CN113518512B

CN113518512B - Electronic device welding method and circuit board welding equipment

Info

Publication number: CN113518512B
Application number: CN202110307622.9A
Authority: CN
Inventors: 沙桂林
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-03-23
Filing date: 2021-03-23
Publication date: 2022-08-26
Anticipated expiration: 2041-03-23
Also published as: CN113518512A

Abstract

The application is applicable to the technical field of electronic devices, and provides a welding method of an electronic device and circuit board welding equipment, wherein the method comprises the following steps: brushing solder paste on the circuit board; attaching an electronic device to the circuit board brushed with the solder paste; fixing the mounted circuit board on a heating platform; fixing the electronic device to make the electronic device static relative to the circuit board; and heating the circuit board by using the heating platform to realize that the electronic device is welded on the circuit board. The embodiment of the application can improve the position precision of the electronic device of the circuit board, so that the deviation of the electronic device of the circuit board is as small as possible, and the delivery yield can be improved.

Description

Electronic device welding method and circuit board welding equipment

Technical Field

The application belongs to the technical field of electronic devices, and particularly relates to a welding method of an electronic device and circuit board welding equipment.

Background

The welding process flow of the traditional LED (Light-Emitting Diode) is as follows: brushing solder paste on a bonding pad of the circuit board; positioning and mounting an LED on a circuit board through a chip mounter; and sending the circuit board with the attached LED into a reflow soldering furnace for tin melting and solidification to complete the welding of the LED and the circuit board.

In the conventional process, due to the reasons that tin melting time difference exists due to non-uniform temperature, or a circuit board is not smooth, or excessive tension or insufficient tension is caused by more tin or less tin, the phenomenon of serious or slight deviation of part of LEDs frequently occurs, and the backlight light-emitting effect of the LED display screen with medium and small sizes is influenced. Because the defects cannot be overcome, the deviation of not more than 0.1mm is taken as an acceptable standard in the industry. However, in actual production, after the circuit products of the reflow oven pass, the proportion of the deviation of the LEDs exceeding 0.1mm is different from 10% to 60%, and the circuit products can be delivered after being repaired manually. Due to the different experience and quality of the repair personnel, the difference of the reject ratio of each factory is large.

The above background disclosure is only for the purpose of assisting in understanding the inventive concepts and technical solutions of the present application and does not necessarily pertain to the prior art of the present application, and should not be used to assess the novelty and inventive step of the present application in the event that there is no clear evidence that the above disclosure has been made prior to the filing date of the present application.

Disclosure of Invention

The embodiment of the application provides an electronic device welding method and circuit board welding equipment, which can improve the position precision of the electronic device of a circuit board, enable the deviation of the electronic device of the circuit board to be as small as possible, and improve the good product yield.

In a first aspect, embodiments of the present application provide a method of soldering an electronic device, the method comprising:

brushing solder paste on the circuit board;

attaching an electronic device to the circuit board brushed with the solder paste;

fixing the mounted circuit board on a heating platform;

fixing the electronic device to make the electronic device static relative to the circuit board;

and heating the circuit board by using the heating platform to realize that the electronic device is welded on the circuit board.

Optionally, the using the heating platform to heat the circuit board to realize soldering the electronic device to the circuit board includes:

raising the temperature of the heating platform to a preset upper limit temperature so as to melt the solder paste;

and reducing the temperature of the heating platform to a preset lower limit temperature so as to solidify the melted solder paste and realize that the electronic device is welded on the circuit board.

Optionally, the fixing the electronic device to make the electronic device static relative to the circuit board includes:

using a mold capable of forming a first clamping space;

and fixing the electronic device in the first clamping space.

Optionally, the method uses a mold comprising a base mold, a first mold half, and a second mold half;

the bottom die comprises a heating platform and a positioning part;

the first half die comprises a first clamping portion and is suitable for being arranged on the bottom die, the first clamping portion comprises a first wall body, and the first half die can move relative to the bottom die so that the first wall body of the first clamping portion is located at a specified position;

the second half mould comprises a second clamping portion, the second clamping portion comprises a second wall body, and the second half mould can move relative to the first half mould so that a first clamping space is formed between the second wall body of the second clamping portion and the first wall body of the first clamping portion.

