JPH0346940A - Lead frame separation mechanism - Google Patents

Abstract

PURPOSE:To hold and separate lead frames completely one by one by installing an arm at the same height as the top surface of a lead frame holding tool in the end of an arm shaft, and providing a wedge facing the end of the arm shaft at the position where the interval from the arm is approximately as wide as the lead frame, at the end of a branched branch shaft. CONSTITUTION:When a box 11 is lowered, arm shafts 21, 22 form clearance ranges because its position is stationary, however, the respective chuck out-of- positions of 19a'', 19b'' and 20a'', 20b'' in a lead frame 1a curved at this time are absorbed by the dovetail parts of claw fixing blocks 13a, 13b, 14a, 14b, and a lead frame 1 is curved without any removal from the chuck parts. When the arm shafts 21, 22 are moved in a direction of c' under this condition, respective wedges 21a, 22b enter the clearances formed at the arm shafts 21, 22, and the respective arms 21a, 22a get out of the lead frame 1a. As a result, the lead frame 1a placed on the top surfaces of holding tools 19a, 19b, 20a, 20b is pushed out in a longitudinal direction.

Description

[Detailed Description of the Invention] [Summary] Regarding the lead frame separation mechanism in the lead frame supply process during semiconductor device assembly, it is possible to reliably hold each lead frame one by one without being affected by irregularities on the peripheral end surface or dimensional variations of the lead frame. For the purpose of improving productivity by A vertically movable housing equipped with a lead frame holder formed with a convex step surface equal to The lead frame holder has a means for moving the lead frame in the longitudinal direction, and the arm shaft has an arm at the tip thereof at a height equal to the top surface of the lead frame holder. At the same time, at the tip of the branch shaft that branches to the left and right from the middle, at a position where the distance from the arm is approximately equal to the width of the lead frame, there is a wedge extending in the direction toward the tip of the arm shaft at a position approximately equal in height to the arm. and configure it.

[Industrial application field]

The present invention relates to a lead frame supply process during semiconductor device assembly, and in particular, lead frame separation that improves productivity by reliably holding each lead frame regardless of irregularities on the peripheral end surface or variations in dimensions. Regarding the mechanism.

In the process of mounting an IC chip onto a glued frame (hereinafter abbreviated as LF), which is one of the assembling processes for semiconductor devices,
A plurality of LFs stacked on a stocker are transferred one by one to a predetermined position, and at the same time an IC chip from another stocker is placed on a predetermined area on the LF to bond them together. Since it is not possible to reliably hold and supply each LF one by one to a predetermined position due to irregularities on the peripheral end surface, variations in dimensions, etc., a solution to this problem is strongly desired.

[Conventional technology]

FIG. 2 is a conceptual diagram explaining the conventional LF separation mechanism,
In order to make it easier to understand, the figure shows the operation sequence of the main parts on the one side that can be displayed in terms of steps, but the opposite side, which is not shown, is configured in the same way.

The explanation will be given below in the order of the figures.

In the figure, ■ indicates a plurality of LFIs, including four fixed guide balls 2 and 9, one on the front side, two on the opposite side (not shown), a total of two arms 3 that move back and forth in the direction shown by the broken line A. This shows the state in which they are stacked and held.

The four guide balls 2 guide the LFI in a planar direction, and when the arm 3 is moved and removed from the bottom of the LFI, the LFI will fall as it is.

Further, on the same surface as the LFla located at the lowest layer on both sides of each of the arms 3, a blade 4a as shown in the circular cross-sectional view (a) is provided on the upper surface side of the tip and the thickness is equal to the LFI, and the broken line As shown in B, there are four first claws 4 that can move forward and backward along the longitudinal direction and up and down, and have approximately the same thickness as the first claws 4, and their tips are as shown in the circular cross-sectional view (b). Na4395a
Four second pawls 5 are provided which are formed as shown in FIG.

Therefore, when the four first pawls 4 are moved forward at the same time as shown by the solid line arrows and the blades 4a at the tips of the pawls 4 bite into the external end surface of the LFla located at the lowest layer, The LF1a is held in a state where it is engaged with the first claw 4 at four locations around the periphery.

