CN110072335B

CN110072335B - Printed circuit board, electronic equipment and manufacturing method

Info

Publication number: CN110072335B
Application number: CN201910464499.4A
Authority: CN
Inventors: 郭静; 王益昕; 周勇
Original assignee: Universal Global Technology Shanghai Co Ltd
Current assignee: Universal Global Technology Shanghai Co Ltd
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2021-03-02
Anticipated expiration: 2039-05-30
Also published as: CN110072335A

Abstract

The invention discloses a printed circuit board, an electronic device and a manufacturing method, comprising the following steps: the substrate comprises a packaging area and a plurality of discontinuous mounting areas which surround the packaging area and are symmetrically distributed, wherein the mounting areas do not contain a conductive layer; a plurality of electronic components soldered within the package area of the substrate; the invention can lead the printed circuit board to be tightly connected with the port needing to be connected, simplifies the back-end assembly process and improves the yield of finished products.

Description

Printed circuit board, electronic equipment and manufacturing method

Technical Field

The present invention relates to a technology in the field of device packaging, and more particularly, to a printed circuit board, an electronic device, and a manufacturing method thereof.

Background

Surface Mounting Technology (SMT), or Surface mount Technology (Surface Mounting Technology). Is the most popular technology and process in the electronic assembly industry at present. The surface mount device (SMC/SMD) is a Circuit mounting technique in which a surface mount device (SMC/SMD) packaged in a matrix arrangement without leads or short leads or balls is mounted on a surface of a Printed Circuit Board (PCB) or a surface of another substrate, and is solder-assembled by a method such as reflow soldering or dip soldering.

System In Package (SIP) is used in the semiconductor industry to assemble multiple integrated circuits, other devices, and passive components in a single package. SIP is attractive because they enable microelectronic systems to be miniaturized, for example, printed circuit boards having dimensions of tens of thousands of square centimeters can be miniaturized into individual packages of about 5 square centimeters or less. SIP can integrate devices, such as digital devices, analog devices, memory, and other devices and components, with different device manufacturing techniques.

Fig. 1 is a schematic view of a conventional printed circuit board. When the printed circuit board 10 ' shown in fig. 1 is required to be connected to an external port, perforated connection pads 20 ' must be soldered to four corners of the printed circuit board 10 ', and then screws 30 are passed through the connection pads 20 ' to fix the printed circuit board 10 ' to a substrate to be connected. Because the welded connecting sheet 20 'is easy to fall off, the printed circuit board 10' can not be tightly fixed with the substrate, and the connection mode makes the rear-section assembly process complicated, and reduces the yield of finished products.

Disclosure of Invention

In view of the problems in the prior art, an object of the present invention is to provide a printed circuit board, an electronic device, and a manufacturing method thereof, in which a substrate is provided with a package region and a plurality of mounting regions, a conductive layer is only disposed in the package region, and no conductive layer is disposed in the mounting regions, and the mounting regions are provided with connection through holes, so that the printed circuit board can be tightly connected to ports to be connected by screws penetrating through the connection through holes, thereby simplifying a rear-end assembly process and improving a yield of finished products.

According to an aspect of the present invention, there is provided a printed circuit board including:

the substrate comprises a packaging area and a plurality of discontinuous mounting areas which surround the packaging area and are symmetrically distributed, wherein the mounting areas do not contain a conductive layer;

a plurality of electronic components soldered within the package area of the substrate; and

and the plastic packaging layer is covered in the packaging area of the substrate to package the electronic elements.

Preferably, the molding compound covers the encapsulation area and the mounting area of the substrate.

Preferably, at least one connecting through hole is formed in each mounting region in the thickness direction of the substrate, and the connecting through hole in the mounting region penetrates through the plastic package layer.

Preferably, the thickness of the plastic package layer of the mounting region is smaller than that of the plastic package layer of the encapsulation region.

Preferably, the mounting region is located at a corner of the substrate.

