CN117912963A

CN117912963A - Ball planting tool, ball planting equipment and ball planting method

Info

Publication number: CN117912963A
Application number: CN202410282629.3A
Authority: CN
Inventors: 邓凌超
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2024-03-13
Filing date: 2024-03-13
Publication date: 2024-04-19
Anticipated expiration: 2044-03-13
Also published as: CN117912963B

Abstract

The application discloses a ball planting tool, ball planting equipment and a ball planting method. The forming die is provided with a plurality of grooves for accommodating solder paste. The net is detachably arranged on the forming die, and solder paste can leak into the grooves through meshes of the net. When the ball planting tool is used, firstly, the ball planting net is placed on a forming die with a groove, the ball planting net is brushed with solder paste, the solder paste leaks into the groove through meshes of the ball planting net, then the ball planting net is removed, a substrate to be planted with balls is placed on the forming die, the substrate and the forming die are heated together through a reflow soldering device, so that the solder paste in the groove is melted and bonded on the substrate, the solder paste is solidified on the substrate after cooling, solder balls are formed on the substrate, and finally the substrate and the forming die are separated. The ball-planting tool has the advantages of low cost, no solder paste falling or shifting, large height of the solder balls, customizable height of the solder balls and the like.

Description

Ball planting tool, ball planting equipment and ball planting method

Technical Field

The application relates to the technical field of chip packaging, in particular to a ball planting tool, ball planting equipment and a ball planting method.

Background

In the electronics industry, ball GRID ARRAY, BGA technology is widely used in the packaging of large scale integrated circuits.

At present, three main ball-mounting technologies are used in the industry: one is an automatic ball planting process, which uses special ball planting equipment to plant balls on a substrate, and has higher shipment quality and shipment efficiency, but higher equipment purchase cost and use cost; secondly, the manual ball-planting process uses a ball-planting steel net to drain solder balls onto a substrate and then performs reflow soldering, however, when the ball-planting steel net is separated from the substrate, the problem of falling or shifting of the solder balls exists, so that the operation difficulty is high; thirdly, the solder paste is directly printed on the substrate to replace the ball placement, but the height of the solder ball formed by the method is relatively low, and the cold joint is easy to occur when the solder ball is welded with a main board.

Therefore, the BGA ball mounting process in the current industry has the defects of high cost, falling or shifting of the solder balls, small height of the solder balls and the like.

Disclosure of Invention

The application aims to provide a ball planting tool, ball planting equipment and a ball planting method, wherein the ball planting tool comprises a forming die with a groove and a ball planting net, and compared with the prior art, the ball planting tool has the advantages of low cost, no falling or shifting problem of a solder ball, customizable ball planting height and the like.

In a first aspect, the application provides a ball planting tool, which comprises a forming die and a ball planting net.

The forming die is provided with a first surface, and the first surface is provided with a plurality of grooves for containing solder paste.

The ball planting net is detachably arranged on the first surface of the forming die, and solder paste can leak into the grooves through the mesh holes of the ball planting net.

When the ball planting tool is used, firstly, the ball planting net is placed on a forming die with a groove, the ball planting net is brushed with solder paste, the solder paste leaks into the groove through meshes of the ball planting net, then the ball planting net is removed, a substrate to be planted with balls is placed on the forming die, the substrate and the forming die are heated together through a reflow soldering device, so that the solder paste in the groove is melted and bonded on the substrate, the solder paste is solidified on the substrate after cooling, solder balls are formed on the substrate, and finally the substrate and the forming die are separated. Compared with ball planting equipment used in an automatic ball planting process in the related technology, the ball planting tool has the advantages of low manufacturing cost and low use cost; compared with a tool used in the manual ball-planting process in the related art, the solder paste is limited in the groove of the forming die, so that the solder paste is not fallen off or shifted when the ball-planting net is removed from the forming die, and the operation difficulty is low; compared with the process of directly printing solder paste on the substrate in the related art, the substrate processed by adopting the ball mounting tool disclosed by the application has large height of the solder balls, and can use forming dies with grooves with different depths, so that the height of the solder balls can be customized.

In one possible design, the ball planting tool further comprises a supporting structure located at the periphery of the first surface of the forming die, wherein the supporting structure is used for expanding a gap between the substrate to be planted with the ball and the forming die.

By additionally arranging the supporting structure on the forming die, a certain gap is formed between the substrate to be planted with the ball and the forming die, and the gap can provide sufficient volatilization space for soldering flux in the solder paste, so that chemical corrosion to a circuit of the substrate caused by excessive soldering flux residue is avoided; in addition, the gap which is spread by the supporting structure has enough width, so that solder paste can be ensured to be gathered near the groove without being spread to the periphery by capillary force even when overflowing out of the groove, and solder balls with complete shapes can be formed after reflow soldering, thus preventing adjacent solder balls from being electrically connected, and further effectively avoiding the occurrence of the problem of substrate short circuit.

In one possible design, the support structure is disposed on the first surface.

The support structure is arranged on the first surface, so that the ball planting tool can be reused compared with the ball planting tool arranged on the substrate.

In one possible design, the ball planting tool further comprises: the base comprises a middle plate and a frame arranged around the middle plate in a circle, and the forming die is located in an accommodating space formed by enclosing the middle plate and the frame.

The forming die is nested in the accommodating space formed by enclosing the middle plate and the frame, so that the forming die is well protected, and the frame can be used as a mounting matrix for mounting a supporting structure.

In one possible design, the support structure is formed by a spacer extending beyond the edge of the first surface, a portion of the spacer being connected to the rim, and another portion of the spacer being in abutment with the first surface.

The shim may be mounted directly to the first surface of the forming die or the shim may be mounted indirectly to the first surface of the forming die.

In one possible design, the thickness of the net is greater than the thickness of the support structure, and the bottom of the net is provided with a relief groove for relief of the support structure.

By arranging the avoidance groove on the net, the net is prevented from being supported by the supporting structure, and the net can be ensured to be attached to the forming die.

In one possible design, the mesh of the net satisfies the following relationship:

x=（L4-L5）/（D+L4-L5）；

S1=S2（1-x）；

Wherein x is the ratio of the lower couch, L4 is the thickness of the net, L5 is the thickness of the supporting structure, D is the required height of the net, S1 is the aperture area of the mesh 21, and S2 is the notch area of the groove 12.

In one possible design, the relief groove is contoured to the support structure so that the net can be positioned relative to the forming mold via the relief groove and the support structure.

The appearance design of dodging the groove is designed to be profiling with bearing structure, can dodge groove and bearing structure like this and remove the relative position of location planting net and forming die to convenient operation improves the overall efficiency of planting the ball process.

In one possible design, the first surface of the molding die protrudes from the top surface of the bezel.

The first surface of the forming die protrudes out of the top surface of the frame as much as possible, so that when the gasket is fixed on the frame, the levelness of the gasket can be conveniently corrected by increasing the thickness at the joint of the gasket and the frame, and the gasket is attached to the first surface as much as possible. If the first surface of the forming mold is recessed in the top surface of the frame, the gasket is likely to hang above the first surface after the gasket and the frame are fixed, and it is difficult to add a support between the gasket and the first surface.

In one possible design, the first surface of the forming die is provided with a barrier coating.

When filling tin cream into forming die's recess through planting the net, also have very narrow and small space between the net and the forming die laminating back, through add the barrier coating at first surface, can form the effect of blockking to the tin cream, when the condition that the tin cream overflows from forming die's recess appears, can prevent that interconnect's condition from appearing in the tin cream in two adjacent recesses, and then avoid the risk that the solder ball links to each other in reflow soldering, reduce the probability that the base plate takes place the short circuit problem.

