JP2009026863A - Printing method of semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily perform precise positioning without using a complicated positioning means and the like, and to perform printing by simple screen printing without using an expensive printing device such as laser equipment in a process for performing printing at the rear face of each chip of a semiconductor wafer. <P>SOLUTION: At the time of performing printing on the rear face so as to correspond to a plurality of semiconductor chips 2 with function regions which are formed on the surface of the semiconductor wafer 1, a part of the semiconductor wafer 1 is cut by two orthogonal straight lines in parallel to orthogonal scribe lines 6 and 7 and two orthogonal positioning cutting edges 8 and 9 which are formed of straight lines are formed. The semiconductor wafer 1 is turned over, and the semiconductor wafer 1 is positioned with respect to the printing device with the two positioning cutting edges 8 and 9 as references. Screen printing is performed on corresponding positions of rear faces of the plurality of semiconductor chips 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor wafer printing method, and in particular, prints identification items of each semiconductor chip such as a product type, a lot number, and a symbol on the back surface of each of a plurality of semiconductor chips in which a functional region is formed on the front surface of the semiconductor wafer. (Also referred to as marking).

  In one semiconductor wafer, usually, a plurality of semiconductor chips (for example, 30,000 semiconductor chips) having a functional region (for example, a Schottky circuit) such as a circuit pattern on the surface are formed. Examples of such semiconductor chips include a wafer level chip size package (WL-CSP), a flip chip (Flip Chip), and the like.

  In such a semiconductor chip, when a plurality of types of semiconductor chips are formed on one semiconductor wafer and then cut to obtain individual semiconductor chips, the type of each semiconductor chip cannot be identified. . In addition, such a semiconductor chip is usually mounted on a circuit board with the surface on which the functional region is formed facing downward. However, after the mounting, the type of the semiconductor chip cannot be identified.

  Therefore, necessary identification items such as product type, lot number, and mark are printed (marked) on the back surface of each semiconductor chip having a functional region formed on the front surface.

  For example, a semiconductor chip obtained by forming a product identification symbol by photoengraving or laser processing on the back surface of a plurality of semiconductor chips on a wafer where element active regions (functional regions) are formed, and cutting and dividing the chip. A configuration for mounting on a circuit board facing downward is known (see Patent Document 1).

  In addition, a configuration in which writing is performed by a laser marking method or the like is known so that an IC pattern surface such as a bump method is mounted on the back surface of the IC chip mounted on the motherboard side (see Patent Document 2). ).

  Furthermore, after the step of forming a plurality of chip formation regions having circuits on the surface of the semiconductor wafer, and before the step of forming the bump electrodes on each chip formation region, the semiconductor corresponding to each chip formation region A method for manufacturing a semiconductor device is known, which includes a step of forming an identification mark by a laser marking method or an ink marking method in a region on the back side of a wafer, respectively (see Patent Document 3).

  In addition, after semiconductor test | inspection, based on the test result, the structure which discharges the liquid for marking to a semiconductor wafer by an inkjet printing method and performs uniform marking is known (refer patent document 4).

JP 58-175820 A JP-A-4-106960 JP 2000-294607 A JP 2004-096097 A

  The means for printing (marking) the product type, lot number, mark, etc. on each chip of the semiconductor wafer is conventionally known as described above, but the back surface corresponds to each chip having the functional area formed on the surface. In order to print on, it must be accurately positioned.

  However, in the above prior art, a positioning mark or the like must be attached to the back surface, and the positioning must be performed by optical reading or the like, and the structure of the positioning means therefor is complicated. there were.

  In addition, laser devices used for conventional printing (marking) are expensive, and laser devices for semiconductor wafers that are necessary for printing predetermined characters, marks, etc. at predetermined positions on each chip of the semiconductor wafer. The positioning means and the like are also complicated and expensive as described above, and particularly when used for printing each chip of a semiconductor wafer produced in a small quantity of other varieties, there is a problem in terms of profitability.

  The present invention realizes a method that enables easy and accurate positioning without using complicated positioning means, etc., for positioning required when printing on the back surface of each chip of the conventional semiconductor wafer, Moreover, it is an object to realize a semiconductor wafer printing method using simple screen printing or ink jet printing without using an expensive printing device such as a laser device.

