JP2001250981A - Light emitting element array chip and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting element array chip and its manufacturing method that array adjacent overlapping chips zigzag chips at a distance, which is as short as possible and constant, and shorten the time needed for die bonding. SOLUTION: The light emitting element array chip having light emission points 11 arrayed linearly on the top surface of a rectangular chip is characterized by that the surface-side edge of one long side of the rectangular chip is formed acutely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light emitting element array chip and a method of manufacturing the same, and more particularly, to a light emitting element array chip used for an electrophotographic print head and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic print head (printer head) is known as a light emitting device formed by connecting a plurality of light emitting element array chips (array chips).
This printer head currently has a resolution of 600 dpi.
(Dots per inch), but development with a higher resolution of 1200 dpi is also in progress.

FIGS. 2A and 2B show an arrangement state of a conventional array chip. FIG. 2A is an explanatory view of a linear arrangement, and FIG. 2B is an explanatory view of a staggered arrangement. As shown in FIG. 2A, for example, in the case of a printer head having a resolution of 600 dpi, a plurality of array chips 1 are arranged such that a plurality of light emitting points 2 linearly arranged on each array chip 1 have the same arrangement interval. Can be connected in a straight line so as to be connected in a straight line while holding.

However, a higher resolution, for example, 12
In the array chip 3 of 00 dpi, the arrangement interval of the light emitting points 4 is narrower than the array chip 1 (see (b)). Therefore, when the array chips 3 are connected in the same manner as the linear arrangement of the array chips 1, the light emitting points 4 of the adjacent array chips 3 are arranged at the same interval. The very close vicinity of the located light emitting point 4 must be cut off. It is technically very difficult to perform such cutting during dicing.

Therefore, in order to avoid such cutting,
It is known to perform a staggered arrangement in which the positions of the array chips are shifted so as to overlap each other, that is, in a so-called staggered state (see JP-A-8-216448).

This is because, as shown in FIG. 2B, the length of the array chip 3 is made longer than that in the case of performing the linear arrangement, and the odd-numbered array chip 3-1 and the even-numbered array chip 3-1 are arranged. The direction of 3-2 is changed by 180 degrees, and the two sides are arranged in a staggered state so that both ends are back to back.

In this case, the straight line connecting the centers of the light emitting points 4 of each array chip 3 is not a single straight line but two parallel straight lines a and b, but a line between the two straight lines a and b. It is desirable that the distance be as short and constant as possible.

FIGS. 3A and 3B show an array chip for performing the staggered arrangement of FIG. 2, wherein FIG. 3A is an explanatory diagram of dicing, and FIG. As shown in FIG. 3, when the array chips 3 are arranged in a staggered manner, the dicing blade 6 is positioned with respect to the array chips 3 on the dicing tape 5 so that the cutting direction is substantially perpendicular to the chip surface 3a. Then, the array chip 3 is cut (see (a)), and the cut array chip 3 is placed between adjacent chips (3-1, 3-2).
3-2) are arranged in a staggered state with the cut end faces 3b on the light emitting point 4 side facing each other (see (b)).

[0009]

However, when the array chip 3 is cut by ordinary dicing, burrs (back burrs) 7 are formed on the back side edges of the array chip 3 after cutting.
Inevitably occur. In the normal dicing, the dicing blade 6 is cut at a right angle to the chip surface 3a and just in the dicing tape attached to the back surface.

Therefore, when the array chips 3 are arranged in a staggered manner, the back burrs 7 hinder the cut end faces 3b from completely contacting each other, and the adjacent array chips 3-1 and 3- A gap is created between the two (Fig. 3
(B)). Such an adjacent array chip 3-1
The gap between 3 and 2 also occurs due to wear of the dicing blade 6 due to repeated dicing.

FIG. 4 shows another example of an array chip for performing the staggered arrangement of FIG. 2, (a) is an explanatory diagram of dicing,
(B) is an explanatory view of an arrangement state. As shown in FIG.
When the dicing blade 6 is worn, the array chip 3 is cut by the dicing blade 6 whose tip side has become thinner and thinner with the wear (see (a)). On the other hand, the cut end face 3b formed substantially at a right angle is formed into a curved surface at an obtuse angle with respect to the chip surface 3a in accordance with the thin front end side shape.