Then, when the claws 4 are lowered at the same time, only LFla is bent around the arm 3, and gap areas as shown in (3) are formed at both ends.

Thereafter, the four second claws 5 are moved forward in the direction of the arrows shown by solid lines to insert the pattern 5a formed at the tip of the winter melon 5 into the gap area.

Now, when the first claw 4 and the arm 3 are moved backward as indicated by the arrows, only the LFla located at the lowest layer falls naturally, as shown in It becomes possible to transport.

Thereafter, the arm 3 is moved forward to support the newly lowermost layer LFlb, and the second claw 5 is moved forward.
By retreating, the state shown in ■, that is, the state shown in ■ can be achieved.

By repeating the same operation, each LF is
can be sequentially extracted and transferred to the next process.

However, in such a conventional wafer separation mechanism, the holding force of the first pawl 4 is affected by differences in the unevenness of the peripheral end surface due to differences in the LF forming method (e.g. etching, stamping, etc.), dimensional differences in the peripheral end surface, etc. Due to variations, it may not be possible to form the above-mentioned predetermined gap region.

Further, when the first claw 4 is lowered to form the predetermined gap area, LFla is bent in an arc shape centered on the arm 3 in response to the linear descending movement of the first claw 4. A positional shift may occur between the biting part of the cough claw 4 and LFla, and the holding by the biting of the claw 4 may be removed, making it impossible to form a gap area.

In addition to this LF separation mechanism, the L
There is a method of magnetically attracting and extracting F one by one.

In this case, the device is simple and has the advantage of not being affected by the shape and dimensions of the LF, but it cannot be applied to LFs that do not have magnetism and are made of non-ferrous metals, for example, which limits its application and makes it generally It has some disadvantages.

[Problem to be solved by the invention]

Conventional LF separation mechanisms have the problem of not being able to securely hold the LF due to unevenness and dimensional differences on the peripheral end surface of the LF. There is a problem in that when the LF is lowered, a positional deviation occurs between the LF, which bends in an arc shape, and the chuck by the claws comes off, making it impossible to hold the LF.

[Means to solve the problem]

The above problem is that the lead frame has independent movement means in the width direction of the lead frame in both side regions near both ends in the longitudinal direction, and a convex stepped surface equal to the thickness of the lead frame is formed on the upper surface. It consists of a vertically movable casing equipped with a lead frame holder, and two arm shafts that are provided at approximately the center of the lead frame in the longitudinal direction and can move in opposite directions in the width direction of the lead frame. , the lead frame holder is provided with a means for moving the lead frame in the longitudinal direction, and the arm shaft has an arm at its tip at a height equal to the top surface of the lead frame holder, and branches halfway to the left and right. At the tip of the branch shaft, at a position where the distance from the arm is approximately equal to the width of the lead frame, there is provided a tree extending in the direction toward the tip of the arm shaft at a position approximately equal in height to the arm. solved by the mechanism.

[For production]

If the movements of the claws that hold the cough LF at four locations on the peripheral end surface of the LF in the pressing direction with respect to the peripheral end surface are made independent, the holding force of the claws caused by unevenness, dimensional differences, etc. of the LF peripheral end surface at the pressing part of the claw can be reduced. It is possible to eliminate variations in

Moreover, if the claw portion is made movable along the longitudinal direction of the LF, even if the claw is lowered linearly, the LF, which bends in an arc, can be held at the same location.

In the present invention, two claw fixing blocks that can mutually slide on the same axis via springs are arranged near both ends of the LF in the longitudinal direction, and the LF is mounted on a total of four winter melon fixing blocks.
The structure is such that a claw having the same thickness as the LF is provided and has means for moving in the longitudinal direction of the LF.

Therefore, variations in the holding force of the claws caused by irregularities or dimensional differences on the peripheral end surface of the LF can be suppressed, and the LF can be held securely. Since the same portion of the LF can be maintained as it is, reliable separation and extraction of the LP can be realized.