Optionally, the fixing the electronic device to make the electronic device stationary relative to the circuit board includes:

placing the first half mold on the circuit board, and moving the first half mold relative to the bottom mold along a first designated direction so that a first wall body of the first clamping part is in contact with a part of the electronic device;

and placing the second half mold on the bottom mold, and moving the second half mold relative to the first half mold along a second designated direction so that a second wall body of the second clamping part is in contact with another part of the electronic device.

Optionally, the method further comprises:

moving the first mold half relative to the bottom mold in a third specified direction such that the first wall of the first clamping portion is out of contact with a portion of the electronic device;

moving the second mold half relative to the first mold half in a fourth specified direction such that the second wall of the second clamp portion is out of contact with another portion of the electronic device.

Optionally, the placing the first half mold on the circuit board includes:

keeping the first wall body of the first clamping part at a distance larger than zero from the edge of the electronic device in a first direction, and lowering the first half mould to the circuit board perpendicular to the first direction.

Optionally, the placing the second mold half on the bottom mold includes:

keeping the second wall of the second clamping part at a distance greater than zero from the edge of the electronic device in the first direction, and lowering the second mold half to the first mold half perpendicular to the first direction.

Optionally, the placing the second mold half on the bottom mold includes: placing the second clamping portion of the second mold half into the first clamping portion of the first mold half.

In a second aspect, embodiments of the present application provide a circuit board soldering apparatus for implementing any one of the methods described above.

In a third aspect, embodiments of the present application provide a mold for an electronic device, the mold comprising:

the bottom die comprises a heating platform and a positioning part;

the first half die comprises a first clamping part and is suitable for being arranged on the bottom die, the first clamping part comprises a first wall body, and the first half die can move relative to the bottom die so that the first wall body of the first clamping part is located at a specified position;

and the second half die comprises a second clamping part, the second clamping part comprises a second wall body, and the second half die can move relative to the first half die so that a second wall body of the second clamping part and the first wall body of the first clamping part form a first clamping space.

Optionally, the bottom die further comprises a plurality of limiting parts; the plurality of limiting parts enclose an inner groove suitable for placing the first half die and the second half die.

Optionally, the first clamping part is a limiting groove, and the second clamping part is an insert; the insert can be inserted into the limiting groove.

Optionally, a step is provided on the top of the insert, and a wall body of the step and a first wall body of the first clamping portion can form the first clamping space.

Optionally, an outer dimension of at least a portion of the first mold half and an outer dimension of at least a portion of the second mold half are both smaller than an inner dimension of at least a portion of the inner groove, the second mold half adapted to be disposed on the first mold half.

Optionally, a gasket adapted to be disposed within the first clamping space is also included.

Optionally, the number of the first clamping parts is multiple, and the first clamping parts are arranged in parallel; the number of the second clamping parts is multiple, and the second clamping parts are arranged in parallel.

Optionally, the first half mold further comprises a first surface, and the thickness direction of the first clamping part is perpendicular to the first surface;

the second half mold further comprises a second surface, and the thickness direction of the second clamping part is perpendicular to the second surface;

the bottom die further comprises a third surface; the plurality of limiting parts are perpendicular to the third surface.

Optionally, the first mold half is flat; the second mold half is adapted to compress the first mold half.

In a fourth aspect, embodiments of the present application provide a circuit board soldering apparatus including the mold according to any one of the above.

Compared with the prior art, the embodiment of the application has the beneficial effects that:

the circuit board that will accomplish the brush tin cream and accomplish the dress is fixed in the heating platform, then the electron device of fixed line board, make the relative circuit board of electron device static, rethread heating platform heating circuit board for the tin cream of circuit board melts, melts at the tin cream and to the refrigerated in-process of tin cream, is kept unchangeable by the relative circuit board in fixed electron device's position, can improve the electron device's of circuit board position precision, makes the off normal of the electron device of circuit board as far as possible little, can improve shipment yields.