According to an aspect of the present invention, there is provided an electronic apparatus including:

a housing; and

at least one printed circuit board is locked in the shell through the connecting through hole of the mounting area by a screw.

According to one aspect of the invention, a packaging mold is provided, which is applied to manufacture the printed circuit board, and a movable mounting block is arranged at a corner of the top of the inner side of an upper mold of the packaging mold.

According to an aspect of the present invention, there is provided a method for manufacturing a printed circuit board, which is applied to manufacturing the printed circuit board, comprising the steps of:

s1, providing a substrate, wherein the substrate comprises an encapsulation area, a plurality of discontinuous installation areas which are symmetrically distributed and surround the encapsulation area, and a continuous non-encapsulation area which surrounds the encapsulation area and the installation area, and the installation area of the substrate does not contain a conductive layer;

s2, soldering a plurality of electronic elements to the packaging area of the substrate to form a printed circuit board to be packaged;

s3, placing the printed circuit board to be packaged in a packaging mold, and enabling the packaging area and the mounting area to be located in a cavity of the packaging mold;

s4, carrying out plastic package on the printed circuit board to be packaged to form a printed circuit board after plastic package;

s5, cutting the printed circuit board after plastic packaging, and cutting off a non-packaging area;

and S6, punching the cut printed circuit board, and forming at least one connecting through hole in the thickness direction of the substrate in the mounting area.

Preferably, in step S3, the package mold is used to perform plastic package, so that the thickness of the plastic package layer in the mounting region is smaller than the thickness of the plastic package layer in the packaging region.

Preferably, the step S5 further includes cutting the molded printed circuit board to make the thickness of the molding layer in the mounting region smaller than the thickness of the molding layer in the encapsulation region.

The beneficial effects of the above technical scheme are:

according to the printed circuit board, the electronic equipment and the manufacturing method, the packaging area and the mounting areas are arranged on the substrate, the conducting layer is only arranged in the packaging area, the conducting layer is not arranged in the mounting areas, and the mounting areas are provided with the connecting through holes, so that the printed circuit board can be tightly connected with ports needing to be connected through screws penetrating through the connecting through holes, the rear-section assembling process is simplified, and the yield of finished products is improved.

Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the specific embodiments described herein. These examples are given herein for illustrative purposes only.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings.

FIG. 1 is a schematic view of a prior art printed circuit board mounting;

FIG. 2 is a schematic top view of a printed circuit board of the present invention;

FIG. 3 is a schematic cross-sectional view along AA' of FIG. 2;

FIG. 4 is a schematic view of a substrate according to the present invention;

FIG. 5 is a schematic flow chart of a method of manufacturing a printed circuit board of the present invention;

FIG. 6 is a front view of an upper die of the package mold;

FIG. 7 is a cross-sectional view taken along line BB' in FIG. 6;

FIG. 8 is a schematic view of a printed circuit board to be packaged;

fig. 9 is a schematic view of the molded printed circuit board.

List of reference numerals:

10 printed circuit board

101 printed circuit board to be encapsulated

102 printed circuit board after plastic packaging

11 encapsulation area

121. 122, 123, 124 mounting areas

131. 132, 133, 134 connecting vias

14 plastic packaging layer

15 electronic component

16 base plate

161 solder mask

162 electrical connection layer

1621 conducting layer

1622 insulating layer

163 insulating dielectric layer

21 upper die of packaging die

211. 212, 213, 214 movable mounting block

22 cutting path

23 lower die of packaging die

24 non-encapsulated area

The features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Throughout the drawings, like reference numerals designate corresponding elements. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

As used in this application, the terms "first," "second," and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

According to one aspect of the present invention, a printed circuit board is provided.

