DE102012200021A1 - Arrangement for soldering terminal pin of THT component in hole of printed circuit board, has heat conducting devices to support heat input to base of circuit board, and solder pad that is mounted on solder preform - Google Patents

Abstract

The arrangement (10) has bore solder pads (16,34,47) whose ends are connected to an upper surfaces (17,38,48) of the circuit boards (11,31,41). The heat conducting devices (23,37,45,50) are provided to support a heat input to the bases (18,39,49) of the circuit board. The solder pad is mounted on solder preform (22).

Description

The invention relates to an arrangement for the indirect soldering of a connection pin of a wired component (also called "THT component") in a bore of a mixed-assembled printed circuit board by means of a Selektivlötverfahrens.

Selective soldering is used for soldering mixed and double-sided printed circuit boards, which are therefore equipped with both SMD and THT components. The SMD components are usually and as far as possible soldered in a reflow soldering furnace, while the THT components are selectively soldered in the reflow soldering oven following the soldering of the SMD components, since they usually do not meet the soldering temperature peaks in a reflow soldering oven may be suspended. Critical THT components of this type are in particular those with problematic plastic housings, for example terminal blocks.

From the German publication DE 10 2006 035 528-A1 For example, a method is known in which a wave soldering machine is used to selectively solder components on an upper surface of a printed circuit board. In this case, a heat transfer from the solder wave, which acts on a lower side of the printed circuit board, is used through the printed circuit board on the upper side of the printed circuit board to melt there solder paste for soldering components on the upper side of the printed circuit board. A transport speed of the printed circuit board via the solder wave is set to lower than in conventional wave soldering.

From the German patent DE 10 2005 043 279-B4 In turn, it is known to solder a terminal pin of a THT device using a Lotformteils, which serves as a solder depot.

The invention has the object of further optimizing the heat transfer through the printed circuit board in the case of a selective soldering method acting on the underside of a mixed printed circuit board, so that a solder deposit on the upper side of the printed circuit board is melted at almost the usual transport speed and connecting pins of THT components are soldered ,

• – eine Leiterplatte mit einer für den Anschlusspin vorgesehenen und mit einer Metallisierung ausgekleideten Bohrung,
• – mindestens ein mit der Metallisierung der Bohrung verbundenes Lötpad auf einer Oberseite der Leiterplatte,
• – eine Wärmeleitvorrichtung zur Unterstützung eines Wärmeeintrags in eine Unterseite der Leiterplatte und durch die Leiterplatte hindurch und
• – wenigstens ein auf dem Lötpad befestigtes Lotformteil

umfasst.This object is achieved according to the invention by an arrangement for the indirect soldering of a connection pin of a wired component in a bore of a mixed-assembled printed circuit board by means of a Selektivlötverfahrens, which arrangement:

• A circuit board with a hole provided for the connection pin and lined with a metallization,
• At least one solder pad connected to the metallization of the bore on an upper side of the printed circuit board,
• - A heat-conducting device for supporting a heat input in a bottom of the circuit board and through the circuit board and
• - At least one fixed on the solder pad Lotformteil

includes.

In a particular embodiment of the arrangement according to the invention, the Selektivlötverfahren is performed with a wave soldering.

In another embodiment of the arrangement according to the invention, the heat conducting device is a polyimide tape covering the bore on the underside of the printed circuit board.

In yet another embodiment of the arrangement according to the invention, the heat conducting device is arranged in the circuit board in the hole projecting metallic foil.

In yet another embodiment of the arrangement according to the invention, the heat conducting device is provided in the bore metallized cross-sectional constriction, wherein in a particular embodiment of this embodiment, the underside of the circuit board is covered in the bore with a Lötstopplack.

In a further embodiment of the arrangement according to the invention, the heat-conducting device is a cup-shaped metallic sleeve inserted into the bore from the upper side of the printed circuit board.

In a further embodiment of the arrangement according to the invention, it is provided that an SMD component already soldered there can be covered by a suitable solder mask on the underside of the mixed printed circuit board.

In yet another embodiment of the inventive arrangement, the solder mask in the region of the bore has a recess for heat input into the circuit board.