In one possible design, the ball planting tool further comprises: the barrier coating forming piece is detachably mounted on the first surface and comprises a connecting portion, a shielding portion and a hollowed-out portion, the shielding portion is used for shielding a notch of the groove, the connecting portion is connected with the shielding portion and encloses with the shielding portion to form the hollowed-out portion, and the barrier coating can be coated on the first surface through the hollowed-out portion to form the barrier coating.

The blocking coating can be conveniently and rapidly formed on the first surface through the blocking coating forming part, and the overall efficiency of the ball planting process is improved.

In one possible design, the connection part is further provided with a through hole, through which a positioning marking part can be formed on the barrier coating, the positioning marking part being used for positioning the net and/or the substrate.

The positioning mark part can be used for positioning the ball planting net at the stage of filling solder paste in the groove, and can also be used for positioning the substrate when the substrate is fixed with the forming die, so that the overall efficiency of the ball planting process is improved.

In one possible design, the ball planting tool further comprises: and the pressing block is detachably arranged on the base and is used for sequentially pressing the substrate, the supporting structure and the forming die.

Can make things convenient for through addding the briquetting and cooperate with the base to with the pressurize of base plate, bearing structure, forming die three, and then when transferring the ball planting frock of carrying the base plate to the reflow soldering station and weld, can ensure that the laminating of base plate, bearing structure, forming die three is stable, guarantees that the solder paste in the recess is stable in shape, and then ensures the stable in shape of solder ball when heating solidification. In addition, the pressing block is placed above the substrate, so that the problem that the substrate is heated and deformed in the non-reflow soldering process can be solved, the flatness of the substrate after ball placement is ensured, and the coplanarity of the solder balls is good.

In one possible design, the support structure is formed by a step integrally formed with the forming die;

or the support structure is comprised of an ink applied to the first surface.

In one possible design, the substrate has a second surface opposite the first surface, and the support structure is disposed on the second surface.

Because the bottom of base plate has bearing structure, consequently can carry out the pressurize through the briquetting to base plate and mainboard, can not collapse the solder ball, and then avoid adjacent two molten solder balls to bond together to avoided the short circuit problem of base plate or mainboard to appear, and after the briquetting pressurize, solder balls and pad can be contacted completely, can avoid appearing the rosin joint problem.

In one possible design, the support structure is constituted by a spacer mounted on the second surface;

Or the support structure is composed of ink coated on the second surface;

or the support structure is formed by a step integrally formed with the base plate.

In one possible design, the aperture area of the mesh is smaller than the slot area of the groove.

The mesh design of planting the net is smaller than the notch of recess to when filling the solder paste into the recess through planting the net, can prevent that the solder paste from leaking in the outside of recess, further prevent that the solder paste of adjacent recess from being connected, avoid the solder ball that finally forms to appear the short circuit problem.

In one possible design, the material of the forming die is ceramic;

or a ceramic layer is arranged on the wall surface of at least the groove on the forming die.

The ceramic material is not infiltrated with the solder paste, so that the solder paste in the groove can smoothly demolding from the groove along with the substrate after reflow soldering.

In a second aspect, the application also provides ball mounting equipment, which comprises a reflow soldering device and any ball mounting tool.

The ball planting device comprises a ball planting tool, and has the advantages of low manufacturing cost and low use cost compared with ball planting devices used in the automatic ball planting process in the related technology; compared with a tool used in the manual ball-planting process in the related art, the solder paste is limited in the groove of the forming die, so that the solder paste is not fallen off or shifted when the ball-planting net is removed from the forming die, and the operation difficulty is low; compared with the process of directly printing solder paste on the substrate in the related art, the substrate processed by adopting the ball mounting tool disclosed by the application has large height of the solder balls, and can use forming dies with grooves with different depths, so that the height of the solder balls can be customized.

In a third aspect, the present application also provides a method for planting balls, including:

Placing a ball planting net on a forming die with a groove, and filling solder paste into the groove through the ball planting net;

after removing the ball planting net, placing the substrate to be planted with the ball on a forming die;

Solidifying the solder paste in the groove by a reflow soldering device to form a solder ball on the substrate;

The substrate and the molding die are separated.

According to the ball-planting method, the adopted ball-planting tool has the advantages of low manufacturing cost and low use cost, solder paste is not dropped or shifted when the ball-planting net is removed from the forming die, so that the operation difficulty is low, the height of the formed solder balls is high, and the forming die with grooves with different depths can be used, so that the height of the solder balls can be customized.

In one possible design, the step of placing the substrate on which the ball is to be planted on the molding die further includes:

And placing the substrate to be planted with the ball on a forming die, and enabling a gap to be formed between the substrate and the forming die through a supporting structure.

When the substrate is placed on the forming die, a gap is formed between the substrate and the forming die, and the gap can provide sufficient volatilization space for soldering flux, so that excessive soldering flux residue is avoided, in addition, solder paste can be ensured to be gathered near the groove and not to spread all around even when overflowing the groove, the situation that adjacent solder balls are electrically connected can be prevented, and the problem of short circuit of the substrate is effectively avoided.

In one possible design, before the step of placing the net on the molding die with the grooves, the method further comprises:

Placing the barrier coating forming part on the surface with the groove of the forming die;

coating barrier coating on one side of the forming die with the barrier coating forming part;

and separating the barrier coating forming piece from the forming die so as to form the barrier coating with the positioning mark part on the forming die.

By additionally arranging the barrier coating on the forming die, a barrier effect can be formed on the solder paste, and the solder paste in two adjacent grooves can be prevented from being connected with each other; the barrier coating can be conveniently and rapidly formed on the forming die through the barrier coating forming piece, so that the overall efficiency of the ball planting process is improved; the positioning mark part can be used for positioning the ball planting net and also can be used for positioning the substrate, so that the overall efficiency of the ball planting process is further improved.

In one possible design, the bottom of the molding die is provided with a base, and before the step of solidifying the solder paste in the recess by the reflow soldering apparatus to form the solder balls on the substrate, the method further comprises:

The pressing block is connected with the base, so that the base plate, the supporting structure and the forming die are sequentially pressed and maintained.

The pressing block is additionally arranged to be conveniently matched with the base, so that the lamination stability of the substrate, the supporting structure and the forming die is ensured, the shape stability of solder paste in the groove is ensured, and the shape stability of the solder balls is further ensured during heating and curing; the substrate placing pressing block can also prevent the problem that the substrate is deformed by heating in the process of non-return flow welding, so that the flatness of the substrate after ball placement and the good coplanarity of the solder balls are ensured.

