Lead-tin solder product cavity removing device and working method thereof

Abstract

The invention belongs to the technical field of cavity removing, and particularly relates to a lead-tin solder product cavity removing device and a working method thereof.The device comprises a machining table internally provided with a solder conveying mechanism; wherein the solder transmission mechanism is suitable for driving a plurality of wafers to move in the processing table; the welding flux processing mechanism is arranged in the processing table and is positioned above the wafer moving path; wherein the welding flux processing mechanism is suitable for heating and liquefying welding flux moving to a wafer below the welding flux processing mechanism, and performing negative pressure suction on the liquefied welding flux so as to reduce cavities in the welding flux; the solder processing mechanism is additionally arranged on the transportation and movement route of the solder product, the solder processing mechanism is used for carrying out high-temperature liquefaction on the solder around the product, bubbles in the solder are separated from the solder, and the bubbles are extracted from the solder in a negative-pressure air extraction mode after the solder is liquefied, so that the size of a cavity in the solder is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of void removal, and in particular relates to a void removal device for a lead-tin solder product and a working method thereof. Background Art

[0002] The role of the chip loading process in the semiconductor packaging process is to fix the separated wafers on the frame through various process flows. Among the various process flows, the lead-tin solder process is favored by clients due to its advantages such as strong fastness, controllable and stable thickness, strong stress resistance, and high reliability. Especially for high-power MOS devices, the lead-tin solder process is the first choice. However, compared with other processes, the voids in the lead-tin solder process cannot be controlled within the range of ≤8% during production. The reason is that air cannot be prevented from entering the product during tinning and chip loading, causing void abnormalities.

[0003] After simulation experiments on products with different void values, it can be seen from the experimental results that when the single bubble inside the chip and the frame is large (>5%), the product is easily affected by thermal stress when it is installed on the circuit board and heated, causing hidden cracks in the chip and resulting in product failure.

[0004] Therefore, a lead-tin solder product void removal device and a working method thereof are designed to solve the problem in the prior art that large voids in the lead-tin solder cause chip hidden cracks due to thermal stress during use of subsequent products, thereby causing product failure.

[0005] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Summary of the invention

[0006] The embodiments of the present disclosure at least provide a lead-tin solder product void removal device and a working method thereof.

[0007] In a first aspect, an embodiment of the present disclosure provides a device for removing voids from a lead-tin solder product, comprising: a processing table, wherein a solder transmission mechanism is disposed inside the processing table; The solder transfer mechanism is suitable for driving a plurality of wafers to move within the processing table; and The solder processing mechanism is arranged inside the processing table and above the wafer moving path; wherein The solder processing mechanism is suitable for heating and liquefying the solder moved onto the wafer below it, and performing negative pressure suction on the liquefied solder to reduce the voids in the solder.

[0008] In an optional embodiment, the solder processing mechanism includes: A high temperature liquefaction mechanism, disposed above a wafer moving path, adapted to generate a high temperature to liquefy solder on the wafer moved below the high temperature melting mechanism; and The negative pressure exhaust mechanism is arranged on one side of the high temperature liquefaction mechanism and is suitable for performing negative pressure suction on the wafer passing through the high temperature liquefaction mechanism to extract the gas in the liquefied solder.

[0009] In an optional embodiment, the high temperature liquefaction mechanism comprises: A heating plate disposed above a wafer moving path; and The fixing piece has one end connected to the upper end surface of the heating plate and the other end connected to the protective cover on the processing table.

[0010] In an optional embodiment, the negative pressure exhaust mechanism includes: A negative pressure cover is arranged on one side of the heating plate; A driver connected to the protective cover, wherein an output end of the driver is connected to the negative pressure cover; and One end of the exhaust pipe is connected to the negative pressure cover, and the other end passes through the protective cover and is connected to the external negative pressure source.

[0011] In an optional embodiment, a plurality of material placing parts are arranged inside the processing table; Each of the material placing members is provided with a material plate; and A plurality of wafers are evenly arranged on each of the material plates.

[0012] In an optional embodiment, the solder transfer mechanism includes: Two lifting rods, and the two lifting rods are connected by a connecting rod; wherein The distance between the two lifting rods is greater than the length of the unloading member; and The control assembly is suitable for controlling the lifting rod to move so that the lifting rod drives each material plate to move.