In yet another embodiment of the arrangement according to the invention, the recess of the solder mask in the region of the bore on a metal insert for heat input into the circuit board.

The invention is described below with reference to various, in the attached Drawing illustrated embodiments described and explained in more detail. Showing:

1 a schematic representation of a first embodiment of the inventive arrangement;

2 a schematic representation of a second embodiment of the inventive arrangement;

3 a schematic representation of a third embodiment of the inventive arrangement;

4 a schematic representation of the soldered inventive arrangement according to 3 ;

5 a schematic representation of a fourth embodiment of the inventive arrangement and

6 a schematic representation of a fifth embodiment of the inventive arrangement

Various components and elements that are not relevant to the invention are provided with the same reference numerals for the sake of simplicity.

1 shows a first embodiment of an arrangement 10 according to the invention. The order 10 includes a mixed printed circuit board 11 , with a single through hole exemplified here 12 for a connection pin 13 a THT component 14 , The hole 12 for the connection pin 13 is preferably with a metal sleeve 15 lined, which is prepared in a known per se, for example, galvanically. On a top 17 and a bottom 18 the circuit board 11 is the metal sleeve 15 with solder pads 16 or conductor tracks for the connection pin 13 of the THT component 14 or connected to not shown here for simplicity interconnects. The circuit board 11 was already on her top 17 assembled and soldered with SMD components, not shown here, preferably in a reflow soldering oven. In the case of the representation in 1 selected embodiment of the invention were also in a previous operation on the bottom 18 the circuit board 11 SMD components assembled and soldered. To illustrate this is in 1 an SMD component 19 sketched that on the bottom 18 the circuit board 11 on designated solder pads 20 was soldered. A solder for the SMD component 19 is there with " 21 " designated.

1 illustrates the arrangement according to the invention 10 , after the assembly, the THT components in a subsequent step on the circuit board 11 be soldered with a Selektivlötverfahren.

According to the invention is for the in 1 exemplified THT component 14 on the top 17 the circuit board 11 on a solder pad 16 right next to the hole 12 for the connection pin 13 of the THT component 14 a solder preform 22 provided, preferably already together with SMD components on the top 17 the circuit board 11 equipped and glued there or soldered with solder paste. In this case, the solder preform has 22 a higher melting temperature than the solder or the solder paste for the SMD components.

solder pad 16 the metal sleeve 15 on the bottom 18 the circuit board 11 is in the in 1 illustrated embodiment by a polyimide film 23 , preferably one available under the name "Kapton tape". The connection pin 13 of the THT component 14 is through the polyimide film 23 plugged and thereby becomes in the bore 12 held. Polyimide films 23 or covers of this type can be applied directly to a circuit board manufacturer. A solder wave passes over the connection pin 13 on the bottom 18 the circuit board 11 , so it transmits due to the polyimide films 23 their heat only on the connection pin 13 of the THT component 14 and the metal sleeve 15 in the hole 12 and not on surrounding areas of the circuit board 11 , through the connection pin 13 and thus through the circuit board 11 through to the top 17 the circuit board 11 to the solder preform 22 , The solder preform 22 is thereby melted and fills an annulus between the terminal pin 13 and the metal sleeve 15 in the hole 12 so that the connection pin 13 is soldered. It has been shown that the polyimide film 23 the heat conduction of the heat of the solder wave through the circuit board 11 Supports by cooling the metal sleeve 15 in the hole 12 delayed until the solder preform 22 on the top 17 the circuit board 11 is melted.

Since the temperature of the solder wave is higher than the temperature in the reflow soldering oven, in the already before the solder paste 21 for the SMD component shown here by way of example 19 has melted, must be a re-melting of the solder 21 of the SMD component 19 be prevented by the solder wave. In the in 1 illustrated embodiment of the invention is the SMD component 19 during selective soldering by the solder wave from a conventional solder mask 24 that the SMD component 19 opposite to the over the bottom 18 the circuit board 11 Shielding solder wave shields. In the area of the connection pin 13 and the metal sleeve 15 in the hole 12 is a recess or opening in the solder mask 24 provided that sweeping the solder wave over the terminal pin 13 and the metal sleeve 15 allowed. After soldering with the solder wave, the polyimide tape can be removed from the printed circuit board without residue 11 be removed.

