INCLUDING SEALING ASSEMBLY

Technical Field

[0001] The present application relates to the technical field of a sealing assembly, and in particular, to a sealing assembly for a reflow furnace.

Background

[0002] Reflow furnaces are commonly used to achieve surface soldering processes for printed circuit boards (PCBs). During the soldering process of printed circuit boards (PCBs), some areas within the reflow furnace need to be kept at high temperatures, and the reflow furnace usually needs to be filled with an inert gas as a protective gas. In order to ensure the heating temperature in the reflow furnace and prevent the escape of inert gas from the reflow furnace, the reflow furnace is often provided with a sealing strip between the upper furnace chamber and the lower furnace chamber. Sealing strips need to carry both the weight of the upper furnace chamber and the high temperature in the reflow furnace, and thus the sealing strips are prone to aging and need to be replaced and renewed in a timely manner.

Summary

[0003] One of the objects of the present application is to provide an improved sealing assembly capable of extending the service life of the sealing assembly.

[0004] The sealing assembly provided in the present application is for sealing between upper and lower furnace chambers of a reflow furnace, the sealing assembly comprises: a first seal and a second seal, the first seal being elongated, the first seal having elasticity; the second seal aligned with a length direction of the first seal, the second seal comprises a fixing portion and a moving portion, the moving portion extending inclined from one side of the fixing portion toward a direction away from the fixing portion, thereby forming a first angle between the moving portion and the fixing portion; wherein, the moving portion is arranged on a side of the first seal closer to the interior of the furnace chamber, the second seal having certain elasticity, so that a distal end of the moving portion is movable relative to the fixing portion.

[0005] The sealing assembly as described above, the second seal being integrally formed of a metallic material.

[0006] The sealing assembly as described above, the second seal being made of a metal plate having a thickness range of: 0.15 mm to 0.3 mm.

[0007] The sealing assembly as described above, the distal end of the moving portion having a contact portion that is curved towards a proximal end of the moving portion, the contact portion having a smoothly transitioned outer surface.

[0008] The sealing assembly as described above mounted on a housing connection extending along a length direction of an upper furnace chamber housing or a lower furnace chamber housing, the fixing portion being fixedly connected with the housing connection.

[0009] The sealing assembly as described above, the first seal having a height greater than that of the second seal when the first seal and the second seal are in a free state.

[0010] The sealing assembly as described above, the first seal having an inner hollow cylindrical body and an extension connected with the cylindrical body, the extension being flat-shaped and connected with the housing connection of the upper furnace chamber housing or the lower furnace chamber housing.

[0011] The sealing assembly as described above, a sharp angle being formed between the moving portion and the fixing portion, the sharp angle having an angle ranging from: 15° to 45°.

[0012] The sealing assembly as described above, further comprises a support disposed between the first seal and the second seal, the support having a height smaller than that of the first seal and the second seal when the first seal and the second seal are in a free state, the support being capable of providing support between the upper furnace chamber housing and the lower furnace chamber housing.

[0013] The present application also provides a reflow furnace comprises: an upper furnace chamber housing, a lower furnace chamber housing, a first sealing assembly and a second sealing assembly, the upper furnace chamber housing comprises two opposing housing connections of the upper furnace chamber extending along a length direction of the furnace chamber; the lower furnace chamber housing comprises two opposing housing connections of the lower furnace chamber extending along the length direction of the furnace chamber; wherein the first sealing assembly or the second sealing assembly is the sealing assembly as described above, the first sealing assembly and the second sealing assembly being respectively mounted along the length direction of the furnace chamber between corresponding housing connections of the upper furnace chamber and housing connections of the lower furnace chamber.

[0014] The sealing assembly in the present application has a second seal made of a metallic material and a first seal made of an elastic material. The second seal can block a flux inside the furnace chamber, preventing the flux from contacting the first seal, thereby extending the service life of the first seal.