  In order to solve the above-described problems, the present invention provides a semiconductor wafer that is divided into a large number of chips by cutting a scribe line, and a back surface corresponding to each of the large number of chips having functional regions formed on the front surface. A method of printing a semiconductor wafer for printing, wherein a part of the semiconductor wafer is cut by two straight lines to form two positioning cutting edges, the semiconductor wafer is turned over, and the two positioning is performed. A method for printing a semiconductor wafer is provided, wherein the semiconductor wafer is positioned with respect to a printing apparatus with reference to a cutting edge for printing, and printing is performed at the position of the back surface corresponding to each of the plurality of chips.

  In order to solve the above-described problems, the present invention provides a semiconductor wafer that is divided into a large number of chips by cutting a scribe line, and a back surface corresponding to each of the large number of chips having functional regions formed on the front surface. A method for printing a semiconductor wafer for printing, wherein a part of the semiconductor wafer is cut by two straight lines orthogonal to each other in parallel to a scribe line orthogonal to each other, and two positionings each consisting of a straight line and orthogonal to each other Forming a cutting edge for the semiconductor wafer, turning the semiconductor wafer upside down, positioning the semiconductor wafer with respect to the printing apparatus with reference to the two cutting edges for positioning, Provided is a method for printing a semiconductor wafer, wherein printing is performed.

  It is preferable that the portions to be cut in order to cut the semiconductor wafer to obtain two positioning cutting edges are in regions where no chips are formed on the semiconductor wafer.

  The portions to be cut to cut the semiconductor wafer to obtain two positioning cutting edges may be scribe lines at the ends of the semiconductor wafer.

  The printing is preferably performed by screen printing.

  The mask used in the screen printing apparatus is formed with one or two or more long and narrow slits formed on two straight lines orthogonal to each other, and all the long and narrow slits are aligned with the positioning cutting edge. The mask is preferably positioned with respect to the semiconductor wafer.

  The printing is performed by ink-jet printing, and in the ink-jet printing, an ink-jet printing apparatus based on the positioning cutting edges so that an ink-jet head moves relatively in parallel to scribe lines orthogonal to each other of the semiconductor wafer. It is good also as a structure which positions.

The semiconductor wafer printing method according to the present invention produces the following effects.
(1) Since printing is performed on the back surface of each chip of the semiconductor wafer, it is possible to easily perform accurate positioning without using complicated positioning means or the like.
(2) Since it is not necessary to use expensive and complicated markings such as a laser device, it is economical, and is extremely useful particularly in the case where a large variety of semiconductor chips are produced from a semiconductor wafer.

(3) If the scribe lines perpendicular to each other are diced at the upper and side edges of the semiconductor wafer, the positioning cutting edge can be obtained more easily and accurately, and the semiconductor wafer printing method of the present invention is easier. And can be implemented accurately.

  The best mode for carrying out a semiconductor wafer printing method according to the present invention will be described below with reference to the drawings based on the embodiments.

(The entire)
FIG. 1A is a plan view showing a semiconductor wafer 1 (silicon wafer) printed on the back surface thereof by the semiconductor wafer printing method according to the present invention. The semiconductor wafer 1 has a plurality of (for example, 30,000 semiconductor chips having a size of about 1 × 1 mm) having functional areas such as circuit patterns (for example, Schottky circuits and integrated circuits), bump electrodes, and the like on the surface. ) Semiconductor chip 2 has already been formed.

  As the semiconductor chip 2, for example, a functional area on the surface thereof such as a wafer level chip size package (WL-CSP), a flip chip (Flip Chip) or the like is directed to the circuit board, and a bump electrode is provided on the circuit board. It is electrically attached and mounted via. With the semiconductor wafer printing method according to the present invention, predetermined identification items, etc. are printed on each semiconductor chip 2 such as product type, lot number, and mark corresponding to the position of each semiconductor chip 2 on the back surface of the plurality of semiconductor chips 2. Is done.

(Dicing cutting edge for positioning)
In the method for printing a semiconductor wafer according to the present invention, first, the vertical and horizontal scribe lines 6 and 7 are parallel at two locations 4 and 5 in the peripheral region 3 where the semiconductor chip 2 of the semiconductor wafer 1 is not formed. Cut along straight lines 12 and 13 in the vertical and horizontal directions perpendicular to each other (see the dashed line in FIG. 1B).

