Utility model content
The technical problems to be solved in the utility model is: in order to overcome the existing welding for solar cell, to peel off pulling force low, there is problem of faulty soldering, firm welding and the package power of welding are affected to a great extent, the utility model provides a kind of welding for solar cell, by preparing groove on welding surface, even if surface pressure is shaped with groove, also can ensure the effectively area of welding, and by groove surface and the welding of silver slurry, can effectively improve the pulling force of peeling off of welding, reduce rosin joint, and can reduce to a certain extent the internal stress after solar battery sheet welding, thereby can not produce because the fragment that expands with heat and contract with cold and cause of welding, thereby ensure the fastness of welding, reduce encapsulation loss.The utility model solves the technical scheme that its technical problem adopts: a kind of welding for solar cell, comprise electric conducting base band, and described electric conducting base band is metal simple-substance or alloy material, it has upper and lower two wide surfaces;
One or two wide surface pressure of described electric conducting base band is shaped with some grooves, between adjacent described groove, leaves base band plane, and the area ratio that the gross area of the described base band plane on same wide surface accounts for its conductive base bandwidth surface, place is 25%-75%;
When electric conducting base band is only when a wide surperficial press flute, described depth of groove is that electric conducting base band thickness h is 1%≤h < 5%;
In the time of the equal press flute in the wide surface of two of electric conducting base bands, 1%≤H < 10% that described upper and lower wide surface groove degree of depth summation is described electric conducting base band thickness H.
On described electric conducting base band, plating or heat scribble solder layer, and solder layer can be that Direct Electroplating or heat are coated on electric conducting base band, can be also first on electric conducting base band, first to make layer protecting film, and then electroplate or heat painting solder layer.And, in order to save scolder consumption, reduce manufacturing cost, electric conducting base band surface can only have a wide electroplating surface or heat to be coated with solder layer, therefore, is with reeded electric conducting base band surface can have solder layer, also can there is no solder layer.
The area ratio that the gross area of base band plane accounts for its conductive base bandwidth surface, place is a key, even if make welding surface pressure be shaped with groove, also can ensure the effectively area of welding, thereby has ensured the fastness of welding.Meanwhile, limited the degree of depth of groove, in described depth bounds, the compacting of groove can not exert an influence to the opposite face of press flute in base band.
Groove on described electric conducting base band is regular on described conductive base bandwidth surface along electric conducting base band length direction to be repeated.On the one hand, the ratio that makes total reflection occurs on electric conducting base band is uniformly distributed; On the other hand, base band uniform plane is distributed, thereby be more conducive to welding, meanwhile, can also be convenient to the processing of electric conducting base band.
Because cell piece is different from the thermal coefficient of expansion of welding, the base band of general welding is copper or copper alloy, and cell piece is silicon chip, and the thermal coefficient of expansion of copper or copper alloy is greater than silicon.When welding, base band all expands in length and Width after being heated, after cooling, base band shrinkage degree is greater than cell piece, because now welding and cell piece are fixing, welding will act on to one of cell piece and make the local aduncate power of cell piece, makes the local generation of cell piece deformation.For the space of a contraction is provided to welding, described groove is linear pattern strip groove and/or shaped form strip groove.
Because base band all expands in length and Width after being heated, described groove, in same wide cross-distribution, comprises existing cross-distribution, has again situation about being parallel to each other.The angle of inclination of two crossed grooves can be consistent, for example, be all 60 degree, i.e. two crossed grooves and electric conducting base band length direction mirror image each other; Also can be different.
In the time that described groove is linear pattern strip groove, between adjacent described groove, form tetragonal base band plane.Because linear pattern strip groove manufacturing cost is lower, and, because base band all expands in length and Width after being heated, can reduce equably internal stress in length and Width.
Between adjacent described groove, form the base band plane of rhombus, and the area ratio that the gross area of the base band plane on same wide surface accounts for its conductive base bandwidth surface, place is 30%-60%; Wherein, described groove is divided into two kinds of incline directions, and the groove of two kinds of described incline directions is with respect to the length direction mirror image each other of electric conducting base band, and the angle of the groove of two kinds of described incline directions all and between the Width of electric conducting base band is between 25 °-65 °.
Described groove is in same wide parallel distribution, and can be groove parallel with the Width of electric conducting base band or tilt, or parallel with the length direction of electric conducting base band.
In described groove, also comprise point-like groove, planar groove, and one or more in the groove forming along the one-sided or bilateral compacting inclined-plane of electric conducting base band length direction.
Certainly within the technical scheme that, described groove is point-like groove or is planar groove is also included within protection range of the present utility model.
Described groove is within the groove forming along the one-sided or bilateral compacting inclined-plane of electric conducting base band length direction is also included within protection range of the present utility model.And, in the time that the one-sided or bilateral of the whole length direction of electric conducting base band is all suppressed the inclined-plane to electric conducting base band outer incline, be a kind of limiting case of described groove, described groove becomes inclined-plane.