Fig. 2 is a schematic top view of a printed circuit board 10 of the present invention. The printed circuit board 10 shown in fig. 2 has a substrate 16 and a molding layer 14 covering a mounting side (upper surface) of the substrate 16. The substrate 16 is divided into a package region 11 and four mounting

regions

121, 122, 123, 124. The mounting

areas

121, 122, 123, 124 surround the encapsulation area 11 and are symmetrically distributed, i.e. the mounting

areas

121, 122, 123, 124 are four corners of the rectangular printed circuit board 10, respectively. And each mounting area is provided with a connecting through hole. For example, the mounting region 121 is provided with a connecting through hole 131, the mounting region 122 is provided with a connecting through hole 132, the mounting region 123 is provided with a connecting through hole 133, and the mounting region 124 is provided with a connecting through hole 134, i.e., at least one connecting through hole is provided in each of the mounting

regions

121, 122, 123, 124. The printed circuit board 10 is fixed to the connected substrate provided with the port through the connection through

holes

131, 132, 133, 134 to realize connection of the printed circuit board 10 with the port provided in the connected substrate. In some embodiments, the number of mounting regions of the substrate 16 may be two or more, and the number of connection through holes located in each mounting region is not limited to one.

FIG. 3 is a schematic cross-sectional view along AA' of FIG. 2. Referring to fig. 2 and 3, the printed circuit board 10 includes a substrate 16, an electronic component 15 disposed on the substrate 16, and a molding layer 14 for encapsulating the electronic component 15. The upper surface of the substrate 16 includes a package region 11 and a plurality of mounting regions surrounding the package region 11. A plurality of electronic components 15 are soldered to the package region 11 of the substrate 16, and the electronic components 15 are electrically connected to the substrate 16 after being soldered to the substrate 16. The molding layer 14 covers the sealing region 11 of the substrate 16 to seal the plurality of electronic components 15, and the electronic components 15 provided on the upper surface of the substrate 16 are sealed by covering the molding layer 14 on the sealing region 11 of the substrate 16. The plastic package layer 14 covers the mounting

areas

121, 122, 123, 124, and the connecting through

holes

131, 132, 133, 134 respectively penetrate through the plastic package layer 14 corresponding to the mounting areas. The thickness of the molding layer 14 covering the mounting

areas

121, 122, 123, 124 is smaller than the thickness of the molding layer 14 of the package area 11. The printed circuit board 10 may include a plurality of electronic components 15. In general, any suitable number of electronic components 15 may be present in printed circuit board 10 (e.g., two, five or more, ten or more, 2-20, less than 40, more than twenty, or other suitable number of components). Substrate 16 may be a flexible printed circuit (e.g., a printed circuit formed from a polyimide sheet or other flexible polymer layer) or a rigid printed circuit (e.g., a printed circuit formed from a rigid printed circuit board material such as fiberglass-filled epoxy). A molding layer (e.g., a thermoset plastic) may be molded over the encapsulation area. In some embodiments, the electronic components 15 are soldered in the encapsulation areas 11 on both sides of the substrate 16 of the printed circuit board, and then a molding layer is molded separately for each side of the encapsulation area to achieve double-sided encapsulation.

Fig. 4 is a schematic structural diagram of a substrate according to the present invention. Referring to fig. 4, the substrate includes a plurality of electrical connection layers and a plurality of insulating dielectric layers, the electrical connection layers and the insulating dielectric layers are disposed at intervals from each other, and the uppermost layer and the lowermost layer of the substrate are both solder resists (a top solder resist and a bottom solder resist), which may be acrylic oligomers, as a protective layer of the substrate. For example, the substrate 16 of FIG. 4 includes four electrical connection layers 162 and three insulating dielectric layers 163. An insulating medium layer 163 is disposed between two electrical connection layers 162 for insulating between two adjacent electrical connection layers 162, and the material of the insulating medium layer 163 may be any one or more of ceramic, thermosetting resin, FR4, and teflon. Each of the electrical connection layers 162 includes a conductive layer 1621 and an insulating layer 1622 adjacent to and on the same layer as the conductive layer 1621, and an overlapping area of orthographic projections of a part of the insulating layers 1622 on the mounting side in all the electrical connection layers 162 is located in the mounting area of the substrate 16. There is no conductive layer in the mounting area of the substrate 16. For example, the uppermost electrical connection layer 162 shown in fig. 4 includes a conductive layer 1621 and an insulating layer 1622 other than the conductive layer 1621, the conductive layer 1621 being located directly below the package region 11. An overlapping area of orthographic projections of a part of the insulating layers 1622 on the mounting side in all the electrical connection layers 162 is located in the mounting area, that is, directly below each mounting area is the insulating layer 1622, and a connection through hole is opened in the mounting area in the thickness direction of the substrate 16, and penetrates through the insulating layer 1622 of each electrical connection layer 162.