Some possible implementations of embodiments of the present application have the following beneficial effects:

the first clamping space is formed by moving in the first direction and descending the first half mold and the second half mold in the direction perpendicular to the first direction, so that a plurality of electronic devices can be fixed at one time, the electronic devices can be prevented from being damaged, and the linear precision of the electronic devices can be ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic flow chart of a soldering method of an electronic device provided by an embodiment of the present application;

fig. 2 is a schematic flow chart of a modification of the method for soldering an electronic device according to the embodiment of the present application;

fig. 3 is a perspective structural view of a mold for an electronic device provided by an embodiment of the present application;

fig. 4 is an exploded view of a mold for an electronic device according to an embodiment of the present application;

FIG. 5 is another exploded view of a mold for an electronic device according to an embodiment of the present application;

fig. 6 is a perspective structural view of a bottom mold according to an embodiment of the present application;

fig. 7 is a front view of a bottom mold provided in an embodiment of the present application;

FIG. 8 is a front view of a first mold half provided by an embodiment of the present application;

FIG. 9 is an enlarged view of area A of FIG. 8;

FIG. 10 is a bottom view of the first mold half of FIG. 8;

FIG. 11 is a perspective view of a second mold half according to an embodiment of the present application;

FIG. 12 is a front view of a second mold half provided in accordance with an embodiment of the present application;

FIG. 13 is an enlarged view of area B of FIG. 12;

fig. 14 is an operation state diagram of a mold for an electronic device according to an embodiment of the present application.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to fig. 1 to 14 and the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of and not restrictive on the broad application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Embodiments of the present application provide a method for soldering an electronic device, which is used to solder the electronic device, such as an LED (Light-Emitting Diode), to a circuit board.

Referring to fig. 1, an embodiment of the present application provides a welding method including steps S1 to S5.

And step S1, brushing solder paste on the circuit board.

The circuit board usually has a pad, and before the electronic device is mounted on the circuit board, the pad is brushed with solder paste, so that the electronic device is soldered to the circuit board by the solder paste.

And step S2, attaching the electronic device to the circuit board after the solder paste is brushed.

After the circuit board is brushed with the solder paste, the electronic device is attached to the circuit board brushed with the solder paste, for example, the LED is positioned and attached on the circuit board by a chip mounter.

And step S3, fixing the mounted circuit board on the heating platform.

After the electronic device is attached to the circuit board, the attached circuit board is fixed on the heating platform. The heating platform is used for heating the circuit board, so that solder paste of the circuit board is melted.

And step S4, fixing the electronic device to make the electronic device static relative to the circuit board.

After the circuit board is fixed on the heating platform, the electronic device such as an LED is fixed, and the electronic device can be clamped by a clamp or a clamping device, so that the position of the electronic device is kept unchanged relative to the circuit board when the subsequent heating circuit board melts solder paste.

And step S5, heating the circuit board by using the heating platform to realize the welding of the electronic device on the circuit board.

After the electronic device is fixed, the heating platform is started to heat the circuit board. In the process, the temperature of the heating platform rises to the preset upper limit temperature, the solder paste of the circuit board melts, then the temperature of the heating platform falls to the preset lower limit temperature, the melted solder paste is solidified, and the electronic device is welded on the circuit board. Thus, the welding of the electronic device is completed through one temperature rise and one temperature reduction.

According to the above, the circuit board which is used for brushing the solder paste and completing the surface mounting is fixed on the heating platform, then the electronic device of the circuit board is fixed, the electronic device is static relative to the circuit board, then the circuit board is heated through the heating platform, the solder paste of the circuit board is melted, in the process from the melting of the solder paste to the cooling of the solder paste, the position of the fixed electronic device is kept unchanged relative to the circuit board, the position precision of the electronic device of the circuit board can be improved, the deviation of the electronic device of the circuit board is enabled to be as small as possible, the delivery yield can be improved, the requirement on the precision of the surface mounting is low, a low-precision and low-cost surface mounting machine is allowed to be adopted, and the production expansion cost is low. In addition, in the whole welding process, the position of the electronic device is kept unchanged relative to the circuit board, and the heating platform only needs to be heated and cooled once.

In some embodiments, the aforementioned step S4 (fixing the electronic device and making the electronic device stationary relative to the circuit board) includes: using a mold capable of forming a first clamping space; the electronic device is fixed in the first clamping space.

The welding method provided by the embodiment of the application uses the die provided by the embodiment of the application, and the die is specifically a die of an electronic device.

The embodiment of the application provides a mould of an electronic device, which is used for welding a circuit board with the electronic device attached. In this embodiment, the electronic device is an LED (Light-Emitting Diode) that can be mounted on a circuit board.

