CN114340219A - Circuit board and method of making the same - Google Patents

Abstract

The present invention provides a manufacturing method of a circuit board, comprising: providing a first body, the first body comprising a first stack structure and a first conductive layer and a second conductive layer disposed on opposite surfaces of the first stack structure; A blind hole is opened on the main body, and the blind hole penetrates the first stack structure and the first conductive layer; a third conductive layer is arranged on the inner wall of the blind hole to form a conductive hole; the first conductive line is obtained by etching the first conductive layer, and the second conductive layer is obtained by etching the second conductive layer. a second conductive circuit; filling the conductive hole with solder paste; removing parts of the second conductive circuit and the third conductive layer to form a conductive through hole penetrating the first body, so that the part of the solder paste close to the side of the second conductive circuit is exposed; providing The second main body, the second main body includes a plurality of welding gaps, the first main body and the second main body are stacked, and the conductive through holes are communicated with the soldering gaps; the solder paste is heated by light, and the solder paste melts and flows into the soldering gaps to solidify to realize the first main body. Welding with the second body. The invention also provides a circuit board.

Description

Circuit board and method of making the same

technical field

The invention relates to the field of electronic products, in particular to a circuit board and a manufacturing method thereof.

Background technique

In recent years, electronic products have been widely used in daily work and life. Light, thin and small electronic products are becoming more and more popular. Circuit boards are the key part of electronic products, and there are more demands for their functionality. Circuit boards often require a soldering process to connect different daughter boards. Low-temperature welding and selective welding are the more common welding technologies, and light-curing welding can ensure local welding and low-temperature welding of products due to its advantages of short time and maskability.

In the existing light-curing soldering, the soldering is usually realized by heating the blind hole to melt the solder paste embedded in the blind hole. However, when the solder paste is heated by this soldering method, part of the structure of the circuit board (such as the solder resist layer and the conductive circuit) is heated at the same time. Due to the different multilayer structure materials, thermal conductivity and thermal expansion coefficient of the circuit board, the circuit board exists. Possibility to explode. Since the traditional heating method does not directly heat the solder paste, it takes a long time to heat the entire circuit board, which further increases the risk of board explosion.

How to solve the above problems is what those skilled in the art need to consider.

SUMMARY OF THE INVENTION

In view of the above situation, it is necessary to provide a method for manufacturing a circuit board and a circuit board manufactured by the method for manufacturing a circuit board.

The present application provides a method for making a circuit board, comprising:

providing a first body, the first body includes a first stack structure and a first conductive layer and a second conductive layer disposed on opposite surfaces of the first stack structure;

A plurality of spaced blind holes are formed on the first body, the blind holes penetrate through the first stack structure and the first conductive layer, and the blind holes do not penetrate or partially penetrate the second conductive layer ;

A third conductive layer is arranged on the inner wall of the blind hole to form a conductive hole;

etching the first conductive layer to obtain a first conductive circuit, and etching the second conductive layer to obtain a second conductive circuit;

filling the conductive holes with solder paste;

removing parts of the second conductive line and the third conductive layer to form a conductive through hole penetrating the first body, so that at least a part of the solder paste on the side close to the second conductive line is exposed;

A second body is provided, and a welding gap is set between the first body and the second body, so that the first body and the second body are stacked and arranged so that the conductive through hole communicates with the welding gap ;as well as

The solder paste is heated by light, and after melting, the solder paste flows into the welding gap and solidifies to realize the welding of the first body and the second body.

In a possible implementation manner, the conductive through hole includes a first end portion and a second end portion, the first end portion is disposed on a side of the conductive through hole close to the first conductive line, the The second end portion is disposed on the side of the conductive through hole close to the second conductive circuit; the second end portion is communicated with the welding gap.

In a possible implementation manner, the solder paste is filled in the conductive via and overflows from the first end to a direction away from the first stack structure; the first body and the After the second main body is stacked, use heating light to irradiate the solder paste on the side close to the first end; part of the solder paste melts and flows into the welding gap through the second end; after melting of the solder paste is cured.

In a possible implementation manner, the conductive through hole includes a first end portion and a second end portion, the first end portion is disposed on a side of the conductive through hole close to the first conductive line, the The second end portion is disposed on the side of the conductive through hole close to the second conductive circuit; after the conductive through hole is formed, solder paste is added to the second end portion; the second body is provided so that the The first end communicates with the welding gap.

