AMxP-XXXX. Application Note. Production Assembly Process (Land Pattern B) Description. AMMP-XXXX Package Plating. Package Features

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1 pplication Note MxP-XXXX Production ssembly Process (Land Pattern B) Description This application note describes and illustrates the attachment and detachment of the 5-mm 5-mm packaged products in a PCB (soft board) environment. The MxP package has a solid copper-filled cavity to allow optimum thermal transfer from the packaged device to the PCB and associated heat sink interface. The MxP package takes into full account the parasitics involved with routing a high frequency signal up and through a ground plane transition. Therefore, these guidelines also illustrate measures that optimize the RF signal interface. Figure 1 illustrates an MxP package assembly. Figure 2 is a cross-sectional view. MMP-XXXX Package Plating Electrolytic Ni-u (Ni 3-8 μm, u μm) is used for backside plating to ensure industry-standard lead or leadfree solder adhesion. Package Features Surface mount package (5.1 mm 5.1 mm 2 mm). Tape and reel capability for chip shooter pick-and-place applications. Package Dimensions and Tolerances Figure 1: The MxP-XXXX DC-45 GHz Package 8 MxP XXXX YWWDNN FRONT VIEW Symbol Min. Max B Dimensions are in mm B SIDE VIEW Figure 2: Cross-Sectional View of an MxP-XXXX Package BCK VIEW Notes: Indicates Pin 1. Dimensions are in millimeters. ll grounds must be soldered to PCB RF ground. Dimension tolerance = 0.05 mm unless otherwise indicated. February 12, 2018

2 Stencil Type stainless steel stencil with trapezoidal walls is recommended. If possible, electropolishing for smooth walls will reduce surface friction and promote good paste release. The trapezoidal section aperture (TS) design also promotes precision solder deposits to assist in component placement and alignment. The resulting, reflowed solder joints on the perimeter I/O lands should measure approximately 50 mm to 75 mm (2 to 3 mils) standoff height. If lead-free solder is required, a no clean Type 3 paste per NSI/J-STD-005 is recommended. Nitrogen purge is also recommended during reflow. For automated assembly, solder paste should be screen printed before reflow. Figure 4 illustrates the solder deposit pattern superimposed on the PCB. Figure 4: Solder Paste Pattern on PCB Figure 3 shows a stencil pattern that will give an optimum amount of solder paste that maximizes contact coverage and minimizes paste thickness, which would degrade RF signal performance. Figure 3: Solder Stencil Dimensions Thickness = 0.12 mm ( in.) Solder Paste Manual Solder Dispensing Guidelines For manual dispensing of solder paste on the PCB, it is critical to distribute the solder paste evenly across the pattern shown in Figure 4. The solder paste should be distributed evenly with a thickness of approximately mm (0.003 in.). n uneven solder distribution may cause voids underneath the package or non-contact on parts of the package bottom. Too much solder paste can bridge the contact pads. Figure 5 illustrates good and poor solder paste distribution. The recommended solder paste is SolderPlus 62NCLR-/ Sn62 Pb36 g2 (Engineered Fluid Dispensing). Details can be obtained from Conductive epoxy is not recommended. Hand soldering is not recommended. If the vias on the PCB are not silver filled, taping the backside of the PCB with thermal tape is recommended prior to dispensing the solder paste. This will help contain the solder in the vias. This is critical for good thermal transfer from the package to the PCB and heat sink. Remove the thermal tape after the cool down period of the solder process. 2

3 Figure 5: 5, 5B, and 5C:Solder Paste Distribution Examples Figure 6: MxP-XXXX Land Pattern [mm] MxP package mounted with good solder distribution under the contact pad area B void 0.41 MxP package mounted with too much solder under the contact pad area (center) For >=2W dissipation, Vias under package should be silver filled. 5C void MxP package mounted with too little solder under the contact pad area (void exists that causes poor heat transfer) PCB Land Pattern and Material The PCB material and mounting pattern, as defined in the data sheet, optimizes RF performance, and strongly recommends it be followed. n electronic drawing of the land pattern is available upon request from sales or application engineering. Figure 6 shows the land pattern. Material is Rogers RO4350 with a thickness of 0.25 mm (0.010 in.). For products with approximately 2W or greater power dissipation, silver filled vias or a solid copper base are highly recommended. Solder Reflow Reliable assembly of surface mount components is a complex process that involves many materials, processes, and equipment factors, including method of heating, circuit board material, conductor thickness, pattern, type of solder paste and solder alloy, thermal conductivity, and thermal loading and mass of components. Reflow temperature settings need to be determined by the end user based on these considerations. lso, moisture sensitivity MSL level 2 has been qualified for this device. The MSL level 2 conditions must not be exceeded. fter ramping up from room temperature, the circuit board with components held in place with solder paste passes through one or more preheat zones. The preheat zones increase the temperature of the board and components to prevent thermal shock and to evaporate solvents from the solder paste. The reflow zone briefly elevates the temperature to produce a reflow of the solder. Profile for Solder Reflow The reflow profile investigated and recommended by for this product is based on JEDEC/IPC standard J-STD-020 revision C. This device has been qualified to withstand a maximum of three cycles of solder reflow according to the conditions of J-SDT-020C, and this device has been qualified for moisture sensitivity level 2a. 3

