VT-44 Overview Of Component Preparation And Manual Insertion Leader s Guide

Transcription

1 VT-44 Overview Of Component Preparation And Manual Insertion Leader s Guide ABOUT THIS IPC TRAINING VIDEO This videotape training package provides overview information on component preparation and manual insertion in the assembly process. We recognize that each company may not have or use all of the specific tools and processes described in the video. Further, we understand that there are a variety of training techniques based on the personal style of the trainer, training objectives, and time available for training. Therefore, IPC has created a learning tool that flexible and useful in a variety of training situations ranging from new employee orientation, to experienced assembly technicians who are evaluating component preparation / manual insertion tools, procedures, and problems. We recommend that you review the video and related Guides in advance, to customize this training program to fit your audience, objectives, time frame, company policies, and material / process selections. ADVANCE PREPARATION The video is divided into sections and allows you to stop the tape and clarify companyspecific details. As you review the video in advance, you may wish to note or highlight your specific training objectives within each section of the Leader's Guide. In order to customize the training, the right hand column is provided for you to note your specific information on equipment, settings, supplies, processes and company policies. (Use a copy of the Leader's Guide to preserve the original.) TRAINING PRESENTATION The more opportunities you can provide your student(s) to experience and review the information in different and creative ways, the better. It's your job to select the training method that works best for your specific situation. We have attempted to provide you with a variety of tools to make this job as efficient and effective as possible. As you present the video to your trainees, we encourage you to pause the tape at the completion of each section. Then, while the information just viewed is fresh in your student(s) short term memory, you can together review information provided in the video, the Leader's Guide and your personal notes on company-specifics. This mid-tape review will facilitate your student(s) transference of the information from their short term memory to long term memory. 1

2 You may want to provide a place for and encourage your trainee(s) to take written notes. If appropriate, provide a fresh copy of the Leader's Guide to each student, which contains much of the information they need for future reference. Their personal notes can be made in the right hand column. A Learner's Workbook is included in this training package. You may request written answers in the corresponding sections of the Workbook. These written responses may be graded and filed as documentation for ISO-9000 certification. When complete, you can go over the answers as a group. This will act as an additional review which will further stimulate long term memory retention. Finally, we have included a Component Preparation / Manual Insertion Checklist (in the Leaders section of this notebook) which you can copy and hand out to each student. The checklist will need to be customized to contain your company s specific process details. You may decide to prepare these forms in advance, or in cooperation with the class. This will assure that each technician receives written, company specific, guidelines for future reference. It is also another opportunity for review. CREATING AN EFFECTIVE LEARNING ENVIRONMENT Remember that providing information and knowledge is only part of the process. It's equally important that your students care about the quality of the work they perform and are not afraid to ask questions during your class or on the job. But how can you as a trainer have any affect on their work attitude or future communications? You can begin by providing an environment for open information exchange. Your training class is an opportunity for the students to define existing problems in the component preparation and manual insertion process and develop their own solutions. We all know that people work harder to make sure that their ideas succeed. Your leadership in encouraging the group to recognize and resolve problems individually and as a team, may be just as important as the technical training you provide. Also keep in mind that for your student(s), you represent your company s attitude toward all its employees. Since the majority of their time is spent working, every personal contact with a company representative is an opportunity for that representative (for you) to recognize their importance as a valuable employee and human being. Self esteem building is one of the simplest ways for you to increase your students learning effectiveness. You may also want to invite their direct supervisor to participate in the training class. On a practical level, the quality of communication between the area supervisor and employees has a direct relationship to the productivity and job performance of each individual and department. 2

3 Finally, research shows that almost everyone learns better, faster and deeper when they are relaxed and enjoying themselves. Stress and fear are recognized at the major learning inhibitors. Your efforts to create a practical, creative, open and enjoyable learning experience will be rewarded with well prepared and confident technicians. EVERY SITUATION REQUIRES A UNIQUE RESPONSE... TAILORED TO THE OBJECTIVES AND RESULTS YOU WISH TO ACCOMPLISH. THE PARTICULAR WAY THAT YOU USE THIS TRAINING TOOL IS UP TO YOU. BE CREATIVE. We'd like to hear your ideas on how we can improve our training materials, as well as additional suggestions for new subjects of interest. Douglas Webb VT-44 Producer IPC Video Kim MacDougall Technical Advisor Manu-Tronics Mark Prichard Division Director IPC Video 3

4 Component Preparation And Manual Insertion Checklist COMPANY POLICIES (include ESD, safety, handling, clothing etc.) AUTOMATED EQUIPMENT (include make, model, settings, etc.) EQUIPMENT OPERATION PROCEDURES HANDTOOLS 4

5 SUPPLIES (include masking materials, cleaners, etc.) TYPES OF COMPONENTS PREFORMED AND INSERTED TYPES OF HARDWARE PREPAIRED AND INSERTED TYPES OF PREFORMS INSERTION SPESEFICS TEMPOARY SOLDER MASK LOCATIONS 5

6 VT-44 COMPONENT PREPARATION AND MANUAL INSERTION Section 1. (The Assembly Process. General Considerations. Manual Insertion: When? Kitting And Picking. Temporary Solder Mask.) A. The Assembly Process. Each company handles board assembly differently depending on board type and type of product. Companies that manufacture their own product may assemble boards differently than companies that assemble boards for others. B. General Considerations. Safety. ESD. Special clothing. Safety glasses. Lifting and carrying. Cleanliness and tidiness. Ask supervisors questions. Learn company-specific policies. Very small Electro Static Discharges can ruin a very expensive component. Use wrist and ankle bands. Board Handling. Careless handling can cause expensive repair. Handle boards by edges. Wear gloves or finger cots. 6

