FIELD OF THE INVENTION
This present invention relates to Fixture for holding non rectangular or any
odd shape flex PCB on SMT line (Printer, PICK & PLACE Machine 10 chine & Reflow
Oven) for Populating SMD. More specifically, it relates to a fixture, which may be
used to hold and locate PCB of small size and less thickness.
A more specific object of this invention is to provide the support to the flex
PCB surface and restricts the movement of PCB in X, Y direction. Fixture also
15 used for the alignment of SMD component for soldering and curing in reflow
oven, to achieve desired finish on PCB after assembly.
BACKGROUND OF THE INVENTION
20
This invention pertains to the fixture for holding the flex PCB on SMT Line.
More particularly to a holding fixture adapted to support PCB to apply solder
paste through stencil on printer & for placement of SMD on pick and place
machine. An object of this invention is the provision of a new and improved
25 holding fixture for SMT machine which is rigid, compact, and capable of high
precision holding of flex PCB. This fixture helps to minimize the setup time and
maximize the productivity of Flex PCB through SMT Line.
.
30
Annexure‐II
SUMMARY OF PRESENT INVENTION
5
In accordance with one aspect of present invention is to provide a fixture
that facilitates holding of thin and small size PCB attached with Flex on Pick &
Place machine and reflow oven of SMT line.
In 10 accordance with second aspect of present invention is to provide a
fixture for accurate positioning of Flex PCB with respect to SMT line.
In accordance with another aspect of present invention is provided a
fixture for holding of flex PCB in a manner to restrict in X, Y direction movement
of PCB to enable the precise mounting of SMD component on the flex PCB.
15 In accordance with yet another aspect of present invention is to provide a
fixture for holding Flex PCB that is adapted to propagate through SMT line.
In another embodiment of present invention is to provide a height to the
base plate with respect to guide for proper placement of flex PCB on SMT line.
. In accordance with yet another aspect of present invention is to provide a
20 rigid fixture for holding rigid flex PCB on SMT line for populating SMD.
In accordance with another aspect of present invention is to provide a
lighter fixture for holding rigid flex PCB on SMT line for populating SMD.
In accordance with yet another aspect of present invention is to provide a
fixture that can be properly and effectively utilized to hold and firmly fixed the
25 PCB on SMT line by lesser skilled individuals.
30
Annexure‐II
BRIEF DESCRIPTION OF THE DRAWINGS
5
The features and advantages of the present invention will become more
apparent and descriptive in the description when considered together with
figures/flow charts presented:
Fig.10 1 is a Top view of fixture for holding flex PCB on SMT line machines
Fig. 2 is a Sectional side view of fixture showed Fig.1
Fig. 3 is a Dowel pin of fixture for locating flex PCB on surface of the holding
Fixture.
15
DETAILED DESCRIPTION
Referring to fig. 1, 2 & 3 present inventions is a fixture 11 used to hold and
position the flex PCB 12, adapted to use on SMT line machines. The fixture 11 is
20 designed to hold the PCB 12 within dimensional tolerance with respect to the
edges of the fixture in X, Y direction.
Fixture 11 for holding a PCB 12 comprises a base plate 1 having a
substantially flat top surface A and bottom surface B. Base plate is made of Al
Alloy of 2.0 mm thickness. Surface B of base plate, rest on guide of SMT line
25 machines.
PCB 12 rests on surface A of base plate 1 located in desired place by two
pin 3. Pin 3 made of hardened dowel pin, are fixed on surface A of base plate 1
to position the PCB with respect to the edges of the fixture in X, Y direction..
Surfaces A & surface B of the base plate 1 are made substantially parallel to
30 each other.
Two no. of guide plate 2 made of Glass Fiber fixed on A surface of Base
plate with six no. countersink screw 4 as shown in Fig 1 .This guide plate 2
provides thickness to the fixture 11 to facilitate the holding of fixture on the guide
bed of SMT line machine and provides height same the thickness of PCB 12 for
Annexure‐II
pick & place of SMD components. Threaded holes 5 at six places on base plate 1
are made to fix the guide plate 2 on the surface A of fixture. Six no. of through
counter sink holes 7 are provided on the guide plate 2 to align and fix the guide
plate 2 5 with base plate 1.
Flex. PCB 12 is hold on the base plate 1 of the fixture 11 with the help of
two diagonally placed Holes 6 of diameter 2.5 mm fabricated on the surface A of
the base plate. Dowel pins 3 are used to align, locate and hold the flex PCB 12
on the fixture.
10 Flex PCB 12 are aligned and fixed on the surface A of the fixture 11.
Fixture 11 is then locate and clamped on the guide of SMT machine. Solder
paste is applied on the flex PCB 12 through stencil. After that pick and place
machine place the SMD component at the desired location on the flex PCB. After
the placement of component on, Flex PCB moves to reflow oven for the melting
15 and fixing of solder paste. After cooling finished PCB is obtained.

WE CALIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We Claim

1. A fixture for holding PCB and supporting the surface of PCB adapted to be positioned on guide of solder paste printer, pick & place machine & Reflow Oven. The fixture comprising:
- Base Plate adapted to be coupled to guide plate and provides supporting surface to the other sub component of the fixture.
- Location Pins that holds the PCB to remain in pre determined position with respect to guide & surface of base plate and prevent the X, Y direction movement of PCB.
- Guide plate that provides height to the base plate to facilitate placement of the fixture on the guide of SMT machine line and proper alignment of stencil with respect to Flex PCB.
2. The fixture for holding rigid flex PCB on SMT line for populating SMD of claim 1 wherein, top and bottom surfaces of the base plate are substantially flat and parallel to give surface for proper alignment of Stencil and precise application of solder paste on it.
3. The fixture for holding rigid flex PCB on SMT line for populating SMD of claim 1 wherein, bottom surface of the base plate is adapted to positioned and clamped on the top surface of the SMT line machine.
4. The fixture for holding rigid flex PCB on SMT line for populating SMD of claim 1 wherein, guide plate provides to maintain the height of PCB for the proper alignment of stencil with respect to Flex PCB.
5. The fixture for holding rigid flex PCB on SMT line for populating SMD of claim 5 further comprising diagonally placed dowels pins for alignment of PCB in X-Y direction. ,TagSPECI:As per Annexure-II