Referring to fig. 3, an embodiment of the present application provides a mold including a first mold half 1, a second mold half 2, and a bottom mold 3. The first half-mould 1 and the second half-mould 2 are both arranged in a bottom mould 3, such as: the first half mould 1 is placed on the surface of the bottom mould 3, and the second half mould 2 is placed on the surface of the first half mould 1; alternatively, both the first half-mould 1 and the second half-mould 2 are placed on the surface of the bottom mould 3.

In some embodiments, referring to fig. 4 to 7, the material of the bottom mold 3 is high hardness die steel. The bottom mold 3 includes a heating stage 31 and a positioning portion 32.

The heating platform 31 is used for carrying and heating the circuit board. In the example, the heating platform 31 is an aluminum heating platform, a heating pipe is embedded in the heating platform, and a high-precision temperature controller is externally connected to the heating platform, so that temperature control during melting and cooling of solder paste is realized.

Referring to fig. 6 and 7, the positioning portions 32 are of a circuit board design. In some embodiments, the positioning portion 32 is a positioning post. The positioning part 32 (positioning column) is used for limiting the displacement of the circuit board on the bottom die 3; illustratively, each positioning post is disposed around the heating platform 31.

Referring to fig. 8 to 10, the material of the first mold half 1 is high-hardness mold steel or hardened porcelain. Referring to fig. 8, the first mold half 1 comprises a first clamping portion 11, in particular a first clamping portion 11 is provided in the middle of the first mold half 1. The first clamping part 11 is a limiting groove designed for matching the position of an electronic device (such as an LED); wherein, referring to fig. 8 and 10, the first clamping portion 11 (i.e., the stopper groove) is hollow, penetrating through the thickness direction of the first half die 1; the number of the limiting grooves is determined by the number of rows of electronic devices (such as LEDs) on the circuit board, one limiting groove corresponds to one row of electronic devices (such as LEDs), and can be one or more limiting grooves, such as dozens of hollow limiting grooves; the size of spacing groove is greater than the size of electron device for the spacing groove can hold electron device and leave the removal space, and the example, the length and width size of spacing groove exceeds the occupy-place total size of single-row LED, makes first half mould 1 can not damage the LED in the vertical translation process from top to bottom. In other embodiments, the number of the limiting grooves is determined by the number of the electronic devices (such as LEDs) of the circuit board, and one limiting groove corresponds to one electronic device (such as LEDs).

Referring to fig. 9, the first clamping portion 11 includes a first wall 111; for the aforementioned limiting groove, the first wall 111 is an inner wall of the limiting groove.

Referring to fig. 4, the first mold half 1 is separable from the bottom mold 3. The circuit board with the electronic devices (such as LEDs) attached thereto is placed on the bottom mold 3, and the first mold half 1 is adapted to be disposed on the bottom mold 3, so that a first clamping portion 11 (a limiting groove) of the first mold half 1 can cover a row of electronic devices (such as LEDs) located on the bottom mold 3. The first mold half 1 can be moved relative to the bottom mold 3 such that the first wall 111 of the first clamping portion 11 is located at a given position, wherein the given position is a position at which clamping of an electronic device, such as an LED, is subsequently achieved.

Referring to fig. 11 to 13, the second mold half 2 comprises a second clamping portion 21 and a second outer frame 22. The second clamping portion 21 is an insert, such as a precision insert, made of die steel or hardened ceramic. The second frame 22 is made of high-hardness die steel and is a main body of the second mold half 2.

Referring to fig. 11, the number of the second clamping portions 21 (e.g., inserts) is determined by the number of rows of electronic components (e.g., LEDs) of the circuit board, and one insert may correspond to one row of electronic components (e.g., LEDs) of the circuit board, and may be one or more, e.g., tens of precision inserts. The size of the insert (i.e., the second clamping portion 21) is smaller than that of the limiting groove (i.e., the first clamping portion 11), so that the insert can be placed in and moved in the limiting groove, for example, the length and width of the insert is smaller than that of the limiting groove. In other embodiments, the number of inserts is determined by the number of electronics (e.g., LEDs) on the wiring board, one insert for each electronics (e.g., LED).

Referring to fig. 13, the second clamping portion 21 includes a second wall 211. In the insert, the second wall 211 is a wall of the insert.