On the one hand, consider the internal stress that reduces welding, on the other hand, improve as much as possible the ability that described groove is reflected back sunlight cell piece, the more at least tangent plane in groove floor in groove floor on described electric conducting base band is 20.9 °-45 ° with respect to the angle of inclination of conductive base bandwidth face.Light is injected optically thinner medium from optically denser medium, and in the time that incidence angle increases to critical angle, while making refraction angle reach 90 °, refract light disappears completely, only remaining reverberation, and this phenomenon is called total reflection.Because sunlight is 41.8 ° at the glass of photovoltaic cell component and the critical angle of air interface layer generation total reflection, incide the glass of photovoltaic module and the incidence angle of air interface layer is more than or equal to this critical angle as long as make from the sunlight of the groove reflection of welding, sunlight will be in the glass of photovoltaic module and air interface layer generation total reflection, thereby make the sunlight that total reflection occurs again participate in opto-electronic conversion, photovoltaic cell component actual power further can be promoted to 0.2%-2% by surperficial particular groove structure.Described groove can be deep-slotted chip breaker, can be also V-shaped groove.If deep-slotted chip breaker, its inclined bottom surface angle gradually changes, and is generally from slot opening to bottom, and the angle of inclination of groove floor diminishes gradually; And comprise that arc groove bottom surface only has part angle of inclination to meet the sunlight reflecting through welding in the glass of photovoltaic cell component and the requirement of air interface layer generation total reflection, and other parts do not meet the situation of this requirement, can make the sunlight of groove reflection incide the glass of photovoltaic module and the incidence angle of air interface layer is more than or equal to the critical angle that total reflection occurs.Certainly the tangent plane that, also comprises groove floor every bit on bottom surface is the situation of 20.9 °-45 ° with respect to the angle of inclination of wide of welding.
Described electric conducting base band, material is fine copper or albronze, Kufil, copper aerdentalloy or taking high-purity native copper as basis and be added with the alloy of rare earth material.
On electric conducting base band, prepare solder layer by the mode of electroplating or heat is coated with, the scolder using is leypewter, sn-bi alloy, gun-metal, tin-cerium alloy, sn-ag alloy, pure tin, one or more in SAC alloy; Solder layer is one or more layers, and its gross thickness is 3-30 μ m.
Between this external electric conducting base band and solder layer, can be electroplate with one or more layers ultra-thin diaphragm, the thickness of described ultra-thin diaphragm is 0.1-10 μ m.
Groove shapes and the distribution on the same wide surface of electric conducting base band of the present utility model are not limited to one, and, the groove of difformity and different distributions can be set on two wide surfaces of electric conducting base band.
The beneficial effects of the utility model are, welding for solar cell of the present utility model, the wide surface pressure of welding is shaped with groove, accounts for the area ratio on its conductive base bandwidth surface, place by limiting the gross area of base band plane, ensure the area of effective welding, thereby ensured the fastness of welding; Meanwhile, limited the degree of depth of groove, in described depth bounds, the compacting of groove can not exert an influence to the opposite face of press flute in base band; Meeting welding requirements, reduce in internal stress, make considerable part in sunlight that the wide surface of welding receives in the glass air interface total reflection of photovoltaic cell component and rejoin opto-electronic conversion, further lifting subassembly actual power.
Embodiment
By reference to the accompanying drawings the utility model is described in further detail now.These accompanying drawings are the schematic diagram of simplification, and basic structure of the present utility model is only described in a schematic way, and therefore it only shows the formation relevant with the utility model.
Embodiment 1
Select TU1 oxygen-free copper as conductive base, thickness is 0.18mm, on one wide surface or two wide surface pressure be shaped with the linear pattern strip V-type groove 3 of even cross-distribution, between adjacent groove 3, leave the base band plane 4 of rhombus, and the area ratio that the gross area of the base band plane 4 on same wide surface accounts for its place electric conducting base band 1 wide surface is 35%; Wherein, linear pattern strip V-type groove 3 all tilts with Width and the length direction of electric conducting base band 1, and only has the linear pattern strip V-type groove 3 at two kinds of angles of inclination; In the present embodiment, these two kinds of linear pattern strip V-type grooves are with respect to the length direction mirror image each other of electric conducting base band 1, and two kinds of angles of inclination are respectively the inclination angle that is roughly the both direction of 60 ° with the Width of electric conducting base band 1.
