Case Study

Meeting Customers’ Unique Needs

How Our Culture of Problem Solving Brings Success

Background

Unique Needs

We strive to provide fast and first-rate quick turn availability that meets our customers’ production needs, as specified by them. When a customer sent a design with 6 layers, blind vias L1-L5, and L2-L6 with 0.2mm defined via holes (finished), and copper weights on inner layers that could not support proper quality build, a challenge to change the HDI board build to allow a high-yield design emerged.

It is not a straight forward process to have both L1-L5 and L2-L6 blind drilled, since once L1-L5 are in partial build it is then not possible to drill L2-L6 and vice versa. Our goal was to take care of this issue without asking the customer to redesign the board.

The Solution

Since, in this case, the design was already finalized and the request was for a quick turn supply of samples, we knew we couldn’t go back to the drawing board.

After much thought, we realized we could provide what the client wanted. We would build the requested board by changing the manufacturing process as follows:

  • Splitting L1-L5 drilling to L1-L2 laser / L2-L5 buried drilling
  • Splitting 2-6 drilling to L2-L5 buried / L5-L6 laser drilling
  • Building L2-L5 stack first
  • Laminating L1 and L6 final and adding stacked VIA holes
  • Realizing that the laser vias (L1-L2 and L5-L6) could not be 0.2mm due to aspect ratio and were drilled 0.1mm.
  • Reducing the initial copper weights of L2 and L5 to 1Oz to support proper quality of the build, as the outer laminate design would have been unstable with too much copper and thin prepreg between L1 and L2 (L5 and L6 respectively)

What This Process Meant for Our Customer

We identified the problem in early engineering stages, quoted it as HDI, changed the design to support HDI as described above, and had the board in production in 24 hours.

We delivered the requested boards in one week, having made all the changes on our own, and on our own manufacturing floor.

Results

  • We did not send the customer to redesign the board.
  • Met the same netlist and all other aspects of dielectric distances, impedances, current requirements, etc.
  • Met tight lead time of QTA