of the ink, the scraper is always in line contact with the screen printing plate and the circuit board 10 in the printing process, the contact line moves along with the movement of the scraper, and a certain gap is kept between the screen printing plate and the circuit board 10, so that the screen printing plate generates a reaction force to the scraper through the self tension in the printing process, and the reaction force is called as a rebound force. Due to the action of the resilient force, the screen plate is brought into only movable line contact with the circuit board 10, and the other portions of the screen plate are separated from the circuit board 10. The ink and the silk screen are broken, the printing size precision is ensured, and the circuit board 10 is prevented from being smeared. When the scraper blade scrapes the whole page, the scraper blade is lifted, and meanwhile, the screen printing plate is also lifted, and the ink is slightly scraped back to the initial position. This is now a print stroke.

In one embodiment, the circuit board 10 further includes a solder layer 170. The solder layer 170 is disposed on the surface of the lead 120 and on a side of the barrier layer 130 away from the pad 110. The surface of the soldering tin layer is used for welding electrical components. The solder layer may serve as a medium for connecting the leads 120 and the electrical components. The electrical component can also be fixed to the lead 120 by the solder layer.

It is understood that the solder layer may be a tin-lead alloy solder, an antimony-added solder, a cadmium-added solder, a silver-added solder, a copper-added solder, or the like. The solder layer can be formed by fusing solder wires, solder bars, solder paste and the like. The device may be soldered to the pins 120 by a process such as hand soldering, wave soldering, reflow soldering, etc.

The embodiment of the application also relates to an electronic device 20. As shown in particular in fig. 6. The electronic device 20 includes the circuit board 10, a display panel 200, and a housing 180. The display panel 200 is electrically connected to the circuit board 10. The housing 180 encloses a receiving space. The circuit board 10 and the display panel 200 are received in the receiving space. It is understood that the electronic device 20 may be a tablet computer, a mobile terminal, a all-in-one computer, or other electronic devices. The electronic device 20 may also be provided with a processor or the like. The processor may be provided to the circuit board 10. The circuit board 10 may control display of the display panel 200. The power supply may supply power to the display panel 200 through the circuit board 10. The circuit board 10 may also be provided with sensing means. Such as gravity sensors, light sensors, etc. The housing may also be provided therein with an electrical storage device, a signal transmission device, and the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A circuit board, comprising:

a substrate (100);

a pad (110) provided on the substrate (100);

a lead (120) provided on the substrate (100) and connected to the pad (110);

a barrier layer (130) disposed on the surface of the lead (120) away from the substrate (100) and disposed proximate to the pad (110).

2. The circuit board of claim 1, wherein the barrier layer (130) is disposed across the pins (120).

3. The circuit board of claim 1 or 2, wherein a vertical projection of the barrier layer (130) on the substrate (100) is a rectangle having a length of 0.5 mm to 1.2 mm and a width of 0.25 mm to 0.3 mm, and wherein the vertical projection of the barrier layer (130) on the substrate (100) truncates the vertical projection of the leads (120) on the substrate (100).

4. The circuit board of claim 1 or 2, wherein a vertical projection of the barrier layer (130) on the substrate (100) is a half-enclosure structure (140), an opening direction of the half-enclosure structure (140) faces away from the pad (110), and the vertical projection of the half-enclosure structure (140) on the substrate (100) intercepts a vertical projection of the pin (120) on the substrate (100).

5. The circuit board of claim 4, wherein a vertical projection of the barrier layer (130) on the substrate (100) is a V-shaped structure (150).

6. The circuit board of claim 1 or 2, wherein the barrier layer (130) has an oval structure (160) in a vertical projection of the substrate (100), and a major diameter of the oval structure (160) intersects with an extending direction of the leads (120) in the substrate (100).

7. The circuit board of claim 1 or 2, wherein the thickness of the barrier layer (130) is 150 to 200 microns.

8. The circuit board of claim 1, wherein the material of the barrier layer (130) is an ink.

9. The circuit board of claim 1, further comprising a solder layer (170) disposed on a surface of the leads (120) and on a side of the barrier layer (130) away from the pads (110).

10. An electronic device, comprising:

the circuit board (10) of any one of claims 1-9;

a display panel (200) electrically connected to the circuit board (10); and the number of the first and second groups,

and a case (180) surrounding a receiving space in which the circuit board (10) and the display panel (200) are received.