[0013] In an optional embodiment, the control component includes: A lifting unit and a pushing unit; wherein The lifting unit is suitable for controlling the lifting rod to move upward, thereby driving each material plate to be lifted; and The pushing unit is suitable for pushing the lifting rod to move after the upward movement, thereby driving each material plate to move, and after the movement, it moves downward and resets to place each material plate on an adjacent material placing piece.

[0014] In an optional embodiment, the lifting unit includes: A lifting cylinder is arranged inside the processing table, and the output end of the lifting cylinder is connected to the lower end surface of the connecting rod; wherein The lifting cylinder is suitable for pushing the connecting rod and the lifting rods arranged at both ends of the connecting rod to move upward after being started.

[0015] In an optional embodiment, the pushing unit includes: The push cylinder is arranged inside the processing table; The output end of the push cylinder is connected to a push plate; and The lifting cylinder is placed on the upper end surface of the pushing plate.

[0016] In a second aspect, the embodiment of the present disclosure also provides a working method of a lead-tin solder product void removal device, comprising the following steps: Step S1, driving a plurality of wafers to move within a processing table through a solder transfer mechanism; Step S2, heating and liquefying the solder on the wafer moved thereunder by the solder processing mechanism, and performing negative pressure suction on the liquefied solder to reduce the voids in the solder.

[0017] The beneficial effect of the present invention is that the void removal device for lead-tin solder products and its working method add a solder processing mechanism to the transportation route of the solder product, and use the solder processing mechanism to liquefy the solder around the product at high temperature, so that the bubbles in the solder are separated from the solder, and after the solder is liquefied, the bubbles are extracted from the solder by negative pressure extraction to reduce the size of the voids in the solder.

[0018] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, this article specifically cites preferred embodiments and provides detailed descriptions as follows in conjunction with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 An overall stereogram provided for an embodiment of the present disclosure; Figure 2 A three-dimensional diagram of the overall internal structure provided for an embodiment of the present disclosure; Figure 3 A schematic diagram of the overall cross-sectional structure provided for an embodiment of the present disclosure; Figure 4 The embodiments of the present disclosure provide Figure 3 A schematic diagram of the enlarged structure of part A.

[0022] In the figure: 1. Processing table; 11. Protective cover; 12. Material placement; 2. Sheet; 20. Wafer; 3. Solder transfer mechanism; 30. Lifting rod; 300. Connecting rod; 31. Pushing cylinder; 32. Lifting cylinder; 33. Pushing plate; 4. Solder processing mechanism; 40. Heating plate; 400. Fixing part; 41. Driver; 410. Negative pressure cover; 411. Exhaust pipe. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In this article, when it is mentioned that the first component is located on the second component, this may mean that the first component may be directly formed on the second component, or the third component may be interposed between the first component and the second component. In addition, in the drawings, in order to effectively describe the technical content, the thickness of the components may be exaggerated or reduced.

[0025] In this article, when an element or layer is referred to as being "located on," "engaged to," "connected to," "attached to," or "coupled to" another element or layer, it may be directly located on, engaged, connected, attached to, or coupled to another element or layer, or there may be intermediate elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," "directly attached to," or "directly coupled to" another element or layer, there may be no intermediate elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0026] Herein, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as "at least one of..." modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0027] The terms used herein are only used to describe specific exemplary configurations and are not intended to be limited. As used herein, the singular articles "one", "an" and "the" may also be intended to include plural forms, unless it is clearly indicated above that this is not the case. The terms "comprise", "include" and "have" are inclusive, and therefore specify the presence of features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or combinations thereof. The method steps, processes and operations described herein should not be interpreted as necessarily requiring them to be performed in the specific order discussed or shown, unless specifically identified as an execution order. Additional or alternative steps may be adopted.

[0028] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Therefore, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, so that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. On the contrary, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0029] Research has found that during the lead-tin solder production process, the voids often cannot be controlled within the range of ≤8%. The reason is that air cannot be prevented from entering the product during the tinning and chip mounting process, causing void abnormalities. After simulation experiments, according to the experimental results, when the single bubble inside the chip and the frame is large (>5%), the product is easily affected by thermal stress when it is heated after being installed on the circuit board, causing hidden cracks in the chip and resulting in product failure.