In 2 is a second embodiment of an arrangement 30 illustrated according to the invention. The order 30 again includes one, as in 1 illustrated mixed assembled circuit board 31 with an exemplary single through bore 32 for the connection pin 13 of the THT component 14 , The hole 32 for the connection pin 13 is like in 1 preferably with a metal sleeve known per se 33 lined with solder pads 34 and interconnects is connected. The circuit board 31 is in this example a multilayer printed circuit board 31 what through conductive inner layers 36 is illustrated. Preferably, an inner layer extends 37 into the hole 32 into and serves to hold the connection pins 13 of the THT component 14 in the hole 32 , The inner layer 37 will do so in the hole 32 provided with a hole that is slightly smaller than the diameter of the connection pin 13 , The circuit board 31 was already on her top 38 and on the bottom 39 equipped with SMD components and soldered, of which here, for example, the SMD component 19 and his lot 21 on the bottom 39 the circuit board 31 are shown.

As 1 also illustrates 2 the inventive arrangement 30 directly before a subsequent work step, in which the populated THT components are soldered using a selective soldering method, here for example with a wave soldering method. As in 1 is for this in the 2 exemplified THT component 14 on the top 38 the circuit board 31 on a solder pad 34 right next to the hole 32 for the connection pin 13 of the THT component 14 a solder preform 22 provided, preferably already together with SMD components on the top 38 the circuit board 11 equipped and glued there or soldered with solder paste. The solder preform 22 has, as already mentioned above, a higher melting temperature than the solder or the solder paste for the SMD components.

solder pad 34 around the metal sleeve 33 on the bottom 39 the circuit board 31 is in the in 2 illustrated second embodiment of the invention not covered and due to the recess 25 in the solder mask 24 directly accessible from the solder wave. A solder wave passes over the connection pin 13 on the bottom 39 the circuit board 31 , so it transmits its heat directly to the connector pin 13 of the THT component 14 and the metal sleeve 33 in the hole 32 , through the circuit board 31 through to the top 38 the circuit board 31 to the solder preform 22 , The solder preform 22 is thereby melted and fills an annulus between the terminal pin 13 and the metal sleeve 33 in the hole 32 so that the connection pin 13 is soldered. It has been shown that the metallic inner layer 37 the heat conduction of the heat of the solder wave through the circuit board 31 is supported. At the same time prevents the pin from the connection 13 pierced inner layer 37 that the connecting pin 13 encloses that molten solder of the solder preform 22 on the bottom 39 the circuit board 31 out of the hole 32 exit.

In the 2 illustrated solder mask 24 fulfills the same purpose as already mentioned above 1 has been described.

In 3 is a third embodiment of an arrangement 40 illustrated according to the invention. The order 40 again includes one, as in the 1 and 2 illustrated mixed assembled circuit board 41 with an exemplary single through bore 32 for the connection pin 13 of the THT component 14 , The hole 42 for the connection pin 13 is like in the 1 and 2 with a metal sleeve 46 lined, however, in contrast to the metal sleeves 15 in 1 and 33 in 2 to a bottom 49 the circuit board 41 rejuvenated. This is realized by the bore 42 from two interlocking individual bores 43 and 41 is formed in the then by galvanizing or similar measures the metal sleeve 46 is introduced. An advantage of the tapered bore 46 is that thereby in the metal sleeve 46 a cross-sectional constriction 45 is formed. Will the connection pin 13 of the THT component 14 in the metal sleeve 46 and in the cross-sectional constriction 45 plugged in he can be jammed there. At the same time it prevents the connection pin 13 enclosing collar 45 in that molten solder of the solder preform 22 on the bottom 49 the circuit board 41 out of the hole 42 exit.

As in the embodiments of the invention according to the 1 and 2 became the circuit board 41 already on their top 48 and on the bottom 49 equipped with SMD components and soldered, of which here again exemplifies the SMD component 19 and his lot 21 on the bottom 49 the circuit board 41 are shown.