7 Checking all work. Learn the habit of checking all work before and after work done. Teamwork: Helping each other improve each day. C. Manual Insertion: When? Pre-wave insertion. Post-wave insertion. After cleaning insertion. D. Kitting And Picking. Kits include: Different types of components. Various types of hardware. The board. Assembly instructions. (Traveler) Other? Component Identification. Avoid mixing components that look similar but have different functions. Pay attention! IPC Component Desk Reference Manual #18. 7

8 E. Temporary Solder Mask. Why? Where? Types: Keeping melted solder out or off of a certain part of the board. Holes in board for various types of hardware, like screws and conductor posts. Holes of components inserted after wave soldering. Holes of components installed on the back or termination side of the board. The contact surfaces of gold finger edge connectors. Liquid solder resist. Solder boots. Tape dots. Resist tape. Application method. All types of resist can be applied by hand. Machine application speeds process if a number of holes or large areas need masking. 8

9 Things to remember. Removal. Apply mask to correct through holes. Check instructions that go with each board. Follow board legends: Machine: Water soluble resist washes away during machine rinse process. Hand: no-clean resist removed by hand in no-clean assembly process. Remove resist tape and dots slowly to avoid ESD damage. Potential Problems. Liquid resist. Too much. Too little. Not dry enough. Wrong proportions. Solder resist, tape dots or boots: Improper application could result in gaps or openings that solder could seep into. 9

10 Section 2. (Component Preparation: Clipping Leads. Preforming Leads. Checking.) A. Clipping Leads. Too short: doesn t form good solder joint or fillet. Too long: doesn t sit on board in correct position; or, if wave soldered: molten solder may web or bridge across to another component s through hole. After clipping: heat shrink sleeving may be used to avoid short circuits if leads cross over non-common conductor(s). B. Pre-forming leads. What kind and why? Stress relief. As board heats and cools, leads pulling on board could damage through hole lands, crack a solder fillet or component end. Lock-in Crimping: for boards subject to high-vibration. Above-board shapes: For components that heat up and damage board surface. For real estate considerations : so components take up less of board surface area. 10

11 All shapes. Preforming equipment. Leads must be bent properly so components fit in their holes correctly, avoiding damage to land or component. Preform machines. Motor driven. Hand-powered. All preform machines use different dies to create specific shapes. Basic preform machine operation process Select correct die for specific types of bends. Insert die into machine, lock down tight taking care to avoid contaminants. Adjust position of die in jaws using adjustment setting screw. If the machine has one, load components into feeder chute. Keeping hands, clothing, hair etc. clear of jaws, activate machine by hand switch, lever or foot pedal. 11

12 Hand tools used to create preforms: Specially shaped pliers. A wide variety jigs. Several types of cutters. C. Checking Procedure. After first component lead is trimmed and shaped, it is carefully checked. Adjustments made, if necessary. Continue process of checking and adjusting until correct preforms are made and component fits correctly in its through holes. Thereafter: spot-check lead preforms. Errors to watch for: Incorrect die selection. Incorrect height setting. Drifting jaw settings. (loose lock-down screws) No-give leads. (insufficient stress relief) Incorrect center-to-center lead spacing. Leads deformed or damaged with kinks, cracks or heavy indents. Leads preformed too close to component body, causing cracks or chips at component ends. 12

13 Section 3. (Manual Insertion: Polarity. Orientation. Polarity And Orientation Markings. Some Simple Rules. Clinching Leads; Adhesive Bonding. Semi-Automated Manual Insertion Machines. Assembly Line. Wave Soldering. A. Polarity. Examples Capacitors. I.C. s. Sockets. Filters. Transistors. Polarized components have plus or positive lead and minus or negative lead. Component leads are marked positive or negative. Board legends show positive lead location; negative lead location. If leads are placed in wrong holes the component will not function properly. B. Orientation. Polarity determines orientation. Leads and holes are numbered. Number one lead must go in the number one hole. Board legends often show outline of component with number one lead marked. 13

14 C. Some Simple Rules: Always check the part before insertion. Check that insertion location is correct according to the instructions. Never force a component into its through holes if leads are not pre-formed for proper fit. Insert components in order, according to the instructions. Usually smallest first. Check that component is straight; then make a last check of work. D. Clinching Leads; Adhesive Bonding. Why? What? If boards are stored or moved in vertical position. If finished product is subjected to heavy vibrations as part of its normal use. Bending ends of leads that extend through holes. Adhesive bonding involves gluing a component to the board after insertion. Rules regarding specific standards of acceptability. IPC Reference Manual A-610: Acceptability of Electronic Assemblies. A-610 standard approved by the American National Standards Institute. 14

15 E. Semi-Automated Manual Insertion Machines. Uses low-powered lasers to show operators where to insert different types of components and in what order. Pre-formed components placed in special bins; correct bin for next component automatically presented to operator. F. Assembly Line. Board mounted in pallet: A way to handle an assembly without touching or scraping. Also protects against ESD. Each operator responsible for certain number of parts; certain area of board. Follow instructions exactly. Finished work either placed on motor driven line or pushed/ slid down line to next person. Requires team work. Operators must know: Who is doing what on either side. How long it takes. 15

16 G. Wave Soldering. When molten solder cools and hardens, it forms a solid mass that creates a mechanical and an electrical connection. Each component will be held firmly in place. Electricity will flow through the connection. 16