Drawings

FIG. 1 is an exploded view of an example of a ball mounting fixture according to an embodiment of the present application;

FIG. 2 is an assembly view of the ball mounting fixture of FIG. 1;

FIG. 3 is a schematic diagram of a portion of a ball placement tool for placement of balls according to an embodiment of the present application;

FIG. 4 is an exploded view of another example of a ball mounting fixture according to an embodiment of the present application;

FIG. 5 is an assembly view of the ball mounting fixture of FIG. 4;

FIG. 6 is a schematic view of a substrate provided by an embodiment of the present application on a molding die;

FIG. 7 is a schematic view showing an example of a support structure and a molding die according to an embodiment of the present application;

FIG. 8 is an exploded view of a net and support structure provided in accordance with an embodiment of the present application;

FIG. 9 is a top view of a net and molding die provided by an embodiment of the present application;

FIG. 10 is a schematic view of a net, a supporting structure and a forming mold according to an embodiment of the present application;

FIG. 11 is a schematic view of a forming die and barrier coating provided by an embodiment of the present application;

FIG. 12 is a top view of a forming die and barrier coating provided by an embodiment of the present application;

fig. 13 is a schematic diagram of a solder paste filled in a groove according to an embodiment of the present application;

FIG. 14 is a top view of a barrier coating molded article provided by an embodiment of the present application;

FIG. 15 is a schematic view of a briquette provided in an embodiment of the application in use;

FIG. 16 is a schematic view of another example of a support structure provided by an embodiment of the present application;

FIG. 17 is a schematic view of another example of a support structure provided by an embodiment of the present application;

FIG. 18 is a schematic view of another example of a support structure provided by an embodiment of the present application;

FIG. 19 is a top view of a substrate provided by an embodiment of the present application;

FIG. 20 is a schematic diagram of a related art substrate and motherboard interconnected by solder balls;

FIG. 21 is a schematic diagram of a substrate and motherboard interconnected by solder balls in an embodiment of the present application;

FIG. 22 is a flowchart of an example of a ball placement method according to an embodiment of the present application;

FIG. 23 is a flowchart of another example of a ball placement method according to an embodiment of the present application;

FIG. 24 is a flow chart of providing a barrier coating provided by an embodiment of the present application;

FIG. 25 is a flowchart of another example of a ball placement method according to an embodiment of the present application;

fig. 26 is a flowchart of solder ball height reconstruction provided by an embodiment of the present application.

Reference numerals:

10. A forming die; 11. a first surface; 12. a groove; 13. a barrier coating; 131. a positioning mark part; 14. a gap;

20. net planting; 21. a mesh; 22. an avoidance groove;

30. a support structure; 31. a gasket; 32. a step; 33. printing ink;

40. a base; 41. a middle plate; 42. a frame; 43. an accommodation space;

50. briquetting;

60. A barrier coating molding; 61. a connection part; 611. a through hole; 62. a shielding part; 63. the hollow part is hollowed out;

80. A main board;

90. a substrate; 91. a second surface; 92. solder balls; 93. solder paste; 94. and a chip package.

Detailed Description

The following is an exemplary description of the relevant aspects of embodiments of the present application that may be referred to. It will be apparent that the described embodiments are only some, but not all, embodiments of the application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present application, it should be understood that the terms "upper," "lower," "side," "inner," "outer," "top," "bottom," and the like indicate or are based on mounting orientations or positional relationships, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

It should be further noted that, in the embodiments of the present application, the same reference numerals denote the same components or the same parts, and for the same parts in the embodiments of the present application, reference numerals may be given to only one of the parts or the parts in the drawings, and it should be understood that, for other same parts or parts, the reference numerals are equally applicable.

In the description of the present application, it should be noted that the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone.

In the electronic industry, ball grid array packaging technology is widely used in packaging of large-scale integrated circuits, such as central processing units (cpu's), bus controllers, data controllers, display controller chips, etc. in computers, memory chips, logic chips, system on Chip (SoC) in mobile phones, etc. BGA packaging technology is to make array solder balls at the bottom of the package substrate as the I/O terminals of the circuit to electrically and mechanically interconnect with a Printed Circuit Board (PCB).

At present, three main ball-mounting technologies are used in the industry: one is an automatic ball planting process, which uses special ball planting equipment to plant balls on a substrate, and has higher shipment quality and shipment efficiency, but higher equipment purchase cost and use cost; secondly, the manual ball-planting process uses a ball-planting steel net to drain solder balls onto a substrate and then performs reflow soldering, however, the problem that the solder balls fall off or shift when the ball-planting steel net is off-line exists, and the operation difficulty is high; thirdly, the solder paste is directly printed on the substrate to replace the ball placement, but the height of the solder ball formed by the method is relatively low, and the cold joint is easy to occur when the solder ball is welded with a main board.

In view of the above, the present application provides a ball-planting tool, a ball-planting device and a ball-planting method, wherein the ball-planting tool comprises a forming mold with a groove and a ball-planting net, and the ball-planting tool is used for ball-planting, which has the advantages of low cost, no drop or shift of solder balls, and customizable ball-planting height compared with the related art.

The embodiment of the application firstly provides a ball planting tool, and the ball planting tool provided by the embodiment of the application is described in detail with reference to the accompanying drawings.

Fig. 1 is an exploded view of an example of a ball mounting tool according to an embodiment of the present application. Fig. 2 is an assembly view of the ball mounting fixture in fig. 1.

As shown in fig. 1-2, the ball planting tool provided by the embodiment of the application comprises a forming die 10 and a ball planting net 20. In addition, the ball mounting fixture can further comprise a base 40, and the base 40 can play a role of protecting the forming die 10 and can serve as a base body for mounting and connecting other components.

The molding die 10 has a first surface 11, and the first surface 11 is provided with a plurality of grooves 12 for accommodating solder paste 93.

The net 20 is detachably mounted on the first surface 11 of the molding die 10, and the solder paste 93 can leak into the recess 12 through the mesh 21 of the net 20.

In the ball mounting fixture according to the embodiment of the application, when in use, the ball mounting net 20 is firstly placed on the forming die 10 with the groove 12, the solder paste 93 is brushed on the ball mounting net 20, the solder paste 93 leaks into the groove 12 through the mesh 21 of the ball mounting net 20, then the ball mounting net 20 is removed, the substrate 90 (the substrate 90 can be provided with the chip package 94) to be mounted with balls is placed on the forming die 10, the substrate 90 and the forming die 10 are heated together through a reflow soldering device, so that the solder paste 93 in the groove 12 is melted and adhered on the substrate 90, the solder paste 93 is solidified on the substrate 90 after cooling, the solder balls 92 are formed on the substrate 90, and finally the substrate 90 and the forming die 10 are separated. Compared with ball planting equipment used in an automatic ball planting process in the related technology, the ball planting tool has the advantages of low manufacturing cost and low use cost; compared with the tooling used in the manual ball-planting process in the related art, the solder paste 93 is limited in the groove 12 of the forming die 10, so that the solder paste 93 is not fallen off or shifted when the ball-planting net 20 is removed from the forming die 10, and the operation difficulty is low; compared with the process of directly printing solder paste on a substrate in the related art, the height of the solder balls 92 is large by adopting the substrate 90 processed by the ball mounting tool according to the embodiment of the application, and the forming mold 10 with the grooves 12 with different depths can be used, so that the height of the solder balls 92 can be customized.

Hereinafter, the ball-planting method provided by the embodiment of the application will be described in detail to facilitate understanding of the advantages of the ball-planting tool in the embodiment of the application.

The use process of the ball planting tool is described in detail above. However, during use, it was found that there were cases where too much flux remained on the substrate 90 processed by the ball placement tool of the previous embodiment and electrical connection between adjacent solder balls 92 was likely to occur. The reason for this problem will now be described in detail with reference to the accompanying drawings.

Fig. 3 is a schematic diagram of a portion of a ball-implanting tool for implanting balls according to an embodiment of the present application. Fig. 3 (a) is a schematic view of the substrate 90 when attached to the molding die 10; fig. 3 (b) is a schematic diagram of the substrate 90 after the solder balls 92 have been formed thereon.

As shown in fig. 3, a substrate 90 to be ball-mounted is fixed on a molding die 10, solder paste 93 is solidified and molded into solder balls 92 by reflow soldering, and finally the molding die 10 is separated from the substrate 90 to obtain the substrate 90 with the solder balls 92.