As the 1 and 2 also illustrates 3 the inventive arrangement 40 right before a subsequent work step, in which the assembled THT components 14 be soldered with a Selektivlötverfahren, here for example with a Wellenlotverfahren. As in the 1 and 2 is for this in the 3 exemplified THT component 14 on the top 48 the circuit board 41 on a solder pad 47 right next to the hole 42 for the connection pin 13 of the THT component 14 a solder preform 22 provided, preferably already together with SMD components on the top 48 the circuit board 41 equipped and stuck there or with Solder paste had been soldered. The solder preform 22 has, as already mentioned above, a higher melting temperature than the solder or the solder paste 21 for the SMD components 19 ,

The solder pad 47 around the metal sleeve 46 on the bottom 49 the circuit board 31 and surrounding areas on the bottom 49 the circuit board 41 are in the in 3 illustrated third embodiment of the invention of a known Lötstopplack 50 covered, so that the lower single hole 44 the bore 42 remains free. A solder wave passes over the connection pin 13 on the bottom 39 the circuit board 31 , so she transmits her heat directly over the collar 45 the metal sleeve 46 through the circuit board 41 through to the top 48 the circuit board 41 to the solder preform 22 , The solder preform 22 is thereby melted and fills an annulus between the terminal pin 13 and the metal sleeve 46 in the hole 42 so that the connection pin 13 is soldered.

In the 3 illustrated solder mask 24 fulfills the same purpose as already mentioned above 1 and 2 has been described.

In 4 is the in 3 illustrated inventive arrangement 40 illustrated after successful selective soldering with a solder wave. That before on the top 48 the circuit board 41 located Lotformteil is melted and his lot 52 has the connection pin 13 of the exemplary THT device 14 in the metal sleeve 46 the bore 42 soldered. Due to the conical shape of the metal sleeve 46 is not a lot 52 from the metal sleeve 46 leaked.

5 illustrates a fourth embodiment of the inventive arrangement 60 , which illustrates its suitability for metal sleeves in the bore for THT components. Again, here is a circuit board 61 to see with a hole 62 for the connection pin 13 of the exemplified THT component 14 However, here not with a preferably prepared by electro-chemical metal sleeve according to the preceding 1 - 4 is equipped but with one from a top 63 the circuit board 61 into the hole 62 used cup-shaped metal sleeve 65 into which then the connection pin 13 of the THT component 14 , as in 4 shown, is used. To the top 63 the circuit board 61 towards the cup-shaped metal sleeve 65 a collar with a solder pad 67 and possibly conductor tracks top side 63 the circuit board 61 connected is. Similar to the previously described embodiments is on the top 63 the circuit board 61 is on a solder pad 67 right next to the hole 62 for the connection pin 13 of the THT component 14 a solder preform 22 provided as a solder deposit, preferably already together with SMD components 19 on the top 63 the circuit board 61 equipped and glued there or soldered with solder paste. The solder preform 22 has, as already mentioned above, a higher melting temperature than the solder or the solder paste 21 for the SMD components 19 ,

As the 1 . 2 and 3 also illustrates 5 the inventive arrangement 60 right before a subsequent work step, in which the assembled THT components 14 be soldered with a Selektivlötverfahren, here for example with a Wellenlotverfahren. As the cup-shaped metal sleeve 65 at the in 5 illustrated embodiment of the invention is not up to a bottom 64 the circuit board 61 passes through, is the hole 62 from the bottom 64 the circuit board 61 through a stopper 66 closed, which is made of a material that is as high heat-conducting. A solder wave passes over the plug 66 in the bottom 64 the circuit board 61 , so it transmits its heat directly over the plug 66 and thus on the cup-shaped metal sleeve 65 through the circuit board 61 through to the top 63 the circuit board 61 to the solder preform 22 , The solder preform 22 is thereby melted and fills an annulus between the terminal pin 13 and the cup-shaped metal sleeve 65 so that the connection pin 13 is soldered.

In the 5 illustrated solder mask 24 is in turn designed as it already was 1 - 3 described and fulfills the same purpose as described above.