  As a result, on the back surface of the semiconductor wafer 1 cut along a straight line (which is of course also on the front surface), as shown in FIG. 1 (b), each consists of straight lines parallel to the vertical and horizontal scribe lines 6 and 7, respectively. Two positioning cutting edges 8 and 9 which are orthogonal to each other are formed.

  The semiconductor wafer 1 is cut by dicing (cutting with a diamond blade) by attaching the semiconductor wafer 1 on a cutting work table using a tape and using the chip surface pattern as an alignment. In this dicing process, cutting is performed by straight lines 12 and 13 (see the alternate long and short dash lines in FIG. 1B) in the vertical and horizontal directions orthogonal to each other so as to be parallel to the vertical and horizontal scribe lines 6 and 7. Therefore, the semiconductor wafer 1 must be positioned so that the direction of the diamond blade (cutting direction) and the scribe lines 6 and 7 are parallel.

  Specifically, using a known dicing apparatus that is commercially available, alignment is performed on a scribe line formed on the wafer surface, and the straight lines 12 and 13 that are orthogonal to each other may be cut.

  By the way, one of the two positioning cutting edges 8 and 9 may use the orientation flat 15 (commonly referred to as “orientation flat”) of the semiconductor wafer 1. That is, as shown in FIGS. 1A and 1B, a part of the semiconductor wafer 1 is linearly cut in advance and an orientation flat 15 is formed.

  Therefore, the edge 16 (see FIG. 1C) of the orientation flat 15 on the back surface of the semiconductor wafer 1 is formed of a straight line that is cut completely parallel (or orthogonal) to the scribe lines 6 and 7. If it is an edge, one of the two positioning cutting edges 8 and 9 may use the edge 16 of the orientation flat 15. However, usually, the orientation flat 15 is often cut relatively rough (not a highly accurate direct mounting surface).

(Screen printing)
In the present embodiment, printing on the back surfaces of the plurality of semiconductor chips 2 of the semiconductor wafer 1 is performed by screen printing (silk printing). As described above, the semiconductor wafer 1 on which the two positioning cutting edges 8 and 9 are formed is turned over and placed on the screen printing support base 17 in FIG.

  As shown in FIGS. 2A and 2B, the screen printing support 17 includes a rectangular support frame 19 into which a rectangular screen mask 18 (hereinafter simply referred to as “mask”) is fitted. A mask support surface 20 for supporting and placing the fitted mask 18 is formed along the inner periphery of the support frame 19. On the surface of the support surface 20 of the mask, a wafer support recess 21 for fitting and supporting the semiconductor wafer 1 is formed.

  A shallow step surface 22 is formed along the inner periphery of the recess 21 for supporting the wafer. When the semiconductor wafer 1 is turned upside down and fitted into the wafer support recess 21, a portion of the region 3 where the semiconductor chip 2 is not formed is in contact with and supported by the step surface 22.

  A bottom portion 23 having a depth that does not come into contact with the surface of the functional region of any semiconductor chip 2 is formed in a portion inside the stepped surface 22 in the recess 21 for supporting the wafer. The tip of the tube 24 for use is open. The proximal end of the tube 24 is connected to a vacuum pump 25.

  Since the support base 17 for screen printing is configured as described above, the semiconductor wafer 1 can be sucked and held by the vacuum pump 25 if the semiconductor wafer 1 is turned upside down and fitted into the recess 21 for supporting the wafer. Once the semiconductor wafer 1 is fitted and positioned in the wafer support recess 21, the position does not shift even when an external force is applied in screen printing.

  In this way, after the semiconductor wafer 1 is turned upside down and supported on the support base 17 with the surface having the functional region facing downward, as shown in FIGS. 2 (c) and 2 (d), the semiconductor wafer 1 The mask 18 is placed on the back surface and the mask support surface 20 so as to fit into a rectangular support frame 19.

  FIG. 3A is a plan view showing the mask 18. The mask 18 is formed of a thin plate (thickness of about 10 μm) of metal (for example, a material such as SUS), and the periphery thereof is reinforced and supported by a reinforcing frame 26. The mask 18 is formed with a screen printing stencil 27 for printing predetermined items such as a product type, a lot number, and a mark on each of a plurality of semiconductor chips.