4 Table 1 lists the parameters and peak temperatures as indicated by JEDEC/IPC. Figure 7 shows the standard leadfree JEDEC/IPC profile. The most recommended and most common reflow method uses a belt furnace with convection/ IR heat transfer. Table 1 shows the actual temperature range that should occur on the surface of a test board at or near a central solder joint. During this type of reflow soldering, the circuit board and solder joints tend to heat first. The components on the board are then heated by conduction. The circuit board, because it has a large surface area, absorbs thermal energy more efficiently, and then distributes this heat to the components. prolonged preheat stage is not recommended as oxidation may occur on the solder paste surface. reflow temperature over 217 C is critical and will determine the appearance of the solder joint after reflow. Longer reflow time may result in a dull and gritty solder joint appearance and charring of flux residues. Time below 30 seconds may result in insufficient wetting and poor intermetallic formation. Too fast of a cooling rate could result in insufficient wetting and poor intermetallic formation. s a general guideline, the MxP package should be exposed to only the minimum lead-free process temperature and times necessary to achieve a uniform reflow of solder on the board. The rates of change of temperature for the ramp-up and cool-down zones are specified by the J-STD-020C standard to be low enough to not cause deformation of the board or damage to components due to thermal shock. This profile allows a reflow temperature which is low enough to avoid damaging the internal circuitry during solder reflow operations provided the time of exposure at peak reflow temperature is not too excessive. lso refer to the specific MxP-XXXX product data sheet for further information. Table 1: Lead-Free Reflow Profile Recommendation (IPC/JEDEC J-STD-020C) Reflow Parameter Lead-Free ssembly verage Ramp-up Rate (Liquidus Temperature T S(max) to Peak) 3 C/s max Preheat Temperature Min (T S(min) ) 150 C Temperature Max (T S(max) ) 200 C Time (min to max) (t S ) 60s to 180s T S(max) to T L Ramp-up Rate 3 C/s max Time Maintained bove: Temperature (T L ) 217 C Time (T L ) 60s to 150s Peak Temperature (T P ) / 5 C Time within 5 C of ctual Peak Temperature (T P ) 20s to 40s Ramp-down Rate 6 C/s max Time 25 C to Peak Temperature 8 min max Notes: ll temperatures refer to topside of the package, measured on the package body surface. Reference: JEDEC/Electronic Industries lliance, Inc, Moisture/Reflow Sensitivity Classification for Non-hermetic Solid State Surface Mount Devices (IPC/JEDEC J-STD-020C), July

5 Hydrogen Poisoning of Gas Semiconductors Metals sensitive to hydrogen poisoning are palladium (Pd), platinum (Pt) and titanium (Ti). The MxP Gas devices contain some of these metals in the gate structure. Hydrogen Getter hydrogen getter is a material typically made with hydrogen-absorbing platinum or palladium metals or oxides like PdO. Current suppliers of hydrogen getters are shown in the following table. Electroplated metal packages can release hydrogen that is absorbed during the plating process; thus, sealing an MxP packaged device in a hermetic environment, where hydrogen may be present, will subject it to hydrogen which may penetrate into the gate structure through the package. Precautionary measures are recommended for use of MxP-XXXX parts in hermetic enclosures where hydrogen might be present. Hi-Rel SES Group KR FB Vacuum Energy Figure 7: Standard J-STD-020C Lead-Free Solder Reflow Profile tp T P RMP UP CRITICL ZONE T L TO T P TEMPERTURE T L Ts max Ts min t L ts PREHET RMP DOWN 25 t 25 C TO PEK TIME 5

6 Desoldering the MxP Package Desoldering can be done by hot-air, hot-tip contact or on a hot plate. n example of hot-plate desoldering is shown in Figure 8. n aluminum block, sized to fit under the 5 mm 5 mm package, is used to transfer the heat from the hot plate. The aluminum block centralizes the heat under the package; thus, avoiding reflow of surrounding components. When the solder has reflowed, the package should be removed by gripping it with tweezers from the bottom section. Figure 10 and Figure 11 show the manual removal of an MxP package using tweezers. Figure 10: MxP Package on an luminum Block MxP PCB assembly on top of aluminum block Figure 9 shows a typical hot plate set to approximately 200 C, an MxP PCB assembly and an aluminum block that fits under the package area. Figure 8: Hot Plate Desoldering PCB Package Top Package Bottom luminum Block PCKGE Figure 11: Removal of an MxP Package with Tweezers Hot Plate Figure 9: Typical Hot Plate and Components luminum block Gold plated copper block MxP PCB assembly 6