In a possible implementation manner, the opening diameter of the first end portion is larger than the opening diameter of the second end portion; the solder paste is filled in the conductive through hole and extends from the first end portion to the overflowing in the direction away from the first stack structure; when adding solder paste at the second end portion, the added solder paste overflows in the direction away from the first stack structure from the second end portion; After the first body and the second body are stacked and arranged, heating light is used to irradiate the solder paste on the side close to the second end;

Part of the solder paste flows into the soldering gap through the first end after melting; the melted solder paste is solidified.

In a possible embodiment, one of the welding gaps communicates with at least two of the first ends.

The application also provides a circuit board, comprising:

a first body, the first body includes a first stack structure and a first conductive circuit and a second conductive circuit disposed on opposite surfaces of the first stack structure;

a second body, the second body and the first body are stacked and disposed, and a welding gap is sandwiched between the first body and the second body;

a conductive through hole, which penetrates through the first body and communicates with the soldering gap, a plurality of the conductive through holes are arranged on the first body at intervals, and the conductive through hole includes a conductive hole and a first openings, the conductive holes pass through the first conductive lines, the first openings pass through the second conductive lines, the conductive holes communicate with the first openings; and

Solder paste, the solder paste is filled in the conductive through holes and the welding gap to weld the first body and the second body.

In a possible implementation manner, the conductive through hole includes a first end portion and a second end portion, the first end portion is disposed on a side of the conductive through hole close to the first conductive line, the The second end portion is disposed on the side of the conductive through hole close to the second conductive circuit, and the solder paste is filled in the conductive through hole and extends from the first end portion to the side away from the first stack structure. The direction overflows, and the second end communicates with the welding gap.

In a possible implementation manner, the conductive through hole includes a first end portion and a second end portion, the first end portion is disposed on a side of the conductive through hole close to the first conductive line, the The second end portion is disposed on the side of the conductive through hole close to the second conductive circuit, and the solder paste is filled in the conductive through hole and directed to the first end portion and the second end portion respectively. Overflowing in a direction away from the first stack structure, the first end communicates with the welding gap.

In a possible implementation manner, the opening diameter of the first end portion is larger than the opening diameter of the second end portion, and the first conductive line and the second conductive line are far away from the first stack structure. Part of the surface is provided with a first solder resist layer.

For the circuit board and the manufacturing method thereof provided by the embodiment of the present invention, the solder paste can be made by printing, without adding other equipment such as ball-mounting machines, and thus reducing costs; Blind holes or circuit board body heat transfer can effectively reduce the risk of board explosion; solder paste is directly in contact with conductive through holes, and the hole wall of conductive through holes is added on the soldering contact surface to improve the welding tensile strength.

Description of drawings

1 to 7 are schematic diagrams of the manufacturing process of the circuit board according to the first embodiment of the present invention.

FIG. 8 is a schematic structural diagram of a circuit board according to the first embodiment of the present invention.

9 to 16 are schematic diagrams of the manufacturing process of the circuit board according to the second embodiment of the present invention.

FIG. 17 is a schematic structural diagram of a circuit board according to a second embodiment of the present invention.

Description of main component symbols

Circuit board 1, 2

The first body 11, 21

first stack structure 110, 210

The first conductive layer 111, 211

Second conductive layer 112, 212

The third conductive layer 113, 213

first conductive traces 115, 215

Second conductive traces 116, 216

First solder mask 117, 217

Second body 12, 22

Second stack structure 120, 220

Solder pads 121, 221

Fifth conductive line 125, 225

Sixth conductive line 126, 226

Second solder mask 127, 227

Welding gap 129, 229

Blind hole 131, 231

Conductive holes 132, 232

Conductive vias 133, 233

first end 134, 234

second end 135, 235

The first window 136, 236

Solder paste 15, 25

The following specific embodiments will further illustrate the present invention with reference to the above drawings.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When an element is referred to as being "disposed on" another element, it can be directly disposed on the other element or intervening elements may also be present.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

first embodiment

As shown in FIG. 1 to FIG. 7 , a manufacturing method of a circuit board 1 provided by the first embodiment of the present application includes the following steps:

Step S11 : As shown in FIG. 1 , a first body 11 is provided. The first body 11 includes a first stack structure 110 and a first conductive layer 111 and a second conductive layer 112 disposed on opposite surfaces of the first stack structure 110 .