  Specifically, when the mask 18 is positioned and placed on the semiconductor wafer 1, the product type, lot number, mark, and the like are printed on each semiconductor chip 2 at the position on the back surface corresponding to each semiconductor chip 2. A fine character hole 27 ′ for displaying a character for displaying a predetermined identification item is formed.

  Further, the mask 18 is a position corresponding to the region 3 where the semiconductor chip 2 of the semiconductor wafer 1 is not formed, and is orthogonal to each other when the mask 18 is positioned and placed on the semiconductor wafer 1. One or two or more long and narrow positioning slits 28 and 29 are formed at positions on the lines 12 ′ and 13 ′ corresponding to the two positioning cutting edges 8 and 9 (FIG. 3A). 3 is formed in (b)). Each dimension of the positioning slits 28 and 29 is, for example, about 0.20 × 1.0 mm.

  When the mask 18 is fitted into the support frame 19 and placed on the semiconductor wafer 1 and the support surface 22, the positioning slits 28 and 29 are formed by the two positioning cutting edges 8 perpendicular to each other of the semiconductor wafer 1. , 9 and the support base 17 is formed in advance so that the two positioning cutting edges 8, 9 can be visually recognized from above through the positioning slits 28, 29.

  However, when the positioning slits 28 and 29 and the positioning cutting edges 8 and 9 are slightly displaced, the mask 18 is slightly moved within the support frame 19 to position the positioning slits 28 and 29 and the positioning cutting edges 8 and 9. Tweaks to match exactly.

  In this way, the mask 18 is fitted into the support frame 19, placed on the back surface of the semiconductor wafer 1 and the mask support surface 22, finely adjusted, and completely positioned, and then mounted on the support frame 19. The reinforcing frame 26 of the mask 18 is fixed by the screw 19 '. As a result, the mask 18 is also positioned and fixed, and is not displaced during screen printing.

  After placing the mask 18 on the back surface of the semiconductor wafer 1 in this manner, a roller (not shown) coated with ink on the mask 18 is rolled. Thus, printing can be performed by applying ink to the back surface of the semiconductor wafer 1 through the stencil 27 of the mask 18. As the ink, it is preferable to use a durable epoxy ink.

  By the semiconductor wafer printing method according to the present invention comprising the above steps, the type, lot number, mark, etc. are misaligned at each position on the back surface corresponding to each semiconductor chip 2 formed on the front surface of the semiconductor wafer 1. It is possible to print accurately and easily without the need for printing.

  A second embodiment of the semiconductor wafer printing method according to the present invention will be described below. In the second embodiment, as in the first embodiment, identification items such as a product type, a lot number, and a mark are printed on the back surface of a plurality of semiconductor chips 2 having a functional area such as a circuit pattern on the front surface. The specific steps and the like are almost the same as those in the first embodiment.

  However, in the second embodiment, unlike the first embodiment, the semiconductor wafer 31 to be printed is different from the first embodiment in that the functional regions of the plurality of semiconductor chips 2 are formed on the entire surface of the semiconductor wafer 31 as shown in FIG. Is formed. In short, the semiconductor wafer 31 of the second embodiment does not include the region 3 in which the functional regions of the plurality of semiconductor chips 2 are not formed, unlike the semiconductor wafer 1 of the first embodiment.

  In the second embodiment, in order to obtain two positioning cutting edges 8 and 9 each consisting of a straight line and orthogonal to each other, as shown in FIG. In the embodiment, it is the left end portion, but it may be the right end portion.) The scribe lines 32 and 33 orthogonal to each other are diced.

  According to the second embodiment, unlike the first embodiment, it is not necessary to provide an alignment work and a device for the same so that the straight lines 34 and 35 in the cutting direction of the diamond blade are parallel to the scribe lines 32 and 33. Therefore, the two positioning cutting edges 8 and 9 orthogonal to each other can be obtained with a simpler work and apparatus.

  A third embodiment of the semiconductor wafer printing method according to the present invention will be described below with reference to FIGS. In the third embodiment, as in the first embodiment, printing is performed on the back surfaces of a plurality of semiconductor chips 2 having a functional region such as a circuit pattern on the front surface, and a series of specific steps are performed. It is almost the same as Example 1.