In the ball mounting process described above, when the substrate 90 to be mounted with balls is fixed to the molding die 10, there is no large gap after the substrate 90 is bonded with the molding die 10 because the surface of the molding die 10 is a flat surface. Solder paste 93 is usually doped with a flux, the flux volatilizes from the solder paste 93 along with the temperature rise, and as there is insufficient volatilization space between the substrate 90 and the molding die 10, the flux cannot volatilize completely in the reflow soldering process, so that excessive flux residue is caused, the residual flux can cause chemical corrosion to a circuit, and the circuit fails after a long time; meanwhile, due to the influence of the machining tolerance and the assembly tolerance, there is a very narrow gap between the bonded substrate 90 and the molding die 10, when the solder paste 93 overflows too much from the inside of the groove 12 of the molding die 10, the solder paste 93 is easily spread out to the periphery along the narrow gaps due to the capillary force, as shown in (a) of fig. 3, at the position indicated by a, the solder paste 93 is spread out on the plane around the groove 12, and there is a risk that the solder paste 93 overflowed by the adjacent groove 12 is connected, and when the solder paste 93 is cured by reflow, as shown in (b) of fig. 3, the adjacent solder balls 92 are electrically connected in fact at the position indicated by a, which causes a problem that the substrate 90 is easy to have a short circuit.

Fig. 4 is an exploded view of another example of the ball mounting tool according to the embodiment of the present application. Fig. 5 is an assembly view of the ball mounting fixture of fig. 4. Fig. 6 is a schematic view of a substrate 90 provided in an embodiment of the present application when the substrate is on the molding die 10.

As shown in fig. 4 to 6, in order to solve the above-mentioned problems, in some embodiments of the present application, the ball mounting fixture further includes a support structure 30 located at the periphery of the first surface 11 of the forming mold 10, where the support structure 30 is used to prop the gap 14 between the substrate 90 to be mounted with balls and the forming mold 10.

In the ball mounting tool of the embodiment, by adding the supporting structure 30 on the forming die 10, a certain gap 14 is formed between the substrate 90 to be mounted with balls and the forming die 10, and the gap 14 can provide sufficient volatilization space for the soldering flux in the solder paste 93, so that chemical corrosion to the circuit of the substrate 90 caused by excessive soldering flux residue is avoided; in addition, the gaps 14 supported by the supporting structure 30 have a sufficient width, so that solder paste 93 can be ensured to gather near the grooves 12 without being spread out by capillary force, even when overflowing the grooves 12, and solder balls 92 with complete shapes can be formed after reflow soldering, thereby preventing the adjacent solder balls 92 from being electrically connected, and further effectively avoiding the problem of short circuit of the substrate 90.

Alternatively, in some embodiments provided by the present application, the shape of the recess 12 comprises at least one of a semi-ellipsoid, a semi-sphere, a cylinder, a polygon prism.

Fig. 7 is a schematic diagram of an example of the support structure 30 and the forming mold 10 according to the embodiment of the present application.

As shown in fig. 7, alternatively, the depth of the groove 12 may be set according to the desired implant height, and the depth of the groove 12 satisfies the following relationship in consideration of the thickness of the support structure 30 such as the spacer 31:

L1=D-L5。

Where L1 is the depth of the recess 12, D is the desired implant height, and L5 is the thickness of the support structure 30.

As further shown in fig. 7, the diameter L2 of the recess 12 is optionally the largest diameter at the plane, and may also be the largest diameter of the desired implant.

As shown in fig. 7, optionally, the critical dimension tolerance of the grooves 12, the center-to-center spacing L3 between the grooves 12 is less than or equal to 0.05mm, so as to avoid the offset of the ball placement; the diameter L2 of the groove 12 has a dimensional tolerance less than or equal to 0.03mm, the depth L1 of the groove 12 has a dimensional tolerance less than or equal to 0.05mm, and the dimensional tolerance can ensure that the uniformity of the volume of tin printed on the groove 12 and the uniformity of coplanarity after ball implantation are good.

Alternatively, the support structure 30 may be a spacer 31, a step 32, ink 33, or the like provided on the molding die 10; or the support structure 30 may also be a spacer 31, a step 32, ink 33, etc. disposed on the substrate 90. The embodiments described below will be described in detail with reference to the accompanying drawings.

Alternatively, the net 20 may be made of iron, steel, metal alloy, or the like.

Alternatively, the specific composition of the solder paste 93 may be at least one of PbSn, auSn, snAg, snAgCu.

Alternatively, the molding die 10 may be a ceramic, a polymer material, or the like, which is resistant to high temperatures.

In one embodiment of the present application, the material of the forming die 10 is ceramic.

In this embodiment, the ceramic material is not infiltrated with the solder paste 93, so that the solder paste 93 in the groove 12 can be smoothly released from the groove 12 following the substrate 90 after reflow soldering.

In one embodiment of the present application, the material of the forming mold 10 is other high temperature resistant materials except ceramic, for example, the forming mold 10 is made of polymer material, and at least the groove wall surface of the groove 12 on the forming mold 10 is provided with a ceramic layer.

In this embodiment, a ceramic layer is disposed on the wall surface of the groove 12, so that the solder paste 93 in the groove 12 can be smoothly released from the groove 12 following the substrate 90 after reflow soldering.

When the forming mold 10 is made of ceramic material, the forming mold 10 is fragile in tin printing and turnover, and the forming mold 10 is nested in the base 40 of conventional metal or plate, the base 40 plays a role in protecting the ceramic forming mold 10, and the following embodiments are specifically described.

As shown in fig. 4, in an embodiment of the present application, the base 40 includes a middle plate 41 and a rim 42 disposed around the middle plate 41, and the forming mold 10 is located in a receiving space 43 defined by the middle plate 41 and the rim 42.

In this embodiment, the forming mold 10 is nested in the accommodating space 43 formed by enclosing the middle plate 41 and the frame 42, which plays a good role in protecting the forming mold 10, and the frame 42 can also be used as a mounting base for mounting the support structure 30.

In one embodiment provided by the present application, the support structure 30 is formed by a spacer 31 mounted on the first surface 11.

Alternatively, the shim 31 may be mounted directly to the first surface 11 of the forming die 10, for example: the spacer 31 may be adhered to the first surface 11 by an adhesive; or the gasket 31 is locked to the first surface 11 by means of screws; or snap-fit structures are provided on the spacer 31 and the first surface 11, respectively, by means of which they are fixedly connected.

Alternatively, the gasket 31 may be mounted on the first surface 11 of the forming die 10 in an indirect manner, as shown in the following embodiments.

In one embodiment of the present application, as shown in fig. 7, the pad 31 extends beyond the edge of the first surface 11, a portion of the pad 31 is connected to the frame 42, and another portion of the pad 31 abuts against the first surface 11.

In this embodiment, the frame 42 of the base 40 is used to fix the gasket 31, so that damage to the forming mold 10 can be reduced, and particularly when the forming mold 10 is made of ceramic material, the gasket 31 is directly mounted on the ceramic surface, so that breakage and cracking easily occur.

Alternatively, when the gasket 31 is fixedly connected with the frame 42, the gasket 31 may be adhered to the frame 42 by an adhesive; or the gasket 31 is locked on the frame 42 by a screw; or the gasket 31 and the frame 42 are respectively provided with a clamping structure, and the gasket 31 and the frame 42 are fixedly connected through the clamping structure; or the gasket 31 and the frame 42 are magnetically connected by a magnetic attraction manner.

As further shown in fig. 7, in one embodiment of the present application, the first surface 11 of the forming mold 10 protrudes from the top surface of the frame 42.