In one embodiment, the first stacking structure 110 may be a multi-layer board, the first stacking structure 110 may include at least two layers of substrates, and the substrate material may be a resin such as polyimide (PI), and is disposed on the two layers. Adhesive layer used for connection between substrates. In other embodiments, the first stack structure 110 may be other multi-layer circuit structures, for example, may be a multi-layer circuit board including embedded components.

In one embodiment, the first conductive layer 111 and the second conductive layer 112 are conductive materials, such as copper, and the first conductive layer 111 and the second conductive layer can be formed by an additive method, a subtractive method, or the like. 112.

Step S12 : as shown in FIG. 1 , a plurality of blind holes 131 are formed on the first body 11 at intervals, and the blind holes 131 penetrate through the first stack structure 110 and the first conductive layer 111 .

In one embodiment, the blind hole 131 can be formed by a laser drilling method. During the laser drilling process, the second conductive layer 112 is not penetrated by the laser.

In one embodiment, the second conductive trace layer 112 may be partially broken down. Step S13 : As shown in FIG. 2 , a third conductive layer 113 is disposed on the inner wall of the blind hole 131 to form the conductive hole 132 .

In one embodiment, the third conductive layer 113 at least covers the inner wall of the blind hole 131 and extends to at least part of the surface of the first conductive layer 111 away from the first stack structure 110 .

In step S14 , as shown in FIG. 3 , the first conductive layer 111 is etched to obtain the first conductive circuit 115 , and the second conductive layer 112 is etched to obtain the second conductive circuit 116 .

In one embodiment, the first conductive layer 111 and the second conductive layer 112 can be processed and patterned by an image transfer process.

In one embodiment, the third conductive layer 113 may be subjected to surface treatment, and the inner wall of the third conductive layer 113 forms the microstructure 114 .

In one embodiment, a first solder resist layer 117 is formed on the surfaces of the first conductive lines 115 and the second conductive lines 116 away from the first stacked structure 110 , and the first solder resist layer 117 can cover the first conductive lines 115 and the second conductive lines 110 . The exposed surface of the circuit 116 ; the conductive via 133 is not covered by the first solder resist layer 117 , and at least part of the second conductive line 116 corresponding to the conductive via 133 is not covered by the first solder resist layer 117 .

Step S15 , as shown in FIG. 4 , the conductive holes 132 are filled with solder paste 15 .

In one embodiment, the solder paste 15 may be disposed by printing, so that the solder paste 15 fills the conductive holes 132 , and the solder paste 15 overflows from the openings of the conductive holes 132 and covers the conductive holes 132 away from the first stack structure 110 . surface.

Step S16 , as shown in FIG. 5 , parts of the second conductive line 116 and the third conductive layer 113 are removed to form a conductive via 133 penetrating the first body 11 , so that at least part of the solder paste 15 is close to the second conductive line 116 side exposed.

In one embodiment, a portion of the second conductive line 116 and the third conductive layer 113 is removed to form a first opening 136 , and the first opening 136 communicates with the conductive hole 132 to form a conductive via 133 .

In one embodiment, the portion of the second conductive trace 116 not covered by the first solder resist layer 117 is removed to expose the bottom end of the conductive hole 132 , and the third conductive layer 113 at the bottom end of the conductive hole 132 is further removed so that the bottom end of the conductive hole 132 is removed. The solder paste is exposed, and the conduction structure of the conductive hole 132 is changed from a blind hole to a through hole to obtain a conductive through hole 133 .

In one embodiment, parts of the second conductive lines 116 and the third conductive layer 113 can be removed by laser cutting.

In one embodiment, the conductive via 133 includes a first end portion 134 and a second end portion 135 , the first end portion 134 is disposed on the side of the conductive via 133 close to the first conductive line 115 , and the second end portion 135 is disposed on the side of the conductive via 133 close to the first conductive line 115 . The conductive via 133 is close to the side of the second conductive trace 116 . In this embodiment, the cross-sectional area of the first end portion 134 is larger than the cross-sectional area of the second end portion 135 .