Referring to fig. 4 and 5, the second mold half 2 is provided on the bottom mold 3. As mentioned above, the first mold half 1 is also disposed on the bottom mold 3, and referring to fig. 14, the second mold half 2 can move relative to the first mold half 1 so that the second wall 211 of the second clamping portion 21 and the first wall 111 of the first clamping portion 11 form the first clamping space 100, so that the electronic device (such as an LED) of the circuit board is clamped in the first clamping space 100.

During production, the bottom mold 3 of the mold is mounted on a platform (e.g., a base) and is fixed. Referring to fig. 4 to 6, the entire circuit board with the electronic device (such as an LED) mounted thereon is placed on the bottom mold 3, and specifically, the positioning hole of the circuit board passes through the positioning post (i.e., the positioning portion 31) of the bottom mold 3, so as to position the circuit board, and the circuit board will not be deviated. At this time, the wiring board is positioned directly above the heating stage 32 of the bottom mold 3. The first half mold 1 is placed on the bottom mold 3, so that the first half mold 1 is used as a limiting groove of the first clamping portion 11 to cover the electronic device of the circuit board, or the limiting groove surrounds the electronic device. The first mold half 1 is moved horizontally in a first predetermined direction, for example, 12 o' clock, relative to the bottom mold 3 so that the first wall 111 of the first clamping portion 11 is in a predetermined position. At the predetermined position, the inner wall of the first wall 111 abuts against the electronic device (e.g., LED). Then, the second mold half 2 is placed on the first mold half 1, with reference to fig. 14, such that the second clamping portion 21 of the second mold half 2 is inserted into the first clamping portion 11 of the first mold half 1. Referring to fig. 14, the second mold half 2 moves horizontally relative to the first mold half 1 along a second designated direction, such as 6 o' clock direction, until it cannot move, so that the second wall 211 of the second clamping portion 21 contacts with an electronic device (such as an LED), and the second wall 211 of the second clamping portion 21 and the first wall 111 of the first clamping portion 11 form a first clamping space 100. Referring to fig. 14, the electronic devices (such as LEDs) of the wiring board are clamped in the first clamping space 100. The first and

second mold halves

1, 2 are locked to the base mold 3 so that the electronic device (e.g., LED) is fixed relative to the circuit board. Therefore, the first half die 1, the second half die 2 and the bottom die 3 can be linked in sequence to realize accurate clamping of the LED, a heating structure (a heating platform 32) is matched with the bottom of the die to realize molten tin soldering, and in the process that tin paste is melted until the tin paste is cooled, the position of a fixed electronic device is kept unchanged relative to a circuit board, so that the position accuracy of the electronic device of the circuit board can be improved, and the deviation of the electronic device of the circuit board is as small as possible.

In some embodiments, referring to fig. 4 and 6, the bottom mold 3 further includes a limiting portion 33, such as a plurality of limiting portions 33. Referring to fig. 7, each of the stoppers 32 defines an inner groove 300 for placing the first mold half 1 and the second mold half 2. In this way, both the first mold half 1 and the second mold half 2 can be placed in the inner tank 300. Correspondingly, referring to fig. 8, the first mold half 1 further includes a first limit contact portion 13, referring to fig. 11, the second mold half further includes a second limit contact portion 23, and the number of the first limit contact portion 13 and the second limit contact portion 23 may be one or more; after the first half mold 1 horizontally moves relative to the bottom mold 3 along a specific direction (for example, a first specific direction) for a positioning movement, referring to fig. 5, at least one first limiting contact portion 13 contacts with a limiting portion 33 of the bottom mold 3, and the first half mold 1 cannot horizontally move relative to the bottom mold 3 along the specific direction any more, so as to limit the first half mold 1; when the second mold half 2 moves horizontally relative to the bottom mold 3 along a predetermined direction (for example, a second predetermined direction) for a positioning movement, at least one second position-limiting contact portion 23 contacts with the position-limiting portion 33 of the bottom mold 3, and the second mold half 2 cannot move horizontally relative to the bottom mold 3 along the predetermined direction any more, so as to limit the second mold half 2.