It is difficult to achieve perfect coplanarity of the first surface 11 of the forming die 10 and the top surface of the rim 42 due to machining tolerances and assembly tolerances, and if this occurs, the gasket 31 fixed to the rim 42 will not be able to closely abut against the first surface 11. Therefore, in order to solve the problem, the first surface 11 of the forming mold 10 is protruded from the top surface of the frame 42 as much as possible in the present embodiment, so that when the gasket 31 is fixed on the frame 42, the levelness of the gasket 31 can be easily corrected by increasing the thickness at the junction of the gasket 31 and the frame 42, so that the gasket 31 is attached to the first surface 11 as much as possible. It is assumed that if the first surface 11 of the forming mold 10 is recessed on the top surface of the frame 42, the spacer 31 is likely to hang above the first surface 11 after the spacer 31 and the frame 42 are fixed, and it is difficult to add a support between the spacer 31 and the first surface 11.

When the solder paste 93 is filled into the groove 12 of the forming die 10 through the ball planting net 20, the ball planting net 20 and the supporting structure 30 need to be avoided, so that the ball planting net 20 is prevented from being supported by the supporting structure 30, and the ball planting net 20 is ensured to be attached to the forming die 10. To achieve this effect, this may be accomplished by reducing the size of the net 20 such that the net 20 directly leaves the support structure 30 clear. Further, it can be realized by the following examples.

Fig. 8 is an exploded view of the net 20 and the support structure 30 provided by an embodiment of the present application.

As shown in FIG. 8, in one embodiment of the present application, the net 20 has a thickness greater than that of the support structure 30, and the bottom of the net 20 is provided with a relief groove 22 for relieving the support structure 30.

In this embodiment, the avoidance groove 22 is formed on the net 20, so that the net 20 is prevented from being supported by the support structure 30, and the net 20 and the forming mold 10 can be ensured to keep being attached.

The mesh 21 of the net 20 is designed as: after the net 20 is tin printed, the upper surface of the solder paste 93 is higher than the surface of the supporting structure 30 by the height=the thickness of the net 20-the thickness of the supporting structure 30; during reflow, the amount of solder paste 93 that is deposited = the height of solder paste 93 that is raised, the deposition ratio = the deposition amount/(depth of recess 12 + thickness of net 20) = (thickness of net 20-thickness of support structure 30)/(desired height of net 20 + thickness of net 20-thickness of support structure 30). After the ratio of the couch is obtained, the mesh 21 can be designed according to the slot area of the groove 12, specifically, the aperture area of the mesh 21=the slot area of the groove 12 (1-ratio of the couch).

In summary, when manufacturing the net 20, the mesh 21 thereof needs to satisfy the above condition, that is, in one embodiment provided by the present application, the mesh 21 of the net 20 satisfies the following relationship:

x=（L4-L5）/（D+L4-L5）；

S1=S2（1-x）。

where x is the ratio of the table, L4 is the thickness of the net 20, L5 is the thickness of the support structure 30, D is the desired height of the net, S1 is the aperture area of the mesh 21, and S2 is the slot area of the groove 12.

Fig. 9 is a top view of the net 20 and the forming mold 10 according to the embodiment of the present application.

In one embodiment provided by the present application, as shown in fig. 9, the aperture area of the mesh 21 is smaller than the slot area of the groove 12.

In this embodiment, the mesh 21 of the ball-planting net 20 is designed to be smaller than the notch of the groove 12, so that when the solder paste 93 is filled into the groove 12 through the ball-planting net 20, the solder paste 93 can be prevented from leaking outside the groove 12, the solder paste 93 of the adjacent groove 12 is further prevented from being connected, and the problem of short circuit of the solder balls 92 finally formed is avoided.

Fig. 10 is a schematic view of the net 20, the supporting structure 30 and the forming mold 10 according to the embodiment of the present application.

As shown in FIG. 10, in one embodiment of the present application, the relief groove 22 is contoured to the support structure 30 so that the net 20 can be positioned relative to the forming die 10 via the relief groove 22 and the support structure 30.

In this embodiment, the shape of the avoidance groove 22 is designed to be contoured with the support structure 30, so that the relative positions of the net 20 and the forming mold 10 can be positioned through the avoidance groove 22 and the support structure 30, thereby facilitating the operation.

In this embodiment, the avoidance groove 22 and the support structure 30 are contoured, which means that the shapes are approximately the same, and the groove depth of the avoidance groove 22 is slightly larger than the thickness of the support structure 30, so that the raising of the net 20 by the support structure 30 is avoided.

The supporting structure 30 is not easy to be too thick, otherwise, the thickness of the ball planting net 20 is increased, when the ball planting distance is too small and dense, the solder paste 93 is not easy to leak downwards from the ball planting net 20 after the ball planting net is used, and the filling effect of the groove 12 is further affected; the support structure 30 is not easily thinned, otherwise, the effects of preventing solder overflow short circuit and soldering flux volatilization are poor.

Based on the above, the thickness L5 of the supporting structure 30 is 0.03mm, the groove depth of the avoiding groove 22 is 0.04mm, and the thickness L4 of the net 20 is less than or equal to 0.1mm.

Fig. 11 is a schematic view of a molding die 10 and a barrier coating 13 provided in an embodiment of the present application. Fig. 12 is a top view of the forming die 10 and barrier coating 13 provided by an embodiment of the present application.

As shown in fig. 11-12, in one embodiment provided by the present application, a barrier coating 13 is disposed on the first surface 11 of the forming die 10. Wherein the barrier coating 13 is only provided on the first surface 11 of the forming die 10, and the groove 12 is not provided therein.

Fig. 13 is a schematic diagram of the embodiment of the present application when the solder paste 93 is filled into the groove 12, as shown in fig. 13, in this embodiment, when the solder paste 93 is filled into the groove 12 of the forming mold 10 through the ball planting net 20, a very small gap is formed between the ball planting net 20 and the forming mold 10 after the ball planting net is attached, and by adding the barrier coating 13 on the first surface 11, a barrier effect can be formed on the solder paste 93, and when the solder paste 93 overflows from the groove 12 of the forming mold 10, the solder paste 93 in two adjacent grooves 12 can be prevented from being connected, so that the risk of connecting the solder balls 92 in reflow soldering is avoided, and the probability of occurrence of a short circuit problem of the substrate 90 is reduced.

Alternatively, the barrier coating 13 may be applied slowly around the groove 12 by brushing the barrier coating; or by a rapid application through the barrier coating former 60, as in the case of the following embodiments.

Fig. 14 is a top view of a barrier coating former 60 provided in an embodiment of the present application.

As shown in fig. 14, in one embodiment of the present application, the ball planting tool further includes a barrier coating forming member 60, where the barrier coating forming member 60 is detachably mounted on the first surface 11, the barrier coating forming member 60 includes a connection portion 61, a shielding portion 62, and a hollowed portion 63, the shielding portion 62 is used for shielding a notch of the groove 12, the connection portion 61 is connected with the shielding portion 62 and encloses the shielding portion 62 to form the hollowed portion 63, and the barrier coating can be coated on the first surface 11 through the hollowed portion 63 to form the barrier coating 13.

In this embodiment, the barrier coating 13 can be conveniently and rapidly formed on the first surface 11 by the barrier coating forming member 60, so as to improve the overall efficiency of the ball planting process.

Because the connection portion 61 is blocked, a part of coating blind area exists on the first surface 11, so that the blocking coating forming piece 60 can be removed from the first surface 11, and the blocked area of the connection portion 61 can be covered by a secondary coating mode.

Alternatively, the barrier coating former 60 may be a film or dry film.

Alternatively, the barrier coating former 60 may be removably mounted to the first surface 11 of the forming die 10 by electrostatic attraction, adhesion, or the like.