Step S17 , as shown in FIG. 6 , the second body 12 is provided, so that the first body 11 and the second body 12 are stacked, and a soldering gap 129 is provided between the first body 11 and the second body 12 , so that the conductive through holes 133 It communicates with the welding gap 129 .

In one embodiment, the second body 12 may include a second stack structure 120 , at least one surface of the second stack structure 120 is provided with a plurality of solder pads 121 , and the plurality of solder pads 121 are arranged in the solder gap 129 .

In one embodiment, the second end portion 135 is communicated with the soldering gap 129 . Specifically, the second end portion 135 is directly opposite to the soldering gap 129 and communicated with the space in the soldering gap 129 so as to facilitate the solder paste 15 in the subsequent heating process. inflow.

In one embodiment, the second stacked structure 120 may be a multi-layer board, and the second stacked structure 120 may include at least one layer of substrate (eg, PI), and fifth conductive lines disposed on opposite surfaces of the layer of substrate. 125 and the sixth conductive line 126 , the surface of the fifth conductive line 125 and the sixth conductive line 126 may be provided with a second solder resist layer 127 , and a plurality of solder gaps 129 may be separated by the second solder resist layer 127 . In other embodiments, the second stacked structure 120 may be other multi-layer structures, for example, may be a multi-layer circuit board including inner-layer conductive lines or buried elements.

In step S18 , as shown in FIG. 7 , the solder paste 15 is heated by light, and the solder paste 15 flows into the welding gap 129 after being melted and solidified to realize the welding of the first body 11 and the second body 12 .

In one embodiment, the solder paste 15 is filled in the conductive via 133 and overflows from the first end portion 134 in a direction away from the first stack structure 110 ; the solder paste 15 is irradiated on the side close to the first end portion 134 by heating light. The solder paste 15 overflowing from the first end portion 134 is directly irradiated by light and then heated and melted. The melted solder paste 15 flows into the soldering gap 129 through the second end portion 135 under the action of gravity and contacts the solder pad 121 .

Soldering between the first body 11 and the second body 12 is achieved by curing the melted solder paste 15 .

As shown in FIG. 8 , for the circuit board 1 provided in the first embodiment of the present invention, the circuit board 1 includes a first body 11 , a second body 12 and a solder paste 15 , and the first body 11 and the second body 12 are stacked and pass through Solder paste 15 for soldering.

The first body 11 includes a first stack structure 110 and a first conductive line 115 and a second conductive line 116 disposed on opposite surfaces of the first stack structure 110 . In one embodiment, the first stacked structure 110 may be a multi-layer board, and the first stacked structure 110 may include at least two layers of substrates (eg, PI), and an adhesive layer disposed between the two layers of substrates for connection. . In other embodiments, the first stack structure 110 may be other multi-layer circuit structures. The first conductive traces 115 and the second conductive traces 116 are conductive materials, such as copper. In one embodiment, the first body 11 further includes a first solder resist layer 117 , and the first solder resist layer 117 can cover the exposed surfaces of the first conductive lines 115 and the second conductive lines 116 .

A plurality of conductive vias 133 are formed on the first body 11 at intervals. The conductive vias 133 penetrate through the first body 11 . The inner wall of the through hole 133 is provided with a third conductive layer 113 . The third conductive layer 113 is electrically connected to the first conductive line 115 and the second conductive line 116 , and the third conductive layer 113 covers the first conductive line 115 close to the conductive through hole 133 . peripheral surface.

In one embodiment, the conductive via 133 includes a conductive hole 132 and a first opening 136 , the conductive hole 132 penetrates the first conductive line 115 , the first opening 116 penetrates the second conductive line 116 , and the conductive hole 132 and the first opening Window 136 communicates.

In one embodiment, the conductive vias 133 are not covered by the first solder resist layer 117 , and at least part of the second conductive lines 116 corresponding to the conductive vias 133 are not covered by the first solder resist layer 117 .