The inner groove 300 is used to restrict the displacement of the wiring board in the inner groove 300 of the bottom mold 3. The depth of the inner groove 300 is determined by the thickness of the first and

second mold halves

1 and 2, and the limitation of the horizontal movement range of the first and

second mold halves

1 and 2 is achieved.

In some embodiments, with reference to fig. 8, the number of first clamping portions 11 is multiple, each first clamping portion 11 of the first half-mould 1 being arranged parallel to each other; with reference to fig. 12, the number of second clamping portions 21 is multiple, each second clamping portion 21 of the second half-mould 2 being arranged parallel to each other; referring to fig. 8 and 10, the first half die 1 further includes a first surface 101, and the thickness direction of the first clamping portion 11 is perpendicular to the first surface 101; with reference to fig. 11 and 12, the second half-mold 2 further comprises a second surface 201, the thickness direction of the second clamping portion 21 being perpendicular to the second surface 201; referring to fig. 7, the bottom mold 3 further includes a third surface 301, and each of the position-limiting portions 33 is perpendicular to the third surface 301. Thus, the first clamping space 100 can be formed by vertically lowering and horizontally moving the first mold half 1 and the second mold half 2, a plurality of electronic devices can be fixed at one time and prevented from being damaged, and the linear accuracy of the plurality of electronic devices can be ensured.

Referring to fig. 4, the outer dimensions of the first and

second mold halves

1 and 2 are each smaller than the outer dimensions of the inner tank 300; illustratively, the outer contour dimension of at least a portion of the first mold half 1 and the outer contour dimension of at least a portion of the second mold half 2 are each smaller than the inner contour dimension of at least a portion of the inner groove 300; thus, after the first mold half 1 and the second mold half 2 are placed in the inner groove 300 of the bottom mold 3, the first mold half 1 and the second mold half 2 have a moving space, and can move relative to the bottom mold 3 by a limited displacement.

Referring to fig. 4, the second mold half 2 is adapted to be provided to the first mold half 1. After the first half die 1 is placed on the bottom die 3 to press the circuit board, the second half die 2 is placed on the first half die 1 to press the first half die 1. The first mold half 1 is illustratively flat and facilitates the cooperation between the first mold half 1, the second mold half 2 and the bottom mold 3, for example, the second mold half 2 presses against the first mold half 1.

In some embodiments, referring to fig. 12 and 13, a step 212 is provided as the top of the insert 21 (i.e., the second clamping portion 21), the insert 21 is inserted into the first clamping portion 11 (i.e., the retaining groove 11), and the wall of the step 212 can form the first clamping space 100 with the first wall 111 of the first clamping portion 11.

The dimensions of the step 212 of the insert 21 are designed to match the dimensions of the electronic devices (such as LEDs) used in the production. The step 212 extends beyond the second outer frame 22 by a height that is approximately the thickness of the first mold half 1.

In some embodiments, referring to fig. 14, embodiments of the present application provide a mold for an electronic device further comprising a gasket 4 adapted to be disposed within the first clamping space 100. The gasket 4 may be a micron-sized steel gasket. The spacer 4 is used to adjust the distance between the inserts 21 to match the tolerance of the limiting groove 11 of the first half-mold 1, so that the electronic device (such as a single-row LED) can be deviated to a high precision standard infinitely close to zero after the welding is completed.

Based on the mold provided by the embodiment of the present application, the welding method provided by the embodiment of the present application is specifically implemented as follows.

Step S3 (fixing the mounted circuit board to the heating platform) specifically includes:

referring to fig. 4 to 6, the entire circuit board with the LEDs mounted thereon is placed in the inner groove 300 of the bottom mold 3, and the positioning holes on the circuit board penetrate through the positioning posts 32 of the inner groove 300 to position the circuit board, so that the circuit board is not displaced.

Step S4 (fixing the electronic device and making the electronic device stationary with respect to the wiring board) includes step S41 and step S42.

Step S41, the first mold half 1 is placed on the circuit board, and the first mold half 1 is moved relative to the bottom mold 3 along a first designated direction, so that the first wall 111 of the first clamping portion 11 contacts with a portion of the electronic device.

