{"id":2160,"date":"2009-07-31T09:52:55","date_gmt":"2009-07-31T16:52:55","guid":{"rendered":"http:\/\/mightyohm.com\/blog\/?p=2160"},"modified":"2015-09-26T11:11:05","modified_gmt":"2015-09-26T18:11:05","slug":"tonys-diamond-chop-saw-part-1","status":"publish","type":"post","link":"https:\/\/mightyohm.com\/blog\/2009\/07\/tonys-diamond-chop-saw-part-1\/","title":{"rendered":"Tony’s Diamond Chop Saw (Part 1)"},"content":{"rendered":"
\n
\"dicer_small\"<\/a><\/div>\n
This is guest blogger Tony reporting on my latest project, a very small, precise circular chop saw.\u00a0 Why would anyone\u00a0want to build such a saw you might ask?\u00a0 Well, to make parts for another project of course!<\/div>\n<\/div>\n

So here’s the background….I’m building a ham radio that operates at 47 GHz.\u00a0 At\u00a0such a high\u00a0frequency there are very few components that can be soldered on to circuit boards, let alone components that even come packaged!\u00a0\u00a0The\u00a0easiest way to build a high performance radio at these frequencies is to use MMICs (Monolithic Microwave Integrated Circuits).\u00a0\u00a0 These are really just fancy, yet fairly simple circuits made from exotic materials, most commonly Gallium Arsenide (GaAs) instead of the usual Silicon used for normal chips.\u00a0 Before MMICs were in widespread use, individual transistors had to be used, requiring delicate and hard to make external matching elements.\u00a0 MMICs are like nice little 50 ohm building blocks.\u00a0 Low Noise Amplifiers (LNAs), mixers, Power Amplifiers (PAs), phase shifters, etc. etc. are all available in this form.\u00a0 Trouble\u00a0is that you have to connect these pieces up to make a functional radio (or at least the microwave portion of it).<\/p>\n

\"My<\/a>
My WestBond wedge bonder<\/figcaption><\/figure>\n

Wire bonding is the usual method for connection and is really just\u00a0a\u00a0method of welding a wire\u00a0(or ribbon) from one\u00a0chip to the next.\u00a0\u00a0It turns out that you actually need space in between the chips, for thermal reasons, RF reasons, and for placing the requisite bypass capacitors.\u00a0\u00a0So what goes in between the chips?\u00a0 Well, coax cable is pretty much out, and most common circuit board materials start getting pretty lossy at\u00a010+ GHz, and even the good stuff (PTFE-based usually) starts getting kinda lousy at 40+ GHz.\u00a0\u00a0 At very high frequencies, materials like ceramics and quartz become worthwhile.\u00a0 In my radio I chose to use pre-made alumina<\/a> ceramic substrates (tiny circuit boards).\u00a0\u00a0 These come with a gold layer on the back, and a gold line on top etched to perform as a 50 ohm\u00a0transmission line (just like coax and just what the MMICs want to see). \u00a0I bought these with a number of other hams last year in a group buy.\u00a0 They are fairly expensive being that they are 5 and 10 mils thick!<\/p>\n

\"test<\/a>
My first test bonds on an alumina ceramic substrate (ugly)<\/figcaption><\/figure>\n

To make the best use of the sections that I bought I decided I needed to cut them to length.\u00a0 Well how do I do that?\u00a0 The thickest pieces are 10 mils thick (a piece of printer paper is 4 mils thick) and they are brittle!\u00a0\u00a0Beyond cutting, how do I hold the piece while cutting and when it’s done?\u00a0 The resulting pieces may be just 100 mils long, and 50 mils wide.\u00a0\u00a0 Obviously a pair of vice-grips simply won’t do.<\/p>\n

So my first thought was a\u00a0Dremel tool and tape.\u00a0\u00a0This method could work, but it does not lend itself well to making measured cuts.\u00a0 At 47 GHz,\u00a0a few hundredths of an inch is a lot!\u00a0Also, the available diamond blades for dremel\u00a0tools are fairly\u00a0wide and I wanted to waste as little of the\u00a0\u00a0small substrates as possible.\u00a0 At this point I made\u00a0 a lucky find on eBay<\/a>.<\/p>\n

