Transcript
Stealth dicer DISCO DFL 7340 user manual Eric Lebrasseur (Mita Lab) 2016/02/24 Please, leave this manual here. You can find an electronic version in the TakedaCR Wiki: http://takeda-cr.t.u-tokyo.ac.jp (accessible only from inside Utokyo) This equipment separates chips by using a laser beam. The stealth dicing method forms a modified layer in the work piece, by focusing a laser inside the work piece, and then implements die separation with a machine such as a tape expander. Merits of stealth dicing: • Able to suppress cutting waste because it modifies an internal portion of the work piece. Therefore, it is suitable for work pieces that are vulnerable to contamination. • It is a dry process that does not require cleaning; therefore it is suitable to processes (such as MEMS) that are vulnerable to load. • Greatly contributes to street reduction because the kerf width can be made narrow. If there is a small amount of resist over the dicing zone or another transparent layer, it maybe possible to dice, but if there is some material that reflects the laser beam (like metal), dicing is not possible. The 6 inch (150mm) chuck is normally set up, but it can be replaced with an 8 inch (200mm) chuck in order to process 8 inch wafers (cf. §10). There are particular cut techniques that enable circular cut (cf. §11) and dotted line cut.
1. Starting up 1.1. Power ON 1.1.1. Switch on the tape mounter (red button) (it needs about 10min to reach 50°C) 1.1.2. Distribution Board B2P-7: Stealth Dicer Breaker ON 1.1.3. On the wall behind the machine: 1.1.3.1. Open the Air and Nitrogen valves, 1.1.3.2. Open the two cooling water valves, both at the same time (close in horizontal position and open in vertical position) 1.1.4. On the left side of the machine: Breaker ON 1.1.5. On the front side of the machine: Turn the key to position START until POWER LAMP turns on 1.1.6. Wait until the soft finish to start up 1.2. Initialization of the machine From now on, unless otherwise noted, we will talk about the front side screen. This screen is a touch screen, so “click” means “tap” actually. 1.2.1. Click on "System initialization" ("システムイニシャル") → Wait until the message "System Initialization Completed" ("システムイニシャル終了") appears on the top part of the screen. 1.2.2. Click on "Diode" ("ダイオード"): set ON. 1.2.3. Laser Setup ("レーザセットアップ") → "Laser Idling" ("レーザアイドリング") → “START” 1.2.3.1. When the laser idling is completed (~10min), an alarm will ring. Click on "Alarm/Clear" ("アラーム・ クリア"). 1.2.3.2. Click "Enter" → "Exit" to return to the laser setup screen. 1.2.4. Laser Setup (" レーザセットアップ ") → "Full Power Check" (" フルパワーチェック ") → "START/STOP". Write the result in the log then click “Exit” (if the "output of the processing spot" ( 加工点出力) is less than 1.2W, contact the person in charge) 1.2.5. Antenna maintenance (アッテネータメンテナンス) Normally not used. If you change some parameters here (mostly sample thickness), set them back after use. Default parameters are: • Sample thickness > 100µm • Checkboxes BP calibration (BP キャリブレーション) and Antenna calibration (アッテネータキャリブ レーション) are checked
1/5
1.2.6. Set the device data according to §2. 1.2.7. Power Setup 1.2.7.1. Be sure to have set up and selected the device data before next step. If not, do it now (cf. §2) 1.2.7.2. “Laser setup” (“レーザセットアップ”) → "Power Setup" ("パワーセットアップ") → "START/STOP". 1.2.7.3. When finished, click "EXIT" several times to go back to the top menu.