Brief Description of Drawings

[0015] Fig. 1A is a perspective view of a furnace chamber body of a reflow furnace according to an example of the present application;

[0016] Fig. 1 B is an exploded view of the furnace chamber body in Fig. 1 A;

[0017] Fig. 2A is an enlarged view of the reflow furnace body shown in Fig. 1 B at position A;

[0018] Fig. 2B is a perspective view of the sealing assembly in Fig. 2A;

[0019] Fig. 2C is an exploded view of the sealing assembly in Fig. 2A;

[0020] Fig. 3A is a perspective view of a second seal shown in Fig. 2B;

[0021] Fig. 3B is a partial perspective view of the second seal shown in Fig. 2B;

[0022] Fig. 3C is a partial perspective view from another angle of the second seal shown in Fig. 3B;

[0023] Fig. 4 is a perspective view of a support in Fig. 2C;

[0024] Fig. 5 is a perspective view of a first seal in the present application; [0025] Fig. 6 is a side view of the furnace chamber body of the reflow furnace in Fig. 1A.

Detailed Description

[0026] Various specific embodiments of the present application will be described below with reference to the attached drawings that form a part of the present specification. It should be understood that while terms denoting orientation, such as “front,” “rear,” “upper,” “lower,” “left,” “right,” etc., are used in the present application to describe various exemplary structural parts and elements of the present application, these terms are used herein for convenience of illustration only and are determined based on the exemplary orientations shown in the attached drawings. Since the embodiments disclosed in the present application may be disposed in different orientations, these terms denoting orientation are for illustrative purposes only and should not be considered as limiting.

[0027] FIG. 1 A is a perspective view of a furnace chamber body of a reflow furnace of an example of the present application, and Fig. 1 B is an exploded view of the furnace chamber body in Fig. 1 A. As shown in Fig. 1 A, the furnace chamber body

100 of the reflow furnace is generally rectangular in shape and has a length direction L, a height direction H and a width direction W. The furnace chamber body 100 of the reflow furnace comprises an upper furnace chamber housing 101 and a lower furnace chamber housing 102. The upper furnace chamber housing 101 is aligned with the length direction of the lower furnace chamber housing 102, and the upper furnace chamber housing 101 is located above the lower furnace chamber housing 102. The upper furnace chamber housing 101 and the lower furnace chamber housing 102 are disposed opposite to each other to together form a furnace chamber containing space 153. When the reflow furnace requires cleaning and maintenance, etc., an operator may disassemble the upper furnace chamber housing 101 from above the lower furnace chamber housing 102. The upper furnace chamber housing

101 comprises a top 124, a first upper side 121 , and a second upper side 122, the first upper side 121 and the second upper side 122 extending downward from both sides of the top 124, respectively. As a result, the upper furnace chamber housing 101 encloses an upper furnace chamber containing space 143. The lower furnace chamber housing 102 comprises a bottom 134, a first lower side 131 , and a second lower side 132, the first lower side 131 and the second lower side 132 respectively extending upwardly from both sides of the bottom 134. As a result, the lower furnace chamber housing 102 encloses a lower furnace chamber containing space 144. When the upper furnace chamber housing 101 is covered above the lower furnace chamber housing 102, the upper furnace chamber containing space 143 and the lower furnace chamber containing space 144 are integrated to form the furnace chamber containing space 153. The furnace chamber containing space 153 is used to accommodate a printed circuit board (PCB) to be soldered and a transmission device for carrying and transferring the printed circuit board (PCB).

[0028] The distal ends of the first upper side 121 and the second upper side 122 respectively comprise a housing connection 114 and a housing connection 115, and the housing connection 114 and the housing connection 115 are arranged symmetrically. The distal ends of the first lower side 131 and the second lower side 132 each comprise a housing connection 116 and a housing connection 117, the housing connection 116 and the housing connection 117 being arranged symmetrically. The housing connection 114, the housing connection 115, the housing connection 116 and the housing connection 117 respectively extend along the length direction of the housing. In the width direction W of the furnace chamber body, the housing connection 114 and the housing connection 116 are on the same side, and the housing connection 115 and the housing connection 117 are on the same side. In one example of the present application, the housing connection 116 and the housing connection 117 are respectively provided with a first sealing assembly 111 and a second sealing assembly 112. Here, the first sealing assembly 111 is used for sealing between the first upper side 121 and the first lower side 131 and the second sealing assembly 112 is used for sealing between the second upper side 122 and the second lower side 132. The first sealing assembly 111 and the second sealing assembly 112 are arranged symmetrically.

[0029] In another example of the present application, the first sealing assembly 111 and the second sealing assembly 112 are respectively provided on the housing connection 114 and the housing connection 115 of the upper furnace chamber housing 101.