As shown in fig. 14, in an embodiment of the present application, the connection portion 61 is further provided with a through hole 611, and the positioning mark portion 131 can be formed on the barrier coating 13 through the through hole 611, and the positioning mark portion 131 is used for positioning the net 20 and/or the substrate 90.

In this embodiment, through holes 611 are formed on the connecting portion 61, so that the positioning mark portion 131 is formed on the finally formed barrier coating 13, and as shown in fig. 10, the positioning mark portion 131 can be used for positioning the net 20 at the stage of filling the solder paste 93 in the groove 12, and can also be used for positioning the substrate 90 when the substrate 90 is fixed with the forming mold 10.

In use, the operator visually observes the positioning mark 131 to adjust the position of the net 20 or the base plate 90 on the molding die 10, and the fool-proof structure is similar in industrial design.

Fig. 15 is a schematic view of a briquette 50 provided in an embodiment of the application in use.

As shown in fig. 15, in an embodiment of the present application, the ball planting tool further includes a pressing block 50, where the pressing block 50 is detachably mounted on the base 40, and the pressing block 50 is used to sequentially compress the substrate 90, the support structure 30, and the forming mold 10.

In this embodiment, the pressing block 50 is added to be able to cooperate with the base 40 conveniently, so as to keep the pressure of the substrate 90, the supporting structure 30 and the forming mold 10, and further ensure that the substrate 90, the supporting structure 30 and the forming mold 10 are stably attached, and the solder paste 93 in the groove 12 is stable in shape, and further ensure the shape stability of the solder balls 92 during heating and curing.

In addition, the pressing block 50 is placed above the substrate 90, so that the problem that the substrate 90 is deformed by heat in the process of non-reflow soldering can be prevented, the flatness of the substrate 90 after ball placement is ensured, and the coplanarity of the solder balls 92 is good.

Fig. 16 is a schematic view of another example of a support structure 30 according to an embodiment of the present application.

In one embodiment provided by the present application, as shown in fig. 16, the support structure 30 is formed by a step 32 integrally formed with the forming die 10.

Fig. 17 is a schematic view of another example of a support structure 30 according to an embodiment of the present application.

In one embodiment provided by the present application, as shown in fig. 17, the support structure 30 is comprised of an ink 33 applied to the first surface 11.

Fig. 18 is a schematic view of another example of a support structure 30 according to an embodiment of the present application.

As shown in fig. 18, in one embodiment provided by the present application, the substrate 90 has a second surface 91 opposite the first surface 11; the support structure 30 is constituted by a spacer 31 mounted on the second surface 91.

Alternatively, the fixing manner of the spacer 31 and the substrate 90 is the same as the fixing manner of the spacer 31 and the forming mold 10 mentioned above, and will not be repeated here.

In one embodiment provided by the present application, the support structure 30 is comprised of ink 33 coated on the second surface 91.

In one embodiment of the present application, the support structure 30 is formed from a step 32 integrally formed with the base plate 90.

Fig. 19 is a top view of a substrate 90 according to an embodiment of the present application.

As shown in fig. 19, in the above embodiments, the supporting structure 30 is disposed on the second surface 91 of the substrate 90, so that the substrate 90 and the forming mold 10 can be separated by the gap 14 when the solder balls are planted, so as to facilitate the volatilization of the soldering flux and ensure the shape of the solder balls 92, and prevent the solder paste 93 from being connected and prevent the substrate 90 from being shorted.

Furthermore, when the support structure 30 is disposed on the second surface 91 of the substrate 90, it is also possible to avoid the problem of cold soldering and the risk of short circuits when the substrate 90 is interconnected with the motherboard 80, and how this technical effect is understood, the applicant will now be described in detail with reference to the accompanying drawings.

Fig. 20 is a schematic diagram of a related art substrate 90 and motherboard 80 interconnected by solder balls 92. Fig. 21 is a schematic diagram of a substrate 90 and a motherboard 80 interconnected by solder balls 92 in an embodiment of the present application.

In the related art, after the substrate 90 is completely embedded with the balls, the substrate may be interconnected with the motherboard 80 by a Package-on-Package (PoP) technique, specifically, the solder balls 92 of the substrate 90 are melted by a reflow soldering device and then connected with the pads on the motherboard 80, and the substrate 90 and the motherboard 80 cannot be maintained by the pressing block 50 because the bottom of the substrate 90 does not have the supporting structure 30, which may cause the solder balls 92 and the pads to be unable to be fully contacted, resulting in a cold solder problem. If the pressing block 50 is forcibly added to maintain the pressure, as shown in fig. 18, when the pressing block 50 is used to maintain the pressure of the substrate 90 and the motherboard 80, two adjacent melted solder balls 92 are easily collapsed and then bonded together, for example, two solder balls 92 in fig. 18, which causes a short circuit problem of the substrate 90 or the motherboard 80.

In contrast, in the substrate 90 in the embodiment of the present application, as shown in fig. 19, since the bottom of the substrate 90 has the supporting structure 30, the pressure of the substrate 90 and the motherboard 80 can be maintained by the pressing block 50, so that the solder balls 92 will not collapse, and further, the adjacent two melted solder balls 92 are prevented from being bonded together, thereby avoiding the occurrence of the short circuit problem of the substrate 90 or the motherboard 80, and the solder balls 92 and the bonding pads can be completely contacted after the pressure of the pressing block 50 is maintained, and the occurrence of the cold joint problem can be avoided.

The embodiment of the application also provides ball planting equipment which comprises a reflow soldering device and the ball planting tool in any one of the embodiments.

Alternatively, the reflow soldering apparatus may be a reflow soldering machine or reflow oven, which is a device that allows the surface mount components and the pads of the substrate 90 to be reliably bonded together by the solder paste 93 alloy by providing a heated environment to heat and melt the solder paste 93.

Alternatively, the reflow soldering apparatus may also be an infrared heating lamp or a heat gun.

Fig. 22 is a flowchart of an example of a ball-planting method according to an embodiment of the present application. Wherein (a) in fig. 22 is a schematic view of the net 20 placed on the molding die 10; fig. 22 (b) is a schematic view of the ball grid 20 filling the recess 12 with solder paste 93; fig. 22 (c) is a schematic view of the forming mold 10 with the net 20 removed; fig. 22 (d) is a schematic diagram of the placement of the substrate 90; fig. 22 (e) is a schematic diagram of the substrate 90 after the solder paste 93 is collapsed; fig. 22 (f) is a schematic diagram of the solder balls 92 formed on the substrate 90 after being heated and cured by the reflow apparatus.

Step 101, as shown in fig. 22 (a) and (b), the ball-planting net 20 is placed on the molding die 10 having the groove 12, and the solder paste 93 is filled into the groove 12 through the ball-planting net 20.

Step 102, as shown in fig. 22 (c), (d) and (e), the net 20 is removed, and the substrate 90 to be planted with balls is placed on the forming mold 10.

At step 103, the solder paste 93 in the recess 12 is cured by the reflow apparatus to form the solder balls 92 on the substrate 90.

Step 104, as shown in fig. 22 (f), separates the substrate 90 from the molding die 10.

In the ball-implanting method according to the embodiment of the present application, the ball-implanting tool has the advantages of low manufacturing cost and low use cost, and the solder paste 93 will not fall off or shift when the ball-implanting net 20 is removed from the forming mold 10, so that the operation difficulty is small, the height of the formed solder balls 92 is large, and the forming mold 10 with the grooves 12 of different depths can be used, so that the height of the solder balls 92 can be customized.