2. Setting the device data To enter numbers, push the button "123" at the bottom right of the screen. Then a numeric keypad will appear. If you push the button "abc", an alphabetic keypad will appear. You can change between capital and small letters by pressing "Shift". 2.1. From the top menu, click "Device Data" ("デバイス・データ") 2.2. Select the data file that you want to use and click "Enter" (to create a new data file, chose an existing data file, then click "copy" ("コピー") and indicate the copy folder and device ID, maximum of 8 characters) 2.3. Set the work shape and size. 2.3.1. Work shape ("ワーク形状"): "ROUND" for a circle, "SQUARE" for a rectangle. 2.3.2. Work size ("ワークサイズ"): Set the size of the sample 2.4. Click "Street Cut Sequence" ("ストリートカットシーケンス") to set the depth of the laser exposure 2.4.1. If you check "Valid/Invalid" ("有効・無効"), the cut will become valid. The first one at the left should always be checked with the items fixed to 0W/0.00mm. 2.4.2. Amount of Defocus ("デフォーカス量"): it expresses the depth of the laser exposure (0 is the surface. The higher is the value, the deeper is the position. Unit is mm). However, this value is not the real depth: in the case of Si the value should be multiplied by 4 to get the real depth (to take into account the refractive index of the material). 2.5. Click "Sub index" ("サブインデックス") to set the number of cutting lines, the space between the cutting lines etc (in the case of a circular cut, ignore the sub index and set up the circular cut according to §11) 2.5.1. Number of cutting lines ("カット本数"): set the number of lines to dice. If the number is set to 0, if at all possible it will cut within the sample size. 2.5.2. Cutting direction ("カット方向"): "REAR" means "from your position to the inside part of the machine" (on the screen, from the bottom to the top), "FRONT" means "from inside the machine to your position" (on the screen, from the top to the bottom). 2.5.3. Cutting sequence (Channel) (カット順序（チャンネル）): set the channel that you want to use. "12" means that you will use CH1 (horizontal) and CH2 (vertical). "1" means that you will use only one channel CH1 (horizontal), that is you will cut in only one direction. 2.5.4. Y Index ("Yインデックス"): the space between the cutting lines 2.6. When the setup is finished click "Enter". The setup will be saved. 2.7. Click several times on "Exit" to return to the top menu.
3. Setting the sample 3.1. Setting the sample on the plastic film. This section describes how to fix the wafer on the plastic film using the tape mounter equipment which is placed on front of the dicing saw. For this purpose, we use 6inch metallic frames which are stored on the dicing saw. 3.1.1. Switch on the "POWER" of the tape mounter and wait until the temperature reaches 50°C 3.1.2. Switch on the vacuum pump under the desk 3.1.3. Adjust the metallic frame on the tape mounter by matching it to the pins 3.1.4. Switch on the 4 breakers in front of the machine 3.1.5. Pull the film until the front of the machine and fix it to the metallic frame using the roller 3.1.6. Cut the film along the metallic frame with a cutter and throw away the unneeded film 3.1.7. Turn the metallic frame upside down 3.1.8. Put the sample in the center of the frame. In the case of a wafer, the flat should be placed on your side. 3.1.9. Improve the adhesion of the film to the wafer by rubbing it with your fingers, from the backside. If the air bubbles are two big, you can cut it with the cutter and flatten. 3.2. Setting the sample in the dicer 3.2.1. Click "Shutter" ("シャッタ"): it turns OFF the light blue square at the top left of the shutter button. 2/5
3.2.2. Open the door at the right side of the equipment and put the film with the sample on it on the chuck. CH1 correspond to the direction from the front side to the back side of the equipment while CH2 correspond to the direction from the left side to the right side. 3.2.3. Close the door. Click "C/T vacuum" ("C/T バキューム") and "Shutter" ("シャッタ"): check that the squares at the top left of the buttons turn on (light blue color). If it doesn't, check if there are no air bubbles at the back of the sample.