When electric conducting base band 1 is only when a wide surperficial press flute 3, groove 3 degree of depth are roughly 4.5% of electric conducting base band 1 thickness;
In the time of the equal press flute 3 in the wide surface of 1 two of electric conducting base bands, groove 3 degree of depth are 4%-5% of electric conducting base band 1 thickness, and upper and lower wide surface groove 3 depth capacity summations are no more than 9% of electric conducting base band 1 thickness;
Select gun-metal scolder, electroplate on fluted 3 electric conducting base band 1 at this or heat is coated with 7um solder layer 2, obtain the welding for solar cell.
Adopt 60 156*156 polysilicon chips, use a wide reeded welding for solar cell, and groove surface and the positive silver soldering of cell piece are connect, the component power that the power ratio of preparation one Battery pack assembly is used common welding to prepare exceeds 0.2W.
Adopt 60 156*156 polysilicon chips, use two wide fluted weldings for solar cell, the component power that the power ratio of preparation one Battery pack assembly is used common welding to prepare exceeds 0.5W.
The pulling force of peeling off of welding is to pass through tensiometer, spend along cell piece 180 that direction is counter draws welding until welding is peeled off required pulling force from cell piece, generally peel off pulling force requirement and be greater than 1.5N, after fluted of the welding of the present embodiment and the welding of silver slurry, welding is peeled off pulling force and is greater than 3.5N, meets the demands.
Fig. 1, Fig. 2 have provided this structure chart for the welding of solar cell.And groove 3 can be also circular arc as shown in Figure 3.In Fig. 3, the bore of the groove 3 on electric conducting base band 1 from opening to bottom dwindles gradually, and the more at least tangent plane on groove 3 bottom surfaces on groove 3 bottom surfaces is 20.9 °-45 ° with respect to the angle of inclination of wide of electric conducting base band 1.
Embodiment 2
As shown in Figure 4, the structural representation of embodiment 2 of the present utility model.As different from Example 1, on wide surface of conductive base or two wide surface pressure be shaped with the linear pattern strip V-type groove 3 of even parallel distribution, between adjacent groove 3, leave the base band plane 4 of strip, the area ratio that the gross area of the base band plane 4 on same wide surface accounts for its place electric conducting base band 1 wide surface is 45%, groove 3 degree of depth are 1% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.23W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 3
As shown in Figure 5, the structural representation of embodiment 3 of the present utility model.As different from Example 1, the only linear pattern strip V-type groove 3 at oriented two kinds of angles of inclination, part linear pattern strip V-type groove 3 is parallel with the Width of electric conducting base band 1, another part and electric conducting base band 1 length direction tilt, form base band plane 4, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 25%, and groove 3 degree of depth are 3% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.22W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 4
As shown in Figure 6, the structural representation of embodiment 4 of the present utility model.As different from Example 1, the only linear pattern strip V-type groove 3 at oriented two kinds of angles of inclination, part linear pattern strip V-type groove 3 is parallel with the length direction of electric conducting base band 1, another part and electric conducting base band 1 Width tilt, form base band plane 4, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 75%, and groove 3 degree of depth are 3.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.23W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 5
As shown in Figure 7, the structural representation of embodiment 5 of the present utility model.As different from Example 1, the only strip V-type groove 3 at oriented two kinds of angles of inclination, linear pattern strip V-type groove 3 is parallel with the Width of electric conducting base band 1; Another part groove 3 tilts with electric conducting base band 1 length direction, the groove 3 tilting with electric conducting base band 1 length direction is shaped form strip V-type groove 3, form base band plane 4, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 45%, groove 3 degree of depth are 2.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.18W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3N, meets the demands.
Embodiment 6
As shown in Figure 8, the structural representation of embodiment 6 of the present utility model.As different from Example 1, linear pattern strip V-type groove 3 all changes shaped form strip V-type groove 3 into, form base band plane 4, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 45%, groove depth groove 3 degree of depth are 2% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.20W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3N, meets the demands.