Fig. 23 is a flowchart of another example of a ball planting method according to an embodiment of the present application. Wherein (a) in fig. 23 is a schematic view of the net 20 placed on the molding die 10; fig. 23 (b) is a schematic view of the ball grid 20 filling the recess 12 with solder paste 93; fig. 23 (c) is a schematic view of the recess 12 filled with solder paste 93; fig. 23 (d) is a schematic view of the net 20 removed from the molding die 10; fig. 23 (e) is a schematic diagram when the substrate 90 is placed; fig. 23 (f) is a schematic diagram of the substrate 90 after the solder paste 93 is collapsed; fig. 23 (g) is a schematic diagram of the solder balls 92 formed on the substrate 90 after being heated and cured by the reflow apparatus.

As shown in fig. 23, the embodiment of the application further provides a ball planting method, which comprises the following steps.

Step 201, as shown in (a), (b) and (c) in fig. 23, the ball-planting net 20 is placed on the forming mold 10 with the groove 12, and the solder paste 93 is filled into the groove 12 through the ball-planting net 20 by using a scraping plate.

Step 202, as shown in (d), (e) and (f) in fig. 23, after removing the ball-planting net 20, the substrate 90 to be planted with balls is placed on the forming mold 10, and pressure is applied to the substrate 90 or gravity is used to collapse the solder paste 93 by the substrate 90, and then the gap 14 is opened between the substrate 90 and the forming mold 10 by the supporting structure 30.

In step 203, the ball mounting fixture carrying the substrate 90 is transferred to a reflow station, and the solder paste 93 in the recess 12 is cured by the reflow apparatus to form the solder balls 92 on the substrate 90.

In step 204, as shown in fig. 23 (g), the substrate 90 and the molding die 10 are separated to obtain the substrate 90 having the solder balls 92.

According to the ball-mounting method, the supporting structure 30 is arranged on the adopted forming die 10, so that a certain gap 14 is formed between the substrate 90 to be ball-mounted and the forming die 10, and the gap 14 can provide sufficient volatilization space for soldering flux in the solder paste 93, so that chemical corrosion of a circuit of the substrate 90 caused by excessive soldering flux residue is avoided; in addition, the gaps 14 supported by the supporting structure 30 have a sufficient width, so that solder paste 93 can be ensured to gather near the grooves 12 without being spread out by capillary force, even when overflowing the grooves 12, and solder balls 92 with complete shapes can be formed after reflow soldering, thereby preventing the adjacent solder balls 92 from being electrically connected, and further effectively avoiding the problem of short circuit of the substrate 90.

Fig. 24 is a flowchart of providing the barrier coating 13 according to the embodiment of the present application. Wherein (a) in fig. 24 is a schematic view of the barrier coating molded article 60; fig. 24 (b) is a schematic view of the molding die 10; fig. 24 (c) is a schematic view of the placement of the barrier coating molded article 60 on the molding die 10; fig. 24 (d) is a schematic view of the barrier coating applied; fig. 24 (e) is a schematic view of the molding die 10 after removal of the barrier coating molded member 60.

As shown in fig. 24, in one embodiment of the present application, the following steps are further included before the step of placing the net 20 on the molding die 10 having the recess 12.

Step 301, as shown in (a), (b) and (c) of fig. 24, the barrier coating molded article 60 is placed on the surface having the groove 12 on the molding die 10.

Step 302, as shown in (d) of fig. 24, a barrier coating is applied to the side of the molding die 10 having the barrier coating molded member 60.

Step 303, as shown in (e) of fig. 24, separates the barrier coating molded article 60 from the molding die 10 so that the barrier coating 13 with the positioning mark portion 131 is formed on the molding die 10.

In this embodiment, by adding the barrier coating 13 on the forming die 10, a barrier effect can be formed on the solder paste 93, and when the solder paste 93 overflows from the grooves 12 of the forming die 10, the solder paste 93 in two adjacent grooves 12 can be prevented from being connected with each other, so that the risk of connecting the solder balls 92 in reflow soldering is avoided, and the probability of short circuit problem of the substrate 90 is reduced; the barrier coating 13 can be conveniently and rapidly formed on the forming die 10 through the barrier coating forming piece 60, so that the overall efficiency of the ball planting process is improved; the positioning mark portion 131 can be used for positioning the ball-planting net 20 at the stage of filling the solder paste 93 in the groove 12, and can also be used for positioning the substrate 90 when the substrate 90 is fixed with the forming die 10, so that the overall efficiency of the ball-planting process is further improved.

Fig. 25 is a flowchart of another example of a ball planting method according to an embodiment of the present application. Wherein (a) in fig. 25 is a schematic view of the net 20 placed on the molding die 10; fig. 25 (b) is a schematic view of the ball grid 20 filling the recess 12 with solder paste 93; fig. 25 (c) is a schematic view of the recess 12 filled with solder paste 93; fig. 25 (d) is a schematic view of the net 20 removed from the molding die 10; fig. 25 (e) is a schematic view when the substrate 90 is placed; fig. 25 (f) is a schematic view of the substrate 90, the support structure 30, and the molding die 10 after being pressed by the pressing block 50; fig. 25 (g) is a schematic diagram of the solder balls 92 formed on the substrate 90 after being heated and cured by the reflow apparatus.

As shown in fig. 25, in one embodiment of the present application, the bottom of the forming mold 10 is provided with a base 40, and the ball planting method includes the following steps.

Step 401, as shown in (a), (b) and (c) in fig. 25, the ball-planting net 20 is placed on the forming mold 10 with the groove 12, and the solder paste 93 is filled into the groove 12 through the ball-planting net 20 by using a scraping plate.

Step 402, as shown in (d) and (e) in fig. 25, after removing the net 20, the substrate 90 to be planted with balls is placed on the forming mold 10, and the gap 14 is opened between the substrate 90 and the forming mold 10 by the supporting structure 30.

In step 403, as shown in fig. 25 (f), the pressing block 50 is connected to the base 40, and the substrate 90, the support structure 30, and the molding die 10 are sequentially pressed and held.

In step 404, the ball mounting fixture carrying the substrate 90 is transferred to a reflow station, and the solder paste 93 in the recess 12 is cured by the reflow apparatus to form the solder balls 92 on the substrate 90.

In step 405, as shown in fig. 25 (g), the briquette 50, the molding die 10, and the substrate 90 are separated to obtain the substrate 90 having the solder balls 92.

In this embodiment, the pressing block 50 is added to be able to be conveniently matched with the base 40, so as to maintain the pressure of the substrate 90, the supporting structure 30 and the forming die 10, and further ensure that the substrate 90, the supporting structure 30 and the forming die 10 are stably attached when the ball mounting fixture carrying the substrate 90 is transferred to a reflow soldering station for soldering, and the solder paste 93 in the groove 12 is stable in shape, and further ensure that the solder balls 92 are stable in shape when being heated and solidified; the placement of the pressing block 50 on the substrate 90 can also prevent the substrate 90 from being deformed by heat during the non-reflow soldering process, so that the flatness of the substrate 90 after ball placement and the good coplanarity of the solder balls 92 are ensured.

In one embodiment of the present application, before the step of placing the net 20 on the molding die 10 having the recess 12, the method further comprises:

forming a net 20 having a mesh 21, wherein the mesh 21 satisfies the following relationship:

x=（L4-L5）/（D+L4-L5）；

S1=S2（1-x）；

In addition to realizing the ball implantation of the substrate 90, the ball implantation tool and the ball implantation method provided by the embodiment of the application can also perform the height reconstruction of the solder balls 92 of the substrate 90.

