CN201115032Y

CN201115032Y - Open loop kettle mouth inside tin overflow hole

Info

Publication number: CN201115032Y
Application number: CNU2007200755365U
Authority: CN
Inventors: 庄春明
Original assignee: Suzhou Mingfu Automation Equipment Co Ltd
Current assignee: Suzhou Mingfu Automation Equipment Co Ltd
Priority date: 2007-10-18
Filing date: 2007-10-18
Publication date: 2008-09-10
Anticipated expiration: 2017-10-18

Abstract

The utility model relates to a tinning furnace component used for a PCBA plate soldering, in particular to a tinning furnace spout. A rectangular inner tube and an outer tube form a dual rectangular spout; a tin overflowing port is arranged on a tin discharging port on the spout of the inner tube, the tin overflowing port is a rectangular opening with a depth of 2 to 8 mm. The tinning furnace spout of the utility model has the advantages of simple structure, can effectively improve the soldering efficiency, and applies to large-scaled automatic production; in addition, the tinning furnace spout effectively prevents the oxidation layer on the tin fluid surface from remaining on the surface of the PCBA plate, thus guaranteeing the quality of soldering spots.

Description

The tin internal open loop kettle mouth overflows

Technical field

The utility model relates to a kind of tin stove parts of the PCBA of being used for boards solder, especially a kind of tin furnace kettle mouth.

Background technology

Common wave-soldering adopts manual operations usually, and production efficiency is lower, for the comparatively intensive PCBA plate of need pad, this welding manner is more inadequate, in addition, because stannum export too small (generally long 2 millimeters), can bring the obstruction of scruff, thereby cause the large tracts of land of rosin joint to produce Hu Kou; At the comparatively intensive PCBA plate of pad, the kettle of employing mouth structure is also arranged, but common tin furnace kettle mouth is flat mouthful design, in order to realize scolding tin operation to the PCBA plate, generally need maintenance distance once between PCBA plate and kettle mouth, guarantee to make tin liquor can the electric elements on the PCBA plate of top be welded on the one hand from the Hu Kou ejection, guarantee simultaneously can in time discharge Hu Kou from the tin liquor of Hu Kou ejection subsequently, prevent that the kettle mouth pressure is excessive, influence welding quality, but also there is fault of construction in this structure: when tin liquor when Hu Kou sprays, because the tin liquor of upper space is owing to directly contact the formation oxide layer with air, this part oxide layer at first contacts with the PCBA plate of top along with tin liquor is gushed out from Hu Kou, in the wings under the frontal impact of tin liquor, make this part oxide layer oppressed on PCBA plate face, be difficult for it being taken away, make oxide layer remain between solder joint and the PCBA plate, have a strong impact on welding quality by the kettle mouth tin liquor of gushing out subsequently.

Summary of the invention

In order to overcome the deficiency that above-mentioned various scolding tin exists, when especially adopting the intensive PCBA plate of the point-to-point wave-soldering butt welding point of automatic selectivity to weld, inefficiency, be unsuitable for extensive batch machining, and contact easily forms the deficiency of rosin joint, it is a kind of simple in structure that the utility model provides, and can effectively improve welding efficiency, guarantees the tin furnace kettle mouth of the quality of welded contact.

The technical scheme that its technical problem that solves the utility model adopts is: a kind of excessive tin internal open loop kettle mouth, form back shape Hu Kou by the interior pipe and the outer tube of rectangle, and the kettle mouth stannum export of interior pipe is provided with the Xi Kou that overflows.The electronic devices and components to be welded that described structure is mainly used on the PCBA plate are mainly concentrated the welding that is distributed in back the close medial region in shape weld zone.

For the ease of the processing of the Xi Kou that overflows, guarantee the tin liquor Xi Kou outflow of can overflowing equably simultaneously, further: described excessive Xi Kou is a rectangle gap.

For the degree of depth of the Xi Kou that overflows rationally is set, cross shallow may rising and come the Xi Kou that overflows excessive tin effect should be arranged, cross may cause deeply tin liquor before the kettle mouth of emerging just from the Xi Kou outflow of overflowing, make the emerge height of Hu Kou of tin ripple on the low side, influence welding quality, more further: the degree of depth of described excessive Xi Kou is 2～8mm.