6 illustrates a fifth embodiment of the inventive arrangement based on the multilayer printed circuit board 31 to 2 , The order 30 again includes one, as in 2 illustrated mixed assembled circuit board 31 with an exemplary single through bore 32 for the connection pin 13 of the THT component 14 , The hole 32 for the connection pin 13 is like in 1 preferably with a metal sleeve known per se 33 lined with solder pads 34 and interconnects is connected. As in the second embodiment of the invention, the circuit board 31 in 6 a multilayer printed circuit board 31 what through conductive inner layers 36 is illustrated. Preferably, an inner layer extends 37 into the hole 22 into and serves to hold the connection pins 13 of the THT component 14 in the hole 32 , The inner layer 37 will do so in the hole 32 provided with a hole that is slightly smaller than the diameter of the connection pin 13 , The circuit board 31 was already on her top 38 and on the bottom 39 equipped with SMD components and soldered, of which here, for example, the SMD component 19 and his lot 21 on the bottom 39 the circuit board 31 are shown.

As in the 1 . 2 . 3 and 5 also illustrates 6 the inventive arrangement 30 directly before the following work step, in which the populated THT components are soldered using a selective soldering method, here, for example, using a wave soldering method. As in the 1 . 2 . 3 and 5 is on the solder pad 34 right next to the hole 32 a solder preform 22 for the connection pin 13 of the THT component 14 on the top 38 the circuit board 31 provided, which Lotformteil 22 preferably already together with SMD components on the top 38 the circuit board 11 equipped and glued there or soldered with solder paste. The solder preform 22 has, as already mentioned above, a higher melting temperature than the solder or the solder paste for the SMD components.

Unlike in the 1 and 3 is the solder pad 34 around the metal sleeve 33 on the bottom 39 the circuit board 31 in the 6 illustrated fifth embodiment of the invention not covered. One with the recess 25 in the solder mask 24 after the 1 . 2 . 3 and 5 comparable recess 25b in the solder mask 24 of the 6 is with a metal insert 68 lined. This has, for example, a cylindrical part 69 and a tapered part 71 on. As in 6 is illustrated in the cylindrical part 69 of the metal insert 68 one of the circuit board 31 facing blind hole or recess 70 on, one over the metal sleeve 33 on the bottom 39 the circuit board 31 protruding end of the connection pin 13 of the THT component 14 receives. Due to the centric recess 70 in the cylindrical part 69 of the metal insert 68 becomes a circuit board facing, annular part of the metal insert 68 formed in operation on the metal sleeve 33 on the bottom 39 the circuit board 31 flush. The conical part 71 of the metal insert 68 serves for better attachment of the metal insert 68 in the solder mask 24 , It also improves over the cylindrical part 69 larger area of the conical part 71 the heat conduction to the metal sleeve 33 ,

The metal insert 68 in the solder mask 24 is directly accessible from the solder wave. A solder wave sweeps over the metal insert 68 , so it transfers its heat over the cylindrical part 69 of the metal insert 68 directly on the metal sleeve 33 and through the circuit board 31 through on top of it 38 to the solder preform 22 , The solder preform 22 is melted and fills the annulus between the terminal pin 13 and the metal sleeve 33 in the hole 32 so that the connection pin 13 is soldered.

It has been shown that the metal insert 68 in the solder mask 24 by contact with the solder wave acts as a so-called thermode and the heat conduction of the heat of the solder wave through the circuit board 31 supported in a special way. The from the terminal pin 13 pierced inner layer 37 that the connecting pin 13 encloses, prevents molten solder of Lotformteils 22 on the bottom 39 the circuit board 31 out of the hole 32 resigned.

For the rest, the in 6 illustrated solder mask 24 fulfills the same purpose as already mentioned above 1 . 2 . 3 and 5 has been described.

For the sake of simplification, in the 1 . 3 . 4 and 5 no multilayer printed circuit boards shown. However, it is clear to the person skilled in the art that the various exemplary embodiments illustrated there can also be used for multilayer printed circuit boards.

