JPH098193A - Front and rear position aligning jig for photomask - Google Patents

Abstract

PURPOSE: To make it possible to finely regulate the front and rear positions of a photomask by sticking the photomask to an outer bush in an aligning jig bush, engaging an aligning jig pin to an inner bush, and finely moving the jig pin and the inner bush. CONSTITUTION: At the times of sticking front and rear aligning jig pins 3 to a glass photomask, sticking it to the photomask and regulating front and rear aligning jig bush 3', the insertion holes 3C', 3C" of an auxiliary frame 3C are engaged with a taper pin member 6. Thus, when an inner bush 13 is finely moved, its insertion hole 14 is finely moved. When the hole 14 is finely moved, the pins 3 are finely moved, the photomask stuck with the pin 3 is finely moved, and the positional deviations of the front and rear patterns of the photomask are corrected. In this manner, the front and rear positions of the photomask can be finely regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask front and back alignment jig, and more particularly to a photomask front and back alignment jig used when a lead frame is manufactured by double-sided etching.

[0002]

2. Description of the Related Art Conventionally, a lead frame has been used for packaging semiconductor integrated circuit (hereinafter referred to as IC) elements. This lead frame is formed by continuously forming a large number of central portions on which IC elements are stacked and a plurality of outer lead portions in the periphery connected to the electrodes on the IC elements, and the central portion and the outer leads. The tip of the is usually plated with precious metal. The lead frame is made of a thin plate or strip of iron, copper, or an alloy thereof, and is subjected to etching using a photomask of the lead frame to remove unnecessary parts, and the tip of the outer lead is exposed. It is manufactured by applying the precious metal plating. In the etching process using the photomask of the lead frame, both front and back surfaces are exposed, and at this time, the front and back of the photomask are aligned.

On the other hand, after the lead frame is assembled,
The outer lead is bent, but at this time, if the lead pattern of the lead frame has a difference in front and back, so-called deviation, the outer lead is bent at an angle, and mounting becomes impossible.

In order to prevent this, in a recent high integration IC, the positional deviation between the front and back of the pattern is 1.
It must be 0 μm or less. Therefore, the relative positional deviation between the front and back surfaces of the photomask has to be ± 10 μm or less when the front and back surfaces are exposed by etching.

The front and back alignment of the photomask will be described in detail with reference to FIGS. FIG. 1 is a schematic plan view of a photomask on each of the front and back sides, and FIG. 2 is a schematic explanatory view of a photomask front and back alignment jig in a conventional technique.
FIG. 3 is a schematic explanatory view of alignment by a photomask front and back alignment jig according to a conventional technique.

In FIG. 1, reference numeral 1 is a front glass photomask and 2 is a back glass photomask. The front glass photomask 1 has two mounting fixing holes 1a,
1b and the back glass photomask 2 are provided with two attachment fixing holes 2a and 2b, respectively.

Further, in the central portions of the photomasks 1 and 2, a pattern to be exposed is, for example, 500 mm × 5.
It is drawn in an area of about 00 mm.

In FIG. 2, (a) is a schematic explanatory view of the front and back positioning jig pins 3a including a partial sectional view, and (b) is a schematic view of the front and back positioning jig bush 3b including a partial sectional view. FIG.

As shown in FIG. 2 (a), the front and back positioning jig pins 3a are formed by winding a stainless spring 5 and a taper pin member 6 which is urged by the wound spring 5 to move up and down. A cylindrical mounting member 8 having the photomask adhesive surface having the lower end portion extending horizontally in the shape of a disk through which the taper pin member 6 is inserted, and a screw provided on the outer surface of the upper end portion of the cylindrical portion of the mounting member 8. Cap 7 to be screwed with the joint
It is composed of As shown in FIG. 2B, the front and back positioning jig bush 3b has a flat plate shape, has an upper surface serving as a bonding surface of the photomask, and has a convex portion at the bottom, and the taper pin member 6 at the center thereof. It has an insertion hole for insertion.

Attachment and fixation of the photomask 1 and the photomask 2 will be described with reference to FIG. In FIG. 3, since the same reference numerals as those in FIGS. 1 and 2 are the same parts, the repetitive description will be omitted and only new reference numerals will be described. 4 is a lead frame material.

The front and back position adjusting jig pin 3a is constructed by inserting the taper pin member 6 into the mounting member 8 and screwing and fixing the cap 7. After that, the taper pin member 6 is inserted into the attachment fixing hole 1a of the front glass photomask 1, and the adhesive surface of the attachment metal 8 is attached to the photomask 1.

The front and back positioning jig bush 3b has its upper bonding surface bonded to the back glass photomask 2.

Since the photomask 1 is provided with two fixing holes 1a and 1b, and the photomask 2 is provided with two fixing holes 2a and 2b, respectively, the front and back positioning jig pins 3a and the front and back positioning jigs are provided. Two bushes 3b are used.