Therefore, the array chip 3 after cutting is placed in a staggered state in which adjacent chips (3-1, 3-2) face each other with the cut end face 3b on the light emitting point 4 side (see (b)). In this case, since the front side edge is obtuse, the back side edge portion disturbs and the cut end faces 3b cannot be brought into complete contact with each other.
A gap is formed between -1 and 3-2 (see (b)).

That is, the back burr 7 (see FIG. 3) and the obtuse angle of the front side edge (see FIG. 4) are generated, so that when the array chips 3 are arranged in a staggered manner, the adjacent chips which are adjacent to each other and overlap with each other It is difficult to reduce the distance between (3-1, 3-2) to a point where they are completely in contact with each other. Also, even if the adjacent chips can be brought into contact with each other, a constant contact state at the same distance does not occur.

FIG. 5 shows a state of occurrence of a problem when the conventional dicing array chips are arranged in a staggered manner.
(A) is an explanatory diagram of a defect (No. 1), and (b) is an explanatory diagram of a defect (No. 2). As shown in FIG.
For example, when the back burr 7 (see FIG. 3) occurs and the adjacent array chips (3-1, 3-2) do not come into a constant contact state, the array chips 3 arranged in an inclined manner.
1 appears, and the array chips 3-1 and 3
The two straight lines a and b connecting the centers of the -2 light-emitting points 4 are not parallel straight lines.

In addition, since the array chips 3 arranged in an inclined manner are not taken out, as shown in FIG. 5B, contact between the array chips (3-1, 3-2) to be back-to-back occurs. However, in this case, not only the distance between the two straight lines a and b is increased, but also the positioning performed by pressing the array chip 3 cannot be performed. The time required for bonding becomes very long.

An object of the present invention is to provide a light emitting element array chip capable of performing a staggered arrangement in which the distance between adjacent overlapping chips is made as short and constant as possible, and furthermore, the time required for die bonding can be shortened. It is to provide a manufacturing method.

[0017]

In order to achieve the above object, a light emitting element array chip according to the present invention is a light emitting element array chip having a plurality of light emitting points linearly arranged on the surface of a rectangular chip. A surface side edge of one long side of the rectangular chip is formed at an acute angle.

With the above structure, a light emitting element array chip having a plurality of light emitting points linearly arranged on the surface of a rectangular chip has a long edge on one long side of the rectangular chip formed at an acute angle. Is done. This makes it possible to perform a staggered arrangement in which the distance between the overlapping and adjacent chips is made as short and constant as possible, and furthermore it is possible to reduce the time required for die bonding.

Further, the above light emitting element array chip can be manufactured by the method for manufacturing a light emitting element array chip according to the present invention.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show a light emitting element array chip according to an embodiment of the present invention. FIG. 1A is an explanatory diagram of dicing, and FIG. 1B is an explanatory diagram of an arrangement state. As shown in FIG. 1, an array chip (light emitting element array chip) 10 is cut into individual rectangular pieces including light emitting points 11 by dicing (see FIG. 1A). -1, 10-2) are arranged back to back (see (b)).

A plurality of the array chips 10 are connected in a staggered arrangement in a so-called staggered state in which the array chips 10 are arranged back-to-back with their positions shifted so as to partially overlap each other (FIG. 2 ( b)) to form an electrophotographic print head (printer head) as a light emitting device.

By connecting a plurality of array chips 10 in a staggered arrangement, two straight lines a and b connecting the centers of a plurality of light emitting points 11 linearly arranged on the chip surface of each array chip 10. Is a parallel straight line (see FIG. 2B). The light emitting point 11 is arranged in parallel with one long side of the rectangular chip and on the side closer to one long side with respect to a chip center line parallel to the one long side.

When the array chip 10 is cut into individual pieces by dicing, the dicing blade 13 is positioned with respect to the array chip 10 on the dicing tape 12 so that the cutting direction is inclined at a predetermined angle with respect to the chip surface 10a. Then, the long side of the array chip 10 is cut.
At this time, the dicing blade 13 tilts the tip so as to be below the adjacent light emitting point 11, that is, into the adjacent light emitting point 11 side, and the cut end face 10b of each array chip 10 on the light emitting point 11 side is , All, chip surface 10a
(See (a)).

That is, when the array chips 10 are arranged in a staggered arrangement, the angle of the long side edge on the side that comes into back-to-back contact with the adjacent chip is the angle between the cut end face 10b on the light emitting point 11 side and the chip surface 10a. α, that is, the angle of the front side edge of one long side of the rectangular chip is an acute angle, and the angle β formed with the chip back surface 10c is an obtuse angle ((b)
reference).