Embodiment 7
As shown in Figure 9, the structural representation of embodiment 7 of the present utility model.As different from Example 1, linear pattern strip V-type groove 3 all changes planar V-type groove 3 into, and each planar V-type groove 3 does not all intersect mutually, form base band plane 4, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 55%, groove 3 degree of depth are 2.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.25W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 8
As shown in figure 10, the structural representation of embodiment 8 of the present utility model.As different from Example 1, linear pattern strip V-type groove 3 changes the combination of linear pattern strip V-type groove 3 and point-like V-type groove 3 into, and each groove 3 does not all intersect mutually, form base band plane 4, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 45%, groove 3 degree of depth are 2.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.20W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 9
As shown in Figure 11-13, the structural representation of embodiment 9 of the present utility model.As different from Example 1, linear pattern strip V-type groove 3 all changes point-like arc groove 3 into, each point-like groove 3 is evenly distributed on the wide surface of electric conducting base band 1, the base band plane 4 on electric conducting base band 1 wide surface is the large plane of a connection, and the area ratio that the gross area of the base band plane 4 on same wide surface accounts for its place electric conducting base band 1 wide surface is 55%.And as shown in figure 12, base band plane 4 is metal passivation face, electric conducting base band 1 surface electrical is coated with ultra-thin diaphragm 5; Electric conducting base band 1 only wide surface band is fluted 3, and the described conductive base bandwidth surface with fluted 3 does not have solder layer, and its excess-three face is all electroplate with solder layer.And the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 40%, and groove 3 degree of depth are 1.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.3W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 10
As shown in figure 14, the structural representation of embodiment 10 of the present utility model.As different from Example 1, only be shaped with groove 3 in a wide surface pressure of conductive base, and the distribution of groove 3 is identical with embodiment 1, groove 3 is linear pattern strip V-type groove, and also there is on this basis the linear pattern strip V-type groove 3 that is parallel to electric conducting base band Width, the area ratio that accounts for its place electric conducting base band 1 wide surface with the gross area of reeded wide lip-deep base band plane 4 is 30%, and groove 3 degree of depth are 3% of electric conducting base band 1 thickness, prepare solder layer 2 by plating mode.Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.23W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 11
As different from Example 10, except a wide surface pressure at conductive base is shaped with the groove identical with embodiment 10 3, another wide face also has groove 3, as shown in figure 15, is another structural representation of wide of embodiment 11.Another groove of wide 3 is for being parallel to the linear pattern strip V-type groove of electric conducting base band Width, and the upper and lower wide lip-deep linear pattern strip V-type groove that is parallel to electric conducting base band Width does not overlap mutually, i.e. the upper and lower wide lip-deep linear pattern strip V-type groove that the is parallel to electric conducting base band Width compacting that intermeshes.And the surperficial area ratio that the gross area of upper wide upper base band plane 4 accounts for its place electric conducting base band 1 is 30%, on lower wide surface, to account for the surperficial area ratio of its place electric conducting base band 1 be 75% to the gross area of base band plane 4, and groove 3 degree of depth of upper surface are 0.5% of electric conducting base band 1 thickness, groove 3 degree of depth of lower surface are 0.6% of electric conducting base band 1 thickness.Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.23W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 12
As shown in Figure 16-17, the structural representation of embodiment 12 of the present utility model.As different from Example 1, the groove of the present embodiment is that now, groove 3 becomes inclined-plane along the inclined-plane to electric conducting base band outer incline of electric conducting base band 1 length direction both sides compacting.Electric conducting base band 1 middle part forms the base band plane 4 along electric conducting base band 1 length direction, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 50%, groove inclined-plane 3 degree of depth are 2% of electric conducting base band 1 thickness, prepare solder layer 2 by plating or hot painting mode.Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.32W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 13
As shown in Figure 18-19, the structural representation of embodiment 13 of the present utility model.As different from Example 1, in the present embodiment, along the one-sided compacting of electric conducting base band 1 length direction to the tilted inclined-plane of electric conducting base band, form groove 3.Electric conducting base band 1 opposite side forms the base band plane 4 along electric conducting base band 1 length direction, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 65%, groove inclined-plane 3 degree of depth are 2.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating or hot painting mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.23W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 14
As shown in figure 20, the structural representation of embodiment 14 of the present utility model.As different from Example 1, the groove of the present embodiment is the linear pattern strip V-type groove 3 along electric conducting base band 1 length direction both sides compacting, electric conducting base band 1 middle part forms the base band plane 4 along electric conducting base band 1 length direction, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 70%, groove inclined-plane 3 degree of depth are 2.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating or hot painting mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.27W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.
Embodiment 15
As shown in Figure 21-22, the structural representation of embodiment 15 of the present utility model.As different from Example 14, the groove of the present embodiment is the linear pattern strip V-type groove along electric conducting base band 1 length direction both sides compacting, wherein, the inclined-plane to electric conducting base band outer incline of suppressing along the middle part of electric conducting base band 1 length direction both sides, form inclined plane groove, linear pattern strip V-type groove and inclined plane groove form the groove 3 of the present embodiment jointly.Electric conducting base band 1 middle part forms the base band plane 4 along electric conducting base band 1 length direction, and the area ratio that the gross area of the base band plane 4 of same wide accounts for its place electric conducting base band 1 wide surface is 75%, groove inclined-plane 3 degree of depth are 2.5% of electric conducting base band 1 thickness, prepare solder layer 2 by plating or hot painting mode.
Adopt 60 156*156 polysilicon chips, use this welding for solar cell to prepare a Battery pack assembly, groove connects with positive silver soldering, and the component power that the power ratio of assembly is used common welding to prepare exceeds 0.31W.
Adopt the measuring method of tensile force of peeling off of embodiment 1, after the present embodiment welding groove surface welds with silver slurry, the pulling force of peeling off of welding is greater than 3.5N, meets the demands.