The front glass photomask 1 configured as described above is brought into close contact with the front side of the lead frame material 4, and the back glass photomask 2 is brought into close contact with the back side of the lead frame material 4. Then, the taper pin member 6 is inserted into the insertion hole in the central portion of the front and back positioning jig bush 3b to align the pattern, and a load force such as vacuum drawing is applied to fix the pattern.

The positions of the front and back sides of the photomask are 10 to 1 when fixing the jig pin 3a and the jig bush 3b.
It was usual to confirm with a magnifying glass of about 00 times and then adhere.

Further, the taper pin member 6 and the insertion hole at the central portion of the bush 3b are precisely machined so as not to be displaced once they are positioned.

[0017]

SUMMARY OF THE INVENTION In the above conventional technique,
An adhesive is used to fix the front and back alignment jigs after alignment to the glass photomask.Before the adhesive dries and the pin members of the front and back alignment jigs are fixed. It took a long time. Depending on the type of adhesive used, it took 12 hours.

Further, the above-mentioned conventional technique has the following problems.

When fixing the front and back alignment jigs,
Confirm the position with a magnifying glass of about 100 times and bond it,
This work requires skill. After adhering or fixing, a relative positional deviation of the photomask may be found due to a work error or the like. In that case, the front and back alignment jigs must be removed from the photomask and re-bonded, which is troublesome and requires a long time again.

The present invention has been made in order to solve the above-mentioned problems of the prior art. After the photomask is completely attached to the lead frame material, the front and back position aligning and fixing of the front and back positions of the photomask can be finely adjusted. Its purpose is to provide a tool.

[0021]

In order to achieve the above-mentioned object, the structure of the present invention relating to the front and back alignment jig of a photomask includes an alignment jig pin to be bonded to one photomask and another alignment jig pin. In a front and back alignment jig of a photomask for double-sided etching, which comprises an alignment jig bush that is bonded to the photomask and is fitted with the alignment jig pin, the alignment jig bush is bonded to the photomask. And a member to be fitted to the positioning jig pin, and the member to be fitted to the positioning jig pin is configured to be slightly moved.

[0022]

The function of each of the above technical means is as follows.

According to the structure of the present invention, the positioning jig bush is composed of a member to be bonded to the photomask and a member to be fitted to the positioning jig pin, and to be fitted to the positioning jig pin. Since the member is configured to be moved minutely, as a result, the position adjustment jig pin can be moved minutely and the positional deviation of the photomask can be corrected. This allows the photomask to
For example, it is possible to finely adjust the front and back pattern positions of the photomask after completion of mounting on both sides of the lead frame material, so that it is possible to correct a minute positional deviation of the front and back positions of the photomask once mounted. The completion time of the double-sided photomask can be shortened.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described below with reference to FIGS.

FIG. 4 is a schematic explanatory view of the members of the front / back positioning jig according to one embodiment of the present invention, and FIG. 5 shows the other members of the front / back positioning jig according to the embodiment of the present invention. FIG. 6 is a schematic explanatory view, and FIG. 6 is an auxiliary frame of the front and back alignment jig used in this embodiment. More specifically, FIG. 4 is a schematic explanatory view of the front and back positioning jig pins 3 including a partial sectional view, and FIG. 5A is a front and back positioning jig bush 3 ′ including a partial sectional view. Schematic front view of FIG. 5 (b)
[Fig. 6] is a bottom view of the front and back positioning jig bush 3'shown in Fig. 5 (a).

The front and back alignment jig pins 3 shown in FIG.
The same configuration as the front and back alignment jig pin 3a of FIG.
Since this is a function, and the attachment and completion of the glass photomask 1 and the glass photomask 2 are almost the same, the repetitive description will be omitted.

In this embodiment, the correction of the front / back position misalignment of the mask pattern by the front / back position alignment jig bush 3'of FIG. 5 will be described.

First, the front and back alignment of the mask pattern will be described.

In FIGS. 4 and 5, 3 is a front and back position adjusting jig pin, 3'is a front and back position adjusting jig bush, and 1 '.
0a, 10b, 10c, 10d are horizontal mounting bolts, 1
1a, 11b, 11c, 11d are vertical mounting bolts, 1
Reference numeral 2 is an outer bush, 13 is an inner bush, and 14 is an insertion hole for the front and back alignment jig pins 3 provided in the inner bush.

The outer bush 12 adhered to the glass photomask 2 is fixed by horizontal mounting bolts and vertical mounting bolts, and the inner bush 13 is moved by adjusting the bolts loosely. Then, the bolts are fixed again and the glass photomask 2 is positioned.