[0030] Based on the above research, the embodiments of the present disclosure provide a void removal device for a lead-tin solder product and a working method thereof, by adding a solder processing mechanism to the transportation route of the solder product, and utilizing the solder processing mechanism to liquefy the solder around the product at high temperature, so that the bubbles in the solder are separated from the solder, and after the solder is liquefied, the bubbles are extracted from the solder through negative pressure extraction to reduce the size of the voids in the solder.

[0031] The defects existing in the above solutions are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed by the present invention in this article for the above problems should be the contributions made by the inventor to the present invention during the disclosure process.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0034] In some embodiments, Figure 1 As shown, a protective cover 11 is connected to the upper bearing of the processing table 1. When the solder product needs to be processed, the protective cover 11 is rotated and pressed onto the upper end surface of the processing table 1 to protect the solder product to be processed on the processing table 1.

[0035] In some embodiments, Figure 2 As shown, a plurality of welded wafers 20 are arranged on the material plate 2, and a plurality of material plates are placed on the material placing member 12 in sequence. Figure 2 It can be seen that the length of the material sheet 2 is greater than the length of the material discharge piece 12. Therefore, by driving the lifting rod 30 upward, the material sheet 2 can be driven to move upward, and the lifting rod 30 can be controlled to move horizontally. The moving distance is the distance between every two adjacent material discharge pieces 12. When it moves into place, the lifting rod 30 moves downward to place the material sheet 2 on the corresponding material discharge piece 12, and the lifting rod 30 is reset to prepare for the next lifting movement.

[0036] In some embodiments, Figure 2As shown, when a certain material plate 2 moves to under the heating plate 40, the heating plate 40 heats several wafers 20 on the material plate 2 currently under it, so that the solder on the wafer 20 is liquefied. At this time, when the solder is in a solid state, the air in the internal cavity will overflow the liquefied solder, and with the start of the lifting rod 30, the material plate 2 with the current solder liquefied continues to move forward and moves to under the negative pressure cover 410. At this time, the driver 41 is started, and its output end drives the negative pressure cover 410 to move down and cover the upper end surface of the material plate 2. The external negative pressure source is connected to the negative pressure cover 410 through the exhaust pipe 411, and negative pressure suction is performed on the chamber between the negative pressure cover 410 and the material plate 2 to extract the air in the liquefied solder. Then, the current material plate 2 continues to move forward, and the solder on the wafer 20 is naturally cooled and solidified. At this time, the cavity in the solder is reduced.

[0037] In some embodiments, Figure 3 and Figure 4 As shown, for the movement of the material sheet 2 in the processing table 1, when the operator places the material sheet 2 on the material discharge piece 12, the lifting cylinder 32 is started first, and the output end of the lifting cylinder 32 is connected to the connecting rod 300, thereby pushing the connecting rod 300 and the lifting rods 30 fixed at both ends of the connecting rod 300 to move upward. After the lifting rod 30 moves up, it contacts the lower end surface of the material sheet 2. As the lifting rod 30 continues to move upward, the material sheet 2 is driven to move up and away from the material discharge piece 12, and then the pushing cylinder 31 is started, and its output end is connected to the pushing plate 33, driving the pushing plate 33 and the lifting cylinder 32 fixed on the upper end surface of the pushing plate 33 to move. At this time, the moving distance is the distance between every two material discharge pieces 12, that is, several material sheets 2 are moved to the top of the adjacent material discharge pieces 12, and then the lifting cylinder 32 is reset to place the material sheet 2, and the pushing cylinder 31 is retracted to reset for the next lifting movement.

[0038] On the other hand, a working method of a lead-tin solder product void removal device is also provided, comprising the following steps: Step S1, a plurality of wafers 20 are driven to move in a processing table 1 by a solder transfer mechanism 3; In step S2, the solder on the wafer 20 moved to the bottom is heated and liquefied by the solder processing mechanism 4, and the liquefied solder is sucked under negative pressure to reduce the voids in the solder.

[0039] In summary, the void removal device for lead-tin solder products and its working method add a solder processing mechanism to the transportation route of the solder product, and use the solder processing mechanism to liquefy the solder around the product at high temperature, so that the bubbles in the solder are separated from the solder, and after the solder is liquefied, the bubbles are extracted from the solder through negative pressure extraction to reduce the size of the voids in the solder.

