## 3 Methodology
### Introduction to DCOR Processes
#### 3.3.3 Level 3 of DCOR  
According to Level 2 of the DCOR model, the NPD process of the case company needs to define the design items, such as functions of product signals, needs of product frequencies and their corresponding issues derived during design, and adoption of product materials. Complete design rules are then developed using the details expanded from these design items and delivered to the design company to design. For example, the clock (CLK) signals of products must be insulated by a ground line or a ground via so that they will not disturb other normal signals resulting in inaccurate testing results or frequency shifts from signal interferences. When the testing products need to run at high speeds, the product materials must be high end, such as N4000-13 or Rogers, to satisfy the high standards and high speed requirements. When such rules of relevant design items are made and clarified, they continue the PCB prototype building and the subsequent design for simulating PCB prototype testing. After all the processes are confirmed, the design can be released to the customer for verification. As the medium between the design company and the customers, the case company dominates the process planning of the project R&D process (see Figure 5). The case company evaluates the PCB design's required data provided by the customer, including test frequencies, test speed, pin function, necessary materials, and fabrication capability. The case company clarifies with the customer the relevant needs and engineering problems related to the product design after a comprehensive evaluation and then makes product design rules after the customer returns the engineering problems and places the order. The case company provides the design rules to the design company for reference and notifies the design company to start the design diagram plotting process. Figure 4: Level 2 of the DCOR model of the PCB R&D processes. The design company evaluates design rules and specifications after receiving the design request and discusses relevant engineering problems, design directions, design concepts, and details with the case company. After clarifying the engineering problems, the design company finishes a single IC schematic and sends it to the case company for verification. Once the verification is passed, the design company then starts designing multiple IC schematics, which are also validated after they are finished. The case company provides mechanical drawings to the design company for the next step placement design only after validating the multiple IC schematics. The case company reconfirms the placements done by the design company; if the placements do not fit the requirements of the case company or customers, the design company needs to correct the placements and repeat the validation procedure with the case company until there is no mistake and the design company can proceed to the next step for PCB layout. Once PCB layout design is completed, the design diagram is sent to the case company for review. The case company asks the design company to make corrections to its design problems during examination. The case company again reviews the design company's modification, and then prepares all the design documents, reports, and files for the customer to review. If the customer has concerns or requests modifications of the design, the case company first explains the design philosophy to the customer or returns the design to the design company for modifications. On the other hand, if the customer does not have issues with the design files and approves the PCB fabrication, the case company sends the relevant data and Gerber files to the fabrication suppliers for PCB manufacturing. The case company performs part and probe assembly and outgoing quality control (OQC) after the fabrication suppliers finish and deliver the PCB. The assembled probe card is sent to the customer for wafer testing.