  However, the third embodiment is different in that the printing unit is not screen printing as in the first embodiment but an inkjet printing apparatus. Specifically, the configuration is as follows. The third embodiment includes an XY movable table device 36. The XY movable table device 36 has a positioning support table 38 that supports the semiconductor wafer 1 and moves relative to the inkjet head 37 of the inkjet printing apparatus in the XY direction.

  In the XY movable table device 36, the groove 42 of the X direction movable table 41 is slidably mounted on the ridge guide rail 40 formed on the upper surface of the base 39, and the X direction movable table 41 moves in the X direction. Is possible. Further, the groove 44 of the positioning support base 38 is slidably mounted in the Y direction on the ridge guide rail 43 formed on the upper surface of the X direction movable base 41, and the positioning support base 38 moves in the Y direction. Is possible.

  Although not shown, the X-direction movable table and the positioning support table 38 of the XY movable table device 36 are configured to be movable in the X direction and the Y direction by a feed screw linear motion mechanism, a gear mechanism, a linear motor mechanism, and the like, respectively. ing. An ink jet head 37 of the ink jet printing apparatus is disposed so as to face the XY movable table device 36.

  On the upper surface of the positioning support base 38, a semiconductor wafer support recess 45 is formed for fitting the semiconductor wafer 1 upside down and receiving it. The semiconductor wafer supporting recess 45 is in contact with two positioning cutting edges 8 and 9 orthogonal to each other at the inner peripheral edge of the semiconductor wafer 1, so that the semiconductor wafer 1 is accurately placed in the XY direction with respect to the inkjet head 37. Two positioning straight edges 46 and 47 are formed for positioning relative to each other.

  The semiconductor wafer supporting recess 45 is formed with a bottom 23 so that the functional region of the semiconductor chip 2 does not come into contact with the bottom 23 as in the wafer supporting recess 21 of the first embodiment. A tube 24 connected to the pulling pump 25 is provided so as to open.

  In the third embodiment, as in the first embodiment, two positioning cutting edges 8 and 9 are formed on the semiconductor wafer 1 so as to be orthogonal to each other. It fits into the semiconductor wafer support recess 45 of the support base 38. Thereby, the semiconductor wafer 1 is positioned relatively accurately in the XY direction with the back surface to be printed facing upward and facing the inkjet head 37.

  Then, the semiconductor wafer 1 is moved relative to the inkjet head 37 in the XY direction by the XY movable stand device 36 and printed, so that the kind, lot number, mark, etc. are respectively formed on the back surface of the plurality of semiconductor chips 2. It is possible to print the predetermined identification items. Note that an ink jet printing apparatus that fixes the support base 38 that supports the semiconductor wafer 1 and prints by scanning the ink jet head 37 relatively in the XY directions may be used.

  The best mode for carrying out the method for printing a semiconductor wafer according to the present invention has been described based on the embodiments. However, the present invention is not limited to such embodiments, and the scope of the claims is as follows. It goes without saying that there are various embodiments within the technical scope described.

  In the semiconductor wafer printing method according to the present invention, the two positioning cutting edges 8 and 9 of the semiconductor wafer 1 are formed so as to be orthogonal to each other so as to be parallel to the scribe lines 6 and 7. The two positioning cutting edges 8 and 9 are not necessarily provided if they are positioned with respect to the apparatus and printed on the back surface of each of the plurality of semiconductor chips so that predetermined identification items and the like do not deviate. The lines 6 and 7 may not be formed so as to be orthogonal to each other.

  For example, one positioning cutting edge 8 or positioning cutting edge 9 is formed in parallel to the scribe line 6 or the scribe line 7, and the positioning cutting edge 8 or the positioning cutting edge 9 is different from the other one. The book may be formed at a predetermined angle (eg, 100 degrees). In this case, the semiconductor wafer positioning table in the printing apparatus is also compatible, and the semiconductor wafer needs to be positioned so as to be printed on the back surface of the printing apparatus without shifting predetermined identification items. .

  The semiconductor wafer printing method according to the present invention is configured as described above, and is particularly suitable for printing on the back surface of a semiconductor chip such as a wafer level chip size package (WL-CSP), a flip chip (Flip Chip) or the like. It is useful as a printing method for IC chips and other chips having marks for identifying the history of chips.