[0040] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, terms such as "first", "second" and other numerical terms do not imply an order or sequence when used in this document unless explicitly indicated above. Therefore, without departing from the teachings of the example embodiments, the first element, component, region, layer or section discussed above may be referred to as a second element, component, region, layer or section.

[0042] Spatially relative terms, such as "inside", "outside", "below", "below", "down", "above", "on", etc., may be used herein to facilitate description of the relationship of one element or feature to another element or feature as illustrated in the figure. In addition to the orientation depicted in the figure, spatially relative terms may be intended to cover different orientations of the device in use or operation. For example, if the device in the figure is turned over, the elements described as "below" or "below" other elements or features will be oriented to be "above" other elements or features. Therefore, the example term "below" can cover the orientation above and below. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0043] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A device for removing voids from lead-tin solder products, characterized in that: include: A processing table is provided with a solder transmission mechanism inside; The solder transfer mechanism is suitable for driving a plurality of wafers to move within the processing table; as well as The solder processing mechanism is arranged inside the processing table and above the wafer moving path; in The solder processing mechanism is suitable for heating and liquefying the solder moved onto the wafer below it, and performing negative pressure suction on the liquefied solder to reduce the voids in the solder.

2. The lead-tin solder product void removal device according to claim 1, characterized in that: The solder processing mechanism comprises: A high temperature liquefaction mechanism, disposed above a wafer moving path, adapted to generate a high temperature to liquefy solder on the wafer moved below the high temperature melting mechanism; and The negative pressure exhaust mechanism is arranged on one side of the high temperature liquefaction mechanism and is suitable for performing negative pressure suction on the wafer passing through the high temperature liquefaction mechanism to extract the gas in the liquefied solder.

3. The lead-tin solder product void removal device as claimed in claim 2, characterized in that: The high temperature liquefaction mechanism comprises: A heating plate disposed above a wafer moving path; and The fixing piece has one end connected to the upper end surface of the heating plate and the other end connected to the protective cover on the processing table.

4. The lead-tin solder product void removal device as claimed in claim 3, characterized in that: The negative pressure exhaust mechanism comprises: A negative pressure cover is arranged on one side of the heating plate; A driver connected to the protective cover, wherein an output end of the driver is connected to the negative pressure cover; and One end of the exhaust pipe is connected to the negative pressure cover, and the other end passes through the protective cover and is connected to the external negative pressure source.

5. The lead-tin solder product void removal device according to claim 1, characterized in that: The processing table is provided with a plurality of material placing parts inside; Each of the material placing members is provided with a material plate; and A plurality of wafers are evenly arranged on each of the material plates.

6. The lead-tin solder product void removal device as claimed in claim 5, characterized in that: The solder transmission mechanism comprises: Two lifting rods, and the two lifting rods are connected by a connecting rod; wherein The distance between the two lifting rods is greater than the length of the unloading member; and The control assembly is suitable for controlling the lifting rod to move so that the lifting rod drives each material plate to move.

7. The lead-tin solder product void removal device as claimed in claim 6, characterized in that: The control component comprises: A lifting unit and a pushing unit; wherein The lifting unit is suitable for controlling the lifting rod to move upward, thereby driving each material plate to be lifted; and The pushing unit is suitable for pushing the lifting rod to move after the upward movement, thereby driving each material plate to move, and after the movement, it moves downward and resets to place each material plate on an adjacent material placing piece.

8. The lead-tin solder product void removal device as claimed in claim 7, characterized in that: The lifting unit comprises: A lifting cylinder is arranged inside the processing table, and the output end of the lifting cylinder is connected to the lower end surface of the connecting rod; wherein The lifting cylinder is suitable for pushing the connecting rod and the lifting rods arranged at both ends of the connecting rod to move upward after being started.

9. The lead-tin solder product void removal device as claimed in claim 8, characterized in that: The pushing unit comprises: The push cylinder is arranged inside the processing table; The output end of the push cylinder is connected to a push plate; and The lifting cylinder is placed on the upper end surface of the pushing plate.

10. A method for operating the lead-tin solder product void removal device as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, driving a plurality of wafers to move within a processing table through a solder transfer mechanism; Step S2, heating and liquefying the solder on the wafer moved thereunder by the solder processing mechanism, and performing negative pressure suction on the liquefied solder to reduce the voids in the solder.

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