In the semiconductor industry, one of the last steps of making a chip is called “wafer dicing<\/a>.”\u00a0 After a wafer full of chips is made, they need to be cut out into individual parts.\u00a0 To do this, wafer dicing machines were developed.\u00a0 These are CNC saws that use a high speed (as high as 60,000 rpm) air bearing spindles with diamond abrasive blades.\u00a0\u00a0 They can cut lines across large dinner plate sized wafers that are as narrow as only a few tens of microns.\u00a0\u00a0 Luckily there is enough wafer dicing going on in the world that there is a source of surplus blades on eBay<\/a>.\u00a0 Not all blades are well suited for all materials, so do some research if you are interested.\u00a0 Disco<\/a> (a Japanese company) is one of the largest dicing blade manufacturers.<\/p>\n

\"dicingblade\"<\/a>
Large (4.6 inch diameter) wafer dicing blade in it's packaging.<\/figcaption><\/figure>\n

While reading the last paragraph you may have spotted a few words indicating unobtanium.\u00a0 Those words are “high speed air bearing spindle.”\u00a0\u00a0 Well I chose to use a hard drive motor instead, because\u00a0they have excellent bearings and are readily\u00a0availble\u00a0\u00a0for free.\u00a0 While they don’t move as fast, I don’t care.\u00a0 I have a few short cuts to make, not millions of chips.<\/p>\n

So that is an introduction to what I’m doing.\u00a0 For the most part the saw has been built using surplus parts and remnant pieces of metal from my favorite local metal supply house M&K Metals<\/a> in lovely Gardena, CA<\/a>.\u00a0\u00a0 As of this entry, the saw is nearly complete, all that is left is the splash guards.\u00a0 I’ll be posting the build of this project in several parts, so stay tuned.<\/p>\n

And a link to my Flickr photo set for this project: Dicing saw<\/a><\/p>\n

-Tony<\/p>\n","protected":false},"excerpt":{"rendered":"