[0030] Fig. 2A is an enlarged view of the reflow furnace body shown in Fig. 1 B at position A, wherein a sealing assembly is shown. Fig. 2B is a perspective view of the sealing assembly in Fig. 2A, and Fig. 2C is an exploded view of the sealing assembly in Fig. 2A. As shown in Figs. 2A to 2C, the housing connection 115 and the housing connection 117 are respectively provided on the left sides of the upper furnace chamber housing 101 and the lower furnace chamber housing 102, and the second sealing assembly 112 is provided on the housing connection 117. Since the first sealing assembly 111 and the second sealing assembly 112 are of the same structure and are symmetrically arranged, and the first lower side 131 and the second lower side 132 are of the same structure and are symmetrically arranged, the structure of the sealing assembly will be described below with the second lower side 132 and the second sealing assembly 112 located on the second lower side 132 as examples.

[0031] The second lower side 132 comprises a sidewall 251 and a platform portion 283, the sidewall 251 extending along the length direction and the height direction of the furnace chamber body, a proximal end of the sidewall 251 connected with the bottom 134, a distal end of the sidewall 251 connected with the platform portion 283, and the platform portion 283 extending along the width direction and the length direction of the furnace chamber body. In the width direction of the furnace chamber body, a central portion of the platform portion 283 is connected with the sidewall 251 so that the platform portion 283 comprises a first portion 211 located at the inner side of the sidewall 251 and a second portion 212 located at the outer side of the sidewall 251 . Here, the first portion 211 is formed from a metal plate having a flat upper surface and the second portion 212 is formed by bending a metal plate that forms the sidewall 251 . The second portion 212 comprises a horizontal portion 241 and a vertical portion 242. The vertical portion 242 helps to enhance the stability of the platform portion 283. The horizontal portion 241 extends from an end of the sidewall 251 in a direction generally perpendicular to the sidewall 251 , and the vertical portion 242 extends downward from an end of the horizontal portion 241 away from the sidewall 251 in a direction generally parallel to the sidewall 251 . The upper surface of the first portion 211 and the upper surface of the horizontal portion 241 of the second portion 212 are on the same plane, and the first portion 211 and the horizontal portion 241 are proximate to each other, forming a continuous plane. In one example of the present application, the platform portion 283 is formed from a monolithic metal plate. In another example of the present application, the platform portion 283 includes only the second portion 212 located at the outer side of the sidewall 251 . The platform portion 283 forms the housing connection 117. Similarly, the housing connections 114, 115, and 116 are also formed by the platform portion.

[0032] The second sealing assembly 112 comprises a first seal 201 , a support 202, and a second seal 203, and the first seal 201 , the support 202, and the second seal 203 are all in an elongated shape and connected to the housing connection 117. In the width direction of the furnace chamber body, the first seal 201 is closer to the interior of the furnace chamber than the second seal 203. The support 202 is located between the first seal 201 and the second seal 203. The second seal 203 is used to seal a gap between the upper furnace chamber housing 101 and the lower furnace chamber housing 102. The support 202 is used to provide support between the upper furnace chamber housing 101 and the lower furnace chamber housing 102 to prevent excessive deformation of the second seal 203. The first seal 201 is used to block flux inside the furnace chamber to prevent high-temperature flux from splashing onto the second seal 203.

[0033] In one example of the present application, the respective platform portions of the housing connections 114, 115, 116 and 117 each include portions extending beyond the corresponding side walls. This can keep the sealing assembly disposed between the corresponding pair of housing connections as far away from the furnace chamber of the reflow furnace as possible to reduce the high temperature in the furnace chamber and the effect of flux from the printed circuit board (PCB) on the sealing assembly, thereby improving the service life of the sealing assembly.

[0034] Fig. 3A is a perspective view of the second seal shown in Fig. 2B, Fig. 3B is a partial perspective view of the second seal shown in Fig. 2B, and Fig. 3C is a partial perspective view from another angle of the second seal shown in Fig. 3B. Here, Figs. 3B and 3C are one section in the length direction of the second seal shown in Fig. 2B to more clearly illustrate the structure of the second seal.