〔Example〕

FIG. 1 is a conceptual diagram showing a configuration example of a lead frame separation mechanism according to the present invention.

In FIG. 1, a plurality of stacked LFs at 1 and four fixed guide balls at 2 are equivalent to those described in FIG. 2.

Furthermore, the housing 11 having the opposing walls 11a is moved approximately 4 mm in the direction of the arrow (vertical direction in the figure) by a mechanical part not shown.
Two pairs of shafts 12a, 12a' and 12b, 12b' are arranged in parallel at a predetermined pitch between the opposing walls 11a.
are provided, and a shaft 12a forming a pair thereof.

Two claw fixing blocks 13a, 13b and 14a, 14b each having a substantially T-shaped cross section are fitted to each shaft and can move smoothly in the axial direction (direction a in the figure). It is installed.

In the figure, 2 is rotatably fixed to the housing 11.
Opening/closing cams 15 and 16 (16 is not shown because it is located on the left side of the claw fixing blocks 14a and 14b in the drawing) are used to change the spacing between the claw fixing blocks 13a and 13b and 14a and 14b. 17 in the figure and 1 in the corresponding position not shown.
Reference numeral 8 denotes a tension spring that presses the protrusions provided on each of the claw fixing blocks 13a, 13b and 14a, 14b against the cam surfaces of the opening/closing cams 15 and 16.

In this case, by rotating the opening/closing cams 15 and 16, for example, in the R direction in the figure, the claw fixing blocks 13a and 13b and between 14a and 14b can be opened and closed independently.

On the other hand, a dovetail 13a is provided on the upper surface of each of the claw fixing blocks in a direction perpendicular to the moving direction of the block.

13b' and 14a f14b' are formed, and each dovetail portion has a dovetail groove that fits into each of these dovetails.LF holder 19a, 19b, 20a, 20
b is attached.

Furthermore, the LF holders 19a, 19b and 20a,
The upper surface of 20b has convex stepped surfaces 19a', 19b' and 20a that are equal in thickness to the LFI.
', 20b' are formed, and the surfaces parallel to the above-mentioned dovetail grooves of each step diamond surface are blades 19a'', 19b'' and 20a'', as shown in the inner diagram (1).
20b'' is formed.

Therefore, each LF holder 19a, 19b and 20a,
When the opening/closing cams 15 and 16 are rotated with the stacked LFIs placed on the upper surface of the holder 20b, the claw fixing blocks move in the direction a in the figure, and as a result, the holder 1
Convex stepped surfaces 19a, 19b' and 20a' provided on the upper surfaces of 9a, 19b, 20a and 20b.
, 20b' each month 19a'', 19b
",", "20a", and "20b" bite into four locations on the peripheral end surface of LFla located at the lowest layer.

At the same time, each of the above LF holders 19a, 19b and 20
a.

20b can freely move in the direction perpendicular to the moving direction of the claw fixing blocks 13a, 13b, and 14a, 14b, that is, in the direction shown in the figure.

On the other hand, arm shafts 21 and 22 whose ends (not shown) are connected to a mechanism control section and which can move in the same direction as each nail fixing block, that is, in mutually opposite directions as shown in C, penetrate the wall 11a of the casing 11 from both sides. The arms are disposed so that their tips are offset from each other and positioned on the side of the other arm shaft, but movement in opposite directions is performed, for example, via gears (not shown). .

In particular, arms 21a and 22a are provided at the tips of the arm shafts 21 and 22 at a height equal to the upper surface of the LF holders 19a, 19b and 20a, 20b, and extend in a direction perpendicular to the direction of movement of the arm shafts, At the tip of the branch shaft that branches left and right from the middle, &f 21b and 22b are provided, respectively, at approximately the same height as the arm, as shown in the circle diagram (2) in the direction toward the tip of the arm shaft.

Particularly in this case, the distance between the arm 21a and the wedge 21b and the distance between the arm 22a and the wedge 22b are made approximately equal to the width of the LF1.