In some embodiments, the molding compound covers the encapsulation area of the substrate and at least one mounting area, and the connection through holes in the mounting area penetrate through the molding compound. The plastic packaging layer in the mounting area is cut so that the thickness of the plastic packaging layer in the mounting area is smaller than that in the packaging area. Each mounting area of the substrate is provided with the plastic packaging layer, and when the connecting through holes are formed, the connecting through holes penetrate through the plastic packaging layers in the mounting areas, so that the packaging strength of the electronic element can be improved, and the printed circuit board is tightly matched with the ports.

According to one aspect of the present invention, an electronic device is provided.

The electronic device includes: a housing; and at least one printed circuit board 10 as described above, the printed circuit board 10 being disposed in the housing. The printed circuit board 10 can be locked in the housing by screws through the connection through-holes of the mounting area. Among other things, the electronic device may be a computing device such as a notebook computer, a computer monitor containing an embedded chip, a tablet, a cellular telephone, a media player, a handheld or portable electronic device, a smaller device (such as a wristwatch device), a hanging device, an earphone or earpiece device, a device embedded in eyeglasses or a device worn on the head of a user, a wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system (such as a system in which the electronic device with a display is installed in a kiosk or an automobile), a device that implements two or more of the functions of these devices, an accessory (e.g., an ear-piece, a remote control, a wireless touchpad, etc.), or other electronic device. The housing may be formed of plastic, glass, ceramic, fiber composite, metal (e.g., stainless steel, aluminum, etc.), or a combination of any two or more of these materials. The housing may be formed using a one-piece construction in which some or all of the housing is machined or molded as a single structure, or the housing may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form an external housing surface, etc.).

According to one aspect of the present invention, a printed circuit board manufacturing method is provided.

Fig. 5 is a flow chart illustrating a method of manufacturing the printed circuit board 10 of the present invention. The method of manufacturing the printed circuit board 10 shown in fig. 5 includes: step S1, step S2, step S3, step S4, step S5, and step S6. Specifically, in step S1, a substrate 16 is provided, the substrate 16 includes an encapsulation region, a plurality of discontinuous mounting regions symmetrically distributed around the encapsulation region, and a continuous non-encapsulation region surrounding the encapsulation region and the mounting region, wherein the mounting region of the substrate 16 does not include a conductive layer. In step S2, a plurality of electronic components 15 are soldered to the package area of the substrate 16, forming the printed circuit board 101 to be packaged. In step S3, the pcb 101 to be packaged is placed in a packaging mold such that the packaging region and the mounting region are located in the cavity of the packaging mold, and the non-packaging region is located in the bonding region of the packaging mold. In step S4, the printed circuit board 101 to be packaged is molded to form the molded printed circuit board 102. In step S5, the printed circuit board 102 after the plastic package is cut to cut off the non-package region. In step S6, the cut printed circuit board is punched to form at least one connection through hole in the thickness direction of the substrate in the mounting area.

According to one aspect of the invention, a package mold is provided.

Fig. 6 is a front view of an upper mold of the package mold. Fig. 7 is a cross-sectional view along BB' in fig. 6. As shown in fig. 6 and 7, the side surface of the upper mold 21 of the package mold is an isosceles trapezoid, and the angles between the two side edges and the bottom edge of the trapezoid are the draft angles. The four corners of the top of the inner side of the upper mold 21 of the packaging mold are respectively provided with movable mounting

blocks

211, 212, 213 and 214. The size of the

movable mounting blocks

211, 212, 213, 214 is limited by the size of the mounting area of the printed circuit board 10. An appropriate movable mounting block may be selected according to the size of the mounting area. The thickness of the movable mounting block is the difference between the thickness of the plastic packaging layer in the packaging area and the thickness of the plastic packaging layer in the mounting area. The thickness of the molding layer of the mounting region may be made smaller than that of the packaging region by the

movable mounting blocks

211, 212, 213, 214 of the packaging mold shown in fig. 6.