[0035] As shown in Figs. 3A to 3B, the second seal 203 is long strip-like and formed from a bent metal plate. The second seal 203 comprises a fixing portion 301 and a moving portion 302. The fixing portion 301 is flat and has a first side 311 and a second side 312. Several holes 325 are provided on the fixing portion 301 to allow a fastener to pass through, such that the second seal 203 can be connected to the housing connection 117 by the fastener. In another example of the present application, the second seal 203 is connected with the housing connection 117 by soldering or bonding. The moving portion 302 has a moving portion body 340, a proximal end 341 , and a distal end 342, and the proximal end 341 is connected with the second side 312 of the fixing portion 301 . The moving portion 302 extends inclined from the proximal end 341 and the distal end 342 in a direction away from the fixing portion 301 , thereby forming a first angle a between the moving portion 302 and the fixing portion 301 . In one example of the present application, the first angle a is a sharp angle, and the angle range is 15° to 45°. In another example of the present application, the first angle a is an obtuse angle, and the angle setting of the first angle a enables the moving portion 302 to move relative to the fixing portion 301 along the proximal end 341 and to have a suitable elasticity. In one example of the present application, the spacing between the top of the moving portion 302 and the upper surface of the fixing portion 301 is 6 mm to 20 mm.

[0036] The distal end 342 of the moving portion 302 comprises a contact portion 315 extending from the moving portion body 340 towards the proximal end of the moving portion 302. The cross section of the contact portion 315 is generally arcuate, and thus the contact portion 315 has a smoothly transitioned outer surface. The contact portion 315 also has a continuous smooth transition at the connection with the moving portion body 340. The moving portion 302 can be deformed by external forces such that the contact portion 315 can contact the upper furnace chamber housing 101 , thereby enabling the second seal 203 to seal the gap between the upper furnace chamber housing 101 and the lower furnace chamber housing 102. The moving portion 302 extends continuously along the length direction, and fluids cannot pass through both sides of the moving portion 302. Therefore, the moving portion 302 can prevent the flux inside the furnace chamber from flowing outward. The moving portion body 340 forms an inclined surface to guide the flux attached to the moving portion 302 to flow downward along the inclined surface and back to the interior of the furnace chamber.

[0037] In one example of the present application, the second seal 203 is integrally formed from a metal plate, the metal material is a 302 1/4H stainless steel plate, and the thickness of the metal plate ranges from 0.15 to 0.30 mm, so that the second seal 203 has a suitable elasticity. In a particular example of the present application, the thickness of the metal plate is 0.2 mm. [0038] Fig. 4 is a perspective view of the support in Fig. 2C. As shown in Fig. 4, the support 202 comprises a support portion 401 and a support connection portion 402. The support is formed by a bent metal plate, and the support portion 401 has a top portion 411 and a pair of side portions 412 and 413, the pair of side portions extending from both sides of the top portion 411 in a direction generally perpendicular to the top portion 411 . The support connection portion 402 extends from an end of the side portion 413 away from the top portion 411 in a direction away from the side portion 413. The support connection portion 402 is generally perpendicular to the top portion 411 . The outer profile of the cross-section of the support portion 401 is generally rectangular. The support connection 402 is connected with the housing connection 117 by screws or soldering. The support 202 is made of a relatively thick metal plate, and the support portion 401 does not have elasticity and can support the upper furnace chamber housing. In another example of the present application, the support portion is a solid body. In yet another example of the present application, the support 202 is made of a non-metallic material. In the present application, the support only needs to be a structure that is not easily compressed and can support the upper furnace chamber housing 101.

[0039] Fig. 5 is a perspective view of the first seal in the present application. As shown in Fig. 5, the first seal 201 has a cylindrical body 501 and an extension 502. The cylindrical body 501 is a hollow structure with a generally circular cross-section. In other examples, the cross section of the cylindrical body 501 may also be other shapes, such as trapezoid or the like. The extension 502 extends in a horizontal direction from the bottom of the cylindrical body 501 , and the extension 502 is connected with the housing connection 117 by screws or bonding, etc. The first seal 201 is made of an elastic material, such as rubber, so that the cylindrical body 501 is prone to deformation. When the cylindrical body 501 is deformed by compression of the housing connection 115 of the upper furnace chamber housing, the cylindrical body 501 fits against the housing connection 115, thereby forming a seal between the housing connection 115 and the housing connection 117.