In the LF separation mechanism having such a configuration, the plurality of LFIs in a stacked state are attached to the LF holders 19a and 19b.
and the upper surfaces of 20a, 20b and the arms 21a, 22
The figure shows this state.

Therefore, as described above, by rotating the opening/closing cams 15 and 16, the LF holders 19a and 19b are moved from the bottom layer to the LF holders 19a and 19b.
and 20a, 20b each month 19a'', 19b
``and 20a'' and 20b''.

In this case, since each of the moons presses the peripheral end surface of the LF1a independently by the tension springs 17 and 18, it is not affected by irregularities or dimensional differences in the portion.

In this state, when the housing 11 is lowered by about 41 degrees in the direction shown in the figure, the arm shafts 21 and 22 remain stationary, so a gap region as shown in FIG. 2 can be formed. 19a"19b" and 20 for each month above
Since the positional deviation of the chucks ``a'' and 20b'' can be absorbed by the dovetail portions, the chuck portions do not come off and the LP can be reliably bent.

In this state, when the arm shafts 21 and 22 are moved in the direction of force C' shown in the figure, the wedges 21a and 22b enter the gaps and the arms 21a and 22a are separated from the LF1a, resulting in the state shown in Figure 2 (2). .

When the opening/closing cams 15 and 16 described above are operated to remove the chuck of each month, only the LF1a is removed from the pFLF holder 19a.
, on the top surface of 19b and 20a, 20b! ! Since the LF1 is placed in the
Only a can be pushed out in the longitudinal direction.

Thereafter, while raising the housing 11, the arm shafts 21 and 22
can be moved in the direction of cIt to return to the state shown in the figure, that is, the initial state.

[Effects of the Invention] As described above, the present invention provides a lead frame separation mechanism that improves productivity by reliably holding lead frames one by one regardless of irregularities on the peripheral end surface or variations in dimensions. be able to.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing a configuration example of a lead frame separating mechanism according to the present invention, and FIG. 2 is a conceptual diagram illustrating a conventional lead frame separating mechanism. In the figure, 1.1a is a lead frame, 2 is a guide ball, 11 is a housing, lla is a wall, 12a, 12a'
, 12b, L2b' is the axis, 13a, 13b, 1
4a, 14b are claw fixing blocks, 13a',
13b', 14a', 14b' are ants, 15
17 is an opening/closing cam, 17 is a tension spring, 19a, 19b,
20b is a lead frame holder, 19a, 19b
', 20b' are convex stepped surfaces, 19a'', 1
9b", 20b" are blades, 21.22 are arm shafts, 2
1a and 22a represent arms, and 21b and 22b represent models, respectively.

Claims (1)

[Claims] The lead frame (1) has independent movement means in the width direction of the lead frame (1) in both side regions near both ends in the longitudinal direction, and has an independent moving means in the width direction of the lead frame (1) on the upper surface. Convex stepped surfaces equal to the thickness (19a', 19b', 20a'
, 20b') are formed on the lead frame holder (
19a, 19b, 20a, 20b) that can be moved up and down, and a housing (11) that can be moved vertically, and a casing (11) that can be moved up and down in the width direction of the lead frame (1), which is provided at approximately the center in the longitudinal direction of the lead frame (1). It consists of two movable arm shafts (21, 22), and the lead frame holder (19a, 19b, 20a,
20b) is provided with a means for moving in the longitudinal direction of the lead frame (1), and the arm shafts (21, 22) have a height equal to the top surface of the lead frame holder (19a, 19b, 20a, 20b) at the tip thereof. The arms (21a, 22a) are provided at the positions, and the arms (21a, 22a) are provided at the tips of the branch shafts that branch from the middle to the left and right, and the distance from the arms (21a, 22a) is approximately equal to the width of the lead frame (1). (21a, 2
The arm shafts (21, 22) are located at approximately the same height as 2a).
) A lead frame separation mechanism characterized by being provided with wedges (21b, 22b) directed toward the tips of the lead frames.