4. Laser focus 4.1. Move to the position of the cutting line. 4.1.1. In the top menu, click "Manual operation" ("マニュアルオペレーション") and "Autocut" ("オートカット"). 4.1.2. Click "Just Focus". 4.1.3. Click "Move the position of the alignment camera" ("アライメントカメラ位置移動"). 4.1.4. Adjustment of the microscope focus: 4.1.4.1. "Change magnification" ("倍率変更"): change magnification from "HI" (for high magnification) to "LO" (for low magnification). 4.1.4.2. Click "Intensity" ("光量") and adjust the light to a suitable intensity. Then "Exit". 4.1.4.3. Click "Focus" (" フ ォ ー カ ス ") and "Autofocus" (" オ ー ト フ ォ ー カ ス "). When the autofocus is completed, click "Exit". 4.1.4.4. Move to the position of your cutting line (refer to the explanations at the end of this section about how to change the position). 4.1.5. Click "Exit" to return to the focus adjustment screen. 4.2. Adjust the focus the laser. 4.2.1. In the laser adjustment screen, click "Focus" (" フ ォ ー カ ス ") then "Full". A kind of square target like shape should appear. If not, try with “Work surface”. 4.2.2. Click "SLD ON/OFF": check that the light hit the sample inside the green square. 4.2.3. Click "Sensor" ("センサー") and "LASER". 4.2.4. Check that the light quantity is more than 1.0V. It will not cut at a lower quantity. For a silicon wafer, we expect a quantity larger than 2V. 4.2.5. Click "Exit" to go back to the laser adjustment screen. 4.2.6. Click "Save Laser Focus" ("レーザ焦点保存") than "Enter" and "Exit" to go back to the autocut screen 4.2.7. Click "Sensor" ("センサー"): the sensor window disappears.
5. Manual alignment 5.1. Click "Manual Alignment" ("マニュアルアライメント") 5.2. Align CH1 (CH1 direction is from the front to the back of the machine. On the screen it correspond to the direction from the left to the right) 5.2.1. Change magnification to "LO" 5.2.2. Adjustment of the microscope focus (refer to 4.1.4) 5.2.3. Align the rotation (θ) 5.2.3.1. Displace the screen to an extremity of a cutting line (or a line parallel to the cutting line) and align it with the line on the screen 5.2.3.2. Click "θ adjustment" ("θ 合わせ"): the screen will move to the opposite extremity of the line 5.2.3.3. Align the cutting line with the line on the screen 5.2.3.4. Click "θ adjustment": the screen return to the first position. The rotation is aligned. 5.2.4. Change magnification to "HI" 5.2.5. Align the rotation again 5.2.6. Align the first cutting line with the alignment line on the screen 5.3. Click "Enter" and align the CH2 (if there is any CH2) Do the same procedure as for CH1, and finish with the alignment of the first cutting line with the line on the screen. 5.4. Click "Enter"
3/5
6. Start the cutting Start the cutting by clicking "START". When the cutting is completed, press "Exit".
7. Sample unloading and separation 7.1. Unloading the sample 7.1.1. Click the button "C/T vacuum" ("C/T バキューム") (vacuum will be turned of and the shutter will open) 7.1.2. Open the door on the right side of the machine, unload the sample and close the door If you need to cut another sample, go back to §2. 7.2. Sample separation The sample may separate only by pushing with the finger from the backside, but it can be done more properly by using the film expander. This section describes how to use the film expander. 7.2.1. There is a frame with a black part and a white part. Separate the two parts and set the white part on the film expander chuck. 7.2.2. Set the sample (frame + film + sample) on the chuck. 7.2.3. Turn the power "ON" and click "Operation screen" ("操作画面") 7.2.4. Click "Start rising" ("上昇開始"): the film will expand as the chuck rise and the chips will separate 7.2.5. Put the black frame around the sample to fix the film in the expended state 7.2.6. Take the sample out of the frame 7.2.7. Click "Return to Origin" ("原点復帰") to move the chuck back to its original position 7.2.8. Turn the power "OFF"
8. Shutting down 8.1. Set back the 6inch chuck if you used the 8inch chuck 8.2. Click "Diode" ("ダイオード") to turn it OFF 8.3. Turn the key in front of the machine to OFF and wait until it shut down 8.4. Turn the breaker OFF on the left side of the machine 8.5. On the wall behind the machine: 8.5.1. Close the Air and Nitrogen valves, 8.5.2. Close the two cooling water valves, both at the same time 8.6. Distribution Board B2P-7: Stealth Dicer Breaker OFF 8.7. Fill in the paper log and the iPod log
9. Annex 1: How to move the position on the screen. There are two ways to do that: 9.1. Directly by touching the screen: There are two modes for that: the JOG mode and the IMMEDIATE mode. The current mode is displayed on the top right of the screen. Click on the top right side of the screen to toggle the mode. 9.1.1. JOG mode: the point where we touch the screen move to the center of the screen 9.1.2. IMMEDIATE mode: a circle representing the sample appears on the screen, and when we touch a point on the sample, the screen will move to that position. 9.2. By using the displacement panel: Click the button "分割されたウェハのボタン" at the bottom right of the screen to make the panel appear 9.2.1. "IND.": by touching the arrow key, it will move by the distance defined by the Y index set in §2.5.4 9.2.2. "SCR IND.": by touching the arrow key, it will move by one third of the screen 9.2.3. "SCAN": to move precisely. If you press for a long time, the displacement speed will increase.
