Method for assisting alignment of a pin header

Abstract

The present invention relates to a method and tool for assisting alignment of one or more pin headers. In particular, the invention relates to a tool-assisted method of aiding alignment of one or more pin headers placed on a printed circuit board (PCB) prior to soldering, as well as to the tool itself.

Claims

1. A method of assisting alignment of a pin header prior to soldering, the pin header comprising pins supported by a collar, the method comprising: placing the pin header on a printed circuit board (PCB) such that the pins on a first side of the collar engage the surface of the PCB, and such that the collar contacts the surface of the PCB; and positioning in contact with the pins on the first side of the collar a removable tool so as to exert a force on the pins on the first side of the collar, thereby causing the collar to urge the pins on a second side of the collar into a soldering position.

2. The method of claim 1, wherein the pin header is a right-angled pin header.

3. The method of claim 1, wherein the positioning step comprises removably positioning the tool in contact with the pins of multiple pin headers placed on the PCB, thereby assisting alignment of the multiple pin headers simultaneously.

4. The method of claim 1, wherein the tool comprises a supporting element removably engageable with the PCB, and wherein the method further comprises engaging the supporting element with the PCB.

5. The method of claim 4, wherein the tool comprises a biasing portion joined to the supporting element, and wherein positioning step comprises removably positioning the biasing portion in contact with the pins of the pin header.

6. The method of claim 3, wherein the supporting element is arranged to stabilise the tool when the tool is positioned in contact with the pins of the pin header.

7. The method of claim 3, wherein the supporting element comprises members for engaging with corresponding apertures in the PCB.

8. The method of claim 1, wherein the collar contacts the surface of the PCB at a fulcrum point, and wherein the positioning step comprises removably positioning the tool in contact with the pins on the first side of the collar, thereby urging the pins on the second side of the collar into the soldering position by causing the collar to rotate about the fulcrum point.

9. The method of claim 1, wherein the tool comprises one or more recessed portions, and wherein the method further comprises receiving the collar of the pin header in a recessed portion during positioning of the tool.

10. The method of claim 9, wherein the one or more recessed portions are each sized such that, when receiving the collar of the pin header, a clearance is maintained between the collar and the tool.

11. The method of claim 1, wherein the tool is weighted so as to prevent the pins on the second side of the collar from tending away from the soldering position when the tool is positioned in contact with the pins on the first side of the collar, by exerting an axial force along the pins on the first side of the collar and in a direction of the PCB.

12. The method of claim 1, wherein the centre of gravity of the pin header causes the pins on the second side of the collar to tend away from the soldering position, and wherein the centre of gravity of the tool counterbalances the centre of gravity of the pin header during the positioning step, thereby preventing the pins on the second side of the collar from tending away from the soldering position.

13. The method of claim 1, wherein in the soldering position the pins on the second side of the collar are substantially parallel to the surface of the PCB.

14. The method of claim 1, wherein the positioning step comprises positioning the tool using a pick-and-place machine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention will now be described in connection with the drawings, in which:

(2) FIG. 1 is a side-on view of a typical right-angled pin header;

(3) FIG. 2 is a side-on view of a pin header placed on a PCB prior to soldering;

(4) FIG. 3 is a perspective view of a tool in accordance with a first embodiment of the invention;

(5) FIG. 4 is a cross-sectional view of the tool of FIG. 3 in use with the pin header of FIG. 2;

(6) FIG. 5 is a perspective view of the underside of the tool of FIG. 3, engaged with the PCB;

(7) FIG. 6 is a perspective view of a tool in accordance with a second embodiment of the invention;

(8) FIG. 7 is a cross-sectional view of the tool of FIG. 6 in use with two pin headers placed on a PCB;

(9) FIG. 8 is a second perspective view of the tool of FIG. 6; and

(10) FIG. 9 is a third perspective view of the tool of FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(11) The present invention seeks to provide an improved tool for assisting alignment of one or more pin headers prior to soldering. Whilst various embodiments of the invention are described below, the invention is not limited to these embodiments, and variations of these embodiments may well fall within the scope of the invention which is to be limited only by the appended claims.

(12) FIG. 1 shows a typical right-angled pin header 10. Pin header 10 comprises a yoke or collar 12 supporting a plurality of conductive pins. Pins are divided by collar 12 into a section of substantially straight pins portions 14 and a section of right-angled pins portions 16. In the present embodiment, only two pins are visible, each comprising a straight pin portion and a right-angled pin portion. However, as known to a person skilled in the art, pin header 10 may comprise any number of pins and in particular collar 12 is arranged to support two rows or banks of pins (as seen for example in FIG. 5), with pin portions 14 forming two parallel pin rows, and pin portions 16 forming two rows of right-angled pins shaped in conformity with one another. In other embodiments, there may be other types of pin configurations. For example, the pin header may have only one row of pins, or may have more than two rows of pins. Each pin portion 16 comprises a right-angle-bend 18. Collar 12 is typically formed of plastic but other suitable materials may be used. For the sake of clarity, in what follows, pin portions may be referred to simply as pins, and the two are used interchangeably.

(13) FIG. 2 shows pin header 10 positioned on a PCB 20 prior to soldering. The ends 11 of one row of pins 16 are placed into PCB 20 to anchor pin header 10 in position. Whilst pins 16 are seen to be inserted within PCB 20, it shall be appreciated that in other embodiments pins 16 may merely rest on PCB 20. Collar 12 engages or otherwise contacts PCB 20 at contact point or fulcrum F1. Because of the weight of pin header 10, the ends 13 of the lower bank of pins 14 rest on PCB 20.