7 Hot ir Desoldering Hot ir Equipment Figure 12: HKKO FM202 Digital Soldering SMD Rework Station Figure 15 shows an illustration of blowing hot air underneath a demonstration board by using the hot air nozzle, and at the same time using tweezers to grip the bottom side walls of the MxP package. Figure 15: Blowing Hot ir Underneath the PCB Nozzle: 1130 Figure 13: MxP-XXXX Package Soldered on a PCB Hot Tip Contact Desoldering Hot Tip Equipment Figure 16: HKKO 850D SMD Rework Station Figure 14: PCB Secured for ccess Underneath the PCB Tip P/N: T7-D4 7

8 When unsoldering a part using a hot iron tip, the size of the tip will actually depend on the thickness and material composition of the PCB. #T7-D4 tip is sufficient for the mmwave demonstration board PCB stack ups. Figure 17 illustrates the tip contact to a copper heat sink that is soldered to a two-layer PCB with either silver filled vias or a solid copper base under the ground area of the MxP device. Figure 17: Hot Tip Desoldering PCKGE TOP PCKGE PCKGE BOTTOM PCB COPPER HETSINK Direct contact is made under the package surface area PCB PCKGE TOP PCKGE BOTTOM PCKGE Lift package, with tweezers, from the bottom side walls when solder has reflows COPPER HETSINK Keep direct contact under the package surface area 8

9 Special Handling Notes for utomatic and Manual SMT Rework Package should be cooled down before any solution cleaning after IR reflow. Follow ESD precautions while handling packages. Solder coverage should be evenly distributed across the bottom contact area to obtain good, reliable DC and RF contact. lignment and good wetting of the RF input and output pads to the PCB is critical to ensure optimum signal transmission. Handle the package along its edges with tweezers. utomatic placing with a vacuum force from the top of the lid is recommended. DC probe or other sharp instrument contact is prohibited in the bottom center area outlined in Figure 18. DC probe contact or other sharp instrument contact is allowed in the area marked. For volume production, the MxP package can be treated as a standard surface mount component (reference IPC/JEDEC J-STD-020C standard or equivalent) with a standard assembly process (e.g., stencil solder printing, standard pick and place and solder reflow oven). Marking code: MxP = x refer to wafer technologies XXXX = device code YWWDNN = date code Y= year WW = work week D = day of the week (Mon = 1, Tue = 2, Wed = 3, Sun = 7) NN = number of lot in the day (Lot 01-10) Example: If the date code is , 9 = = ww23 2 = Tuesday 08 = lot # 8 Figure 18: Prohibited Probing rea RF IN MxP XXXX YWWDNN 5.08 mm No direct probing allowed on this area mm 9

10 RF Port Transitions It is important to note that RF port hardware, such as SM 2.92-mm or 2.4-mm connectors, will directly contribute loss and limit MxP performance within the hardware s bandwidth. Table 2 is a list of recommended edge launch connectors used in mmwave evaluation and demonstration board modules. Other connectors similar to the performance of these connectors will also be suitable. Websites for Connector Manufacturers Bypass Capacitors Bypass capacitors, as recommended in MxP data sheets for the DC output pins, should be as close to the package as possible. Table 3 lists two typical capacitor values and their part numbers. Other capacitors similar in specification can be substituted. Table 2: Recommended Edge Launch Connectors Connector Type Bandwidth Manufacturer Female Part Number Male Part Number SM (screw on) DC-27 GHz Southwest Microwave SM (solderable) DC-26.5 GHz Johnson SM (solderable) DC-26.5 GHz Johnson SM (solderable) DC-26.5 GHz Johnson mm (screw on) DC-40 GHz Southwest Microwave mm (screw on) DC-50 GHz Southwest Microwave Table 3: Typical Capacitors Capacitor Type Value Manufacturer Part Number SMT μf VX VX0402YG104ZT2 SMT-0805 >1 μf (4.7 μf) Phycomp 08052F47SZ6BBOD 10

11 Carrier Tape and Pocket Dimensions SEE NOTE # B R 0.50 TYP. o B o B o K o SECTION B-B B (MIN.) K o o SECTION - Notes: 1. o & B o measured at 0.3mm above base of pocket pitches cumulative tolerance ±0.2mm o : 5.30 B o : 5.30 K o : 2.20 PITCH : 8.00 WIDTH : o B o K o MIN NOM MX Device Orientation (Top View) 4 mm 12 mm MxP XXXX YWWDNN MxP XXXX YWWDNN MxP XXXX YWWDNN Table 4: Ordering information Part Number Devices Per Container Container MxP-XXXX-BLKG 10 ntistatic bag MxP-XXXX-TR1G Reel MxP-XXXX-TR2G Reel 11

12 , the pulse logo, Connecting everything, vago Technologies, vago, and the logo are among the trademarks of and/or its affiliates in the United States, certain other countries, and/or the EU. Copyright ll Rights Reserved. The term refers to Limited and/or its subsidiaries. For more information, please visit reserves the right to make changes without further notice to any products or data herein to improve reliability, function, or design. Information furnished by is believed to be accurate and reliable. However, does not assume any liability arising out of the application or use of this information, nor the application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others.