(A) is a figure explaining the semiconductor wafer of Example 1 of the printing method of the semiconductor wafer of this invention, (b) is a figure explaining the cutting | disconnection, (c) is a perspective view of a semiconductor wafer. . (A), (b) is the top view and AA sectional drawing of the screen support stand for the positioning for the printing of the semiconductor wafer of Example 1, (c), (d) is a support stand It is the top view explaining the state which set the semiconductor wafer and the mask, and BB sectional drawing. (A) is a top view of a mask, (b) is a figure explaining the state which covered the mask on the semiconductor wafer. (A) is a figure explaining the semiconductor wafer of Example 2 of the printing method of the semiconductor wafer of this invention, (b) is a figure explaining the cutting | disconnection. (A) is a top view explaining Example 3 of the printing method of the semiconductor wafer of this invention, (b), (c) is AA sectional drawing and BB sectional drawing of (a), respectively. .

Explanation of symbols

1 Semiconductor wafer
2 Semiconductor chip
3 Region where no semiconductor chip is formed 4, 5 Two places where positioning cutting edges are formed 6, 7 Vertical and horizontal scribing lines 8, 9 Positioning cutting edges 12, 13 Crossing lines orthogonal to each other 15 Orientation flat
16 Orientation flat edge 17 Support base for screen printing
18 Screen mask
19 Mask support frame 19 'Screw
20 Mask support surface
21 Recess for wafer support
22 steps
23 Bottom
24 tubes
25 Vacuum pump
26 Reinforcing frame for screen mask
27 stencil 27 'letter hole in stencil
28, 29 Slit for positioning 31 Semiconductor wafer 32, 33 Scribe line 34, 35 Straight line in cutting direction of diamond blade 36 XY movable table device
37 Inkjet head
38 Positioning support
39 Base 41 X direction movable stand
40 Convex guide rail
42 X-direction movable stand groove
43 Convex guide rail
44 Concave groove of positioning support
45 Recess for supporting semiconductor wafer
46, 47 Linear edge for positioning of recess for supporting semiconductor wafer

Claims (7)

A method for printing a semiconductor wafer, in which, on a semiconductor wafer divided into a large number of chips by cutting a scribe line, printing is performed on the back surface corresponding to each of the large number of chips having functional areas formed on the front surface. ,
Cutting a portion of the semiconductor wafer with two straight lines to form two positioning cutting edges;
The semiconductor wafer is turned upside down, the semiconductor wafer is positioned with respect to a printing apparatus with reference to the two positioning cutting edges, and printing is performed on the corresponding back surface positions of the multiple chips. A method for printing a semiconductor wafer. A method for printing a semiconductor wafer, in which, on a semiconductor wafer divided into a large number of chips by cutting a scribe line, printing is performed on the back surface corresponding to each of the large number of chips having functional areas formed on the front surface. ,
A part of the semiconductor wafer is cut by two straight lines orthogonal to each other in parallel to the scribe lines orthogonal to each other to form two positioning cutting edges each made of a straight line and orthogonal to each other,
The semiconductor wafer is turned upside down, the semiconductor wafer is positioned with respect to a printing apparatus with reference to the two positioning cutting edges, and printing is performed on the corresponding back surface positions of the multiple chips. A method for printing a semiconductor wafer.   3. The semiconductor wafer according to claim 1, wherein the semiconductor wafer is cut to obtain two positioning cutting edges in a region where no chip is formed in the semiconductor wafer. 4. Printing method.   3. The method of printing a semiconductor wafer according to claim 1, wherein the portions to be cut in order to cut the semiconductor wafer to obtain two positioning cutting edges are scribe lines at the ends of the semiconductor wafer, respectively. .   The method for printing a semiconductor wafer according to claim 1, wherein the printing is performed by screen printing.   The mask used in the screen printing apparatus is formed with one or two or more long and narrow slits formed on two straight lines orthogonal to each other, and all the long and narrow slits are aligned with the positioning cutting edge. 6. The method for printing a semiconductor wafer according to claim 5, wherein the mask is positioned with respect to the semiconductor wafer.   The printing is performed by ink jet printing, and in the ink jet printing, an ink jet printing apparatus based on the positioning cutting edges so that an ink jet head moves relatively in parallel to scribe lines orthogonal to each other of the semiconductor wafer. The method for printing a semiconductor wafer according to claim 1, wherein the semiconductor wafer is positioned.

Images