The conductive via 133 includes a first end portion 134 and a second end portion 135 . The first end portion 134 is disposed on the side of the conductive via 133 close to the first conductive circuit 115 , and the second end portion 135 is disposed on the conductive via 133 close to the first conductive line 115 . On one side of the two conductive lines 116 , the solder paste 15 is filled in the conductive vias 133 and overflows from the first end portion 134 away from the first stack structure 110 , and the second end portion 135 communicates with the solder gap 129 . In this embodiment, the cross-sectional area of the first end portion 134 is larger than the cross-sectional area of the second end portion 135 .

The first body 11 and the second body 12 are stacked and disposed, a welding gap 129 is sandwiched between the first body 11 and the second body 12 , and the conductive through holes 133 communicate with the welding gap 129 . In one embodiment, the second body 12 may include a second stack structure 120 , at least one surface of the second stack structure 120 is provided with a plurality of solder pads 121 , and the plurality of solder pads 121 are arranged in the solder gap 129 . The second stack structure 120 may be a multi-layer board, and the second stack structure 120 may include at least one layer of substrate (eg, PI), and fifth conductive lines 125 and sixth conductive lines disposed on opposite surfaces of the layer of substrate 126 . A second solder resist layer 127 may be provided on the surfaces of the fifth conductive line 125 and the sixth conductive line 126 , and a plurality of soldering gaps 129 may be separated by the second solder resist layer 127 . In other embodiments, the second stack structure 120 may be other multi-layer structures, for example, may be a multi-layer circuit board including embedded components.

Second Embodiment

As shown in FIG. 9 to FIG. 16 , a manufacturing method of a circuit board 2 provided by the second embodiment of the present application includes the following steps:

Step S21 : As shown in FIG. 9 , a first body 21 is provided. The first body 21 includes a first stack structure 210 and a first conductive layer 211 and a second conductive layer 212 disposed on opposite surfaces of the first stack structure 210 .

In one embodiment, the first stacking structure 210 may be a multi-layer board, the first stacking structure 210 may include at least two layers of substrates, and the substrate material may be a resin such as polyimide (PI), and is disposed on the two layers. Adhesive layer used for connection between substrates. In other embodiments, the first stacked structure 210 may be other multi-layer circuit structures, for example, may be a multi-layer circuit board including embedded components.

In one embodiment, the first conductive layer 211 and the second conductive layer 212 are conductive materials, such as copper, and the first conductive layer 211 and the second conductive layer can be formed by an additive method, a subtractive method, or the like. 212. Step S22 : as shown in FIG. 9 , a plurality of blind holes 231 are formed on the first body 21 at intervals, and the blind holes 231 penetrate through the first stack structure 210 and the first conductive layer 211 .

In one embodiment, the blind hole 231 can be formed by a laser drilling method. During the laser drilling process, the second conductive layer 212 is not penetrated by the laser.

In one embodiment, the second conductive trace layer 212 may be partially broken down.

Step S23 : As shown in FIG. 10 , a third conductive layer 213 is disposed on the inner wall of the blind hole 231 to form the conductive hole 232 .

In one embodiment, the third conductive layer 213 at least covers the inner wall of the blind hole 231 and extends to at least a part of the surface of the first conductive layer 211 away from the first stack structure 210 .

Step S24 , as shown in FIG. 11 , the first conductive line 215 is obtained by etching the first conductive layer 211 , and the second conductive line 216 is obtained by etching the second conductive layer 212 .

In one embodiment, the first conductive layer 211 and the second conductive layer 212 can be processed and patterned by an image transfer process.

In one embodiment, the third conductive layer 213 may be subjected to surface treatment, and the inner wall of the third conductive layer 213 forms the microstructure 214 .

In one embodiment, a first solder resist layer 217 is formed on the surfaces of the first conductive lines 215 and the second conductive lines 216 away from the first stack structure 110 , and the first solder resist layer 217 can cover the first conductive lines 215 and the second conductive lines 217 . The exposed surface of the lines 216 ; the conductive vias 233 are not covered by the first solder resist layer 217 , and at least part of the second conductive lines 216 corresponding to the conductive vias 233 are not covered by the first solder resist layer 217 .

Step S25 , as shown in FIG. 12 , the conductive holes 232 are filled with solder paste 25 .

In one embodiment, the solder paste 25 may be disposed by printing, so that the solder paste 25 fills the conductive holes 232 , and the solder paste 25 overflows from the openings of the conductive holes 232 and covers the conductive holes 232 away from the first stack structure 210 . surface.

