FLX 70 antenna issue disposed

1、FLX 70 antenna issue disposed Prepared: QA Vigor Kang 6/1708 Checked: Lily Yang 6/1708 2/2308 K2 Final assembly 發(fā)現(xiàn)BT Neu 有 PCAB 上天線直接脫落現(xiàn)象， 如下圖： 2/2308 裝配產(chǎn)線反映有78 pcs天線脫落; 2/2508 SMT反映有20%不良； 2/2608 確認(rèn)SMT PCBAs antenna broke off 50%-60% defects antennaantenna 小結(jié)：1. 立刻找出不良嫌疑批； 2. 天線脫落不良原因分析； 3. 后續(xù)對(duì)策 Ba

2、ckBack 從倉(cāng)庫(kù)中BY LOT 抽取近期生產(chǎn)的嫌疑批，驗(yàn)證天線推力并確認(rèn)PCBA生產(chǎn)日期 （紅色為天線脫落品） 依天線20%-50%的不良率推算：2/1808之后生 產(chǎn)的PCBA均存在天線脫落風(fēng)險(xiǎn); 之前無(wú)。 MI: C107802MI: C107802 nextnext C107802 目前倉(cāng)庫(kù)存在物料MI C107618 最后一批已出貨給客人物料MI C107618 抽樣20 pcs：用手推到第8 個(gè)天線脫落， 不良率1/8=12.5% 抽樣20 pcs，全部實(shí)測(cè)推力 Min 8 Kg, Max 19 Kg. 確認(rèn) 5pcs PCBA 最晚為2/1308 生產(chǎn) 調(diào)查確認(rèn)PCBA均為年前

3、生產(chǎn) 結(jié)論：Fail結(jié)論：Pass結(jié)論：無(wú)天線脫落風(fēng)險(xiǎn) 抽樣測(cè)試確認(rèn)品質(zhì) 小結(jié)：1. 目前出倉(cāng)庫(kù)產(chǎn)品均無(wú)天線脫落風(fēng)險(xiǎn)； 2. NAMTAI庫(kù)存品均有天線脫落風(fēng)險(xiǎn)。 BackBack 結(jié)論：有機(jī)物存在天線焊接面導(dǎo)致SMT之后天線存在脫落風(fēng)險(xiǎn)。 BackBack Cosmetic Inspection Water Drop Test Solder ability Experiment EDX analysis SEM analysis 在1000倍顯微鏡下觀察不良天線pad，發(fā)現(xiàn)可焊接焊盤(pán)上鍍金稀少。 Cosmetic Inspection ReturnReturn Water drop test

4、 To identify if there is oxidation or organic coating on the surface of the pad, we do droplets test. Put an extreme small water droplet on the surface of antenna pad, this drop of water can not emanate to any direction and it simply keeps its own shape. For more detailed image about the droplet tes

5、t result, please refer to figure as below ReturnReturn Solder ability test Per the direction of IPC J-STD-003, use dipping solder method to check the solder ability. But the solder ability test is failed per below test condition. The test temperature is 2455 and the continuous time is 3-5 seconds. A

6、cceptable Standard: More than 95% pad area has solder. ReturnReturn EDX analysis For normal antennas the total Carbon weight percentage should have no Carbon or be less, but the antennas have more the Carbon weight percentage,It also reach high to 44.3% for the old antennas which have been apart fro

7、m the PCB. ReturnReturn SEM analysis There is no IMC between antenna pad and solder. Please refer to below pic for more detailed image. ReturnReturn 后續(xù)改善后續(xù)改善 為杜絕此類異常再次發(fā)生，經(jīng)與客人討論，決議通過(guò)點(diǎn)膠方案來(lái)固化天線的焊接，增 強(qiáng)粘住性，QA確定如下實(shí)驗(yàn)方案。 Purpose: Find a better work procedure Ways and Groups: 1. Use a underfill bead around t

8、he corner between PCBA and antenna; 2. Use a bead ofSMT glue”. Above both, Bake the glue to cure it. Steps as below: 1. Range test 2. Pull force test Sampling From the bad lot; 10 pcs/ Group nextnext Step 1 First following the technics as Lars comments, Headset A. Use a underfill bead all around the

9、 corner between the antenna and the PCB. Bake for the underfil to cure. (normal underfill baking) 2. Headset B. Use a bead of SMT glue (like you do for some tact switches) on the two ends of the antenna. Bake the glue to cure it. 1. Few underfill bead overflow on the PCBA; Bad cosmetic 2. Range test

10、 passed; 3. Pull force test: 11pcs. All were more than 8 Kg.f as the same as normal term It is failed. NT checked 2 pcs , pull force test. They were less than 2 Kg.f nextnext Step 2 NT did another 2 ways as below, 3. Use underfill bead one side between antenna and PCBA, 4. Use SMT glue all around th

11、e corner. From this side Cosmetic is OK; Range test is OK. Pull force test. 5pcs, The average is about 5 Kg.f. Visual check is bad; Range test is OK; Pull force test. 11pcs. All were more than 8 Kg.f nextnext The 2nd way is failed. We should give it up; The 1st and 4th way is OK as the normal term. Pull force test is more than 8 Kg.f . But cosmetic is bad. The 1st is better than the 4th. The 3rd way visual check is OK; The pull force is less than normal level.