Technical Center Analytical Laboratory Report #: . Request Date: Mar, 07, 2002 Completion Date: Mar, 15, 2002 1041 STC ANALYTICAL LABORATORY REPORT Requester: A.C. Shiah, Process Engineer From: Tuyen Nguyen, FA/Lab Analyst Manager: Alfred Kwong, Manager STC Analytical Laboratory Contacts 408-956-6691 408-956-6356 408-935-5805 Objective: Provide Cross Section and Pull Test Analysis On Cypress Lead Free Test Vehicles Boards. Assembly: Cypress Test Vehicle Board. Customer: Cypress Semiconductor. Tile: Lead Free Solder Joint Evaluation. Originator: Tuyen Nguyen Date 03/13/02 User Manager: Alfred Kwong Date 03/15/02 04/29/03 FA1041-Cypress Lead Free Solder Joint Evaluation 1 of 13 Technical Center Analytical Laboratory . Four Cypress Test Vehicle (TV) Boards were submitted into the FA lab for cross-sectional and pull test analysis. The above picture is the sample of the Cypress test vehicle board. U6 and U3 were chosen for cross-section and pull test (4 pins/side), respectively. The four TV boards have a HASL surface finish and are identified, as follows: Board 1 – Lead free solder paste with Ni/Pd/Au surface finish on component leads. Board 2 – Lead free solder paste with Sn/Pb surface finished leads. Board 3 – Sn/Pb solder paste with Sn/Pb surface finished leads. Board 4 – Sn/Pb solder paste with Ni/Pd/Au surface finished leads. 1. PULL TEST DATA RESULTS. Four pins for each side of U3 were subjected to pull test. Table 1 Pull Test Data - Lbs Trial # Board 1 Board 2 Board 3 Board 4 1 1 1.1 0.6 1 2 1 1.1 1 1.4 3 1.8 0.8 1.8 0.8 4 2.2 0.8 1.6 1 5 1 0.7 2 0.8 6 1.4 0.7 1.2 0.8 7 1.6 2 2 1 8 1.2 1 1 0.8 9 1.8 1.8 1 2.2 10 0.8 1.6 1.2 0.8 11 0.8 1.8 1.2 1.4 12 1.2 1.2 1.6 1.2 13 1.2 1 1.8 1.2 14 1.2 0.8 0.8 1.8 15 1.6 2.2 1 2.2 16 1.2 2 1.2 2 Average 1.31 1.29 1.31 1.28 FA1041-Cypress Lead Free Evaluation 2 of 9 Technical Center Analytical Laboratory . Table 1 showed that the lowest and the highest pull force for board 1, board 2, board 3, and board 4 are 0.8 and 2.2 lbs, 0.7 and 2.2 lbs, 0.6 and 2 lbs, and 0.8 and 2.2 lbs, respectively. Board 2 2.5 Pull Force (lbs) Pull Force (lbs) Board 1 2 1.5 1 0.5 2.5 2 1.5 1 0.5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 3 4 5 6 7 Trial # Pull Force (lbs) Pull Force (lbs) 2.5 2 1.5 1 0.5 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Board 4 Board 3 1 8 Trial # 9 10 11 12 13 14 15 16 2.5 2 1.5 1 0.5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Trial # Trial # 2. CROSS-SECTION RESULTS. 2.1 BOARD 1 – Lead free solder paste with Ni/Pd/Au surface finished. Figure 1 shows cross-sectional over view of U6 with left and right leads, board 1 FA1041-Cypress Lead Free Evaluation ~12x 3 of 9 Technical Center Analytical Laboratory . Figure 2 shows a solder joint formation of the left lead. Voids were shown at the board pad. 50x. Figure 3 shows a solder joint formation of the right lead. 50x Figure 4, SEM image shows the IMC layer at the board side. The IMC layer thickness is about 2 to 3microns. FA1041-Cypress Lead Free Evaluation 4 of 9 Technical Center Analytical Laboratory . Figure 5, SEM image shows the IMC layer at the component side (heel). The IMC layer thickness is about 2 to 3 microns Figure 6, the EDX spectrum showed that there are the present of Ni, Pd, Au and no lead. FA1041-Cypress Lead Free Evaluation 5 of 9 Technical Center Analytical Laboratory . 2.2 BOARD 2 - Lead free solder paste with Sn/Pb surface finished. Figure 1 shows cross-sectional over view of U6 with left and right leads, board 2. ~12x Figure 2 shows a solder joint formation of the left lead. 50x. Figure 3 shows a solder joint formation of the right lead. FA1041-Cypress Lead Free Evaluation 50x 6 of 9 Technical Center Analytical Laboratory . Figure 4, SEM image shows the IMC layer at the board side. The IMC layer thickness is about 2 to 3 microns. Figure 5, SEM image shows the IMC layer at the component side (heel). The IMC layer thickness is about 1 to 2 microns. FA1041-Cypress Lead Free Evaluation 7 of 9 Technical Center Analytical Laboratory . Figure 6, the EDX spectrum showed the presence of Sn and Cu. 2.3 BOARD 3 – Sn/Pb solder paste with Sn/Pb surface finished Leads Figure 1 shows cross-sectional over view of U6 with left and right gull wing leads, board 3 ~12x FA1041-Cypress Lead Free Evaluation 8 of 9 Technical Center Analytical Laboratory . Figure 2 shows the solder joint formation of the left lead. 50x. Figure 3 shows the solder joint formation of the right lead. 50x Figure 4 SEM image shows the IMC layer at the board side. The IMC layer thickness is about 1 to 1.5 microns. FA1041-Cypress Lead Free Evaluation 9 of 9 Technical Center Analytical Laboratory . Figure 5 SEM image shows the IMC layer of the component lead (heel). The IMC layer thickness is about 1 to 1.5 microns. Figure 6, the EDX spectrum shows that the intermetallic is composed of Sn and Cu. 2.4 BOARD 4 – Sn/Pb solder paste with Ni/Pd/Au surface finished leads. FA1041-Cypress Lead Free Evaluation 10 of 9 Technical Center Analytical Laboratory . Figure 1 shows cross-sectional over view of U6 with left and right leads, board 4. Figure 2 shows a solder joint formation of the left lead of board 4. ~12x 50x. Figure 3 shows a solder joint formation of the right lead. 50x FA1041-Cypress Lead Free Evaluation 11 of 9 Technical Center Analytical Laboratory . Figure 4 SEM image shows the IMC layer at the board pad.. The IMC layer thickness is about 1 to 1.5 microns. Figure 5 SEM image shows the IMC layer at the component lead side at the heel. The IMC layer thickness is about 1.5 to 2 microns. FA1041-Cypress Lead Free Evaluation 12 of 9 Technical Center Analytical Laboratory . Figure 6, the EDX spectrum of IMC on component side at the heel of the lead shows the presence of Sn, Pd, and Au. FA1041-Cypress Lead Free Evaluation 13 of 9