As a result, it is possible to prevent the contact position of the array chip 10 that is in contact with the array chip 10 from becoming unstable due to the back burr or the thinning of the dicing blade 13. Even if back burr occurs, the contact position will not be affected unless the amount of protrusion from the chip back surface 10c protrudes outward from the edge of the chip surface 10a. The cut end face 10b functions sufficiently if it is shifted inward by about 1 degree with respect to the vertical line. The cut shape of the other long side and both short sides is not particularly defined.

The length L of the array chip 10 is represented by L ₀ where L ₀ is the length obtained by dividing the effective length of the printer head to be manufactured by connecting the array chips 10 by the number of chips to be connected. <L <2L ₀ ,
Preferably, from _{L = L 0 + 0.2mm L =} 1.5L 0
The degree is appropriate. The width and thickness of the array chip 10 are not particularly limited.

As a result, a stable staggered arrangement becomes possible. If a small number of chips malfunction due to some cause after a wire bonding process or the like, it is necessary to remove these abnormal chips for repair. Can also be easily done.

When the light emitting points 11 are arranged at positions deviated from the center of the array chip 10, the long side edges that are in contact with the adjacent array chips 10 in a staggered arrangement are:
The edge closer to the light emitting point 11 is better, and the position of the light emitting point 11 is better as close to the cutting edge as possible. As a result, the distance between two straight lines a and b (see FIG. 2B) connecting the centers of the light emitting points 11 of the respective chips 10 becomes shorter.

In order to sharpen the specified long side edge, the attachment of the spindle of the dicer is adjusted to a position at an angle from the horizontal, and the array chip 10 is cut in this state. The cut end face of the long side edge which is formed by cutting and is opposed to the long side edge processed into an acute angle is not specially defined, but in an actual cutting step, separation from an adjacent chip is performed by one cut. , Automatically becomes obtuse.

When the array chips 10 are arranged in a staggered arrangement, it is required that the long side edge that comes into contact with the adjacent chip back to back has sufficient positional accuracy with respect to the light emitting point 11. Therefore, when dicing is performed, the reference of the cutting position is set so that the center position of the cutting groove (kerf) is not fixed, but the edge position on the chip surface 10a side, which becomes an acute angle by cutting, is fixed. .

As a result, even if the blade thickness of the dicer varies, the acute edge position becomes constant, and the edge position of each cut array chip 10 does not vary. With the stable edge position,
When arranged in a staggered pattern to be back to back, the array chip 10
The two straight lines a and b connecting the centers of the light-emitting points 11 are substantially parallel, and the distance between the lines becomes stable and constant (FIG. 2B).
reference). And adjacent chips that are back to back,
The surface side edge of the cut end face 10b comes into close contact.

When the cut array chips 10 are arranged in a staggered manner, first, the odd-numbered array chips 10 (for example, 10-1) are arranged linearly with a space therebetween and die-bonded. Next, the even-numbered array chips 10 (for example, 10-2) are switched 180 degrees, and are arranged in a staggered state so that both ends of the odd-numbered array chips 10 are back-to-back. ,
Die bonding is performed (see FIG. 2B). At this time, the position of each array chip 10 is determined by pressing the array chip 10 on the odd-numbered array chip 10 already die-bonded.

That is, the array chip 10 already placed
Since the positioning can be performed by pressing against the die, the time required for the positioning at the time of die bonding is reduced, and the cost is reduced. In addition, since the angle of the cut end face 10b and the cutting position of the edges on the chip surface 10a side that are in contact with each other are both optimized, even if the positional displacement of the array chip 10 occurs, it can be minimized. .

Therefore, when forming a light-emitting device such as an electrophotographic print head (printer head), the odd-numbered chips are arranged and fixed at an interval shorter than the long side of one chip to form an acute angle. The staggered arrangement is formed by contacting the even-numbered chips such that a part of the surface-side edges of the chip long sides contact each other. At this time, each array chip 10
Two straight lines a and b connecting the upper light emitting point 11 become parallel.

As described above, according to the present invention, when the long sides of the array chip 10 are cut, when the array chips 10 are arranged in a staggered manner, the edge angle of the side that comes into contact with the adjacent chip back to back becomes an acute angle. (See FIG. 1 (b)),
A dicer positioning reference is provided so that the calf edge position is constant.