The existence of excessive Xi Kou can effectively change the flow direction of tin liquor behind ejection Hu Kou.After tin liquor sprays from Hu Kou, tin liquor can preferentially flow out from the Xi Kou that overflows, so just form certain tin stream that flows to, making the oxide layer of the superiors can directly do not impacted is adsorbed onto on the PCBA plate, even there is the partial oxidation layer to be adsorbed onto on the PCBA plate, can be washed away by the tin liquor that sprays from Hu Kou subsequently, having guaranteed can residual oxide layer not influence the soldering quality between scolding tin and PCBA plate yet; On the other hand, because surface tension, tin liquor upper surface in the kettle mouth is spherical shape, make under the not high situation of furnace pressure, may appear at kettle mouth edge and form rosin joint, influence welding quality, the existence of excessive Xi Kou, change the flow direction of kettle mouth tin liquor, made tin liquor can maximum possible cover the PCBA plate of kettle mouth top, guaranteed the adequacy and the fastness of welding.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is the utility model kettle mouth structure schematic diagram.

Fig. 2 is the placement location schematic diagram of the utility model on the PCBA plate.

1. interior pipe 2. outer tubes 3. excessive tin mouth 4.PCBA plate 5. electronic devices and components among the figure

Embodiment

A kind of excessive tin internal open loop kettle mouth is as shown in Figure 1 formed back shape Hu Kou by the interior pipe 1 and the outer tube 2 of rectangle, and the kettle mouth stannum export of interior pipe 1 is provided with the tin mouth 3 that overflows.Described excessive tin mouth 3 is a rectangle gap, and its degree of depth is 2～8mm.

As shown in Figure 2, Hu Kou described in the utility model is mainly used in the electronic devices and components to be welded 5 main concentrated welding that are distributed in back the shape weld zone near medial region on the PCBA plate 4.

During use, PCBA plate 4 is placed on the precalculated position of kettle mouth top, and board plane and kettle mouth stannum export are maintained a certain distance, generally be controlled at 2～6mm.The shape of Hu Kou can be determined according to the distribution situation of PCBA plate 4 welding positions.Tin liquor keeps earlier certain liquid level to store in the kettle mouth 1～3 minute, the PCBA plate to be welded 4 of top is carried out preheating, so that preceding operation is removed the oxide layer on the PCBA plate 4 at the scaling powder generation chemical reaction of PCBA plate 4 positions to be welded sprayings.Afterwards, the electronic startup of tin stove, push to Hu Kou by the tin liquor of exerting pressure the tin furnace interior, the continuous lifting of tin liquor face in the kettle mouth, and tin liquor ejects kettle mouth stannum export the most at last, contacts with the PCBA plate 4 of top and welds, guaranteeing that tin liquor and PCBA plate 4 fully weld, excessive tin mouth 3 on the interior pipe 1 is discharged, and takes away the oxide layer and the impurity of tin liquor top layer, also makes the electronic devices and components 5 near excessive tin mouth 3 obtain the welding of abundant tin liquor.At last, take off PCBA plate 4, finish the welding of kettle mouth top electronic devices and components 5 on the ground PCBA plate 4 from kettle mouth top.

Because adopted kettle mouth method for designing flexibly, enlarged effective solder side, thereby made speed of welding fast on year-on-year basis more than three times with international " automatic selectivity welding tin stove ".

Because Hu Kou has adopted excessive tin mouth design, this scheme has just been removed the main scruff of welding quality and the oxide skin on tin liquor surface of influencing before welding, make the qualification rate of welding reach 99.More than 9%.

Claims

1. excessive tin internal open loop kettle mouth, it is characterized in that: interior pipe (1) and outer tube (2) by rectangle are formed back shape Hu Kou, and the kettle mouth stannum export of interior pipe (1) is provided with the Xi Kou (3) that overflows.

2. excessive tin internal open loop kettle mouth according to claim 1 is characterized in that: described excessive Xi Kou (3) is a rectangle gap.

3. excessive tin internal open loop kettle mouth according to claim 2 is characterized in that: the degree of depth of described excessive Xi Kou (3) is 2～8mm.