10. Annex 2: change the chuck In order to cut 8 inch samples, it is necessary to replace the 6 inch chuck with the 8 inch chuck. 10.1. “Machine maintenance” (マシンメンテナンス) → “Change frame size” (フレームサイズ変更) 10.1.1. Change the chuck table (チャックテーブル) size from 6 to 8 inch. 10.1.2. Change the frame (フレーム) from “2-6” to “2-8”. 10.1.3. Press F3 (C/T 取り外しON/OFF).
4/5
10.2. Open the lateral door 10.2.1. Extend the 4 parts that maintain the frame to 8 inch position. There is a button at the side of the parts. Push this button and push the part outward until reaching the notch. 10.2.2. Take out the 6 inch chuck, and set the 8 inch chuck. 10.2.3. Close the door and press F3 (C/T 取り外しON/OFF). 10.3. Click “Focus maintenance” (フォーカスメンテナンス). An error occurs. Ignore and click again. 10.3.1. Set the light intensity to 100%. 10.3.2. Set the measurement marks to 5 or 9 and click “Enter”. 10.3.3. Click “Execute measurement” (測定実行) and wait few minutes until it is finished. 10.3.4. If the autofocus fail because the light is to intense, lower a little the light intensity and try again. 10.3.5. Exit x4 to return to top menu. 10.4. Proceed with usual cutting procedure. 10.5. After cutting, be sure to re-install the 6 inch chuck and execute the “Focus maintenance” procedure. Notice that the 4 parts that maintain the frame should be set back to the second notch.
11. Annex 3: circular cut A circular cut is needed when cutting a 4 inch wafer out of a 6 inch wafer for instance. Warnings: • The circular chuck is centered around the chuck table rotation axis. After the frame is set on the chuck, it is not possible to align. • When circle cut is selected, the sub index setup is ignored. • When cutting 2 inch wafer out of 4 inch wafer, there is better chance of success if you do it in two steps: 4 inch to 3 inch, then 3 inch to 2 inch (the smaller the size, the less chance of success). 11.1. In the screen displayed after selecting “Device data”: 11.1.1. Click “Z compensation data” ( Z 補正データ) 11.1.2. Set the edge detection voltage (エッジ検出電圧) to 0.1V. 11.1.3. Click “Enter” → “Exit” to go back to device data screen. 11.2. Click “Circle cut” (サークルカット) at the right. 11.3. Check the circle cut check-box. 11.4. Circle cut data (サークルカットデータ) (CH1) 11.4.1. Set the circle size (サークルサイズ) to the diameter of the circle that you want to cut. 11.4.2. Set the circle cut speed (サークルカット速度) to 90deg/s. 11.5. Splitting cut data (分割カットデータ) (CH2) 11.5.1. Set the number of splitting line (分割本数) (4~8, typically 4). 11.6. Click “Enter” → “Exit” to go back to device data screen. 11.7. Set the rest of the device data as usual (except the sub index)
12. Remarks, troubleshooting 12.1. E1245 SD エンジンでエラーが発生しました。(code=402) Just ignore and continue by pressing 続行 (ぞっこう) (resuming). It might occur several times. This error may be due to the presence of resist on the surface, or to a non horizontal position of the sample etc. leading to bad focusing of the laser. If this error occurs too often, the laser engine might be out of order. Contact the person in charge. 12.2. Chiller problem Check the water level of the chiller behind the machine. If no more water, refill with pure water. 12.3. The maximum number of items in the street cut sequence menu is 50. If you have a thick sample and increase this number above 50, the defocus values closest to the surface (from no.50) will be automatically deleted.
5/5