This is guest blogger Tony reporting on my latest project, a very small, precise circular chop saw.\u00a0 Why would anyone\u00a0want to build such a saw you might ask?\u00a0 Well, to make parts for another project of course! So here’s the background….I’m building a ham radio that operates at 47 GHz.\u00a0 At\u00a0such a high\u00a0frequency there are … Continue reading Tony’s Diamond Chop Saw (Part 1)<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[5,443],"tags":[36,501,214,215,265],"class_list":["post-2160","post","type-post","status-publish","format-standard","hentry","category-electronics","category-projects-2","tag-diy","tag-electronics","tag-ham-radio","tag-microwave","tag-tools"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pioCd-yQ","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":1080,"url":"https:\/\/mightyohm.com\/blog\/2009\/02\/forrest-mims-engineers-mini-notebooks\/","url_meta":{"origin":2160,"position":0},"title":"Forrest Mims Engineer’s Mini-Notebooks","author":"Jeff","date":"February 17, 2009","format":false,"excerpt":"I previously posted about Forrest M. Mims III's Getting Started in Electronics, one of the best books out there for someone who wants a thorough, yet unintimidating introduction to electronic components and circuits. From the mid-1980's through the late 1990's, Forrest Mims also published several mini-notebooks, each dedicated to a\u2026","rel":"","context":"In "Books and Resources"","block_context":{"text":"Books and Resources","link":"https:\/\/mightyohm.com\/blog\/category\/books-and-resources\/"},"img":{"alt_text":"Engineer's Mini-Notebook","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/51iveq6oql_ss500_.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":1810,"url":"https:\/\/mightyohm.com\/blog\/2009\/04\/chuck-houghton-wb6igp\/","url_meta":{"origin":2160,"position":1},"title":"Chuck Houghton – WB6IGP","author":"Tony","date":"April 30, 2009","format":false,"excerpt":"Ed. note: This is a guest post by a good friend of mine, Tony Long, KC6QHP.\u00a0 Hopefully Tony will be contributing more to the blog in the future and we'll get to see some of the interesting things he's working on in his lab in SoCal.\u00a0 Let's all welcome Tony\u2026","rel":"","context":"In "Electronics"","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"Chuck WB6IGP operating his lasercom system","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/04\/oyj_6.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":2279,"url":"https:\/\/mightyohm.com\/blog\/2010\/01\/tonys-diamond-chop-saw-part-4\/","url_meta":{"origin":2160,"position":2},"title":"Tony’s Diamond Chop Saw (Part 4)","author":"Tony","date":"January 4, 2010","format":false,"excerpt":"Finally, I bring you the conclusion of my Diamond Chop Saw series! In this part I'll cover a few remaining issues, but mostly I'll report on my use of the machine in the construction of my 47 GHz radio, for which this project was intended.\u00a0 If you're not already familiar\u2026","rel":"","context":"In "Amateur Radio"","block_context":{"text":"Amateur Radio","link":"https:\/\/mightyohm.com\/blog\/category\/amateur-radio\/"},"img":{"alt_text":"Method for centering the blade","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2010\/01\/blade_gluing1.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":2145,"url":"https:\/\/mightyohm.com\/blog\/2009\/09\/ham-radio-studying-for-the-general-class-exam\/","url_meta":{"origin":2160,"position":3},"title":"Ham Radio – Studying for the General Class Exam","author":"Jeff","date":"September 11, 2009","format":false,"excerpt":"When my renewal notice came in the mail, I was surprised to learn that I've had my ham radio license for just over ten years. I received my Technician class license in college shortly after my classmate Tony introduced me to the world of amateur radio.\u00a0 I started out playing\u2026","rel":"","context":"In "Amateur Radio"","block_context":{"text":"Amateur Radio","link":"https:\/\/mightyohm.com\/blog\/category\/amateur-radio\/"},"img":{"alt_text":"10GHz Transverter","src":"https:\/\/i0.wp.com\/mightyohm.com\/files\/flickr\/3902350922_30122f670e.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":76,"url":"https:\/\/mightyohm.com\/blog\/2008\/07\/new-flickr-group-for-photos-of-printed-circuits\/","url_meta":{"origin":2160,"position":4},"title":"New Flickr group for photos of printed circuits","author":"Jeff","date":"July 30, 2008","format":false,"excerpt":"Printed circuit boards can be interesting and beautiful, with their delicate traces and colorful components in all shapes and sizes.\u00a0 I just created a new Flickr group for photos of printed circuits like the one shown above.\u00a0 More details about the group can be found on Flickr: Photos exploring the\u2026","rel":"","context":"In "Electronics"","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"U1405","src":"https:\/\/i0.wp.com\/mightyohm.com\/files\/flickr\/2717399417_a3a9c6e8c4.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":2277,"url":"https:\/\/mightyohm.com\/blog\/2009\/08\/tonys-diamond-chop-saw-part-3\/","url_meta":{"origin":2160,"position":5},"title":"Tony’s Diamond Chop Saw (Part 3)","author":"Tony","date":"August 19, 2009","format":false,"excerpt":"Welcome to Part 3 of the Diamond Chop Saw build.\u00a0 In this installment I'm going to focus on the construction of the mechanical aspects of the saw structure, motor attachment, vacuum chuck, and splash guard.\u00a0\u00a0 This is a\u00a0 picture-heavy entry... After thinking for a while about how to build the\u2026","rel":"","context":"In "Electronics"","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"Completed Dicing Saw","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/08\/888.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/2160","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/comments?post=2160"}],"version-history":[{"count":18,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/2160\/revisions"}],"predecessor-version":[{"id":5001,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/2160\/revisions\/5001"}],"wp:attachment":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/media?parent=2160"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/categories?post=2160"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/tags?post=2160"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}