Step S26 , as shown in FIG. 13 , parts of the second conductive line 216 and the third conductive layer 213 are removed to form a conductive via 233 penetrating the first body 21 , so that the solder paste 25 is close to at least part of the side of the second conductive line 216 exposed.

In one embodiment, a portion of the second conductive line 216 and the third conductive layer 213 is removed to form a first opening 236 , and the first opening 236 communicates with the conductive hole 232 to form a conductive via 233 .

In one embodiment, the portion of the second conductive trace 216 not covered by the first solder resist layer 217 is removed to expose the bottom end of the conductive hole 232 , and the third conductive layer 213 at the bottom end of the conductive hole 232 is further removed to expose the bottom end of the conductive hole 232 . The solder paste is exposed, and the conduction structure of the conductive hole 232 is changed from a blind hole to a through hole to obtain a conductive through hole 233 .

In one embodiment, parts of the second conductive lines 216 and the third conductive layer 213 can be removed by laser cutting.

In one embodiment, the conductive via 233 includes a first end portion 234 and a second end portion 235 . The first end portion 234 is disposed on the side of the conductive via 233 close to the first conductive line 215 , and the second end portion 235 is disposed on the side of the conductive via 233 close to the first conductive line 215 . The conductive via 233 is close to the side of the second conductive trace 216 . In this embodiment, the cross-sectional area of the first end portion 234 is larger than the cross-sectional area of the second end portion 235 .

Step S27 , as shown in FIG. 14 , after the conductive via 233 is formed, solder paste 25 is added to the second end portion 235 , so that the added solder paste 25 overflows from the second end portion 235 to the direction away from the first stack structure 210 and Cover at least part of the surface of the second conductive trace 216 away from the first stack structure 210 .

In one embodiment, after the opening of the conductive via 233 is completed, the first main body 21 is turned over by 180 degrees, and the solder paste 25 is added to the side of the second end 235 . The solder paste 25 in the hole 233 communicates and contacts through the second end portion 235 .

Step S28 , as shown in FIG. 15 , the second body 22 is provided so that the first body 21 and the second body 22 are stacked and disposed, and a soldering gap 229 is provided between the first body 21 and the second body 22 so that the conductive through holes 233 It communicates with the welding gap 229 .

In one embodiment, the second body 22 may include a second stack structure 220 . At least one side surface of the second stack structure 220 is provided with a plurality of solder pads 221 , and the plurality of solder pads 221 are arranged in the solder gap 229 .

In one embodiment, the first end portion 234 is communicated with the soldering gap 229. Specifically, the first end portion 234 is directly opposite to the soldering gap 229 and communicates with the space in the soldering gap 229 so as to facilitate the solder paste 25 in the subsequent heating process. inflow.

In one embodiment, one welding gap 229 communicates with at least two first end portions 234 . In this embodiment, one welding gap 229 corresponds to the two first end portions 234 , and this structure can reduce the gap between the first body 11 and the second body 12 .

In one embodiment, the second stacked structure 220 may be a multi-layer board, and the second stacked structure 220 may include at least one layer of substrate (eg, PI), and fifth conductive lines disposed on opposite surfaces of the layer of substrate. 225 and the sixth conductive line 226 , the surface of the fifth conductive line 225 and the sixth conductive line 226 may be provided with a second solder resist layer 227 , and a plurality of solder gaps 229 may be separated by the second solder resist layer 227 . In other embodiments, the second stack structure 220 may be other multi-layer structures, for example, may be a multi-layer circuit board including inner-layer conductive lines or buried elements.

In step S29 , as shown in FIG. 16 , the solder paste 25 is heated by light, and the solder paste 25 flows into the welding gap 229 after being melted and solidified to realize the welding of the first body 21 and the second body 22 .

In one embodiment, the solder paste 25 is filled in the conductive via 233 and overflows from the first end portion 234 and the second end portion 235 in a direction away from the first stack structure 210 ; the solder paste 25 is irradiated with heating light close to the second end portion 235 . On the side of the end portion 235, the solder paste 25 overflowing the second end portion 235 is directly irradiated by light and then heated and melted. The melted solder paste 25 flows into the welding gap 229 through the first end portion 234 under the action of gravity, and is connected with the solder pad. 221 Contact.