Referring to fig. 5, after the circuit board is fixed on the heating platform, the first mold half 1 is lowered into the inner groove 300 of the bottom mold 3, so as to place the first mold half 1 on the circuit board. Wherein, placing the first mold half 1 on the circuit board specifically comprises: lowering the first mold half 1 perpendicular to the first direction to the circuit board with the first wall 111 of the first clamping part 11 at a distance greater than zero from the edge of the electronic device in the first direction, e.g. horizontally; illustratively, the first mold half 1 is lowered vertically into the inner groove 300 of the bottom mold 3 centered (or referenced) on the horizontal center position of the LED, pressing the circuit board so that the circuit board abuts against the heating platform 31 at the bottom of the bottom mold 3. Then, the first mold half 1 is horizontally moved in the 12 o' clock direction until the edge of the first mold half 1 is not moved against the inner wall of the inner tank 300, and the first mold half 1 is locked so that the first mold half 1 is kept at this position, and at this time, the first wall 111 is in contact with a part of the electronic device.

Step S42, placing the second mold half 2 on the bottom mold 3, and moving the second mold half 2 relative to the first mold half 1 along a second designated direction, so that the second wall 211 of the second clamping portion 21 contacts another portion of the electronic device.

With reference to fig. 5, after the first half-mold 1 is fixed to the bottom mold 3, the second half-mold 2 is placed on the bottom mold 3: keeping the second wall 211 of the second clamping part 21 at a distance greater than zero from the edge of the electronic device in a first direction, such as a horizontal direction, lowering the second mold half 2 vertically to the first mold half 1, so that the second clamping part 21 of the second mold half 2 is placed in the first clamping part 11 of the first mold half 1; for example, based on the edge of the limiting groove 11 of the first mold half 1 away from the LED, the second mold half 2 descends vertically and clings to the first mold half 1, and the insert 21 of the second mold half 2 extends into the limiting groove 11 of the first mold half 1. The second mold half 2 is then moved horizontally in the 6 o' clock direction until it is immobilized, also remaining locked in this position. At this time, referring to fig. 14, the LED of the circuit board is clamped by one side of the limiting groove 11 of the first mold half 1 and the step 212 on the top of the insert 21 of the second mold half 2 at the middle position and fixed, the one side of the limiting groove 11 of the first mold half 1 and the wall body of the step 212 on the top of the insert 21 of the second mold half 2 form the first clamping space 100, and at this time, the second wall body 211 contacts with another part of the electronic device. And then, the heating platform 31 at the bottom of the bottom die 3 is controlled by a temperature controller to start heating to a set temperature, and solder paste of the circuit board is melted to be connected with the welding feet of the LED. And after the temperature of the heating platform 31 is raised, the temperature begins to be lowered, and after the solder paste is solidified, the welding of the LED and the circuit board can be completed.

Referring to fig. 2, the welding method provided in the embodiment of the present application further includes step S6 and step S7.

Step S6 is to move the first mold half 1 relative to the bottom mold 3 along a third predetermined direction, so that the first wall 111 of the first clamping portion 11 is released from contact with a portion of the electronic device.

After the circuit board is soldered, the first mold half 1 and the second mold half 2 are released from pressing the circuit board, and the first mold half 1 is horizontally moved relative to the bottom mold 3 in a third predetermined direction, which is a direction opposite to the first predetermined direction, so that the first wall 111 of the first clamping portion 11 of the first mold half 1 is separated from the electronic device.

Step S7, moving the second mold half 2 relative to the first mold half 1 along a fourth designated direction, so that the second wall 211 of the second clamping portion 21 is released from contact with another portion of the electronic device.

After the first wall 111 is separated from the electronic device, the second mold half 2 is moved horizontally with respect to the bottom mold 3 in a fourth prescribed direction, which is the opposite direction to the second prescribed direction, so that the second wall 211 of the second clamping portion 21 of the second mold half 2 is separated from the electronic device.

That is, after the circuit board is welded, the first half mold 1 and the second half mold 2 are released from pressing the circuit board, the first half mold 1 and the second half mold 2 are sequentially moved horizontally in reverse directions, the fixing of the LEDs is released, and then the first half mold 1 and the second half mold 2 are lifted. In this way, the soldered circuit board can be taken out for subsequent processes such as inspection.

The embodiment of the application also provides circuit board welding equipment which comprises the die and can realize the method of the embodiment of the application.

The advantages of the soldering method provided by the embodiments of the present application over the current reflow oven process are as follows.