Fig. 8 is a schematic view of the printed circuit board 101 to be encapsulated placed on the lower mold 23 of the encapsulation mold. Fig. 9 is a schematic diagram of the printed circuit board 102 after plastic encapsulation by applying the encapsulation mold of fig. 6 and removing the encapsulation mold. Referring to fig. 5, 8 and 9, in step S3, the pcb 101 to be encapsulated is placed on the lower mold 23 of the encapsulation mold, the upper mold 21 of the encapsulation mold is pressed against the upper surface of the pcb 101 to be encapsulated, and a cavity for filling a molding compound is formed with the upper surface of the pcb 101 to be encapsulated, and the encapsulation region is located in the cavity. Specifically, the substrate 16 includes a non-encapsulation region 24, mounting

regions

121, 122, 123, 124, and an encapsulation region 11, the mounting

regions

121, 122, 123, 124, and the encapsulation region 11 are surrounded by the non-encapsulation region 24, and an upper mold 21 of the encapsulation mold is pressed onto the printed circuit board 101 to be encapsulated. In step S4, the molding compound is melted at a high temperature and injected into the cavity of the package mold, and after the thermosetting plastic in the cavity is cooled, the molding layer 14 is formed by solidification, and the electronic component 15 soldered to the substrate 16 is packaged. Referring to fig. 9, after the thermosetting plastic in the cavity is cooled and molded, the upper mold 21 and the lower mold 23 of the encapsulating mold are removed to form the shape as shown in fig. 9, and the substrate 16 is cut along the cutting street 22 shown in fig. 9, that is, the non-encapsulating region 24 is cut along the cutting street 22. The shape of the printed circuit board 10 shown in fig. 2 is obtained after the cutting, and at least one connection through hole is further formed in the mounting region in the thickness direction of the substrate 16 by step S6, and the printed circuit board 10 shown in fig. 2 is finally obtained. In some embodiments, if the plastic encapsulation is not performed by using the encapsulation mold shown in fig. 6, that is, the

movable mounting blocks

211, 212, 213, and 214 are not installed in the encapsulation mold, the plastic encapsulation layer of the encapsulated printed circuit board 102 formed above the installation region has the same thickness as the plastic encapsulation layer of the encapsulation region, in which case the plastic encapsulation layer in the installation region may be cut so that the thickness of the plastic encapsulation layer in the installation region is smaller than that in the encapsulation region.

In summary, in the printed circuit board, the electronic device and the manufacturing method of the present invention, the substrate is provided with the packaging region and the plurality of mounting regions, the conductive layer is only disposed in the packaging region, the conductive layer is not disposed in the mounting regions, and the mounting regions are provided with the connecting through holes, so that the printed circuit board can be tightly connected to the ports to be connected by the screws penetrating through the connecting through holes, thereby simplifying the rear-end assembly process and improving the yield of the finished product.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. A method of manufacturing a printed circuit board, comprising the steps of:

s1, providing a substrate, wherein the substrate comprises an encapsulation area, a plurality of discontinuous installation areas which are uniformly distributed and surround the encapsulation area, and a continuous non-encapsulation area which surrounds the encapsulation area and the installation area, and the installation area of the substrate does not contain a conductive layer;

2. The method of claim 1, wherein a movable mounting block is provided at a corner of an inner top portion of the upper mold of the package mold.

3. The method of manufacturing a printed circuit board according to claim 1, wherein the step S5 further comprises cutting the molding layer in the mounting region such that the thickness of the molding layer in the mounting region is smaller than the thickness of the molding layer in the encapsulation region.