The melted solder paste 25 is cured to realize the welding between the first body 21 and the second body 22 .

As shown in FIG. 17 , for the circuit board 2 provided by the second embodiment of the present invention, the circuit board 2 includes a first body 21 , a second body 22 and a solder paste 25 , and the first body 21 and the second body 22 are stacked and pass through Solder paste 25 for soldering.

The first body 21 includes a first stack structure 210 and a first conductive line 215 and a second conductive line 216 disposed on opposite surfaces of the first stack structure 210 . In one embodiment, the first stacked structure 210 may be a multi-layer board, and the first stacked structure 210 may include at least two layers of substrates (eg, PI), and an adhesive layer disposed between the two layers of substrates for connection. . In other embodiments, the first stacked structure 210 may be other multi-layer circuit structures, for example, may be a multi-layer circuit board including embedded components. The first conductive traces 215 and the second conductive traces 216 are conductive materials, such as copper. In one embodiment, the first body 21 further includes a first solder resist layer 217 , and the first solder resist layer 217 can cover the exposed surfaces of the first conductive lines 215 and the second conductive lines 216 .

A plurality of conductive vias 233 are formed on the first body 21 at intervals. The conductive vias 233 penetrate through the first body 21 . The inner wall of the through hole 233 is provided with a third conductive layer 213 . The third conductive layer 213 is electrically connected to the first conductive circuit 215 and the second conductive circuit 216 , and the third conductive layer 213 covers the first conductive circuit 215 close to the conductive through hole 233 . peripheral surface.

In one embodiment, the conductive via 233 includes a conductive hole 232 and a first opening 236, the conductive hole 232 penetrates the first conductive line 215, the first opening 216 penetrates the second conductive line 216, and the conductive hole 232 and the first opening Window 236 communicates.

In one embodiment, the conductive vias 233 are not covered by the first solder resist layer 217 , and at least part of the second conductive lines 216 corresponding to the conductive vias 233 are not covered by the first solder resist layer 217 .

The conductive via 233 includes a first end portion 234 and a second end portion 235 . The first end portion 234 is disposed on the side of the conductive via 233 close to the first conductive circuit 215 , and the second end portion 235 is disposed on the conductive via 233 close to the first conductive line 215 . On one side of the two conductive lines 216 , the solder paste 25 is filled in the conductive vias 233 and overflows from the first end portion 234 and the second end portion 235 to the direction away from the first stack structure 210 , and the second end portion 235 and the solder gap 229 Connected. In this embodiment, the cross-sectional area of the first end portion 234 is larger than the cross-sectional area of the second end portion 235 .

The first body 21 and the second body 22 are stacked and disposed, a welding gap 229 is sandwiched between the first body 21 and the second body 22 , and the conductive through holes 233 communicate with the welding gap 229 . In one embodiment, the second body 22 may include a second stack structure 220 . At least one side surface of the second stack structure 220 is provided with a plurality of solder pads 221 , and the plurality of solder pads 221 are arranged in the solder gap 229 . The second stack structure 220 may be a multi-layer board, and the second stack structure 220 may include at least one layer of substrate (eg, PI), and fifth conductive lines 225 and sixth conductive lines disposed on opposite surfaces of the layer of substrate 226, the surface of the fifth conductive line 225 and the sixth conductive line 226 can be provided with a second solder resist layer 227, a plurality of solder gaps 229 can be separated by the second solder resist layer 227, and one solder gap 229 can correspond to a plurality of first ends 234. In other embodiments, the second stack structure 220 may be other multi-layer structures, for example, may be a multi-layer circuit board including embedded components.

In addition, those skilled in the art can also make other changes within the spirit of the present invention. Of course, these changes made according to the spirit of the present invention should all be included in the scope of protection of the present invention.