(14) It is desirable, prior to soldering, that pins 16 be raised away from PCB 20 such that pins 16 may be maintained substantially parallel to the surface of PCB 20. This may assist correct alignment of the pins of pin header 10, resulting in more precise and less wasteful soldering.

(15) FIG. 3 shows a preferred embodiment of a tool 30 in accordance with the present invention. The underside of tool 30 is shown in FIG. 3. Tool 30 comprises a substantially rectangular biasing portion 32, a recessed portion 34, apertures 36 and a supporting element 38.

(16) Supporting element 38 is joined to and at one end of biasing portion 32 at a right angle. Supporting element 38 comprises a pair of engaging members or feet 39 disposed at both ends of supporting element 38. Recessed portion 34 is substantially elongate and rectangular in shape, and is sized so as to receive therein a typical collar or yoke of a pin header. Rounded end portions 34a and 34b are disposed at the ends of recessed portion 34, with each rounded end portion 34a, 34b comprising a flat portion 34c, 34d against which a collar of a pin header may make contact. Apertures 36 are positioned around the periphery of tool 30, and are used for SMT component placement systems (otherwise known in the art as pick-and-place machines) to locate tool 30 prior to and after positioning. Four apertures 36 are shown in FIG. 3, although the number, placement and dimensions of the apertures may vary depending on many factors, such as the size of tool, its, weight, etc.

(17) Prior to soldering (such as wave soldering, as known in the art), tool 30 is positioned in contact with pin header 10 as shown in FIG. 4. Engaging feet 39 of supporting element 38 are removably slotted or inserted into corresponding apertures in PCB 20, providing support for tool 30. Feet 39 are preferably not engaged in PCB 20 so as to lock tool 30 with PCB 20. Rather, tool 30 is substantially free to pivot or rotate about contact point or fulcrum F2 in a clockwise direction. FIG. 5 shows the underside of PCB 20, with feet 39 of supporting element 38 engaged in slots of PCB 20. Returning to FIG. 4, the forward end of biasing portion 32 contacts pins 16 substantially near right-angled bend 18 of pins 16, thereby exerting a downward, axial force along pins 16 in a direction of PCB 20. In doing so, pin portions 16 act on collar 12 which is rotated or pivoted about fulcrum F1 in a clockwise direction, bringing pin portions 14 into a suitable soldering position. Pin portions 14 in FIG. 4 are shown to be aligned in a substantially parallel direction relative to the surface of PCB 20. In other embodiments, it is envisaged that other suitable soldering positions may exist.

(18) Recessed portion 34 advantageously provides clearance for collar 12 as tool 30 is brought into contact with pin header 10. As illustrated by lines AB and CD, the centre of gravity of tool 30, when tool 30 is positioned in contact with pin header 10, is such as to counterbalance the centre of gravity of pin header 10. In particular, for pin header 10 to be kept in a soldering position, AB must be greater than CD, with: A being the distance from fulcrum point F2 to the centre of gravity of tool 30; B being the weight of tool 30; C being the distance from fulcrum point F1 to the centre of gravity of pin header 10; and D being the weight of pin header 10. Tool 30 initially makes contact with pin header generally along line X. As this line does not lie in the same position as the centre of gravity of tool 30, it is not the total weight of tool 30 that acts on the point of contact with pin portions 16.

(19) In an alternative embodiment of the present invention, FIG. 6 shows a possible second version of the tool. Tool 40 is similar to tool 30 in that it also comprises apertures 46 for a pick-and-place machine, and further includes two elongate recesses 44 sized and shaped to receive collars of pin headers. Recesses 44 comprise rounded end portions 44a and 44c, with each rounded end or rounded end portion comprising a substantially flat portion 44b, 44d. Of note is that tool 40 does not comprise a supporting element. Thus, as explained above, rounded end portions 44a, 44c and flat portions 44b, 44d are advantageous in preventing a pin header collar from interfering with tool 40 should tool 40 shift laterally before or during soldering. In other embodiments, the tool of FIG. 6 could comprise one or more supporting elements.

(20) Tool 40 is suited to assist in the alignment of multiple pin headers simultaneously. As shown in FIG. 7, tool 40 is positioned in contact with pins 16a and 16b of a pair of pin headers 10a and 10b. Prior to tool 40 being positioned in contact with pin headers 10a, 10b, pin headers 10a, 10b, were first placed in pre-soldering positions on PCB 20 much like pin header 10 illustrated in FIG. 2. In such a position, ends 13a and 13b of pins 10a, 10b tended towards non-parallel alignment relative to the surface of PCB 20. As explained above in relation to FIG. 4, tool 40 exerts a downwards pressure or force on pin portions 16a and 16b, proximal right-angle bends 18a and 18b. This force may translate into a force on collars 12a and 12b, thereby causing collars 12a, 12b, to rotate or pivot about fulcrum points F1a and F1b in respective clockwise and counter-clockwise directions, bringing pin portions 14a and 14b into soldering positions, preferably in parallel alignment with PCB 20. Due to the added support provided by dual pin headers, supporting elements generally are not required on tools such as tool 40.

(21) FIGS. 8 and 9 show the upper sides of tools 40 and 30, respectively. The circles show the locations of action of pick-and-place machines. The surfaces of tools 30 and 40 must preferably be smooth enough for the suction action of the machine to operate efficiently.

(22) Any feature of the above-described embodiments may be combined with the features of another embodiment, by making the appropriate changes. Whilst the invention has been described in connection with preferred embodiments, it is to be understood that the invention is not limited to these embodiments, and that alterations, modifications, and variations of these embodiments may be carried out by the skilled person without departing from the scope of the invention. For example, the inventive tool may be shaped and sized so as to assist in the alignment of any number of pin headers, should this be desired. In addition, it is envisaged that the tool could be used to assist in the alignment of other electrical components prior to soldering.