In this embodiment, the glass photomask 1 and the glass photomask 2 are attached and completed in the same manner as the front and back alignment jigs 3 and 3'of FIGS. After that, if it is found that the front and back pattern positions of the photomask are, for example, 25 μm, the horizontal mounting bolt 10d and the vertical mounting bolt 11c.
By loosening, the direction A in the figure (from the front of the paper)
Shall be corrected. That is, the inner bush 13
A metal foil having a thickness of 20 μm is sandwiched between and the horizontal mounting bolt 10b, and the horizontal mounting bolt 10d is tightened to position the inner bush 13. In addition, tighten and fix each vertical mounting bolt. As a result, the inner bush 13 is moved by the thickness of the metal foil of 20 μm, and its position is corrected. Tighten each horizontal bolt to fix it, except for the metal foil that was cut off at the end.

Further, the front and back position adjusting jig pins 3 cannot move at their positions themselves. When positioning the inner bush 13 of the front / back positioning jig bush 3 ′, the glass photomask 1 and the glass photomask 2 are combined, or the two front / back positioning jig bushes 3 ′ are inserted. It must be adjusted so that the distance between the centers of the holes 14 does not change.

The above adjustment is performed by using the auxiliary frame of the front and back positioning jig shown in FIG. 6, keeping the distance between the centers of the two front and back positioning jigs constant, and changing only the relative position. Can be reached. The auxiliary frame 3c has through holes 3c 'and 3c "at both ends thereof.
When the front and back alignment jig pins 3 are bonded to the glass photomask 1 and when the front and back alignment jig bushes 3'are adjusted, the insertion holes 3c 'and 3c "and the taper pin member 6 are formed.
And are used by fitting together.

In this way, the inner bush 13 is moved, the insertion hole 14 is moved, and when the insertion hole 14 is moved, the front and back positioning jig pins 3 to be fitted are moved,
The glass photomask 1 to which the front and back alignment jig pins 3 are bonded is moved, and the front and back pattern position shift of the photomask is corrected.

The front and back alignment jig of this embodiment is preferably made of stainless steel because the exposure device is in a clean room. Further, although the case where the number of front and back alignment jigs is two is described, it goes without saying that the number of jigs is not limited to two.

[0036]

As described in detail above, according to the present invention, after the photomask is mounted on both sides of the lead frame material, for example, the front and back position adjustment of the photomask can be finely adjusted. A tool can be provided.

The following effects will be described in more detail.

When it is determined that the front and back positions are misaligned after the photomasks have been attached to both sides of the lead frame material, there is no need to attach the photomasks again, which has the effect of shortening the photomask completion time.

Further, since it is not necessary to peel off and re-bond the front and back alignment jig, the effect of shortening the photomask completion time can be obtained similarly to the above.

Further, after the photomask is attached, the front and back position misalignment is confirmed and finely adjusted, so that the front and back position alignment accuracy is improved.

[Brief description of drawings]

FIG. 1 is a schematic plan view of photomasks on both front and back surfaces.

FIG. 2 is a schematic explanatory view of a photomask front and back alignment jig in a conventional technique.

FIG. 3 is a schematic explanatory diagram of alignment by a photomask front and back alignment jig according to a conventional technique.

FIG. 4 is a schematic explanatory view of members of a front and back alignment jig according to an embodiment of the present invention.

FIG. 5 is a schematic explanatory view of another member of the front and back alignment jig according to the embodiment of the present invention.

FIG. 6 is an auxiliary frame of the front and back alignment jig used in this embodiment.

[Explanation of symbols]

1 Front Glass Photo Mask 2 Back Glass Photo Mask 1a, 1b Attachment Fixing Holes for Front Glass Photo Mask 1 2a, 2b Attachment Fixing Holes for Back Glass Photo Mask 2 3 Front and Back Positioning of this Example Jig pin 3a Conventional front and back alignment jig pin 3'Front and back alignment jig bush 3b of this embodiment 3b Conventional front and back alignment jig bush 3c Auxiliary frame 3c ', 3c "Auxiliary frame insertion hole 4 Lead frame material 5 Stainless steel spring 6 Tapered pin member 7 Cap 8 Cylindrical mounting metal fittings 10a, 10b, 10c, 10d Horizontal mounting bolts 11a, 11b, 11c, 11d Vertical mounting bolts 12 Outer bushing 13 Inner bushing 14 Provided on inner bushing Through hole

Claims (1)

[Claims] 1. A photo for double-sided etching comprising a positioning jig pin to be bonded to one photomask and a positioning jig bush to be bonded to another photomask and fitted with the positioning jig pin. In the mask front and back alignment jig, the alignment jig bush is
The front and back of the photomask, characterized in that it comprises a member to be adhered to the photomask and a member to be fitted with the alignment jig pin, and the member to be fitted with the alignment jig pin is configured to be slightly moved. Positioning jig.