Claims (10)

1. a manufacturing method of a circuit board, is characterized in that, comprises: providing a first body, the first body includes a first stack structure and a first conductive layer and a second conductive layer disposed on opposite surfaces of the first stack structure; A plurality of spaced blind holes are formed on the first body, the blind holes penetrate through the first stack structure and the first conductive layer, and the blind holes do not penetrate or partially penetrate the second conductive layer ; A third conductive layer is arranged on the inner wall of the blind hole to form a conductive hole; etching the first conductive layer to obtain a first conductive circuit, and etching the second conductive layer to obtain a second conductive circuit; filling the conductive holes with solder paste; removing parts of the second conductive line and the third conductive layer to form a conductive through hole penetrating the first body, so that at least a part of the solder paste on the side close to the second conductive line is exposed; A second body is provided, and a welding gap is set between the first body and the second body, so that the first body and the second body are stacked and arranged so that the conductive through hole communicates with the welding gap ;as well as The solder paste is heated by light, and after melting, the solder paste flows into the welding gap and solidifies to realize the welding of the first body and the second body. 2. The manufacturing method of circuit board as claimed in claim 1, is characterized in that: The conductive through hole includes a first end portion and a second end portion, the first end portion is disposed on the side of the conductive through hole close to the first conductive circuit, and the second end portion is disposed on the conductive through hole The through hole is close to one side of the second conductive line; The second end is brought into communication with the welding gap. 3. The manufacturing method of circuit board as claimed in claim 2, is characterized in that: the solder paste is filled in the conductive through hole and overflows from the first end to a direction away from the first stack structure; After the first body and the second body are stacked and arranged, heating light is used to irradiate the solder paste on the side close to the first end; Part of the solder paste melts and flows into the solder gap through the second end; and The melted solder paste is cured. 4. The manufacturing method of circuit board as claimed in claim 1, is characterized in that: The conductive through hole includes a first end portion and a second end portion, the first end portion is disposed on the side of the conductive through hole close to the first conductive circuit, and the second end portion is disposed on the conductive through hole The through hole is close to one side of the second conductive line; adding solder paste to the second end after forming the conductive via; and The second body is provided so that the first end communicates with the weld gap. 5. The manufacturing method of circuit board as claimed in claim 4, is characterized in that: The opening diameter of the first end is larger than the opening diameter of the second end; the solder paste is filled in the conductive through hole and overflows from the first end to a direction away from the first stack structure; When adding solder paste at the second end, the added solder paste overflows from the second end in a direction away from the first stacking structure; After the first body and the second body are stacked and arranged, heating light is used to irradiate the solder paste on the side close to the second end; Part of the solder paste melts and flows into the solder gap through the first end; and The melted solder paste is cured. 6 . The manufacturing method of the circuit board according to claim 5 , wherein one of the welding gaps communicates with at least two of the first ends. 7 . 7. A circuit board, characterized in that, comprising: a first body, the first body includes a first stack structure and a first conductive circuit and a second conductive circuit disposed on opposite surfaces of the first stack structure; a second body, the second body and the first body are stacked and disposed, and a welding gap is sandwiched between the first body and the second body; a conductive through hole, which penetrates through the first body and communicates with the soldering gap, a plurality of the conductive through holes are arranged on the first body at intervals, and the conductive through hole includes a conductive hole and a first openings, the conductive holes pass through the first conductive lines, the first openings pass through the second conductive lines, the conductive holes communicate with the first openings; and Solder paste, the solder paste is filled in the conductive through holes and the welding gap to weld the first body and the second body. 8 . The circuit board of claim 7 , wherein the conductive through hole comprises a first end portion and a second end portion, and the first end portion is disposed near the first end portion of the conductive through hole. 9 . On the side of the conductive line, the second end portion is disposed on the side of the conductive through hole close to the second conductive line, and the solder paste is filled in the conductive through hole and moves away from the first end portion The direction of the first stack structure overflows, and the second end portion communicates with the welding gap. 9 . The circuit board of claim 7 , wherein the conductive through hole comprises a first end portion and a second end portion, and the first end portion is disposed near the first end portion of the conductive through hole. 10 . On one side of the conductive line, the second end portion is disposed on the side of the conductive through hole close to the second conductive line, the solder paste is filled in the conductive through hole and is formed by the first end portion and the second conductive line. The second ends respectively overflow in a direction away from the first stack structure, and the first ends communicate with the welding gap. 10. The circuit board according to claim 8 or 9, wherein the opening diameter of the first end portion is larger than the opening diameter of the second end portion, and the opening diameter of the first conductive line and the second end A first solder resist layer is provided on a part of the surface of the conductive line away from the first stack structure.

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