Fig. 26 is a flow chart of a solder ball 92 height reconstruction provided by an embodiment of the present application. Fig. 26 (a) is a schematic diagram of replanting the solder balls on the substrate 90 based on the original solder balls 92; fig. 26 (b) is a schematic view of the bottom of the substrate 90 after the solder balls 92 are reconstituted; fig. 26 (c) is a schematic diagram after interconnecting the reconstructed substrate 90 and the motherboard 80.

As shown in fig. 26, by adopting the ball-implanting tool and the ball-implanting method provided by the embodiment of the application, the height of the welded ball 92 can be reconstructed: as shown in fig. 26 (a), one or more layers of solder balls 92 are added to the original solder balls 92 at the side of the substrate 90; as shown in fig. 26 (b), a substrate 90 after the reconstruction is obtained, and the height of a part of the solder balls 92 of the substrate 90 is increased. As shown in fig. 26 (c), the substrate 90 and the motherboard 80 are interconnected by a conventional packaging process, and the highly reconfigured solder balls 92 play a supporting role, so that the space between the bottom of the substrate 90 and the motherboard 80 can be increased, and the space can be used for layout of components to save the motherboard 80 area and improve the board performance.

Finally, it should be noted that: the foregoing is merely illustrative of specific embodiments of the present application, and the scope of the present application is not limited thereto, but any changes or substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. Ball frock is planted, its characterized in that includes:

A forming die (10) having a first surface (11), the first surface (11) being provided with a plurality of grooves (12) for accommodating solder paste (93);

And the ball planting net (20) is detachably arranged on the first surface (11) of the forming die (10), and the solder paste (93) can leak into the groove (12) through the mesh (21) of the ball planting net (20).

2. The ball mounting fixture of claim 1, further comprising:

And the supporting structure (30) is positioned at the periphery of the first surface (11) of the forming die (10), and the supporting structure (30) is used for expanding a gap (14) between a substrate (90) to be planted with the ball and the forming die (10).

3. Ball mounting fixture according to claim 2, characterized in that the support structure (30) is arranged on the first surface (11).

4. The ball mounting fixture of claim 3, further comprising:

The base (40) comprises a middle plate (41) and a frame (42), and the forming die (10) is positioned in an accommodating space (43) formed by enclosing the middle plate (41) and the frame (42);

The support structure (30) is composed of a gasket (31), the gasket (31) extends out of the edge of the first surface (11), one part of the gasket (31) is connected with the frame (42), and the other part of the gasket (31) is abutted against the first surface (11).

5. A ball planting tool according to claim 3, wherein the thickness of the ball planting net (20) is greater than that of the supporting structure (30), and an avoidance groove (22) for avoiding the supporting structure (30) is formed in the bottom of the ball planting net (20).

6. Ball mounting fixture according to claim 5, characterized in that the mesh (21) of the ball mounting net (20) satisfies the following relation:

x=（L4-L5）/（D+L4-L5）；

S1=S2（1-x）；

Wherein x is the ratio of the table, L4 is the thickness of the net (20), L5 is the thickness of the supporting structure (30), D is the required height of the net, S1 is the aperture area of the mesh (21), and S2 is the notch area of the groove (12).

7. Ball mounting fixture according to any of claims 1-6, characterized in that a barrier coating (13) is provided on the first surface (11) of the forming die (10).

8. The ball mounting fixture of claim 7, further comprising:

The barrier coating forming piece (60) is detachably mounted on the first surface (11), the barrier coating forming piece (60) comprises a connecting portion (61), a shielding portion (62) and a hollowed-out portion (63), the shielding portion (62) is used for shielding a notch of the groove (12), the connecting portion (61) is connected with the shielding portion (62) and is enclosed with the shielding portion (62) to form the hollowed-out portion (63), and barrier coating can be coated on the first surface (11) through the hollowed-out portion (63) to form the barrier coating (13).

9. Ball mounting fixture according to claim 8, characterized in that the connection part (61) is further provided with a through hole (611), through which through hole (611) a positioning mark part (131) can be formed on the barrier coating (13), the positioning mark part (131) being used for positioning the ball mounting net (20) and/or the substrate (90) to be ball mounted.

10. The ball mounting fixture of any one of claims 2-6, further comprising:

the pressing block (50) is detachably arranged on the forming die (10), and the pressing block (50) is used for sequentially pressing the substrate (90), the supporting structure (30) and the forming die (10).

11. A ball mounting fixture according to claim 3, characterized in that the support structure (30) is constituted by a step (32) integrally formed with the forming die (10);

or the support structure (30) is constituted by an ink (33) applied on the first surface (11).

12. The ball mounting fixture according to claim 2, wherein the substrate (90) has a second surface (91) opposite to the first surface (11), the support structure (30) being arranged on the second surface (91).

13. The ball mounting fixture according to claim 12, wherein the support structure (30) is constituted by a spacer (31) mounted on the second surface (91);

or the support structure (30) is constituted by an ink (33) coated on the second surface (91);

or the support structure (30) is formed by a step (32) integrally formed with the base plate (90).

14. The ball mounting fixture according to any one of claims 1-6, 8-9, 11-13, wherein the material of the forming die (10) is ceramic;

or a ceramic layer is arranged on the wall surface of at least the groove (12) of the forming die (10).

15. The ball mounting fixture according to claim 4, wherein the first surface (11) of the forming mold (10) protrudes from the top surface of the rim (42).

16. Ball planting tool according to claim 5 or 6, characterized in that the relief groove (22) is profiled with the support structure (30) so that the ball planting net (20) can be positioned with the forming mould (10) by means of the relief groove (22) and the support structure (30).

17. Ball placement equipment, characterized by comprising a reflow soldering device and a ball placement tooling according to any one of claims 1-16.

18. A method of implanting balls, comprising:

Placing a ball planting net (20) on a forming die (10) with a groove (12), and filling solder paste (93) into the groove (12) through the ball planting net (20);

Removing the ball-planting net (20), and placing a substrate (90) to be planted with balls on the forming die (10);

Solidifying the solder paste (93) in the recess (12) by a reflow soldering device to form a solder ball (92) on the substrate (90);

-separating the substrate (90) from the forming mould (10).

19. The ball placement method according to claim 18, wherein in the step of placing the substrate (90) to be ball placed on the molding die (10), further comprising:

A substrate (90) to be ball-planted is placed on the forming die (10) and a gap (14) is formed between the substrate (90) and the forming die (10) by means of a supporting structure (30).

20. The ball placement method according to claim 18, characterized in that before the step of placing the net (20) on the forming mold (10) with the recess (12), further comprising:

placing a barrier coating molding (60) on a surface of the molding die (10) having a groove (12);

Applying a barrier coating to the side of the molding die (10) having the barrier coating molded part (60);

Separating the barrier coating forming part (60) from the forming die (10) so as to form a barrier coating (13) with a positioning mark part (131) on the forming die (10).

21. The ball mounting method according to claim 19, wherein a base (40) is provided at a bottom of the molding die (10), and the step of curing the solder paste (93) in the recess (12) by a reflow soldering apparatus to form solder balls (92) on the substrate (90) is preceded by the step of:

the pressing block (50) is connected with the base (40), so that the base plate (90), the supporting structure (30) and the forming die (10) are sequentially pressed and held.

22. The ball placement method according to claim 18, characterized in that before the step of placing the net (20) on the forming mold (10) with the recess (12), further comprising:

-forming a net (20) with a mesh (21), wherein the mesh (21) satisfies the following relation:

x=（L4-L5）/（D+L4-L5）；

S1=S2（1-x）；

Wherein x is the ratio of the lower couch, L4 is the thickness of the net (20), L5 is the thickness of the supporting structure (30), D is the required height of the net, S1 is the aperture area of the mesh (21), and S2 is the slot area of the groove (12).