7711/7721 Rework and Repair
Rework and repair of electronic assemblies. This 5-day course utilizes lecture and practical application to convey the rework skills. Students will remove and replace most common TH and SMT components including DIP rework, chip component rework, SOT & SOIC rework, and QFP & PLCC rework as well as barrel, track & pad repair. boards. In the 7721 portion, the student will repair damaged plated thru holes and reestablish the electrical interconnections, repair lifted SMT pads, repair burned and damaged laminate material, perform an undercut, and complete the repair with two part epoxy. This is IPC’s most comprehensive hands-on training program where students are evaluated on both lab and course work. After the candidate has successfully passed the Common Procedures module any of the remaining 8 modules may be taught in any order. The successful student will be issued an official IPC certification on the completed modules good for two years from the date of completion. Details on individual modules follow:
CIS Class Overview
The common procedures module includes information on:
Module 2 Wire Splicing
This module discusses the four IPC recognized wire splices (Mesh, Wrap, Hook, and Lap) along with a discussion of feasibility of repairing damaged wires and demonstration of wire stripping along with all of the abovementioned wire splices. The session also covers wire tinning using a soldering iron and a solder pot. The students must show proficiency in the above and demonstrate the ability to perform at least two of the splices to IPC Class 3 criteria
Module 3 Through-Hole (TH) Rework
This module covers the various ways to install and remove PTH type components. Students are graded on the IPC Class 3 criteria on installations of various axial and radial leaded devices using conductive applications. The student will watch the IPC video VT-41, Through Hole Rework, instructed on proper stress relief bends and the proper use of vacuum extraction handpieces. The student will also have the opportunity to use a solder flow fountain to remove and install multi-leaded PTH devices. Lastly the student will be instructed in the workmanship standards associated with PTH configurations.
Module 4 SMT chip component and MELF installation and removal
This module instructs the student on various ways to install SMT chips and MELF using both conductive and convective techniques. Students install components ranging from 1206’s down to 0402’s. Students remove components using various conductive tips and focused hot air. Appropriate workmanship standards are reviewed and students must install and remove components to the IPC Class 3 criteria. Pad releveling and tinning is also covered.
Module 5 SMT SOT’s and SOIC’s installation and removal
This module covers various procedures for the installation of small outline transistors and small outline integrated circuits utilizing both conductive and convective techniques. Students will also discuss component polarity and orientation issues associated with multi-leaded SMT devices. Surface mount land preparation is also discussed. Workmanship standards for gull wing devices are presented and the student must install and remove devices to the IPC Class 3 criteria.
Module 6 SMT PLCC’s and QFP’s
This module covers the various procedures for installing and removing surface mount J-leaded devices (Plastic Leaded Chip Carriers) and Quad Flat Packs. Device pitch ranges from 50 mils down to 20 mils. Students will use both conductive (point-to-point and drag soldering) and convective (hot-air and solder paste) techniques. Students will also be taught various ways to remove shorts between leads of PLCC’s and QFP’s. Appropriate workmanship standards are reviewed and, again, students are graded to the IPC Class 3 criteria.
Module 7 Printed Circuit Board Repair
In this module the student will be introduced to various methods used to perform repair on PCB’s including replacement of damaged PTH barrels via the use of replacement eyelets and fullelets, replacement of damaged surface mount pads, replacement of damaged circuits (traces), and installation of jumper wires on PCB’s. The student will be introduced to ‘thermo-bond’ (dry-film adhesive backed pads/circuits) technology.
Module 8 Laminate Repair Workmanship
This module covers the repair of damaged laminate material. Students will repair a burn on a PCB by excavating the damaged material, mixing two-part epoxy, using the epoxy to fill the damaged area, and the use of coloring agents to match the PCB color. Other repair techniques will also be discussed such as tooling hole repair, repair of broken corners, etc.
Module 9 Conformal Coating Removal Workmanship
In this module the student will learn the procedures applicable to, and develop and demonstrate the skills of identifying and removing conformal coating from a PCA in accordance with the procedures of IPC-7711C. The student will also learn the procedures for replacing conformal coating, encapsulants and solder resist.