[0040] Fig. 6 is a side view of the furnace chamber body of the reflow furnace in Fig. 1A, wherein the structure of a sealing assembly is shown. As shown in Fig. 6, a sealing assembly 112 is located between the housing connection 117 and the housing connection 115. In the width direction of the furnace chamber body, the second seal 203, the support 202, and the first seal 201 are arranged side-by-side. The fixing portion 301 of the second seal 203 is in contact with the housing connection 117, the extension 502 of the first seal 201 is stacked above the fixing portion 301 , and the extension 502 of the first seal 201 is stacked above the connection portion 402. A connecting member can pass through the extension 502 of the first seal 201 , the extension 502 of the first seal 201 , the fixing portion 301 of the second seal 203, and the second portion 212 of the platform portion 283 sequentially, thereby fixedly connecting the sealing assembly 112 to the housing connection 117. Here, in one example of the present application, for the stability of the connection, a gasket 613 is further provided above the extension 502 of the first seal 201 so that the connection between the sealing assembly 112 and the housing connection 117 is evenly stressed.

[0041] The support portion 401 of the support 202 is located between the cylindrical body 501 of the first seal 201 and the moving portion 302 of the second seal 203. In a free state, the height of the support portion 401 of the support 202 is smaller than the height of the moving portion 302 of the second seal 203, and the height of the moving portion 302 of the second seal 203 is smaller than the height of the cylindrical body 501 of the first seal 201 . Both the first seal 201 and the second seal 203 have certain elasticity, and the support portion 401 does not have elasticity. When the upper furnace chamber housing 101 is connected with the lower furnace chamber housing 102, the housing connection 115 first contacts the cylindrical body 501 of the first seal 201 and applies pressure to the cylindrical body 501 , forcing the cylindrical body 501 to deform, thereby forming a seal between the cylindrical body 501 and the housing connection 115. Then the housing connection 115 continues to move towards the housing connection 117. As a result, the housing connection 115 contacts the moving portion 302 of the second seal 203 and applies pressure to the moving portion 302, forcing the moving portion 302 to move downward, thereby forming a seal between the contact portion 315 of the moving portion 302 and the housing connection 115. When the housing connection 115 continues to move towards the housing connection 117 until the housing connection 115 comes into contact with the support part 401 , the housing connection 115 cannot move further towards the housing connection 117 because the housing connection 115 is blocked by the support part 401 of the support 202. The support 202 is used to prevent excessive deformation of the first seal 201 and the second seal 203 and to extend the service life of the first seal 201 and the second seal 203. In actual application, the housing connection 115 is in contact with the support 202, or there is a gap between the housing connection 115 and the support 202. In another example of the present application, the support 202 may no longer be provided.

[0042] In some examples of the present application, the first seal 201 , the second seal 203, and the support 202 may also be separately connected with the housing connection to facilitate separate replacement of one or more of the components.

[0043] The second seal 203 is made of a metallic material and the first seal 201 is made of an elastic material (for example, rubber or polymeric material having elasticity). The first seal 201 has a relatively strong elasticity, and thus it has better sealing performance, can better isolate gas inside and outside the furnace chamber, and prevent gas exchange inside and outside the furnace chamber. The sealing performance of the first seal 201 is superior to the sealing performance of the second seal 203. Under the operating conditions of the reflow furnace, the furnace chamber containing space 153 is a high-temperature environment with flux from the printed circuit board (PCB) dispersed inside. However, the high temperature environment can easily cause aging of the first seal 201 , and the flux can corrode the first seal 201 . In the present application, the second seal 203 is provided on a side of the first seal 201 close to the interior of the furnace chamber, and the second seal 203 is made of a metal material, which has better heat resistance and corrosion resistance. The second seal 203 is capable of blocking flux to prevent flux from adhering to the first seal 201 , reducing corrosion to the first seal 201 , and at the same time preventing heat from being transferred to the first seal 201 from the high- temperature flux and slowing down the aging speed of the first seal.

[0044] In some examples of the present application, the sealing assembly is provided on the housing connection of the upper furnace chamber housing, and when the sealing assembly is provided on the connection of the upper furnace chamber housing, the angle between the moving portion and the fixing portion of the second sealing assembly 202 is an obtuse angle, that is, inclined from top to bottom towards the interior of the furnace chamber, so as to facilitate guiding the flux to flow towards the interior of the furnace chamber. [0045] Although only some features of the present application are illustrated and described herein, various improvements and variations may be made by those skilled in the art. It should therefore be understood that the appended claims are intended to cover all of the above improvements and variations falling within the spirit and range of the present application.