The LED has small position deviation which can be infinitely close to 0, and the linear precision is high.

2. The circuit product can one-time welding molding, does not need manual repair, and shipment efficiency is higher, can reduce comprehensive manufacturing cost.

3. The current reflow oven process has the whole time from the circuit board placing to the welding finishing flowing out, which is 2-3 minutes (the time is determined by the temperature zone number equipped by the reflow oven and the moving speed of the conveyor belt). The time of the LED passing through the peak temperature zone (molten tin welding temperature zone) is basically 15-30 seconds, and the time of the front high-temperature preheating temperature zone (lower than the temperature of the peak temperature zone) is added, so that the time of the LED passing through the high-temperature environment above 150 ℃ is more than 1 minute.

The method provided by the embodiment of the application adopts a platform heating mode, the circuit board is taken out from the process of putting in to the completion of welding, the whole time is not more than 1 minute (the time is determined by the moving speed set by equipment in use and the structural design of the heating platform), the time of the peak temperature (the time for the heating platform to be heated from the lower limit temperature to the upper limit temperature and then cooled to the lower limit temperature) is not more than 10 seconds, and the damage of high temperature to the LED can be effectively reduced.

4. The length of the die provided by the embodiment of the application is less than half of that of a reflow oven, and the occupied area is small. The weight is about 1/3, and the installation is convenient.

5. The starting power of the existing reflow oven is generally 50-80KW, the stable working power is also 3-5KW, and the reflow oven can not be stopped within 24 hours. The peak power of the die provided by the embodiment of the application is not more than 5KW, and the die works intermittently, can stop at any time to rotate the wire, and is lower in comprehensive power consumption and cost.

6. In order to reduce the offset rate of the LED, the existing reflow furnace process is generally controlled by adopting a chip mounter with high price and high precision in the industry at present in a mode of improving the chip mounting precision.

The method provided by the embodiment of the application has low requirements on the chip mounting precision, and the chip mounting machine with low precision and low cost can be adopted for mounting the LED, so that the production expansion cost is low.

7. After circuit products (such as circuit board products) manufactured by the existing reflow soldering furnace process are discharged, products with serious LED deviation need to be manually picked up, and then professional repair personnel correct the products one by one on a constant temperature platform; therefore, the efficiency is low, secondary high-temperature damage is caused to the LED (because the constant-temperature platform must be kept at the tin melting temperature for repair), and the requirements on the quality and experience of repair personnel are high.

The method provided by the embodiment of the application can realize one-key operation through equipment, finished products do not need to be repaired, the requirement on the quality and the capability of personnel is low, the high-precision welding standard that the deviation of the LED is 100% and is less than 0.04mm (the precision is related to the adjustment and calibration of a die and can approach to 0 infinitely) can be realized, and the method is particularly suitable for electronic products such as intelligent terminals with high requirements on the welding precision.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of soldering an electronic device, the method comprising:

brushing solder paste on the circuit board;

fixing the mounted circuit board on a heating platform;

heating the circuit board by using the heating platform to realize that the electronic device is welded on the circuit board;

the method uses a mold comprising a bottom mold, a first mold half, and a second mold half;

the bottom die comprises a heating platform and a positioning part;

the second half mould comprises a second clamping part, the second clamping part comprises a second wall body, and the second half mould can move relative to the first half mould so that a second wall body of the second clamping part and a first wall body of the first clamping part form a first clamping space.

2. The method of claim 1, wherein: the use of the heating platform to heat the circuit board to realize soldering of the electronic device to the circuit board comprises:

3. The method of claim 1, wherein said securing said electronic device such that said electronic device is stationary relative to said wiring board comprises:

using a mold capable of forming a first clamping space;

and fixing the electronic device in the first clamping space.

4. The method of claim 1, wherein said securing said electronic device such that said electronic device is stationary relative to said wiring board comprises:

5. The method of claim 4, wherein the method further comprises:

6. The method of claim 4, wherein said placing said first mold half on said wiring board comprises:

7. The method of claim 6, wherein said placing said second mold half onto said base mold comprises:

8. The method of claim 4, wherein said placing the second mold half in the base mold comprises: placing the second clamping portion of the second mold half into the first clamping portion of the first mold half.

9. A circuit board soldering apparatus for carrying out the method according to any one of claims 1 to 8.