Solder

Reballing

GENERAL BGA/CSP REBALLING PROCESS

reballing-technical Solderball The following describes the general methodologies used by BEST for reattaching solder balls to either BGAs or CSPs as part of its BGA rework services. The three methodologies described herein are used by BEST Inc in the reattachment of solder balls to a variety of area array devices.

These BGA reballing methods include:

reballing-plastic Reballing Plastic The materials and tools required for each of the methods as well as critical elements of the BGA reballing operation are detailed in the following pages specifically while being outlined more generally in the IPC Rework and Repair Procedures of IPC 7711. The experience BEST has gained in reballing tens of thousands of devices on hundreds of different pattern configurations, body styles and package materials has shaped the information found in these process descriptions. While several device manufacturers do not recommend the reballing of their devices due to the number of thermal cycles the devices themselves have to go through in the reballing process, BEST has successfully attached solder balls via a variety of reballing processes to every major device type. One has to take care and be aware of the many potential reballing process pitfalls. This has saved BEST customers from having to spend hundreds of thousands of dollars in component acquisition costs or made available devices which are difficult to obtain in times of allocation thereby allowing the end customer to meet mission critical delivery times. Finally BEST has BGA reballing experience going back to the late 1990’s and can provide a wide array of optional services to meet your process validation or unique production requirements. 

BEST REBALLING METHODS

Each of the reballing methods used by BEST Inc. is equal in its outcome -the precise reattachment of solder balls onto area array devices. We make sure that we properly handle the devices The type of method chosen is determined by several criteria including:

  • The lead-time requirements of the customer
  • The customer specification requirements
  • The volume requirements
  • The availability of materials for each of the 2,000 plus known grid array patterns including the solder ball diameter and alloy

There are numerous methods which BEST can employ to perform the BGA reballing that you need done-anywhere form a large 50 x 50 mm package with thousands of IO and high temperature spheres attached to a ceramic substrate to very tiny 1.5 x 1.5mm plastic packages with just a few solder balls down to 6 mils in size. Many ancillary services can be performed by BEST as part of the BGA Reballing Service offering including cleaning, marking, tape/reeling and other testing services.

BEST Inc engineering staff can also consult with you on BGA reballing processes. If you need to develop acceptance criteria for other service providers or for internal development then BEST Inc can be your solutions provider. We can also diagnose and troubleshoot the difficulties you may be having with your own BGA reballing process. Whatever the BGA reballing process need BEST Inc can provide a solution.

REBALLING PROCESS FLOW
BGA Reballing Process Overview Plastic Package, Low Volume
  1. Device Prep
  2. Choose Reballing Materials
  3. Flux Part
  4. Align Solder Ball Preform to Device
  5. Reflow
  6. Remove Preform
  7. Clean
  8. Mark
  9. Inspect
  10. Bake
  11. Package
BGA Reballing Process Overview Ceramic/Metal Package, Low Volume
  1. Device Prep
  2. Choose Reballing Materials
  3. Flux Part
  4. Align Solder Ball Preform to Device
  5. Reflow
  6. Remove Preform
  7. Clean
  8. Mark
  9. Inspect
  10. Bake
  11. Package