LIST OF REFERENCE NUMBERS

10

Arrangement (1st AFB)

11

circuit board

12

drilling

13

connector pin

14

THT component

15

metal sleeve

16

Solder pad around ( 15 )

17

Top of ( 11 )

18

Bottom of ( 11 )

19

SMD

20

Solder pad for ( 19 )

21

Solder Paste / Lot (for 19 )

22

solder preform

23

Polyimide film

24

solder mask

25

Recess / opening

30

Arrangement (2nd AFB)

31

circuit board

32

drilling

33

metal sleeve

34

Solder pad around ( 33 )

36

Inner layer general

37

Inner layer in ( 32 )

38

Top of ( 31 )

39

Bottom of ( 31 )

40

Arrangement (3rd AFB)

41

circuit board

42

drilling

43

1. Single hole

44

2. Single hole

45

Collar / cross-sectional narrowing

46

metal sleeve

47

Solder pad around ( 46 )

48

Top of ( 41 )

49

Bottom of ( 41 )

50

solderstop

52

solder

60

Arrangement (4th AFB)

61

circuit board

62

drilling

63

Top of ( 61 )

64

Bottom of ( 61 )

65

cup-shaped metal sleeve

66

Plug under ( 66 )

67

solder pad

68

Metal insert (Thermode)

69

cylindrical part of 68

70

Subject hole / recess

71

conical part of 68

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006035528 A1 [0003]
• DE 102005043279 B4 [0004]

Claims (10)

Arrangement ( 10 ; 30 ; 40 ; 60 ) for the indirect soldering of a connection pin ( 13 ) of a wired component ( 14 ) in a bore ( 12 ; 32 ; 42 ; 62 ) of a mixed printed circuit board ( 11 ; 31 ; 41 ; 61 ) by means of a selective soldering method, which arrangement comprises: - a printed circuit board ( 11 ; 31 ; 41 ; 61 ) with one for the connection pin ( 13 ) and with a metallization ( 15 ; 33 ; 46 ; 65 ) lined bore ( 12 ; 32 ; 42 ; 62 ), - at least one solder pad connected to the metallization of the bore ( 16 ; 34 ; 47 ; 67 ) on a top side ( 17 ; 38 ; 48 ; 63 ) of the printed circuit board ( 11 ; 31 ; 41 ; 61 ), - a thermal conduction device ( 23 ; 37 ; 45 ; 50 ; 66 ; 68 ) to support a heat input in a bottom ( 18 ; 39 ; 49 ; 64 ) of the printed circuit board ( 11 ; 31 ; 41 ; 61 ) and through the printed circuit board ( 11 ; 31 ; 41 ; 61 ) and - at least one solder preform attached to the solder pad ( 22 ). Arrangement ( 10 ; 30 ; 40 ; 60 ) according to claim 1, wherein the selective soldering process is carried out with a wave soldering machine. Arrangement according to claim 1 or 2, wherein the heat conducting device a the bore ( 12 ) on the underside of the printed circuit board ( 11 ) covering polyimide tape ( 23 ). Arrangement ( 30 ) according to claim 1 or 2, wherein the heat-conducting device in the circuit board ( 32 ) arranged in the bore ( 32 ) projecting metallic foil ( 37 ). Arrangement ( 40 ) according to one of claims 1 or 2, in which the heat-conducting device has one in the bore ( 42 ) provided metallized cross-sectional constriction ( 45 ). Arrangement ( 40 ) according to claim 4, wherein the underside ( 49 ) of the printed circuit board ( 41 ) in the area of the bore ( 42 ) with a solder resist ( 50 ) is covered. Arrangement ( 60 ) according to one of claims 1 or 2, wherein the heat conducting device into the bore ( 62 ) from a top side ( 63 ) of the printed circuit board ( 61 ) used cup-shaped metal sleeve ( 65 ). Arrangement ( 10 ; 30 ; 40 ; 60 ) according to one of claims 1 to 6, wherein on the underside ( 18 ; 39 ; 49 ; 64 ) of the mixed PCB ( 11 ; 31 ; 41 ; 60 ) an already soldered SMD component ( 19 ) through a suitable solder mask ( 24 ) is coverable. Arrangement ( 10 ; 30 ; 40 ; 60 ) according to claim 7, wherein the solder mask ( 24 ) in the area of the bore ( 12 ; 32 ; 42 ; 62 ) a recess ( 25 ) for heat input into the printed circuit board ( 11 ; 31 ; 41 ; 60 ) having. Arrangement ( 30 ) according to claim 8, wherein in the recess ( 25 ) of the solder mask ( 24 ) in the area of the bore ( 32 ) a metal insert ( 68 ) for heat input into the printed circuit board ( 31 ) having.

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