負荷量控管應用於半導體封裝廠

本研究主要探討以IC後段加工製程之半導體封裝廠應用負荷量控管問題。負荷量控管之架構包含三大機制，包含訂單釋放、投料前等候區(Pre-shop pool)中排序、現場派工，其中，訂單釋放機制又可以涵蓋兩大決策，第一，在pre-shop pool中的待釋放訂單進行排序，第二，選擇釋放訂單的決策。因此，主要探討訂單釋放與現場派工機制。本研究所提出之架構為訂單釋放、Pre-shop pool訂單排序、現場派工三個因子，在不同情境之下，需找出一適當的組合才能降低流程時間以及遲交率，考量生產系統的特性與限制，包含：拆批行為、機台限制、順序相依的設置時間。在生產系統中加工時間與設置時間等等具有隨機性的因素，透過建構一模擬模式來進行重複模擬才能去估計每個方案的績效，並利用最佳模擬預算分配法(OCBA)有效分配有限模擬資源，同時節省模擬時間。本研究經模擬分析結果得證，不論是在確定性的環境或是隨機性的環境，訂單釋放法則與派工法則會顯著影響系統績效，且不同於文獻所述，週期性的投料方法較連續性的方法適合應用於封裝廠中。總結來說，訂單釋放、Pre-shop pool訂單排序、現場派工三個因子對半導體封裝產業所注重的績效指標都相當重要。

關鍵字

負荷量控管；派工法則；最佳模擬預算分配法；系統塑模語言

並列摘要

This research applies workload control concept in semiconductor assembly factory. The framework of the workload control includes three mechanisms, order acceptance, order release and dispatching. Order release contains two decisions: (i) a sequencing decision for releasing jobs; and, (ii) a selection decision for choosing jobs to release. This research discusses order release and dispatching. The proposed framework is to discuss the decision, which is composed of order release method, pre-shop pool sequencing rule and dispatching, must be in good cooperation to decrease in-process cycle time and tardy percentage under different scenarios. Considering the production characteristics of semiconductor assembly factory: unrelated parallel machine, job split, machine availability and sequence-dependent setup time. Due to stochastic processing time and setup time in the production system, simulation replications must be performed to estimate the performance of each design. Therefore, an evaluative model is constructed. Moreover, optimal computing budget allocation (OCBA) is applied to efficiently allocate limited simulation budget and reduce the total simulation times. It is proved that combination of order release methods and dispatching rules have significantly impacted on in-process cycle time and tardy percentage, no matter the environment is deterministic or stochastic. Also, periodical order release outperforms continuous order release in performance. In the conclusion, this research examines the effect of order release and dispatching in semiconductor assembly factory and show that they significantly improve overall performance.