For this reason, when the array chips 10 are arranged in a staggered manner, the distance between two straight lines a and b connecting the centers of the light emitting points 11 arranged in two rows can be made as short as possible. This is because the staggered array chips 10 can be brought close to each other until they come into contact with each other.

When the array chips 10 are arranged in a zigzag pattern, the variation in the distance between the two straight lines a and b is reduced. This is because the edge on the chip surface 10a side should be formed at an acute angle so that the burr of the back surface edge generated at the time of dicing and the obtuse angle of the cutting edge due to wear of the dicing blade 13 do not affect the positional accuracy between the array chips 10. This is because the cutting is performed, and the positioning reference of the dicer is provided so that the edge position where the array chips 10 contact each other is constant.

Furthermore, when a plurality of array chips 10 are arranged and die-bonded to manufacture a printer head as a light-emitting device, the time required for die-bonding can be shortened. This means that the even-numbered array chip 10 is replaced by the odd-numbered array chip 10.
This is because the position is determined by pressing against, and the sequence required for positioning can be reduced.

That is, after performing the staggered arrangement for making the distance between adjacent chips as short and constant as possible, the adjacent chips are brought into direct contact with each other to position the array chip 10, thereby reducing the time required for die bonding. it can.

In the above embodiment, a light emitting element array chip for a printer head is described. However, the present invention is not limited to this. For example, a light receiving element array chip used for a light emitting device such as an image sensor may be used. The same can be applied.

[0042]

As described above, according to the present invention, a light-emitting element array chip having a plurality of light-emitting points linearly arranged on the surface of a rectangular chip can be provided on one long side of the rectangular chip. Since the front surface side edge is formed at an acute angle, a staggered arrangement in which the distance between adjacent overlapping chips is as short and constant as possible is performed, and the time required for die bonding can be reduced.

Further, the light emitting element array chip can be manufactured by the method for manufacturing a light emitting element array chip according to the present invention.

[Brief description of the drawings]

FIGS. 1A and 1B show an array chip according to an embodiment of the present invention, wherein FIG. 1A is an explanatory diagram of dicing, and FIG. 1B is an explanatory diagram of an arrangement state.

FIG. 2 shows a connection state of a conventional array chip, and FIG.
Is an explanatory diagram of a linear array, and (b) is an explanatory diagram of a staggered array.

FIG. 3 shows an array chip for performing the staggered arrangement of FIG. 2;
(A) is an explanatory view of dicing, (b) is an explanatory view of an arrangement state.

4A and 4B show another example of an array chip that performs the staggered arrangement of FIG. 2, wherein FIG. 4A is an explanatory diagram of dicing, and FIG. 4B is an explanatory diagram of an arrangement state.

FIGS. 5A and 5B show a state of occurrence of a defect when the array chips formed by the conventional dicing are arranged in a staggered manner. FIG. 5A is an explanatory diagram of the defect (Part 1), and FIG. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Array chip 10a Chip surface 10b Cutting end surface 10c Chip back surface 11 Light emitting point 12 Dicing tape 13 Dicing blade a, b Straight line

Claims (6)

[Claims] 1. A light-emitting element array chip having a plurality of light-emitting points linearly arranged on the surface of a rectangular chip, wherein one long side of the rectangular chip has a surface-side edge formed at an acute angle. A light emitting element array chip comprising 2. The light-emitting point is parallel to the one long side,
2. The light-emitting element array chip according to claim 1, wherein the light-emitting element array chip is arranged on a side closer to the one long side with respect to a chip center line parallel to the one long side. 3. A light-emitting device, wherein a plurality of the light-emitting element array chips according to claim 1 or 2 are arranged in a staggered manner such that the front-side edges formed at acute angles are in contact with each other. 4. The light-emitting device according to claim 3, wherein the light-emitting elements are arranged in a staggered manner so that lines connecting the light-emitting points on the light-emitting element array chips are parallel. 5. A method for manufacturing a light emitting element array chip having a rectangular shape, wherein a long side of the chip is cut while a dicing blade is inclined with respect to the chip surface. 6. An odd-numbered chip is fixedly arranged at an interval shorter than the length of the long side of one chip, and a part of the surface-side edges of the chip long sides formed at an acute angle is in contact with each other.
5. The method for manufacturing a light emitting device according to claim 3, wherein the even-numbered chips are abutted to form a staggered arrangement.